fifth otter survey of england 2009 - 2010 -...

Technical report

Fifth otter survey of England 2009 - 2010

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Author - Andrew Crawford (Environment

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Project Manager - Graham Scholey (Environment Agency)

Main survey contractors - Elizabeth Andrews, Hilary Marshall, John Martin, Robin Roper, Andy Rothwell, Mark Satinet

Alternate squares surveyors - see acknowledgements

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Summary The fifth national otter survey of England has for the first time achieved comprehensive coverage of the whole country. Two field survey techniques were used in parallel – full surveys for sites investigated in previous national surveys (the main survey), and spot-checks for all the alternate 50km squares not covered in the previous surveys. The main survey was carried out between July 2009 and March 2010. Six highly experienced otter surveyors examined 3327 sites across the country using thirty-eight 50 x 50 km squares (the north-west and south-east quarters of each 100km square) as a sampling grid. Footprints and droppings (spraints) represent the most distinctive signs of otter and their presence within the standard 600m survey length of river represented a ‘positive’ site record. Signs of otters were recorded at 1874 (56%) of sites in the main survey. In addition, the alternate squares spot-checks undertaken within the same time frame proved otter presence in 553 of the 718 10km squares surveyed. Direct comparison of positive records from 2940 sites used in all five national surveys reveals the recovery of otters from virtual extinction in most of England during the early 1970s. Positive site records increased from 5.8 per cent in 1977-79, to 9.6 per cent in 1984-86; 23.4 per cent in 1991-94; 36.3 per cent in 2000-02 and 58.8 per cent in 2009-10. Recovery has continued in all but the very south-east where no signs were found in Kent or most of Sussex. Re-colonisation from strongholds in south-west and northern England and Wales has now been consolidated across much of the country and continues to drive recovery. Since 2000-02 there has been a major link-up across several river catchments. For example, there is no longer a gap in otter distribution between the south-west, south Wales, lower Wye and Severn and upper Thames. Similarly, there is now a link between populations in East Anglia, the River Trent catchment, Yorkshire and the traditional Northumbria stronghold. The pattern of recovery differs at a regional scale, with Thames showing the biggest increase in positive signs since 2000-02. In South-West Region and the River Wye catchments otter populations have probably reached a level approximating to carrying capacity, with those in Northumbria, Cumbria, Wessex and the upper Severn close to that. Elsewhere, further recovery and consolidation will take more time. Recovery has been in response to three main factors, the ban on pesticides that caused extinction of otters from many parts of England in the 1960s and early 1970s, legal protection for the otter since 1978, and the significant improvement in water quality in previously fishless rivers since the 1970s. Re-introduction programmes of captive bred and re-habilitated otters in certain parts of the country are likely to have speeded up the recovery locally in East Anglia, Yorkshire and the upper Thames. However the majority of the recovery has been the result of natural expansion from the remnant populations. The prospects are for full recovery across England probably within the next two decades or so. This represents a major success story for pollution control, as well as investment by the water industry and efforts by landowners and river managers to improve river and riparian habitat. Tracking the otter’s recovery has demonstrated the benefits of long-term monitoring and the use of this iconic species to raise awareness of pollution problems and the benefits of action to improve the environment.

The revised (2006) Biodiversity Action Plan (BAP) target for otters in England was for at least 997 10km squares to show signs of otter occupation by 2010 and for 1084 10km squares to show signs of otter occupation by 2015. The 2015 target has already been exceeded, with 1085 squares showing signs of occupation in either the main survey or alternate squares spot-checks. The recovery has thus proceeded at a slightly faster rate than expected in 2006 but is still close to, or slightly below the expected recovery curve published by Strachan and Jefferies (1996). The continued recovery has brought an increase in the number of reported otter road kills. These have nearly doubled from 313 reported deaths on the road during the four year period 2002 to 2005 to 600 in the four year period 2006 to 2009. These and other dead otters reported to the Environment Agency form the basis of the programme of otter post mortem and tissue analysis undertaken with Cardiff University and the Centre for Ecology and Hydrology. This work has shown that the current suite of chemicals monitored in otter tissue has declined to levels where they should not cause significant pathology. One of the results of the recovery of otter populations has been increased concern about predation, particularly on still water fisheries and on specimen fish. This creates a challenge to all those involved in river, wetland and fishery management to ensure that the successful return of our top freshwater predator is not seen as a problem for fisheries interests.

Contents Summary Contents page Introduction Methods Overall results for England Map 1 Alternate 50km squares used in survey Table 1 results for 2009-10 survey by region and comparison with other surveys Table 2 Summary of Results by 50km square Fig 1 Change in percentage of positive sites by region Maps 2-6 Percentage positive by region (1977-79 to 2009-10) Maps 7-11 Positive/new positive (1977-79 to 2009-10) Map 12 Otter distribution by 10km square Map 13 Catchment (Leap) areas in England The regional reports introduction (Regional reports each with maps) North West Northumbrian Yorkshire Dee Severn Trent Wye Anglian Thames South West Wessex Southern Mink Map 14 Mink distribution 2000-02 Map 15 Mink distribution 2009-10 Map 16 Mink distribution by 10km square Otter sightings - PTES Discussion Otters and fisheries Conclusions Priorities for future action Funding Acknowledgements References Appendix 1 Typical site map Appendix 2 Section of spreadsheet Appendix 3 Alternate squares recording sheet

1.0 Introduction The Eurasian or European otter (Lutra lutra) is widely recognised as an emblem for nature conservation in the UK because it is a top predator and important biological indicator of the health of our rivers and wetlands. Monitoring the status of the otter therefore gives us a valuable measure of the state of our water and wetland ecosystems. In England it is a largely nocturnal animal and is rarely observed in the wild. It is however possible to detect its presence by searching for faeces (spraints) and footprints. The otter suffered serious declines throughout most of its European range, and by the mid 1970s the UK otter population had been reduced to a point where they only existed in Scotland, parts of Wales and the West Country with a few remnant populations in other parts of England. Conservation action for the otter in Britain has a long history with many players fulfilling different roles. The Environment Agency is now the contact point for otter conservation under the UK Biodiversity Action Plan (UK BAP) and is a lead partner with the Wildlife Trusts in implementing the Otter Species Action Plan. The Otter BAP Steering Group also includes representatives from the statutory nature conservation bodies – Natural England (NE), Countryside Council for Wales (CCW), Scottish Natural Heritage (SNH), the Northern Ireland Environment Agency and the Joint Nature Conservation Committee (JNCC) as well as Water UK (umbrella body for the water companies), the Scottish Environment Protection Agency (SEPA), the Environment and Heritage Service of Northern Ireland, the Department of Agriculture (N.I.) and the Wildlife Trusts. The first national otter survey of England was carried out in 1977-79 (Lenton et al., 1980). It provided a baseline for the distribution of otters and, together with surveys in Wales, Scotland and Ireland (Crawford et al., 1979; Green & Green, 1980; Chapman & Chapman, 1982), was undertaken in response to growing concern for the status of the otter in Britain (O’Connor et al., 1977). Of the 2,940 sites surveyed in England in 1977-79, only 170 (5.8%) showed evidence of otters. This confirmed the results of the analysis of hunting records (Anon, 1969, 1974; Chanin & Jefferies, 1978), the impression of many naturalists (Walker, 1970, Howes, 1976, Lloyd, 1962) and the results of a volunteer survey by the Mammal Society (O’Connor et al., 1977) that there had been a major decline in otter distribution. The baseline survey showed that the only significant populations of otters remaining in England were in the south west and along the Welsh border, with small and fragmented populations in East Anglia and in northern England. Otters were absent or only sparsely distributed in much of lowland and central England. Subsequent surveys and research have demonstrated that this was probably the nadir of the decline which began in the late 1950s, and was primarily caused by the introduction of the persistent organochlorine pesticides dieldrin and aldrin (Strachan & Jefferies 1996). National surveys were repeated in 1984-86 (Strachan et al., 1990), 1991-94 (Strachan & Jefferies, 1996) and 2000-02 (Crawford, 2003) using the same method and visiting the same sites. A further 249 sites were added during the 1984-86 survey to improve coverage bringing the total to 3189. Of these 284 (8.9%) were positive in 1984-86 and 706 (22.1%) were positive in 1991-94. A further addition of 238 sites was made for the 2000-02 survey bringing the total to 3327 sites. Of these 1137 (34.2%) were positive. In the 2009-10 survey 1874 (56.3%) were positive. These surveys plus a large amount of monitoring effort by the Vincent Wildlife Trust, staff from the Wildlife Trusts and the Environment Agency and by other groups and individuals showed that otter populations were gradually recovering. This recovery however has been markedly slower than that for many raptor species such as the peregrine falcon which were similarly affected by organochlorine compounds. This may reflect the slower breeding rate and recovery potential of otters but a number of other factors may have slowed the rate of recovery of the otter. These include serious continued persecution, particularly hunting, up

to 1977 (when the otter was given full protection in England and Wales), poor water quality, particularly the impact of toxic compounds such as polychlorinated biphenyls (PCBs), increased levels of traffic leading to an increase in road deaths (Strachan & Jefferies, 1996; Bradshaw, 2002; Chadwick, 2007) and possibly increased human disturbance. River and wetland habitat loss and degradation may also have played a part particularly through its impact on fish stocks. In addition otters are restricted to terrestrial habitats (including rivers and streams) which must slow their ability to re-colonise areas remote from remnant populations unlike the bird species similarly affected by organochlorine pesticides. Continued monitoring is essential for assessing the rate of recovery, a fact recognised as far back as 1979 when it was proposed that a regular cycle of surveys should be undertaken (O’Connor et al., 1979). The 2009-10 survey was the fifth in the series and for the first time covered the whole of England. All the 3327 sites surveyed in the fourth survey were re-surveyed and of these 1874 (56.3%) were positive. In addition, for the first time, data was gathered for all those 50km squares not covered in the main survey. It was not possible to survey these to the same level as the main survey so a presence/absence survey by 10km squares was decided upon. Use was made of existing data from Wildlife Trust and Environment Agency surveys, casual records and locations of dead otters reported to the Environment Agency during the period from January 2009 to the end of the survey. All the remaining 10km squares for which there was no existing data were surveyed by carrying out up to 10 spot-checks per 10km square. These were carried out by the author, the contract surveyors, experienced staff from the Environment Agency and Wildlife Trusts and trained individual volunteers. The final squares were surveyed in March 2010. Squares were considered negative if no signs could be found at 10 spot-checks. Otter signs were found in 552 of the 718 10km squares spot-check surveyed as part of the alternate squares survey. The main part of the survey was carried out by five experienced surveyors with the remainder filled by the author and one other experienced surveyor. This enabled the whole survey to be carried out between 20 July 2009 and 20 February 2010, a period of exactly seven months. The alternate squares spot-check work was started in October 2009 and completed by the end of March 2010. The otter is one of over 400 species in the UK for which a species action plan has been produced (HMSO, 1995). The otter was considered a priority species for conservation action because of its earlier decline. It was therefore recognised that co-ordinated action and monitoring were required to ensure the restoration of a fully viable population throughout its historic range across the UK. The otter has one of the highest levels of protection for a species under European and UK law, but this alone does not guarantee its recovery.

2.0 Methods In the 2009-10 survey two survey methods were used in order to give both continuity of data and a comprehensive survey of the whole of England. The main survey followed the standard otter survey methodology used in all previous England surveys, covering the same sites as before, while spot-check surveys were used for the alternate squares to give coverage of previously unsurveyed 50km squares. 2.1 Main survey 2.1.1 Method The standard otter survey method was used following that used by Lenton et al., (1980). At each site a 600m survey was carried out along one bank by searching for otter signs, usually 300m upstream and downstream of a bridge or other access point. For the first national survey in 1977-79 surveys were halted as soon as otter signs were found so the full 600m length was only surveyed at sites where no signs were found. For the second (1984-86) and third (1991-94) surveys a full 600m was usually surveyed at each site even if otter signs were found before this. The 2000-02 and 2009-10 surveys reverted to the 1977-79 methodology to reduce survey time. 2.1.2 Survey sites These were originally selected in 1977-79 at approximately 5-8km intervals along main rivers and coast or lake shore with additional surveys included to ensure that a wide range of aquatic habitats were represented (Lenton et al., 1980). Less than half of England could be covered by one surveyor in two years so only alternate 50km squares, the north-west and south-east quarters of each 100km square of the National Grid, were surveyed to give geographically representative cover of all regions. A total of 2940 sites was surveyed in twenty eight 50km squares and partial squares. Due to time constraints during the first national survey three of the allocated full 50km squares were not surveyed. These were; TQ n/w (which covers central London), because there was little chance of otter presence; TL s/e, which had been surveyed a few months before as part of a county survey; and SK n/w due to time constraints. Seven of the partial 50km squares next to the coast, some of them very small, were also left out due to time constraints. During the second national otter survey in 1984-86 a further four squares or partial squares (NZ s/e, SK n/w, TL s/e and TR n/w) were added, bringing the total of squares and partial squares surveyed to 32 and the number of sites surveyed (including assumed negative sites – see below) to 3189. All these sites were revisited in the 1991-94 survey. For the 2000-02 survey it was decided that all alternate 50km squares would be surveyed, even where they would contain very few sites. A further six previously unsurveyed 50km squares and partial squares were added bringing the total of squares and partial squares surveyed to 38 and the total of sites surveyed to 3327. The 2009-10 survey followed the 2000-02 survey sites. In addition for the first time data was gathered for all those alternate 50km squares not covered in the main survey (see 2.2 below). 2.1.3 Surveyors

The main 2009-10 survey was carried out by five highly experienced otter surveyors with the author and one other surveyor completing any gaps. This allowed the survey to be completed in seven months compared to over two years for all the previous surveys of England. In the alternate squares, those 10km squares, for which prior information was not available, were spot-check surveyed between October 2009 and March 2010. 2.1.4 Data recording (main survey) In the first four surveys, recording was done using a standard recording sheet developed in 1977 (Lenton et al., 1980). These remained largely unaltered through to the 2000-02 survey. Sheets were filled in by hand in the field and included a description of the reach walked or a sketch map both of which were sometimes difficult to interpret. It was therefore not always easy in the field to determine when 600m had been completed or whether exactly the same reach and bank had been surveyed. With the development of Geographical Information System (GIS) mapping, hand held Global Positioning System (GPS) equipment and modern computer equipment, quicker survey recording could be developed and more accurate grid references produced. For the 2009-10 survey each site was located on a GIS mapping system and, using the sketch maps from previous surveys, the exact reach previously surveyed was identified. A map of each site was then printed with the start point indicated and a red line, measured on the map at exactly 600m, indicating the exact reach and bank to be surveyed (see appendix 1). These were provided to the surveyors for use in the field. Recording was done in the field using a laptop computer, directly onto a spreadsheet with one line for each site (see Appendix 2) The spreadsheet was already filled in with the basic site information for each site (Site No., Site Name and (nominal) Start Grid Reference). The opportunity was taken to correct any errors in the start grid reference by locating each start point with a hand held GPS. Any spraint sites located were also accurately located with GPS. Photos were taken at the start point and of each spraint site. 2.1.5 Timing of the surveys In some of the previous surveys attempts were made to carry out surveys at roughly the same time of year as earlier surveys. However the spread of dates for the four previous surveys made this less realistic for the 2009-10 survey and it was therefore not attempted. Since the method is robust the number and distribution of positive sites should not be affected. The distance surveyed and the number of spraints located may differ but these do not influence the results. Comparison of different regions surveyed at different times of year has been a feature of all the previous surveys. 2.1.6 Non-visited and assumed negative sites ‘Non-visited’ sites (assumed to be negative) were introduced in the 1977-79 survey, mainly for those rivers located in large conurbations such as Birmingham. It was assumed that otters would not enter urban areas so these rivers were not surveyed because results were almost certain to be negative. If non-visited sites were excluded from the analysis the proportion of positive sites in a mainly urban square would be highly skewed and would bias the conclusions. In some cases access to a site was refused and an alternative was not available. Survey sheets were filled in for these sites which were categorised as assumed negative. In 1977-79 there were 204 such sites. The number was 136 in 1984-86 and 83 in 1991-94. In 2000-02 and 2009-10 all survey sites were visited and only those where permission was refused or with serious access difficulties were recorded as assumed negative. There were 12 of these in 2000-02 and 13 in 2009-10.

2.1.7 Spot-checks In the 1977-79 survey spot-checks, generally at bridges, were used as a quick way to add to the available knowledge of otter distribution. They were considered particularly useful where there were no positive sites in a catchment and bridges could be easily and quickly checked. In these cases casual records of this sort added greatly to the available knowledge. With the complete coverage of main survey 50km squares in the 2000-02 and 2009-10 surveys they were not considered a necessary part of the main survey. Spot-checks were therefore not used during the main survey but were used in the alternate squares. 2.1.8 Distance to first spraint For each main survey site the distance surveyed, that is the distance to the first otter signs, was recorded. Of the 1874 positive sites, otter signs were found within 10m of the start point at 888 (47.4%). This coincides with the data from the 1977-78 Otter Survey of Wales. In that survey 89/179 (49.7%) of positive sites were recorded as being within 10m of the start point (A. Crawford, unpublished data). Unfortunately similar data is not available for other surveys. Alternate square surveys 2.2.1 Method In order to have a robust data set to report against national BAP targets, data from the 50km squares not previously surveyed was required. It was not possible to carry out full surveys at a comparable level to the main survey so a presence/absence survey by 10km squares was decided upon. For some squares there was existing data from Environment Agency surveys, Wildlife Trust surveys, casual records and locations of dead otters reported to the Environment Agency. This existing data covered the period from January 2009 onwards. 2.2.2 Survey sites All the remaining squares were surveyed by carrying out spot-checks. Spot-check sites were chosen by the surveyors from maps or using local knowledge. Usually a maximum of 10 spot-checks were carried out in each 10km square but in exceptional cases such as partial squares on the coast or highly urbanised areas a smaller number were carried out. Spot-checks in each 10km square ceased when the first signs of otters were found. Squares were considered negative if no signs could be found at any of the 10 spot-checks and there was no data from other sources showing otter presence within the survey period. Survey work on the alternate squares started in October 2009 and the final squares were completed in March 2010. 2.2.3 Surveyors Alternate squares spot-checks were carried out by the author, the contract surveyors, experienced surveyors from the Environment Agency and Wildlife Trusts and experienced individual volunteers. A very large number of individuals gave their time to do this work. 2.2.4 Data recording (alternate squares)

Because of the large number of contributors to the alternate squares survey recording was done on a standard form (Appendix 3). For those squares with existing data from Wildlife Trust or Environment Agency surveys, casual records or locations of dead otters the form was filled in by the author. 2.3 Mink Mink (Neovison vison) signs were also recorded while surveying for otter signs on both the main survey and the alternate squares spot-checks. In both cases the survey was halted as soon as the first otter sign was discovered so the results for mink cannot be considered as a full survey of the occurrence of this species. However the survey does give a minimum distribution for mink. 3.0 Results 3.1 Overall results for England The main survey results for the fifth otter survey of England 2009-10 and the results for each of the ‘regions’ are summarised in Table 1. Results for each 50km square are summarised in Table 2. The results for the baseline survey and subsequent surveys are listed in the same tables. A total of 2940 sites was surveyed in 1977-79. This was increased to 3189 in 1984-86 and 3327 in 2000-02. In 2009-10 the same 3327 sites were surveyed. The number was increased in order to improve coverage but when comparing the percentage of positive sites with the baseline, only those sites which were surveyed in every survey can be used. Of the 2940 sites surveyed in 1977-79, 170 (6%) were positive. The number of the same sites which were positive had increased to 282 (10%) in 1984-86, to 687 (23%) in 1991-94, to 1066 (36%) in 2000-02 and 1726 (59%) in 2009-10. Of the 3327 sites surveyed in 2000-02, 1137 (34%) were positive and in 2009-10 1874 (56%) were positive. Otter signs were found in 36 of the 38 50km squares or partial squares surveyed in the main survey. Only in squares TQ s/e and TR n/w, both in Southern Region, were no signs found. In TR n/w no signs were found during either the 2000-02 or the 2009-10 surveys while in TQ s/e, signs were found in 2000-02 but not in 2009-10. Otter signs were found in 533 of the 704 10 km squares in the main survey. In the alternate squares spot-check survey signs of otters were found in 36 of the 39 50km squares or partial squares surveyed. Some of the partial 50km squares were very small, one of these (TV n/e) consisting of only part of one 10km square. Otter signs were found in 552 of the 718 10 km squares included in the alternate squares survey. Of the total of 1422 10 km squares in England (a figure that excludes some partial coastal squares but includes some squares largely in Wales or Scotland), otter signs were found in 1085 (76.3%).

Table 1 Results of the main survey by region 2009-10 and comparison with previous surveys

Region 1977-79 positive/total

1984-86 positive/total 77-79 positive/total 84-86




North West 9/332 (2.8%) 31/322 (9.6%) 31/331 (9.4%)

93/322 (28.9%) 93/331 (28.1%)

110/322 (34.2%) 110/371 (29.6%)

187/322 (58.1%) 195/371 (52.6%)

Northumbria 14/169 (8.3%)

17/169 (10.1%) 17/174 (9.8%)

45/169 (26.6%) 46/174 (26.4%)

85/169 (50.3%) 90/174 (51.7%)

135/169 (79.9%) 140/174 (80.4%)

Yorkshire 4/227 (1.8%) 5/227 (2.2%) 6/270 (2.2%)

25/227 (11.0%) 28/270 (10.4%)

44/227 (19.4%) 68/284 (23.9%)

144/227 (63.4%) 179/284 (63.0%)

Dee 0/12 (0.0%) 1/12 (8.3%) 5/12 (41.7%) 6/12 (50%) 8/12 (75%) Severn 13/328

(4.0%) 22/328 (6.7%) 105/328

(32.0%) 127/328 (38.7%)

194/328 (59.1%)

Trent 0/238 (0.0%) 0/238 (0.0%) 0/282 (0.0%)

12/238 (5.0%) 18/282 (6.4%)

58/238 (24.4%) 58/282 (20.6%)

92/238 (38.7%) 98/282 (34.8%)

Wye 12/70 (17.1%)

232/70 (32.9%)

49/70 (70.0%)

58/70 (82.9%) 58/70 (82.9%)

Anglian 20/622 (3.2%)

8/622 (1.3%) 8/725 (1.1%)

52/622 (8.4%) 58/725 (8.0%)

166/622 (26.7%) 188/728 (25.8%)

350/622 (56.3%) 414/728 (56.9%)

Thames 0/169 (0.0%) 0/169 (0.0%) 0/179 (0.0%)

4/169 (2.4%) 4/179 (2.2%)

13/169 (7.7%) 18/225 (8.0%)

89/169 (52.7%) 92/225 (40.9%)

South West 91/388 (23.5%)

167/388 (43.0%)

259/388 (66.8%)

322/388 (83.0%) 332/399 (83.2%)

331/388 (85.3%) 341/399 (84.5%)

Wessex 2/151 (1.3%) 1/151 (0.7%) 29/151 (19.2%)

64/151 (42.4%) 69/172 (40.1%)

115/151 (76.2%) 132/172 (76.7%)

Southern 5/244 (2.0%) 7/244 (2.9%) 8/279 (2.9%)

9/244 (3.7%) 12/279 (4.3%)

13/244 (5.3%) 13/282 (4.6%)

23/244 (9.4%) 23/282 (8.5%)

Totals

170/2940 (6 %)

282/2940 (10%) 284/3189 (9%)

687/2940 (23%) 706/3189 (22%)

1066/2940 (36%) 1137/3327 (34%)

1726/2940 (59%) 1874/3327 (56%)

50km Square 1977-1979 Survey 1984-1986 Survey 1991-1994 Survey 2000-2002 Survey 2009-2010 Survey

Positives /Total

% Positive

Positives/Total

% Positive

Positives/Total

% Positive

Positives/Total

% Positive

Positives/Total

% Positive

NT s/e 1/42 2.38% 1/42 2.38% 19/42 45.24% 36/42 85.71% 37/42 88.09% NX s/e 0/0 0.00% 0/0 0.00% 0/0 0.00% 0/5 0.00% 4/5 80.00% NY n/w 3/57 5.26% 7/57 12.28% 31/57 54.39% 40/57 70.18% 47/57 85.45% NY s/e 3/112§ 2.68% 7/112 6.25 19/112 16.96% 48/112 42.86% 88/112 78.57% NZ n/w 13/75§ 17.33% 14/75* 18.67 23/75* 30.67% 42/75* 56.00% 62/75* 82.67% NZ s/e 0/0 0.00% 1/30 0.33% 4/30 13.33% 25/30 83.33% 26/30 86.67% SD n/w 3/108 2.78% 19/108 17.59% 36/108 33.33% 24/108 22.22% 62/108 57.41% SD s/e 0/82 0.00% 0/82 0.00% 6/82 7.32% 2/117 1.71% 18/117 15.38% SE n/w 4/129 3.10% 3/129 2.33% 13/129 10.08% 31/129 24.03% 100/129 77.52% SE s/e 0/114 0.00% 2/114 1.75% 13/114 11.40% 21/114 18.42% 52/114 45.61% SJ n/w 0/23 0.00% 1/23 4.35% 5/23 21.74% 4/23 17.39% 8/23 34.78% SJ s/e 0/148 0.00% 1/148 0.68% 44/148 29.74% 71/148 47.97% 93/148 62.83% SK n/w 0/0 0.00% 0/71§ 0.00% 6/71 8.45% 0/71 0.00% 11/71 15.49% SK s/e 0/138 0.00% 0/138 0.00% 3/138 2.17% 33/138 23.91% 73/138 52.90% SO n/w 25/91 27.47% 38/91 41.76% 70/91 76.92% 80/91 87.91% 84/91 92.30% SO s/e 0/143 0.00% 6/143 4.20% 49/143 34.27% 55/143 38.46% 90/143 62.94% SP n/w 0/161§ 0.00% 0/161 0.00% 4/161 2.48% 19/161 11.80 42/161 26.09% SP s/e 0/146§ 0.00% 0/146 0.00% 2/146 1.37% 4/146 2.74% 70/146 47.95%

50km Square 1977-1979 Survey 1984-1986 Survey 1991-1994 Survey 2000-2002 Survey 2009-2010 Survey

Positives /Total

% Positive

Positives/Total

% Positive

Positives/Total

% Positive

Positives/Total

% Positive

Positives/Total

% Positive

SS s/e 44/182* 24.18% 86/182* 42.25% 140/182* 76.92% 167/182* 91.76% 175/182* 96.15% ST n/w 0/0 0.00% 0/0 0.00% 0/0 0.00% 5/21 23.81% 17/21 80.95% ST s/e 2/92 2.17% 1/92 1.09% 16/92 17.39% 34/92 39.96% 74/92 80.43% SU n/w 0/93* 0.00% 0/93* 0.00% 2/93* 2.15% 12/93* 12.90% 57/93* 61.29% SU s/e 4/100 4.00% 5/100 5.00% 6/100 6.00% 8/100 8.00% 23/100 23.00% SW s/e 6/59 10.17% 10/59 16.95% 26/59 44.07% 48/59 81.36% 41/59 69.49% SX n/w 41/130* 31.54% 70/130* 53.85% 95/130* 73.08% 101/130 77.69% 105/130* 80.77% SX s/e 0/0 0.00% 0/0 0.00% 0/0 0.00% 10/11 90.91% 10/11 90.90% SY n/w 0/46 0.00% 2/46 4.35% 8/46 17.39% 26/46 56.52% 32/46 69.57% SZ n/w 1/42 2.38% 0/42 0.00% 3/42 7.14% 11/42 26.19% 15/42 35.71% TA n/w 0/0 0.00% 0/0 0.00% 0/0 0.00% 4/14 28.57% 10/14 71.43% TF n/w 1/142 0.70% 0/142 0.00% 2/142 1.41% 43/142 30.28% 84/142 59.15%

58.16% TF s/e 16/98 16.33% 1/98 1.02% 7/98 7.14% 17/98 17.35% 57/98 TG s/e 0/0 0.00% 0/0 0.00% 0/0 0.00% 1/3 33.33% 1/3 33.33% TL n/w 2/132 1.52% 4/132 3.03% 15/132 11.36% 36/132 27.27% 61/132 46.21% TL s/e 0/0 0.00% 0/132§ 0.00% 6/113§ 5.31% 24/113 21.24% 63/113 55.75%

66.12% 6.12% 0.00% 0.00%

TM n/w 0/121 0.00% 3/121 2.48% 27/121 22.31% 49/121 40.50% 80/121 TQ n/w 0/0 0.00% 0/0 0.00% 0/0 0.00% 2/49 4.08% 3/49

2.99% 0/134 TQ s/e 0/134 0.00% 2/134 1.49% 3/134 2.24% 4/134 0.00% 0/35 8.57% 0/35 3/35 2.86% 1/35§ 0.00% 0/0 TR n/w

Change in percentage of positive sites for otters by regionpercentage of sites positive

90

80

70

60

50 1977-7940 1984-86

30 1991-942000-0220 2009-10

10

0 Dee WyeTrent

Figure 1

North West Northumbria Yorkshire Severn Anglian ThamesSouth WestWessex Southern

Map 10

Map 11

Map 12

Map 13

4.0 The regional reports The reports of the first three Otter Surveys of England (Lenton et al., 1980, Strachan et al., 1990, Strachan and Jefferies, 1996) presented results by Water Authority or National Rivers Authority (NRA) region. For the 2000-02 survey, Midlands Region was split into the Severn and Trent catchments and the Wye and Dee catchments reported separately. The present survey follows the pattern of the 2000-02 survey. For each ‘region’ the report contains • A list of the 50km squares that lie within that region with the number of sites surveyed in

the main survey shown in brackets. This number refers only to those sites that lie within both that square and the region concerned.

• A brief description of the region and notes on the water quality and fisheries where these

might impact on otters. • A comparison of the results for the suite of sites selected for the 1977-79 survey (which

have been surveyed on all subsequent surveys) and, where survey sites were added during subsequent surveys, the results for the total number of sites surveyed during each survey.

• A summary of the results from the alternate squares survey giving the number of 10km

squares covered through spot-checks (where these lie in whole or part within that region) by 50km square. Where otter signs were found within a 10km square that overlaps two regions this is included as a positive square in both the regional reports. In such cases the positive site will only be shown on the map for the region in which the positive site was found. The number of positive squares will therefore be higher in one region than the number of positive symbols on the region/catchment map.

• A summary of the results for each catchment or subcatchment and comparison with

previous survey results. The catchments and subcatchments used follow the Local Environment Agency Plan (LEAP) areas used in the fourth survey report. The catchment name is followed by a number - these refer to the key on the sub-catchment map. The boundaries and numbers are also shown on the region/catchment maps. In many cases only part of a catchment area was included in the main survey where the remainder lies within an alternate 50km square and in some cases no main survey sites were surveyed in a particular catchment where these lie totally outside the 50km squares of the main survey. In these cases the catchment is listed and the data from the alternate squares spot-checks noted.

• A discussion of the results for the region.

4.1 North West Region Surveys were carried out in the following 50km squares – NX s/e (5), NY n/w (57), NY s/e (56), SD n/w (108), SD s/e (104), SJ n/w (14), SJ s/e (18), SK n/w (9) Description of region The rivers of the North West exhibit a wide range of riverine types from the short upland rivers of the Lake District and the large, fairly natural river systems of the Eden and Lune to the heavily modified rivers of Greater Manchester, Liverpool and lowland Cheshire. The River Eden and tributaries and the Derwent and Bassenthwaite have been notified as Special Areas of Conservation, with otters as listed features. There is an extensive canal network particularly concentrated in Lancashire and Cheshire. Human activity is mainly centred on the large conurbations, with Manchester, Warrington and Liverpool forming an urban chain across the whole region. Other major settlements include the cities of Preston and Carlisle, while the populations of some areas, such as Cumbria, are increased considerably by tourists during the summer months. Outside the industrial centres, upland sheep farming or lowland dairy farming dominate the region’s landscape while coniferous plantations are mainly concentrated in Cumbria. Water quality The large variation of river types and level of human influence in the region gives rise to a wide variation in river quality, from the heavily urbanised rivers of the Manchester and Liverpool conurbations to the very clean rivers of Cumbria. Water quality has improved markedly in the industrial areas in recent years with good fish stocks on the lower Mersey and the Irwell for the first time since the early 20th century. Fisheries The Border Esk, Eden and Lune catchments support the principal salmon and sea trout fisheries of the region but there are salmon runs on several of the smaller rivers such as the Wyre. The fisheries on many of the central and southern rivers of the region have largely recovered from previous industrial pollution and support good populations of coarse fish as well as the return of salmon and sea trout. Good coarse fisheries can also be found on the Weaver, Dane, Gowy and Bollin.

Results for 2009-10 survey and comparison with previous surveys A total of 371 sites was surveyed in the main survey. Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total - 77-79 sites - all sites

9/322 31/322 31/331

93/322 93/331

110/322 110/371

187/322 195/371

% Positive - 77-79 sites - all sites

2.8% 9.6% 9.4%

28.9% 28.1%

34.2% 29.6%

58.1% 52.6%

Spot-checks were carried out in an additional 88 whole or partial 10km squares. Alternate 50km Square NY s/w NY n/e SD s/w SD n/e SE s/w SJ n/e Positive/total 10km squares 25/25 7/7 7/12 18/19 0/1 12/24 Summary of results for each catchment Alt Crossens (1) No main surveys were carried out in this catchment but during the alternate squares spot-checks otter signs were found at two widely spaced sites near Kirby and Southport. These are about 38km apart by river and canal but the data is insufficient to determine the true level of otter use in the area. It is more likely that the otter(s) have reached this area from the Ribble catchment to the north rather than by passing through Liverpool. Douglas (2) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/0 0/0 0/0 0/15 2/15 Otter signs were found in this catchment for the first time in a national survey, both during the main surveys near Chorley and at one site during the alternate squares spot-checks near Lathom. It is likely that otters reached this area from the Ribble catchment to the north. Lune (3) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/18 1/18 3/18 5/18 10/18 The results from the surveys and the alternate squares spot-checks show that otters are now found throughout the catchment. The mix of positive and negative sites in the coastal area around Lancaster indicates that while otters are present there, they are probably still in small numbers in the coastal parts of this catchment. The Lune provides one of the main corridors for the re-colonisation of the area north of the urban area of Manchester/Warrington/Liverpool, particularly the Wyre catchment.

Wyre (4) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/15 0/15 1/15 0/15 1/15 The results from the surveys and alternate squares spot-checks show that otters are widely but probably very thinly distributed in this catchment. There is likely to be consolidation of this population in the near future. Ribble (5) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/55 0/55 5/55 2/56 13/56 There has been a considerable increase in the occurrence of otter signs in the Ribble catchment since the 2000-02 survey but the more industrialised, south western, part of the catchment shows little or no otter presence as yet. The Ribble provides one of the main corridors for the re-colonisation of the area north of the urban area of Manchester/Warrington/Liverpool. West Cumbria (6) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/13 2/13 4/13 1/18 7/18 The surveys and the alternate squares spot-checks show a major increase in otter presence in the West Cumbria catchment. The three yearly surveys carried out by Environment Agency staff indicate that otters have re-colonised this area over many years (Bennet & Butterill, 2010). Eden and Estuary (7) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 6/105 11/105 45/105 75/105 88/105 Otters now use all the rivers in this catchment. The negative sites are mainly in the coastal areas, which are difficult to survey, or in the smaller headwater streams which are probably only used intermittently by otters at present. The catchment was surveyed by Environment Agency staff in 2000, 2004 and 2007 (Ratcliffe, 2008) South Cumbria (8) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 3/82 17/82 13/82 24/82 57/82 Otters are now present throughout this area. There is a group of negative sites around Barrow in Furness and on Walney Island even though this area is known to have been used by otters as an otter was found dead on Walney Island in April 2008 (E. Chadwick pers. comm.). The three yearly surveys carried out by Environment Agency staff indicate that otters have steadily re-colonised this area over many years (Spiby, 2007). Croal and Irwell (9) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10

Positive sites/total 0/2 0/2 0/2 0/14 0/14 No signs of otters were found in this area. Lower Mersey (10) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/14 0/14 1/14 0/14 3/14 Three positive sites were found on the Gowy catchment but no signs were found on the Wirral despite positive sites there in 2005 (Gaskin, 2005). Mersey and Bollin (11) No main surveys were carried out in this catchment but otter signs were found on the Bollin during the alternate squares spot-checks. It is assumed that colonisation has been from the Weaver catchment to the south. Otters are known to have been present on the Bollin since at least 1995 (A. Crawford pers. obs.) but appear to have shown little expansion in range in that time. Roch, Irk and Medlock (12) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/0 0/0 0/0 0/4 1/4 One positive site was found in this area on the River Roch near Bury. The next nearest positive site to this was about 36km away, by watercourse, on the Calder in Yorkshire Region. However a spot-check survey in May 2010 found otter signs on the Rochdale Canal at the watershed between the Roch and the Calder (Yorkshire) near Summit (A. Crawford pers.obs.). This is between the two sites and approximately 18 km from both. It is quite possible that the positive site on the Roch is from a transient animal which used the Calder, the canal and the Roch to cross the watershed. Sankey and Glaze (13) No main surveys were carried out in this catchment and no otter signs were found during the alternate squares spot-checks. Tame Goyt and Etheroe (14) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/0 0/9 0/9 0/12 1/12 Only one main survey site, near Whaley Bridge on the Goyt, was positive and otter signs were found near Marple on the Goyt during the alternate squares spot-checks. Weaver/Dane (15) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/18 0/18 3/18 3/18 12/18

Otters appear to have colonised this area from the Severn catchment to the south. They are now present on most of the rivers and canals in the southern part of the Weaver catchment around Nantwich. The alternate squares spot-checks show that otters are widely distributed in the rest of the area but probably at a low population level. Otter use of the canals in this area is extensive. Discussion The North West region has shown a major increase in otter range since the last survey in 2000-02. The increase has been particularly impressive in the north where otters appear to have re-colonised all the available rivers and streams even in the uplands. In the four northern catchments (3, 6, 7, 8) of the region 162/223 sites (73%) were positive. Regular surveys by Environment Agency staff since 1998 (Bennett & Butterill, 2010; Ratcliffe, 2008; Spiby, 2007) show that otters have been slowly re-colonising the area since then but it will probably be some time before this part of the region reaches full carrying capacity. The northern part of North West region is one of the few areas in Britain with a regular series of surveys over many years enabling the increase in range to be monitored accurately. This is of particular interest as no introductions have taken place in the region. It is thus one of the few areas where we have both a wholly natural increase in range combined with a series of detailed surveys covering the whole period of re-colonisation. In the central part of the region the increase in range has also been considerable. In the 2000-02 survey only three positive sites were found between Lancaster and the Liverpool, Warrington and Manchester urban area. In the 2009-10 survey there were 21 positive sites in that area mainly in the Ribble catchment but also spreading into the Douglas and Wyre and with an outlier on the River Roch. Otters are now widely distributed on the Ribble and Lune catchments. These rivers provide corridors for re-colonisation of the catchments to the north of the urban area of Liverpool, Warrington and Manchester and re-colonisation of the area would be expected in the next few years. The outlying site on the River Roch is 36km from the next nearest positive site, on the Calder in Yorkshire, but a spot-check survey in May 2010 found otter signs on the Rochdale Canal at the watershed between the Roch and the Calder near Summit (A. Crawford, pers.obs.). This is between the two sites and approximately 18 km from both. It is quite possible the positive site on the Roch was a result of a transient animal which used the Calder, the canal and the Roch to cross the watershed. If otters are indeed crossing the Pennines from the Calder catchment to the Roch, then the re-colonisation of this part of North West Region might proceed faster than previously expected. In the report of the 2000-02 survey concern was expressed at the very slow rate of colonisation of the southern part of North West Region. The main surveys and the alternate squares spot-checks show that otters are now widely distributed within the Weaver catchment and appear to have spread from there into adjacent catchments such as the upper Mersey and Goyt. They are now widely distributed south of the urban area of Liverpool, Warrington and Manchester but appear to be present only in small numbers. Initial re-colonisation and consolidation still remains surprisingly slow despite the close connections with the Severn and Dee catchments but it is to be hoped that consolidation of the population will continue. It will be interesting to see if otter populations are able to spread through the urban area and link with the otter population expanding south from Cumbria. 4.2 Northumbrian Region

Surveys were carried out in the following 50km squares – NT s/e (42), NY s/e (52), NZ n/w (75), NZ s/e (5). Description of region The majority of rivers in this region rise in the northern Pennines or the Cheviots and flow through the coastal plains. Land use is predominantly agriculture with sheep, arable and cattle in order of importance. Forestry also covers a large area, particularly around Kielder reservoir. Open cast mining and its side effects are still apparent in the central parts of the region. Gravel extraction occurs next to a number of rivers, in some cases benefitting the wildlife diversity of the area by the creation of post-extraction wetland habitats. Heavy industry is largely confined to the areas around the mouths of the Rivers Blyth, Tyne, Wear and Tees. However, the region’s increased involvement in the service sector has resulted in large-scale redevelopment along many of the region’s former industrial riverbanks. A serious problem in the rural parts of the region is riverbank overgrazing and poaching by cattle and sheep causing habitat degradation and silt pollution of watercourses. This has been exacerbated by high stock density and poor maintenance of riverbank fencing. This region, with the Yorkshire Region, now forms part of the Environment Agency North East Region. Different southern boundaries of the region have been used in the reports of past surveys. In this survey, as in the 2000-02 survey, Northumbrian Region is taken to include the Kilton Beck but not the Easington Beck. Water quality There have been major improvements in water quality in the region but intermittent pollution incidents still occur on some rivers, and storm-water overflows and farm run off cause localised problems. Acidification is still an issue on the upper reaches of many rivers, a problem exacerbated by large scale conifer forests in some catchments. Fisheries Most of the region’s rivers are predominantly game fisheries with runs of migratory salmonids and stocks of brown trout, often supplemented by stocking. The Tyne, Wear and Tees support good populations of mixed coarse fish, mainly dace, chub and roach and the Tweed and Till in the north support smaller populations of these species. There are numerous stillwater fisheries with both game and coarse fish. All three species of lamprey have been recorded and eels, although declining, are present throughout the region. Many of the smaller tributary streams and coastal burns have reduced fish populations as a legacy of past pollution.


14/169 17/169 17/174

45/169 46/174

85/169 90/174

135/169 140/174


8.28% 10.06% 9.77%

26.62% 26.44%

50.30% 51.72%

79.88% 80.46%

Spot-checks were carried out in an additional 61 whole or partial 10km squares. Alternate 50km Square NT n/e NU s/w NY n/e NZ s/w Positive/total 10km squares 1/1 13/14 20/21 25/25 Summary of results for each catchment Cheviot/East Northumberland (16) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 13/86 14/86 33/86 63/86 79/86 The surveys and the alternate squares spot-checks show that otters in this area now use all the available watercourses, even small coastal streams like the Embleton Burn, and the coast. The very small number of negative sites in the area are either on very small streams such as the Portland Burn or at coastal sites which were difficult to survey adequately. Tyne (17) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/39 1/39 9/39 17/39 26/39 The surveys and the alternate squares spot-checks show that otters have now re-colonised most of the available watercourses. The small number of negative sites in the catchment are on very small streams or at coastal sites which were impossible to survey, and were thus assumed to be negative, or those which were very difficult to survey adequately. The upper part of the catchment was only surveyed as part of the alternate squares spot-checks but these show that otters are present on all the major watercourses and at least some minor streams. Wear (18) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/15 0/15 0/15 3/15 8/15 The surveys and the alternate squares spot-checks show that the otter population in the catchment has now expanded to re-occupy all the available watercourses. The small number of negative sites are either on very small streams or at sites at which access was refused and were thus assumed to be negative. An alternate squares spot-check on the Hawthorne Burn and local surveys (T. Coult, pers. comm.) show that otters are now using some of the small coastal streams or ‘denes’ where cover is good but fish stocks are small. It seems likely that otters are accessing these from the sea and probably finding prey on the coast as well. Tees (19)

Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/29 2/34 4/34 7/34 27/34 There has been a major expansion in range in the headwaters of the Tees. The otter population now uses all the available watercourses within the surveyed area. The alternate squares spot-checks show that they are also widely distributed within the rest of the catchment. Discussion There has been a further major expansion of the range of otters in the Northumbrian Region since the last survey and otters are now using all the available watercourses and much of the coast. However while otters now use the overwhelming majority of the rivers and streams in the region, this has happened relatively recently and it is unlikely that otters are yet at carrying capacity (see section 6.4). It is however likely that they will reach this level within a very few years if current trends continue. Otters appear to be using the whole of the coast in this region with otter signs found on the Tweed estuary, at Holy Island and at coastal streams further south, including small coastal streams or ‘denes’. Some of these are quite isolated from the river network so otters are almost certainly accessing these from the sea. They provide a source of freshwater and have good cover for lying up but can have only a small prey resource. It is therefore assumed that otters are also using the sea for foraging in these areas.

4.3 Yorkshire Region Surveys were carried out in the following 50km squares – NY s/e (4), NZ s/e (25), SD s/e (13), SE n/w (129), SE s/e (81), SK n/w (18), TA n/w (14). Description of region The majority of the rivers in the region arise in the Pennines, although the Derwent and Esk arise on the North Yorkshire Moors. In their headwaters all these rivers have steep gradients, but soon reach the more low-lying areas through which they meander to reach the Humber Estuary, with the exception of the Esk which flows directly to the North Sea at Whitby. The floodplains often provide high quality arable farmland, most of which is intensively farmed, while much of the upland area is moorland, including the North Yorks Moors, and there are some large conifer plantations. The River Derwent has been designated a Special Area of Conservation (SAC) with otters as a qualifying species. The human population is concentrated mainly in the south of the region in the older industrial and mining centres of Leeds, Sheffield, Bradford, Huddersfield, Doncaster, Rotherham, Barnsley and Halifax but there are also the urban centres of Hull, York and Harrogate. This region now forms, with the Northumbrian Region, part of the Environment Agency North East Region. Different northern boundaries of the Yorkshire Region have been used in the reports of past surveys. In this survey, as in the 2000-02 survey, Yorkshire Region is taken to include the Easington Beck but not the Kilton Beck. Water quality The northern part of the region is mainly upland and agricultural generally with good water quality although some rivers suffer from acidification and agricultural runoff. The southern part of the region, with a long history of industry and mining, has had serious pollution problems in the past but water quality is now generally good although some problems from minewater seepage and episodic incidents of industrial and sewage discharges persist. Fisheries Populations of coarse fish and trout in the rivers of South and West Yorkshire have increased markedly following reductions in pollution and improvements to habitat. Salmon and sea trout are now returning in good numbers to rivers like the Ure and most rivers support healthy populations of coarse fish. Eel numbers have decreased drastically in the region but they are still present in the lower and middle reaches of most rivers. Ongoing work to improve fish passage for all species should see populations continue to improve.


4/227 5/227 6/270

25/227 28/270

44/227 68/284

144/227 179/284


1.76% 2.20% 2.22%

11.01% 10.37%

19.38% 23.94%

63.44% 63.03%

Spot-checks were carried out in an additional 79 whole or partial 10km squares. Alternate 50km Square NZ s/w SD n/e SE s/w SE n/e TA s/w Positive/total 10km squares

5/5 10/10 20/25 24/25 6/14

Summary of results for each catchment Derwent (20) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/16 1/16 12/16 7/20 15/20 There has been a considerable expansion in otter presence in the part of the Derwent catchment included in the main survey. This and the results of the alternate squares spot-checks show that otters are now found throughout the catchment. Swale, Ure and Ouse (21) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 4/109 3/109 8/109 25/109 82/109 There has been a major expansion of otter range within this area. The small number of negative sites are largely confined to minor headwaters. Nidd and Wharfe (22) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/45 1/45 5/45 6/45 31/45 There has been a major expansion of otter range within this area. The small number of negative sites is largely confined to minor headwaters Esk and Coast (23) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/0 1/25 3/25 20/25 21/25 Most watercourses in this area were found to be used by otters in the 2000-02 survey and there has been little change since. Otters use the small coastal streams in this area indicating re-colonisation of the coast.

Hull and East Riding (24) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/14 0/14 0/14 6/24 16/24 There has been a significant expansion of otter range in this area particularly to the west of Hull but occurrence in the eastern part of the area, where streams are generally very small, is still patchy. Otters are using some of the small coastal streams which indicates re-colonisation of the coast in this area. South Yorks/N.E. Derbyshire (25) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/22 0/40 0/40 3/40 10/40 Although there has been a significant expansion of otter range in this area the main survey and the alternate squares spot-checks show that distribution is still patchy particularly in the southern headwaters. West Yorks Aire (26) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/14 0/14 0/14 1/14 4/14 The main survey was confined to the two ends of the area with the negative sites mainly confined to smaller headwaters at the western end of the catchment. The alternate squares spot-checks show that otters are now widely distributed in the area. West Yorks Calder (27) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/7 0/7 0/7 0/7 0/7 The seven survey sites are all on the headwaters at the western end of the catchment and were all negative. However the results of the alternate squares spot-checks show that otters are widely distributed in the rest of the catchment. A one-off survey in May 2010 (A. Crawford pers. obs.) found otter signs on the Rochdale Canal at Summit only a few metres from the watershed of the Calder (Yorkshire) and the Roch (North West). It seems likely that the single positive site on the River Roch is from an otter that crossed the watershed from the Calder catchment. Discussion The Yorkshire region has shown a major increase both in positive sites and otter distribution since the 2000-02 survey. There has been considerable consolidation in those areas like the Swale, Ure and Ouse which previously had a sparse population of otters and expansion into those areas which did not previously have otters. However the results indicate that this spread has, in many areas, been relatively recent and there is still a small otter population spread over a wide area. There are still areas mainly in the south of the region with few if any otters such as the catchments of the Rother and the Don. The otter population would be expected to re-colonise those areas and to consolidate in the rest of the region within the next few years if present trends continue. If otters are indeed crossing the Pennines from

the Calder catchment to the Roch, then the re-colonisation of this part of North West Region may be augmented by otters from Yorkshire. As in other regions the use of coastal streams in Yorkshire seems to be increasing. It is almost certain that otters are also foraging in the sea as many of the small streams are unlikely to support large fish stocks. There has been a considerable expansion in otter use of the coast on the eastern side of England and otters now use coastal streams, and presumably the coast, from Berwick upon Tweed to Felixstowe including all the coast of Yorkshire. 4.4 Dee Catchment Surveys were carried out in the following 50km squares – SJ n/w (9), SJ s/e (3) Description of region The River Dee rises in the Welsh hills around Bala Lake and flows through a varied landscape, including steep wooded valleys, before descending and meandering across the Cheshire Plain. The river is designated as a Special Area of Conservation (SAC) with otter as one of the designated features and as a Site of Special Scientific Interest (SSSI) with otter as one of the reasons for notification. The whole estuary is designated as a SAC, SPA and Ramsar site. There are about 425,000 people within the whole catchment with commercial and industrial activity centred on Wrexham, Ruabon and Chester. Much of the lower end of the catchment is dominated by intensive dairy farming. Many of the rivers have little cover but there is some very good localised habitat. This survey only covers the small English part of the catchment the rest of which is in Wales and is the subject of a separate survey (Strachan, in prep.). Water quality Water quality is generally very good throughout the catchment but land management practices still lead to diffuse pollution and silt pollution of rivers and there are occasional pollution incidents from both agriculture and industry. These can have impacts both on fish and on the invertebrates upon which they feed. Fisheries The lower Dee suffers from poor channel structure with little fish holding habitat as a result of past engineering works. This may reduce the biomass of fish but many coarse fish species such as chub, dace and barbel are present and most of the lower tributaries hold good stocks of small coarse fish so this is unlikely to affect otters. The river also supports an important rod salmon fishery.

Results for 2009-10 survey and comparison with previous surveys A total of 12 sites was surveyed in the main survey. Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/12 1/12 5/12 6/12 8/12 % Positive 0.00% 8.33% 41.66% 50.00% 75.00% Spot-checks were carried out in one additional partial 10km square. Alternate 50km Square SJ s/w Positive/total 10 km squares 4/4 Discussion The majority of the Dee catchment lies in Wales where there is a strong population of otters. The 2002 Otter Survey of Wales (Jones, 2004) reported 87 per cent of surveyed sites as positive. This level has been maintained since (Strachan, in prep.) and it is to be assumed that otters on the upper Dee have reached carrying capacity. The survey shows only a small expansion of otter range in the English part of the Dee since the 2000-02 survey but it is likely that this rather under-represents the extent of otter use on this part of the catchment. No signs were found at the one site on the Dee estuary but otter signs have been found downstream of Chester near Shotton (R. Strachan, pers. comm.) and it can be assumed that otters do use the estuary. There are large areas of undisturbed coastal wetlands around Neston and it would be expected that otters will utilise these in the near future if they are not already doing so. The otter signs found on the lower Mersey are probably from an otter or otters that have crossed from the Dee catchment. It is to be hoped that this will continue thus strengthening the population in the southern part of North West Region.

4.5 Severn Catchment Surveys were carried out in the following 50km squares – SJ s/e (70), SO n/w (60), SO s/e (101) and SP n/w (97). Description of region The Severn and its tributaries rise in the Welsh hills and flow in a generally westerly direction to the Welsh border then generally south to the estuary. The principal tributaries are the Vyrnwy and Teme, both of which lie partly in Wales, the Tern, Stour and Warwickshire Avon. The larger towns include Shrewsbury, Worcester, Gloucester, Tewkesbury and Bromsgrove. Dudley and Wolverhampton lie on the headwaters of the Stour system and Coventry and Rugby lie within the Avon catchment. This survey only covers the English part of the catchment, the rest of which is in Wales and is the subject of a separate survey carried out concurrently (Strachan, in prep.). Water quality Water quality in the Severn catchment is generally very good although silt from farming and diffuse pollution cause occasional problems. Acidification may still be having an impact upon salmon spawning in the upper reaches. This may have an indirect impact on the English part of the catchment. Fisheries The Severn supports a wide variety of fish. The lowland navigable reaches are dominated by cyprinids such as roach, chub and barbel and native predators such as pike and perch and the non-native zander. The upland reaches have good brown trout and salmon stocks with grayling on some tributaries. The river also supports rarer species such as twaite shad, sea lamprey and river lamprey. The elver run has declined considerably and there is concern about eel stocks. Many fish stocks, although stable, are below the level required to reach ‘good ecological status’ under the Water Framework Directive. In some cases this may be caused by barriers to fish migration such as flap valves on small side streams.

Results for 2009-10 survey and comparison with previous surveys

A total of 328 sites was surveyed in the main survey. Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 13/328 22/328 105/328 127/328 194/328 % Positive 3.96% 6.71% 32.01% 38.71% 59.15% Spot-checks were carried out in an additional 43 whole or partial 10km squares. Alternate 50km Square SJ s/w SO n/e SP s/w Positive/total 10km squares 11/11 22/23 8/9 Summary of results for each catchment Middle Severn – including Tern, Roden and Worfe (28) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/73 1/73 33/73 45/73 54/73 There has been a small increase in positive sites in this area since the last national survey. This and the alternate squares spot-checks show that otters now utilise all the watercourses in the area. In the 1990s otters, probably from this area, re-colonised the Sow and Penk catchments of the Trent to the east and probably the Weaver catchment in North West region to the north. Otter movements across the watersheds are probably continuing and it is to be hoped that, as the otter population in this area approaches carrying capacity, ‘surplus’ individuals will help to re-inforce these adjacent populations. West Midlands (29) No main surveys were carried out in this catchment but the results of the alternate squares spot-checks show that otters are widely distributed in the Stour catchment. Severn Uplands (30) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 1/5 3/5 5/5 5/5 5/5 Most of this catchment is in Wales which was surveyed separately (Strachan, in prep). All sites in the English part of the catchment were positive as in all the last three surveys indicating a healthy otter population. Teme (31) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 12/55 18/55 40/55 44/55 49/55 The full surveys and alternate squares spot-checks show that otters are now present on all the watercourses in the catchment. The small number of negative sites are nearly all on watercourses with positive sites both up and down stream showing that otters are present. Warwickshire Avon (32)

Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/113 0/113 10/113 12/113 40/113 There has been a major expansion of otter range in this catchment since the last national survey. Most rivers are now used by otters but many of the minor watercourses have not yet been re-colonised. Otters now use the headwaters of the Avon and a survey by Environment Agency staff (Farmer, 2007) showed that the areas occupied by otters on the Upper Avon, the Soar (Trent) and the Welland (Anglian) are continuous while the alternate squares spot-checks show that otters have also re-colonised the upper Nene. These catchments are linked by the Grand Union canal which is well used by otters and may be providing a link for otters between them. Severn Vale (33) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/82 0/82 17/82 21/82 46/82 There has been a major expansion of otter range and they now use most watercourses in this catchment. The relatively large number of sites which have changed from positive in 2000 to negative in 2009 is not thought to be significant as despite this the total number of positive sites has more than doubled. The alternate squares spot-checks show that otters are now using many of the smaller streams running into the Severn Estuary. It is possible that the otter(s) using these streams have moved into the area from the Bristol Avon catchment to the south or even crossed from the rivers of South Wales. The estuary of the Severn is a key area for otters as it provides a potential link between the populations of the lower Severn and Wye and those of the upper Thames and Bristol Avon. Discussion The increase in otter range since the 2000-02 survey has been most marked in the south of the catchment and on the Avon in areas which previously had few signs of otters. Otters are now using most of the rivers and streams within the catchment but there is still considerable scope for expansion and consolidation. Crawford (2003) expressed concern about the slow rate of re-colonisation of the Severn below Worcester and on the Avon catchment. Surveys of the main River Severn by boat in 2004 (A. Crawford pers. obs.) showed that otters were using the main river but activity levels appeared to be low. The present survey shows that otters are now using the whole of the Rivers Severn and Avon and many of their tributaries, for example the Leadon. There is now an otter presence on small rivers like the Lyd, the Cam and the Frome that flow into the Severn estuary and it can therefore be assumed that otters are using the estuary. There is now, for the first time, probably since the early 1960s, the possibility of a single population from South Wales and the Wye through the Severn estuary to Wessex region and the Upper Thames via streams like the Hatherley Brook and the River Chelt. The importance of this for gene flow and for the resilience of the whole otter population is considerable.

4.6 Trent Catchment Surveys were carried out in the following 50km squares – SE s/e (24), SJ s/e (57), SK n/w (44), SK s/e (96), SP n/w (61). Description of catchment The River Trent rises just north of Stoke-on-Trent and flows generally south and then north east to the Humber estuary, being joined by the major tributaries of the Sow, Tame, Dove, Derwent and Soar. Land use is diverse and includes moorland, mixed farming, intensive arable and industrial areas. There is a very large population with many big urban and industrial centres including the West Midlands conurbation, Stoke on Trent, Derby, Leicester, Loughborough, Nottingham, Newark and Gainsborough. The majority of rivers have been re-sectioned and deepened leaving very impoverished in-stream habitat which has reduced the holding capacity for fish, a factor that has become more apparent as water quality has improved. Gravel workings on the floodplains of many rivers in the region including the Trent, Tame, Soar and Idle have given opportunities for river restoration and the creation of large areas of wetland. Flooded gravel pits are a major feature of the Trent catchment and provide an important resource for otters. There is an extensive network of canals in the catchment often with good fish stocks. Water quality A unique feature of the catchment is that many of the urban areas are concentrated around the headwaters of rivers resulting in severe urban runoff problems not moderated by dilution of pollutants. The Tame (draining Birmingham and the Black Country) has been particularly badly affected, but the headwaters of the Trent (draining Stoke on Trent) and the Soar (draining Leicester) have also suffered as, to a lesser extent, have the Maun, Erewash and Ryton. Water quality has improved very markedly since the 1980s. These improvements are continuing so that even some highly urbanised rivers now support fish. However urban runoff and pollution incidents still affect a number of watercourses. Minewater seepage also causes problems on several rivers within the Staffordshire and Nottinghamshire coalfields, a factor which is likely to become more of a problem in the future as water levels rise in the coalmeasures. Fisheries The rivers in the catchment contain a wide variety of coarse fish including roach, chub and barbel with brown trout in the more upland rivers while salmon have been reintroduced to the River Dove and are now returning to spawn. Eels have declined in the lower part of the catchment and have always been rare above Nottingham. White clawed (native) crayfish are present in some parts of the catchment, and introduced signal crayfish are common in many rivers and pools. Fish stocks are sparse in the urban River Tame where habitat structure is poor and there are still problems from urban runoff. Serious pollution incidents have caused major fish kills which have temporarily reduced fish stocks in some rivers. There are a very large number of stillwater fisheries in the catchment many of them heavily stocked.


0/238 0/238 0/282

12/238 18/282

58/238 58/282

92/238 98/282


0% 0% 0%

5.04% 6.38%

24.37% 20.57%

38.66% 34.75%

Spot-checks were carried out in an additional 54 whole or partial 10km squares. Alternate 50km Square SJ n/e SK s/w SK n/e SO n/e SP n/e Positive/total 10km squares 2/3 22/25 12/21 1/2 3/3 Summary of results for each catchment Staffordshire Trent Valley (34) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/55 0/55 9/55 24/55 26/55 The increase in positive sites has been quite low but this may be due to high water immediately preceding the survey. Otters now use all the rivers in this area. West Midlands Tame (35) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/42 0/42 0/42 5/42 5/42 The upper Tame and its tributaries fall mainly within the West Midlands conurbation where urban runoff, poor in-stream habitat and intermittent pollution events restrict fish populations and therefore the potential for otters. There has been little change in otter distribution with otters signs being confined, as in the previous survey, to the River Blythe SSSI. There are however casual records of otters penetrating into the edge of the conurbation, such as the otter which was killed on the road near Woodgate in 2007 (S. Bodnar, pers. comm.).

Dove (36) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/1 0/14 1/14 0/14 3/14 The surveys and the alternate squares spot-checks show that otters are now widely distributed within the area. The negative sites are nearly all on the minor upland tributaries of the Dove. Evidence of a female otter with a cub was found on a mink raft near Okeover in 2010 (C. Horsford, pers. comm.). Burton, Nuneaton and Tamworth (37) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/16 0/16 0/16 4/16 6/16 There has been a considerable expansion in otter range on surveyed parts of the Anker while the alternate squares spot-checks show that otters are widely distributed in the rest of the area. The catchment includes the River Mease SAC for which otter is a designated feature. Otters are present on the lower Mease but re-colonisation of the Mease upstream has been very slow despite otter presence for some years on the Rivers Trent, Anker and Sence (C. Farmer, pers. comm., A. Crawford, pers. obs.). This may reflect the rather low biomass of fish on the Mease or a low level of otter population in the surrounding area. Soar (38) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/55 0/55 2/55 13/55 26/55 There has been a considerable expansion of otter range on the Soar catchment. The otter population on the upper Soar now appears to be continuous with the populations on the Avon (Severn) and the Welland and Nene (Anglian). These are linked in part by the Grand Union Canal which has been well used by otters since at least 2005 (Farmer, 2005). Derbyshire Derwent (39) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/0 0/31 5/31 0/31 3/31 The main survey covered only the upper reaches of the Derwent. Otters are present on the lower reaches but have not yet permanently colonised much of the upper catchment. Lower Trent and Erewash (40) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/57 0/57 0/57 9/57 25/57 There has been a considerable expansion of otter range in this area since the last survey. Otters are now present on the Trent between Nottingham and Newark and on the Devon. There appears to be little or no otter activity between Newark and Gainsborough but they use much of the lower part of the catchment including the River Eau and Bottesford Beck. No signs were found on the lowest 10km of the Trent but an otter cub was drowned in a fyke net at Alkborough at the mouth of the Trent in November 2009 (R. Brunt, pers. comm.).

Idle and Torne (41) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/12 0/12 1/12 3/12 3/12 The surveyed sites are all on the Torne catchment. Otters are present but do not appear to have increased their range since the last survey. An otter was found dead on the lower Torne at the end of the survey period (A. Crawford, pers. obs.). The alternate squares spot-checks show that otters are now widely distributed on the Idle. Discussion The increase in positive sites in the Trent region since the 2000-02 survey has been surprisingly low. Otters have now re-colonised the majority of the Trent catchment but there are large areas which appear to have a low level of occupation. A considerable part of the expansion has taken place in 50km square SK s/w, which was only covered by the alternate squares spot-checks, so the increase in range is rather poorly represented by the increase in positive sites in the main survey. Even allowing for this, the increase still seems low. Otters have been present on the lower reaches of the River Mease, (a SAC with otter as a designated feature) for some years but re-colonisation of the Mease upstream has been very slow. This is despite otter presence for some years on the lower reaches of the Mease and on the Rivers Trent, Anker and Sence (C. Farmer pers. comm., A. Crawford pers. obs.) probably indicating the continuing low otter population in this part of the catchment. The Trent catchment has one of the few gaps between otter populations remaining in England. From just upstream of Newark to downstream of Gainsborough, a distance of about 50km by river, only one positive site was found. The positive site was near Marton, close to the western end of the Fossdyke which joins the Trent and the Witham, in Anglian Region, where there is an expanding otter population. This site may represent an otter crossing from the Anglian region. Re-colonisation of the rivers of the Trent catchment upstream of Newark appears to have come from the Tern system of the Severn catchment into the Sow and Penk catchment, beginning in the early 1990s. No signs were found on the Sow and Penk during the surveys in 1977-79 or 1984-86 and only a single spraint was found during a systematic survey of the Sow and Penk system in 1990 (Howell, 1990). Only 7 positive sites were found on the Sow and Penk during the 1991-94 survey but by the 2000-02 survey otters were using much of the Upper Trent catchment. The 2009-10 survey shows that otters now use the whole of the Trent and its tributaries down to near Newark. The initial speed of recolonisation, particularly of the Upper Trent catchment, and the increase in positive sites on the catchment as a whole was very fast between the 1991-94 and 2000-02 surveys. The expansion of otter range on the Trent catchment above Newark since 2002 appears to have slowed and there has even been an apparent pause in expansion. This phenomenon of apparent quick expansion and then a pause followed by consolidation has been observed on the Severn in the 1980s (A.Crawford, pers. obs.) and 1990s (Crawford, 2003). However this apparent stochastic range expansion may be the result of the time gaps between surveys and be more apparent than real. Re-colonisation of the lower tidal Trent and its tributaries including the Idle and Torne appears originally to have been the result of the introduction by the Vincent Wildlife Trust of two otters onto the River Eau catchment in 1996. Since then it appears likely that otters have moved into the area from the Ancholme and/or the Upper Witham catchments in

Anglian Region. The one positive site between Newark and Gainsborough, near Marton, is likely to be an outlier from the upper Witham population as it is close to the western end of the Fosdyke which links the Trent and Witham. The re-colonisation of the Devon may also be by otters moving west from the Upper Witham. It would be expected that the gap on the Trent would be occupied within the next few years. However the Trent in this section is heavily modified for navigation which has reduced fish holding capacity and there are only a few very small tributaries. In most cases moreover the tributaries join the Trent through flap valves which prevent fish movement and reduces the fish resource still further. The Fossdyke is the only exception to this and provides a very good re-colonisation route from the River Till (a Witham tributary) to the Trent. The positive site near Marton is close to the Fossdyke. 4.7 Wye Catchment Surveys were carried out in the following 50km squares – SO n/w (31), SO s/e (39). Description of region The Wye catchment includes some of the finest rural scenery in England. It covers the catchment of the Wye and its tributaries including the Monnow and Lugg. The River Wye and several of its tributaries including the Lugg are an SSSI and SAC and are among the most important rivers in Britain in nature conservation terms. Much of the lower Wye valley is an Area of Outstanding Natural Beauty emphasising its importance in terms of landscape and amenity. The city of Hereford and the principal towns of Ross-on-Wye, Monmouth and Chepstow are all on the banks of the River Wye while the town of Leominster lies on the River Lugg. Water quality Water quality is generally very good in the catchment which supports a salmon and trout fishery. Fisheries The River Wye provides some of the best known river fishing in England. In the past it was best known for its annual salmon run although numbers have decreased substantially in recent years. Trout are present in most parts of the catchment with many species of coarse fish such as barbel, chub, dace, pike and roach present in all but the smallest streams and the Wye itself is now considered to provide some of the best river coarse fishing in England (Woodward, 2009, Anglers Mail, 2010). All three species of lamprey are found and native crayfish are present in parts of the catchment.

Results for 2009-10 survey and comparison with previous surveys A total of 70 sites was surveyed in the main survey. Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 12/70 23/70 49/70 58/70 58/70 % Positive 17/14% 32.86% 70.00% 82.86% 82.86% Spot-checks were carried out in an additional 13 whole or partial 10km squares. Alternate 50km Square SO s/w SO n/e Positive/total 10km squares 10/10 3/3 This survey only covers the English part of the Wye catchment, the Welsh part being covered by the survey of Wales (Strachan, in prep.). There was no increase in the number of positive sites in the Wye catchment since the last survey, however eight sites changed from positive to negative, balanced by eight sites which changed from negative to positive. Seven of the sites which changed to negative are between positive sites so it can be assumed that otters, while not detected, do use these areas. The surveys and the alternate squares spot-checks show that otters are using all the main rivers in the area and it appears likely that the Wye has reached carrying capacity, with South West, one of only two ‘regions’ to do so. Otters re-colonised the English part of the Wye catchment from upstream during the 1980s (Crawford,1979, 1984; Strachan et al., 1990) and were using all watercourses in the catchment by 1993 with carrying capacity probably reached by the mid 1990s. It is therefore encouraging that fisheries interests consider the Wye in general to provide excellent pleasure and specimen fishing (Anglers Mail, 2010; Angling Times, 2010 A; Angling Times, 2010 B) and the river in Hereford to be ‘the best two miles of river fishing in the country’ (Woodward, 2009) with large catches of barbel, chub, roach and dace. A survey of the river in 2010 within the city (A. Crawford pers. obs.) confirmed heavy use of this stretch by otters. It is clear from this that a river with good habitat quality and a well established otter population can easily support high quality match, pleasure and specimen fishing (see section 6.6 on otters and fisheries). 4.8 Anglian Region Surveys were carried out in the following 50km squares – SE s/e (9), SK s/e (42) SP s/e (78), TF n/w (142), TG s/e (3), TL n/w (132), TL s/e (103), TM n/w (121). Description of region Anglian Region is by far the largest of the regions into which England has been divided for this survey. The land is mainly low lying and consists of river floodplains that have been drained for agricultural use and now provide very fertile arable land. Only the Chiltern Hills exceed 200m above sea level. There are very large areas of wetland including the Norfolk Broads and the extensive coastal marshes many of which are designated as Special Areas for Conservation (SACs), Special Protection Areas (SPAs) and Ramsar sites particularly for their bird interest. The Norfolk Broads are a major tourist attraction as well as being very significant for wetland conservation and fisheries. There are no very large urban centres but there are a number of cities and large market towns including Northampton, Peterborough, Milton Keynes, Chelmsford, Colchester, Bedford, Kings Lynn, Norwich, Ipswich, Cambridge, Lincoln and Corby.

Water quality In a predominantly rural landscape, land management practices still lead to diffuse pollution and silt pollution of rivers. This can have impacts both upon fish habitat and on the invertebrates upon which they feed. Catchment based advisory projects working with farmers and other riparian interests are underway on the Wensum, Great Ouse and Nene to reduce these problems. Fisheries The region has over 3,000 miles of rivers and man-made drainage channels. These include the Norfolk Broads which are an important coarse fishery. Roach, bream and pike are the dominant species in slower flowing waters while dace, chub and barbel are important in the upper reaches of major rivers such as the Great Ouse and Nene. Many of the chalk rivers in Norfolk and Lincolnshire support native brown trout populations.


20/622 8/622 8/725

52/622 58/725

166/622 188/728

350/622 414/728


3.22% 1.29% 1.10%

8.36% 8.00%

26.69% 25.82%

56.27% 56.87%

Spot-checks were carried out in an additional 153 whole or partial 10km squares. Alternate 50km Square SK n/e SP n/e TA s/w TF s/w TG s/w Positive/total 10km squares 8/9 21/22 4/9 16/25 21/22 Alternate 50km Square TL s/w TL n/e TM s/w TM n/e TQ n/e Positive/total 10km squares 10/13 25/25 10/15 3/3 1/10 Summary of results for each catchment Upper Witham (59) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/73 0/73 2/73 16/73 44/73 There has been a major expansion of otter distribution on the Witham. The main survey results and the alternate squares spot-checks show that otters are now using most of the watercourses in the catchment. Welland (60) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/26 0/26 1/26 16/26 18/26 The part of the Welland catchment covered in the main survey shows a slight increase in positive sites and the alternate squares spot-checks show that otters are now widely distributed in the area. The otter population on the upper Welland appears to be continuous with the populations on the Avon (Severn), the Soar (Trent) and the Nene (Anglian). These are linked in part by the Grand Union Canal which has been well used by otters since 2005 (Farmer, 2005). Louth Coastal (61) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 1/50 0/50 0/50 24/50 31/50 There has been a small expansion in otter distribution and otters are now using most of the watercourses in this area.

Nene (62) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 1/24 2/24 5/24 14/24 12/24 There has been a slight fall in positive sites in this area but this is not thought to be significant. The alternate squares spot-checks show that otters are present on the lower Nene and widely distributed on the upper Nene. A survey carried out by Environment Agency staff in March 2007 found no otter signs on the upper Nene (N. Loveday pers. comm.) so re-colonisation of this catchment is likely to have occurred since then. Grimsby/Ancholme (63) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/24 0/24 0/24 0/24 12/24 There were no positive sites in this area during previous surveys but otters are now using most of the watercourses on the Ancholme system and some of the small coastal streams. Witham (64) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/20 0/20 0/20 4/20 10/20 There has been a major expansion of otter distribution on the Witham. The alternate squares spot-checks show that otters are now using most of the larger watercourses in the catchment. North Norfolk (65) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 6/17 0/17 1/17 1/17 7/17 There has been a significant expansion of otter distribution in this area. The alternate squares spot-checks show that otters are now using most of the larger watercourses. East Suffolk (66) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 1/60 2/60 10/60 24/60 36/60 There has been a significant overall expansion of otter range in this area and they now use all the main watercourses. A number of previously positive sites were negative during this survey but this is not thought to be significant. North Essex (67) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/0 0/95 3/95 20/95 61/95

There has been a significant increase in otter range in North Essex since the last survey. The results of the yearly surveys by the Essex Wildlife Trust (Tansley, 2008, 2009, 2010) show that the increase has occurred slowly over a period of some years. No signs of otters have been found on the coastal streams in this area. Broadland Rivers (68) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 3/68 0/68 13/68 26/71 48/71 There has been a significant increase in otter range in this area since the last survey. The main survey results and the alternate squares spot-checks show that otters are now using most of the watercourses in this area. South Essex (69) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/0 0/3 0/3 0/3 0/3 No otter signs were found during the main survey or the alternate square spot-checks in this catchment. Yearly surveys by the Essex Wildlife Trust (Tansley, 2008, 2009, 2010) have also found no otter signs in the area. This is now the only catchment in Anglian region in which no otter signs have been found. Old Bedford (70) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/49 0/49 0/49 3/49 21/49 There has been a very significant increase in otter range in this area since the last survey. Otters are now widely distributed but probably with a very low population. Cam (71) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/10 0/15 10/15 8/15 9/15 There has been a very small increase in the number of positive sites in this area since the last survey. Otters are now present on the main watercourses but there appears to be room for expansion. Upper Ouse (72) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/81 0/81 2/81 4/81 39/81

There has been a major expansion in known otter range in this area since the last survey. Otters are now widely distributed on the main rivers but no signs were found on many minor watercourses. Ely Ouse (73) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 2/30 2/30 10/30 14/30 24/30 There has been a significant increase in otter range since 2002 in the part of this area covered by the main survey. The alternate squares spot-checks show that otters are widely distributed in the central part of the catchment. Bedford Ouse (74) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 1/45 2/45 1/45 11/45 17/45 There has been some expansion of otter range in this area since the last survey. The alternate squares spot-checks show that otters are widely distributed in the headwaters of the catchment. North West Norfolk (75) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 5/45 0/45 0/45 3/45 23/45 There has been a significant increase in otter range in this area since the last survey. Otters now use all the main rivers but no signs were found on many minor watercourses. Discussion Anglian Region has seen a major increase in the number of positive sites from 188 to 414, an increase of 120 per cent since the 2000-02 survey. Otter range has also increased dramatically with particularly impressive expansions of range in the Ancholme, the upper Nene and the upper Ouse catchments. Otters are now widely distributed over the whole region except South Essex and the Tendring peninsula around Clacton-on-Sea. The majority of the negative sites found were on small watercourses and re-colonisation of these would be expected in the near future. In the North Essex catchment there was a large increase from 20 to 61 positive sites but this expansion has taken place slowly and has mainly been into the north and west of the area (Tansley, 2008, 2009, 2010). It would be expected that otters will re-colonise the adjacent unoccupied areas in south Essex and the area around Clacton quite soon. Surveys in April 2010 found signs in this latter area (D. Tansley, pers. comm.). With the exception of the Nene (62) and South Essex (69) catchments there has been an increase in positive sites in every catchment in the region. There was a slight, though not significant, fall in positive sites on the part of the Nene covered by the main survey, balanced by a considerable expansion in the previously un-surveyed areas of the catchment (see above). In South Essex no otter signs have yet been found during any of the national surveys or during the Essex Wildlife Trust surveys (Tansley, 2010). In the past it was noted that the pattern of re-colonisation in parts of Anglian differed from that in other regions (Crawford, 2003; Macdonald & Mason 2003). This is almost certainly

because many of the otters in this region originated from a number of small scale introductions. The Otter Trust introduced 81 otters to Anglian region between 1983 and 1998 and the Vincent Wildlife Trust introduced 16 otters between 1994 and 1995. Crawford (2003) noted that the increase in otter signs between the 1994-96 and 2000-02 surveys was mainly concentrated in those catchments into which otters were introduced between the two surveys. The pattern of expansion in Anglian since the 2000-02 survey has been similar to that of other areas such as the Trent catchment and Wessex Region where releases have not been a significant factor. It is very unlikely that any of the released otters would be alive in 2000 and none could still be alive in 2009, so any increase in range in the region since the survey in 2000-02 must be from breeding by the remnants of the previous population and/or the progeny of introduced otters, from immigration from the naturally expanding populations to the west or from all three. Since 2002 some of the largest increases in range in Anglian Region have been in catchments such as the Witham (59) and the Upper Ouse (72) where no otters were released, Grimsby and Ancholme (63), where six otters were released in 1995 but no signs at all were detected in 2000-02 (and it is presumed that the introduction was not successful), and on the Nene (62). All these areas are adjacent to expanding populations. The Grimsby and Ancholme area is adjacent to the Witham and Louth Coastal catchments of Anglian and to the lower Trent, while the Upper Nene and Upper Ouse are adjacent to the Soar (Trent) and Avon (Severn) catchments where otter populations are increasing in range. There is now complete continuity of otter range between these four catchments, with the possibility of easy movement of otters between them via the Grand Union Canal which is known to have been used by otters since at least 2005 (Farmer, 2005; C. Farmer, pers. comm.). It is likely that the otter populations expanding from the west from both the Avon (Severn) and Soar (Trent) have contributed to the increase in range in the western part of Anglian Region. There continues to be a high level of anthropogenic mortality, particularly on the region’s roads. Ten otters were found dead in Essex during 2009, eight of these being road casualties (D. Tansley, pers. comm.) and 12 in Suffolk during the same period (Penny Hemphill, pers. comm.). This certainly underestimates the level of anthropogenic mortality as some dead otters will inevitably not be found or reported. Despite these losses the increase in range by otters within the region has been considerable.

4.9 Thames Region Surveys were carried out in the following 50km squares – SO s/e (3), SP n/w (3), SP s/e (68), SU n/w (77), SU s/e (18), TL s/e (10), TQ n/w (46). Description of region The River Thames rises in the Cotswolds and flows to the sea east of London. Its major tributaries include the Kennet, Lee, Colne, Wey, Cherwell, Mole, Windrush and Thame. It is one of the driest regions in Britain but major aquifers provide a base flow for many of the rivers. The region has a population of 12 million, 20 per cent of the total for the UK in five per cent of the land area, putting a high demand on resources and the environment. A fifth of the land is urban with the massive conurbation of London dominating the lower Thames. There are other large urban areas including Swindon, Oxford and Reading but over a quarter of the land is within designated Areas of Outstanding Natural Beauty and a third of the region is used for arable farming. Water quality There have been substantial improvements in water quality in the Thames catchment over recent decades even though some rivers in the region are strongly affected by flows from sewage treatment works as a consequence of the very high level of urbanisation. Large scale investment in the sewerage system and in sewage works, including fitting a substantial number of works with phosphate reduction plant to reduce eutrophication has been a major factor in this improvement. Further investment will be required to meet the more stringent standards imposed by the Water Framework Directive. Fisheries There is a diverse fish fauna, with 119 species having been recorded in the lower Thames Basin including the estuary. Coarse fish predominate but there are many reaches with mixed coarse and salmonid fisheries and trout predominate on the headwaters of tributaries on the chalk and limestone. However natural recruitment is compromised by habitat availability on many reaches with the majority of watercourses having suffered some form of modification although over the last two decades some habitat restoration has been undertaken. Physical barriers to fish movement remain an important issue for most species. There has been a major decline in eel populations in the Thames in the last decade although a commercial eel fishery still survives in the tidal Thames. Water quality does not appear generally to be limiting fish stocks and the Thames itself has a diverse fish fauna. There have been some concerns about recruitment in some fish species a factor which may be linked to the high biomass of signal crayfish in many parts of the catchment. A research project on this issue is being undertaken in the region (G. Scholey, pers. comm.). Crayfish of course provide an additional food source for otters. There are many artificially stocked fisheries, and a large number of water-filled gravel pits, including the Cotswold Water Park, the largest complex of artificial stillwaters in Britain. These add significantly to the fishery resource and have allowed the creation of numerous carp fisheries.


0/169 0/169 0/179

4/169 4/179

13/169 18/225

89/169 92/225


0% 0% 0%

2.37% 2.23%

7.69% 8.00%

52.66% 40.89%

Spot-checks were carried out in an additional 75 whole or partial 10km squares. Alternate 50km Square SP s/w SP n/e ST n/e SU n/e Positive/total 10km squares 21/21 1/1 0/1 16/25 Alternate 50km Square TL s/w TQ s/w TQ n/e Positive/total 10km squares 5/17 0/7 1/3 Summary of results for each catchment Colne (114) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/1 0/1 0/1 0/13 1/13 Otters appear to have reached this area since the last survey but there was only one positive site near Uxbridge. It is likely to be from a transient animal as the next nearest record from the survey is 30km away, by river, near Dorney on the Jubilee river. North London (115) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/0 0/0 0/0 1/7 0/7 No otter signs were found on the main surveys in this catchment but signs were found on the Small River Lea near Cheshunt during the alternate squares spot-checks.

Roding, Beam and Ingrebourne (116) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/0 0/6 0/6 4/11 2/11 There has been a slight fall in positive sites on the Roding but this is not thought to be significant. The centre of otter activity appears to have moved about 10km downstream but the length of river used appears virtually unchanged. Upper Lee (117) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/0 0/4 0/4 0/4 0/4 No otter signs were found on the main surveys in this catchment but signs were found on the rivers Stort, Rib and Beane during the alternate squares spot-checks. Loddon (118) There are no main survey sites in this catchment but signs were found on the Loddon during the alternate squares spot-checks. Lower Thames (119) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/0 0/0 0/0 0/4 0/4 No otter signs were found on the main surveys in this catchment but signs were found on the Thames during the alternate squares spot-checks. Mole (120) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/0 0/0 0/0 0/5 0/5 No signs were found in this catchment during the main surveys or the alternate squares spot-checks. Ravensbourne and Marsh Dykes (121) No main surveys were carried out in this catchment and no otter signs were found during the alternate squares spot-checks. Thames Tideway (122) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/0 0/0 0/0 0/6 0/6 No signs were found in this catchment during the main surveys or the alternate squares spot-checks.

Wandle, Beverley Brook and Hogsmill (123) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/0 0/0 0/0 0/2 0/2 No signs were found in this catchment during the main surveys or the alternate squares spot-checks. Wey (124) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/18 0/18 0/18 0/23 2/23 Otters appear to have re-colonised this catchment since the last survey but there were only two positive sites in the area which could indicate a transient animal or a low level of re-colonisation. It is possible that the otter(s) have crossed from the Arun catchment (in Southern Region) to the south or have moved from further up the Thames. Cherwell Valley (125) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/30 0/30 1/30 1/30 14/30 There has been a very considerable increase in positive sites since the last survey and this and the results of the alternate squares spot-checks show that otters are now present throughout the area. Kennet Valley (126) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/28 0/28 0/28 0/28 13/28 Otters appear to have re-colonised the Kennet since the last survey and are now present on all the main rivers in the western part of the area. No otter signs were found in the downstream, eastern, part of the catchment so it is possible that they reached this area from the Bristol Avon catchment to the west or the Hampshire Avon to the South. There was a positive site on the Kennet and Avon Canal near Burbage very close to the watershed between the Kennet and Hampshire Avon catchments. However there has been otter activity on the Kennet for some years and previous sporadic evidence of otters on the Thames at Reading where the Kennet joins it (G. Scholey, pers. comm.). It is possible that otters have moved up the Kennet through the town. The lack of evidence on the lower Kennet is surprising. Thames (Buscot to Eynsham) & Windrush (127) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/3 0/3 1/3 2/3 3/3 The three sites surveyed in the main survey are all on the southern edge of the catchment but the alternate squares spot-checks show that otters are now widely distributed.

Thame Valley (128) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/37 0/37 0/37 0/37 18/37 Otters appear to have re-colonised this area since the last survey. They are now present on all the main rivers. Thames (Benson to Hurley) Pang and Wye (129) No surveys were carried out in this catchment but during the alternate squares spot-checks signs were found on the River Thames and on the River Wye, the first record on this river for several decades. Thames and Ock (130) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/20 0/20 2/20 0/20 16/20 Otters were present in this area in 1992 but no signs were found in 2000. They have now re-colonised most of the rivers in the area. Upper Thames (131) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/32 0/32 0/32 10/32 23/32 There has been a considerable increase in positive sites in this area and otters are now present on the majority of watercourses. Discussion The Thames catchment has shown one of the largest increases in positive sites of any region, from eight per cent to 41 per cent between the 2000-02 and 2009-10 surveys and most of the rivers of the western part of Thames Region are now used by otters. Several sub-catchments including the Kennet, Cherwell, Thame and Thame and Ock had no signs of otters in 2000 but otters now use most watercourses in these catchments. There appears to be a good otter population on the main Thames at least as far downstream as Oxford and an otter presence nearly as far downstream as Windsor. Otter activity on the upper Thames and its Cotswold tributaries was under represented in the 2000-02 survey as much of the activity was in the alternate 50km square SP s/w which was not surveyed in the national survey but was covered in a local survey (G. Scholey, pers. comm.). The 2009-10 survey indicates that the population upstream of Oxford may be approaching carrying capacity. Consolidation further down the catchment would be expected within the next few years with expansion to be expected in catchments like the Loddon and downstream on the Thames itself. It is probable that otters crossing into the Upper Thames from the Bristol Avon and into the Kennet catchment from the Bristol Avon and Hampshire Avon (possibly via the Kennet and Avon Canal) have made a major contribution to the increase in otter range in the west of Thames region. However, 17 otters were introduced into the Upper Thames catchment in

1999 and although at least six of these died within six months of the final release there was a significant increase in otter activity in the upper Thames catchment in the period following the releases (G. Scholey, pers. comm.). However the pattern of expansion in the Kennet catchment suggests colonisation from the west possibly via the Kennet and Avon canal although re-colonisation from the Thames near Reading cannot be ruled out. It is evident that the re-introduction of otters into the upper Thames has increased the rate of re-colonisation to some extent. However otters were already present in the catchment and natural re-colonisation was simply a matter of time. None of the released otters will still be alive but the rate of otter range expansion indicates that, in the western part of the region, there is now a healthy population which is reproducing successfully and expanding eastwards. At the eastern end of the region, otters are present on the Lee catchment and on the Roding but probably at low levels. The Otter Trust introduced six otters into the upper Lee in 1991. Although it is known that some of these animals survived for some time, the present low level of otter signs indicates a population of less than six animals 19 years later. The two positive sites and one positive spot-check on the Roding also indicate a very small otter population, possibly even a single animal. Concern has been expressed about the survival of these ‘populations’ (Mason & Macdonald, 2003). It does seem likely that they would eventually die out if isolated but, unlike the populations in Kent and East Sussex, there are otters in adjacent catchments. In the North Essex catchment to the east and the Cam and Ouse catchments to the north otter populations appear to be expanding and if this expansion continues the otters in north east Thames will in time become part of a larger and consequently more robust population. It will be interesting to see when and if this happens. The low level of success of this small re-introduced population may reflect the fact that a relatively large number of animals are required to create a viable population as indicated by the greater success with the partly re-introduced populations of East Anglia, Yorkshire and the upper Thames. Regular surveys should ideally be carried out on the Lee, Roding, Beam and Ingreborne (at the eastern end of the region) to monitor the likely spread from Anglian Region and on the Loddon, Wey and Colne to monitor the expected re-colonisation of the catchment from the west. Surveys of the Loddon and Wey would also help to determine the spread of otters south into Southern Region. Ideally a regular programme of surveys similar to that undertaken by Environment Agency staff in North West Region should be set up.

4.10 South West Region Surveys were carried out in the following 50km squares – SS s/e (167*), SW s/e (59§), SX n/w (130*), SX s/e (11), SY n/w (32) * includes one site just outside the square § one site in the square is counted in a different square Description of region This is one of the most rural of the English regions with a low population concentrated mainly in the coastal towns of Plymouth, Torbay, Exeter, Barnstaple, Newquay, Falmouth and Penzance. Despite the popularity of the region with holidaymakers the level of disturbance on most rivers remains low. The River Camel is designated as a SAC for otters and large areas of Dartmoor and Exmoor are SACs or Sites of Special Scientific Interest (SSSIs). Riparian habitat is generally very good with extensive semi-natural habitat providing cover along river banks and wetlands in the headwaters of many of the streams. Mixed sheep, beef and dairy farming form the principal land use but there are areas of arable production and some large areas of horticulture particularly in west Cornwall. A problem in the region is riverbank overgrazing and poaching by cattle and sheep causing habitat degradation and silt pollution of watercourses. This has been exacerbated by high stock density and increased production of winter fodder crops. Water quality Water quality is generally high throughout the region but there are occasional farm and industrial pollution incidents and there are some problems from mine water seepage and from the past use of organochlorine pesticides in the bulb growing areas of west Cornwall. The elevated silt load in many rivers as a result of more intensive farming practices is also a cause for concern. Fisheries The rivers of the region are classified as game fisheries supporting resident and migratory salmonids and locally good populations of coarse fish but the decline in salmon and eel stocks is a cause for concern. All three species of lamprey are recorded and the region supports many stillwater fisheries including several reservoirs stocked with trout and in some cases coarse fish.

Results for 2009-10 survey and comparison with previous surveys A total of 399 sites was surveyed in the main survey. Main survey 1977-79 1984-86 1991-94 2000-02 2009-10Positive sites/total - 77-79 sites - all sites

91/388 167/388 259/388 322/388 332/399

331/388 341/399


23.45% 43.04% 66.75% 82.99% 83.21%

85.31% 85.46%

Spot-checks were carried out in an additional 58 whole or partial 10km squares. Alternate 50km Square SS s/w ST s/w SW s/w SW n/e SX n/e Positive/total 10km squares 11/11 9/9 4/4 7/9 24/25 Summary of results for each catchment Torridge and Hartland (89) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 16/23 17/23 21/23 22/23 22/23 Only the north eastern part of this catchment was included in the main survey but otters were found at virtually all sites and the alternate squares spot-checks show that otters are present throughout the area, probably at carrying capacity. Taw (90) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 23/73 43/73 60/73 65/73 72/73 There has been a slight increase in the level of positive sites but it is likely that otters were close to carrying capacity within the catchment in 2000 and this represents only a small change since then. Exe (91) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 5/60 25/60 42/60 54/60 59/60 Only the northern part of this catchment was included in the main survey but otters were found at virtually all sites and the alternate squares spot-checks show that otters are found throughout the southern part of the area. They are probably now at carrying capacity.

Sid and Otter (92) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/14 1/14 4/14 11/14 8/14 There has been a slight decline in the number of positive sites within this area. This may be due to high flows at the time of the survey and is not thought to represent an real decrease in otter activity. The alternate squares spot-checks show that otters are also present in the northern part of the area. Axe and Lim (93) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/15 1/15 3/15 7/15 11/15 There has been a small increase in positive sites in this area indicating a continuation of the previous increases. The alternate squares spot-checks show that otters are present in the northern part of the area. North Devon Streams (94) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 1/15 2/15 9/15 15/15 15/15 All the sites within this catchment were positive indicating a healthy otter population. Teign and Torbay (95) No main surveys were carried out in this catchment but the results of the alternate squares spot-checks show that otters are widely distributed. Dart (96) No main surveys were carried out in this catchment but the results of the alternate squares spot-checks show that otters are widely distributed. Rivers Avon and Erme (97) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/0 0/0 0/0 10/10 9/10 There has been a slight decrease in the number of positive sites within this area. This may be due to high flows at the time of the survey and is not thought to represent a real decrease in otter activity. The alternate squares spot-checks show that otters are present in the northern part of the area.

Seaton/Looe/Fowey (98) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/31 9/31 21/31 17/31 18/31 There has been a slight increase in the number of positive sites within this area but the change is too small to be significant. Some sites which were positive in 2000 were negative in 2009. This may be due to high flows at the time of the survey and is also not thought to be significant. Freshwater Tamar and tributaries (99) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 28/45 40/45 41/45 42/45 44/45 There has been a slight increase in the level of positive sites in this catchment but it is likely that otters were already close to carrying capacity within the area by 2000 and this represents no real change. Tamar Estuary and Tributaries (100) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/28 8/28 15/28 20/29 24/29 Only the western part of this catchment was surveyed in the main survey. Otters were found at virtually all survey sites and the alternate squares spot-checks show that otters are found throughout the area. They are probably at, or close to, carrying capacity. Fal and St. Austell (101) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 6/46 10/46 19/46 37/46 33/46 There has been a slight decline in the number of positive sites within this area with some sites which were positive in 2000 being negative in 2009. This may be due to high flows just before the survey and is not thought to represent a real decrease in otter activity. However follow up surveys would be desirable to confirm this. West Cornwall (102) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/15 0/15 8/15 13/15 9/15 There has been a slight decline in the number of positive sites within this area with some sites which were positive in 2000 being negative in 2009. This may be due to high flows at the time of the survey and is not thought to represent a real decrease in otter activity. However follow up surveys would be desirable to confirm this. The alternate squares spot-checks show that otters are widely distributed in the west of the area.

North Cornwall (103) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 12/23 11/23 16/23 19/23 17/23 Only the northern part of this catchment was surveyed in the main survey but the alternate squares spot-checks show that otters are found throughout the area and are using all the available watercourses. Two sites which were positive in 2000-02 were negative in 2009-10. This is not thought to represent a real decrease in otter activity. Discussion The 2000-02 survey found that otters were using virtually all the rivers and streams of the region and the present survey has confirmed that this continues to be the case. The percentage of positive sites in the region has only increased slightly from 83.2 to 85.6 per cent. This apparent stability masks some changes with a slight decline in the number of positive sites in the Fal and St Austell and West Cornwall catchments matched by increases in the eastern catchments. It is thought that the small number of sites that changed from positive to negative is probably due to high water in the period preceding the surveys but the position should ideally be monitored in case the change is a real one. Otters now use all types of watercourses and wetland in the region including the numerous coastal streams. Sightings of otters off the Exmoor coast confirm that they are travelling via the sea between the remote streams in the area (M-R Lane, pers. comm.). They will also be foraging on the coast. The South West, with the Wye catchment, is one of only two of the ‘regions’ in England that are believed to have reached carrying capacity for otters, although even here it is possible that the eastern edge of the region has not yet done so. (See section 6.4 for the definitions used). The fact that it has taken 30 years for the population to increase from the lowest point of otter populations in the mid to late 1970s to reach the level seen today shows how small the remnant otter population must have been even in the south west, the region with the highest percentage of positives in 1977-79, and how close we came in England to losing the otter altogether.

4.11 Wessex Region Surveys were carried out in the following 50km squares – SS s/e (15), ST n/w (21), ST s/e (92), SU n/w (16), SY n/w (14), SZ n/w (14). Description of region The region is predominantly rural in character, with an emphasis on livestock rearing in the west of the region and arable production in the east. There are major urban centres around Bristol and Bath and along the south coast including Bournemouth and Poole. Large scale industry in the region is largely confined to the Avonmouth area. There are a very large number of SSSIs, SACs and SPAs including extensive wetlands on the Somerset Levels and Moors and in the Hampshire Avon Valley. Water quality Most of the rivers of the region have high water quality but there is some pollution around Bristol and Avonmouth. Silt and nutrient run off from farmland is a cause for concern on the classic chalk rivers of the region. Fisheries The region supports a wide range of fisheries including many highly stocked stillwaters and there are a number of reservoirs, particularly in Somerset, which are predominantly stocked with trout but also support well known pike fisheries. Dorset, Hampshire and Wiltshire are well known for their game and coarse fisheries while coarse fisheries predominate in Somerset and the north of the region. Results for 2009-10 survey and comparison with previous surveys A total of 172 sites was surveyed in the main survey. Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total - 77-79 sites - all sites

2/151 1/151 29/151 64/151 69/172

115/151 132/172


1.32% 0.66% 19.21% 40.38% 40.12%

76.16% 76.74%

Spot-checks were carried out in an additional 68 whole or partial 10km squares. Alternate 50km Square ST s/w ST n/e SU s/w SY n/e Positive/total 10km squares 20/20 21/24 11/12 10/12

Summary of results for each catchment Bristol Avon (104) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/15 0/15 0/15 1/15 10/15 There has been a significant increase in positive sites in this catchment. In addition the alternate squares spot-checks show that otters are now widespread. No otter signs were found on the estuary or in Bristol itself but there have been reliable reports of otters within the city limits (J. Field pers. comm.). River Tone (105) No main surveys were carried out in this catchment but otter signs were found along the whole of the Tone during the alternate squares spot-checks. River Parrett (106) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/22 0/22 3/22 12/22 17/22 There has been some increase in the number of positive sites in this area and the alternate squares spot-checks show that otters are widespread in the catchment. Brue and Axe (107) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 2/15 1/15 4/15 7/24 21/24 There has been a major increase in positive sites in this area. Otters are now present on most watercourses. North Somerset Streams (108) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/0 0/0 0/0 4/12 8/12 There has been an increase in positive sites in this area. Otters are now present on most watercourses. West Somerset Streams (109) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/15 0/15 9/15 13/15 11/15 There has been a slight fall in positive sites in this area but this is not thought to be significant. Otters are now present throughout the area including on small coastal streams.

Hampshire Avon (110) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/22 0/22 0/22 4/22 16/22 There has been a very significant increase in otter range in this area since the last survey. The surveys and the alternate squares spot-checks show that otters now use the majority of the catchment. It is likely that otters have moved from the Hampshire Avon into the Test catchment to the east. Frome, Piddle, Poole and Purbeck (111) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/9 0/9 1/9 1/9 8/9 The alternate squares spot-checks show that otters are using the whole of the catchment while the main surveys appear to show that the headwaters and Poole Harbour have been re-colonised since the last survey. West Dorset (113) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/14 0/14 1/14 7/14 10/14 There has been an increase in otter range in this area since the last survey. The alternate squares spot-checks show that otters are widely distributed. Surveys by Dorset Wildlife Trust indicate that this expansion is fairly recent (R. Janes, pers. comm.). Discussion Wessex has seen one of the highest percentage increases in positive sites of any of the regions and catchments with 76 per cent of sites in the main survey being positive. Re-colonisation to this level is fairly recent so it is likely that, while the majority of watercourses show otter presence, the population is still below carrying capacity. Wessex remains a key area for otters in Britain. The recovery of the otter population in Wessex region has linked the otter populations of South Wales, the lower Severn, the South West, the Thames and Southern Region. Otters from Wessex have probably made a contribution to the rapid expansion of otter range in the upper Thames. In the report of the 4th Otter Survey of England (Crawford, 2003) concern was expressed about the very slow re-colonisation of the Brue and Axe and about the gap between the otter populations in east Devon and west Dorset. Otters have now re-colonised the Brue and Axe and the Bristol Avon catchments and these otter populations are now contiguous with those of the lower Severn, the Kennet and upper Thames. With the re-colonisation of the Hampshire Avon catchment the otter population on the Test (Southern Region) is now contiguous with the population to the west and there is no longer a gap between the otter populations of Devon and Dorset. The linking of otter populations is one of the most hopeful aspects of the results of this survey. The otter populations of the Upper Thames, the Kennet and the Test and Itchen have almost certainly been augmented by otters that have crossed the watersheds from the west. The otters of these catchments effectively now form one population. Movement

of otters are now likely in both directions across the watershed which will help to maintain genetic vigour. 4.12 Southern Region Surveys were carried out in the following 50km squares – SU s/e (82), SZ n/w (28), TQ n/w (3), TQ s/e (134), TR n/w (35). Description of region The region comprises the south east corner of England where gently rolling downlands run east to west through Sussex and Kent to form the higher ground, but only reaching a maximum of 250m. The rivers of the region tend to drain north or south from the downs with the area between, the Weald of Kent, giving rise to the Medway, Stour and Rother. To the western end lies the New Forest. There is good riparian habitat for otters on many of the rivers in the region. There is significant pressure on the environment from the high human population. The largest towns are mainly coastal and include Southampton, Portsmouth, Brighton, Margate, Dover, Folkestone, Hastings and Eastbourne with somewhat smaller inland towns such as Winchester, Rochester, Maidstone, Canterbury, Sittingbourne, Tonbridge and Tunbridge Wells. Despite the large population, the area includes the New Forest and South Downs National Parks, several Areas of Outstanding Natural Beauty and a large number of SSSIs, SACs and SPAs especially around the coast. Water quality Most of the rivers of the region have good to fairly good chemical quality and there are few watercourses where water quality seriously impacts upon fish stocks. Fisheries The chalk streams of the region support world famous trout and salmon fisheries. Other rivers support good diverse stocks of coarse fish, trout and sea trout although there are concerns about obstructions to fish passage, fish habitat, abstraction and water quality on a number of rivers. There has been a marked reduction in eels in recent years. The region also has a large number of heavily stocked enclosed stillwaters.

Results for 2009-10 and comparison with previous surveys A total of 282 sites was surveyed in the main survey.

Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total - 77-79 sites - all sites

5/244 7/244 8/279

9/244 12/279

13/244 13/282

23/244 23/282


2.05% 2.87% 2.87%

3.69% 4.30%

5.33% 4.61%

9.43% 8.16%

Spot-checks were carried out in an additional 70 whole or partial 10km squares. Alternate 50km Square SU s/w SZ n/e TQ s/w TQ n/e TR s/w Positive/total 10km squares 14/15 0/8 1/23 2/15 0/9 Summary of results for each catchment New Forest (76) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 1/15 0/15 0/15 1/15 2/15 The small increase in positive sites in this area probably conceals a larger improvement. A casual check close to one of the negative sites was positive and the alternate squares spot-checks showed that otters are widely distributed in the north of the area. Test and Itchen (77) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 4/10 5/10 6/10 8/10 8/10 The number of positive sites within this catchment has not changed but the new positive site near the source of the River Test and the widespread distribution of otter signs found on the alternate squares spot-checks show that otters are now widely distributed in this area. Isle of Wight (78) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/13 0/13 0/13 0/13 0/13 No positive sites were found in this area during either the main survey or the alternate squares spot-checks. However a spraint was found in early April 2010 on the Atherfield Stream (M. Short pers. comm.) at a site which was negative in January 2010 during the main survey. An otter or otters were certainly on the Isle of Wight in March/April but it is not certain whether it/they are resident or crossed from the mainland after the survey was completed.

East Hampshire (79) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/25 0/25 0/25 0/25 10/25 There has been a major expansion of otter range onto the rivers Hamble, Meon and Wallington. It is presumed that the otters have crossed from the Itchen catchment to the west. Cuckmere/Pevensey Levels (80) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/33 0/32 0/32 1/32 0/32 No signs of otters were found at any of the 32 sites in the main survey and all the alternate squares spot-checks were also negative. An otter was killed near Polegate in December 2009, two months prior to the survey. Adur and Ouse (81) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/5 0/5 0/5 0/5 0/5 No signs of otters were found at any of the five sites surveyed or in alternate squares spot-checks. Arun (82) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/47 0/47 0/47 0/47 3/47 Three positive sites were found on the Rother catchment and a single positive site was found on the upper Arun during the alternate squares spot-checks. The Rother forms an important corridor from the strong otter populations to the west to the Adur and Ouse and areas further east. Otters were not recorded in this area in any of the previous national surveys so this is likely to be a recent re-colonisation. The otter population in this area can be seen as an extension of the population to the west and illustrates the slow eastward re-colonisation in Southern Region. It is possible that the otter signs on the Wey catchment (Thames) to the north are from otter(s) that have crossed from the Arun catchment. Darent (84) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/0 0/0 0/0 0/2 0/2 No signs of otters were found during the main surveys or in the alternate squares spot-checks.

Medway (85) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/38 2/38 3/38 1/39 0/39 No signs of otters were found during the main surveys or the alternate squares spot-checks. However a small number of otter signs were found in March 2009 on the Medway near Maidstone and the lower reaches of the Beult (G. Roberts, pers. comm.) but no signs of otters were found when the area was surveyed in March 2010. It is likely that otters have died out in this area but if an otter or otters are still present they cannot any longer be considered to constitute a viable population. East Rother (86) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/56 0/56 0/56 2/56 0/56 No signs of otters were found during the main surveys or in the alternate squares spot-checks. Signs were found at two sites in 2001 but it is likely that the otter population in this area has now died out. North Kent (87) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/6 0/6 0/6 0/6 0/6 No signs of otters were found during the main surveys or in the alternate squares spot-checks. Kentish Stour (88) Main survey 1977-79 1984-86 1991-94 2000-02 2009-10 Positive sites/total 0/3 1/32 3/32 0/32 0/32 No signs of otters were found during the surveys or in the alternate squares spot-checks. Otter signs were found on the Stour in 1986 and 1994 but not in 2002 or 2009. It seems likely that the population on the Stour died out in the 1990s probably as a result of stochastic events, such as road accidents, to which small populations are vulnerable. Discussion There has been a small percentage increase in positive sites since the 2000-02 survey but the results remain very low. This change in the overall number of positive sites in the region masks a significant change in distribution. The small fragmentary population of the eastern part of the region has either died out completely or has declined to a level below which it cannot be detected and probably below viability, while the population on the western edge of the region has increased considerably in range. We cannot be certain if otters were present in the east of the region in the 1970s. Square TR n/w was not surveyed during the 1977-79 survey and no signs were found in the 134 sites in square TQ s/e. A small number of positive sites was recorded in 1986 when signs were found in both the Kentish Stour and Medway catchments. The population(s) there

appear to have been completely isolated since then although the possibility that occasional individuals reached the area from the Anglian or Thames populations, while very unlikely, cannot be completely ruled out. No otter signs were detected on the Kentish Stour in 2002 and it is likely that this population died out between 1993 and 2002. On the Medway catchment, two sites were positive in 1986, three were positive in 1993 but only one in 2001 and none in 2009. It is likely that this population died out between 2001 and 2009. In 2001, for the first time positive sites were found on the south coast, two in the East Rother catchment and one in the Cuckmere/Pevensey Levels catchment. No signs were detected in these areas in 2010 but an otter was found dead near Polegate (in the Cuckmere/Pevensey Levels catchment) in December 2009 (Fran Southgate, pers. comm.). These population(s) managed to survive for several decades with very small and declining ranges and appear finally to have reached a point where they became so fragmented that natural and non-natural mortality was higher than possible replacements. It is possible that the survey method does not allow reliable detection of otters when populations are extremely low but it is more probable that the otter found dead near Polegate was the last one in the east of Southern Region. With the apparent demise of the otter population(s) in Kent and East Sussex the south east of England has become the only part of Britain without otters. The loss of this small isolated population or populations, while very disappointing, is not surprising. The similar decline and eventual extinction of the small otter population in North Norfolk in the 1980s was documented by Spalton and Cripps in 1989. It is unlikely that East Sussex and Kent will be re-colonised for some years as the rivers along the south coast mainly flow from north to south with limited links between their headwaters while otter movement along the coast is likely to be inhibited by the almost continuously developed sea fronts of towns like Worthing, Shoreham, Hove and Brighton. Colonisation from the north is only likely to occur once otters have re-colonised south Essex, consolidated their populations on the southern tributaries of the Thames such as the Mole and the Wey, or spread down the Thames and up the Medway. An equally restricted population on the Test and Itchen on the western edge of the region was found in the 1977-79 and all subsequent surveys. This population appears to have survived but not expanded until at least 2000 despite the release of four otters in this area by the Otter Trust in 1993-4 (Jefferies et al., 2000). One of these is known to have died soon after release (G. Roberts, pers. comm.) and the remaining three, if they survived, were insufficient to allow for expansion of the population. Since then the natural spread of otters from the west, noted by Crawford (2003), has continued with the Test and Itchen, New Forest and East Hampshire catchments and the western part of the Arun catchment now forming part of a continuous range stretching to the west. Further expansion on the Arun catchment and into the Adur catchment would be expected in the near future. Although no otter signs were found on the Isle of Wight during the survey, a single spraint was found in April 2010 on the Atherfield Stream (Mike Short, pers. comm.) at a site which was negative in January 2010 during the main survey. An otter must therefore have been present in March or April. It is recognised that the survey method may not detect otter presence when they are in very low numbers so it is possible that the otter was present during the survey but not detected. It is also possible that an otter crossed from the mainland in this period. The two positive sites on the mainland (near Fareham and near Lymington) are both only 7km from the nearest point on the island and the Atherfield stream is only 25km from the nearest positive site on the Lymington River. The shortest crossing between Round Tower Point on the island and Hurst Castle on the mainland is only 1.2km and Hurst Castle is only 6km along the coast from Lymington.

4.13 Mink evidence During the main survey, searching stopped at each site as soon as otter signs were found and although mink signs were looked for, and noted wherever they were found, the data for mink is inevitably incomplete. In the case of otters, where no signs were found in the main survey over a considerable area it is possible to conclude that the species is absent or at the most present at very low density (Ruiz-Olmo et al., 2001). Strachan and Jefferies in the report for the 1991-94 survey discussed the relative distribution of otters and mink based on the survey results. This was not possible for either the 2000-02 or 2009-10 survey results as in both cases a full 600m survey for mink was not carried out at each site. Mink signs were found in every region during the main survey but often at a small number of sites. For the 2009-10 survey spot-check surveys were also carried out in the alternate 50km squares. These normally only covered the bridge or other access point and up to 10m either side but here too mink presence at each site was noted where it was observed. Mink signs were found in all regions during the spot-check surveys. Of the 704 10km squares included in the main survey, mink signs were found in 289 and of the 718 10km squares included in the alternate squares survey, mink were found in 97. Thus of the 1422 10km squares surveyed mink signs were found at 386. This probably seriously under represents mink occurrence. Because of the way the data was collected it is not possible to draw the conclusion that mink are absent from any area but the results do give a minimum distribution of mink. The occurrence of positive sites for mink by region is shown below. Sites positive for mink 2000-02 and 2009-10 surveys Region 2000-02 2009-10 % Decrease

(Increase) Anglian 144 136 6 Dee 4 1 75 Northumbria 34 12 65 North West 69 25 64 Severn 64 93 (45) Southern 114 47 59 South West 50 15 70 Thames 71 45 37 Trent 64 50 22 Wessex 28 7 75 Wye 13 39 (200) Yorkshire 74 40 46 Mink occurrence, as detected by the otter survey, has fallen in all catchments except two. This fall has been greatest in those catchments such as Northumbria and North West where there has been a significant rise in otter occurrence. It is however impossible to know whether this is because a full 600m has been surveyed at fewer sites (see above). However the results for Southern Region provide stronger evidence for a real decline in mink in this region. In 2000-02 a full 600m was surveyed at 272/282 (96.5%) of sites and in 2009-10 260/282 (92.2%) of sites in the region. The number of full 600m reaches

surveyed is thus both very high and comparable for the two surveys. It is interesting therefore that the occurrence of mink has declined by 59 per cent in this region. Otters are only present in the western end of Southern Region so the decline in mink signs cannot be attributed to competition from otters. There have been a number of local projects to restore water vole populations in the last 10 years, most of which involve co-ordinated mink trapping. Mink trapping may have contributed to the regional decline in mink signs. Only two regions, Severn and Wye show an increase in mink occurrence. It is assumed that the upward change in mink occurrence is because mink have tended to move into the small headwaters of these catchments, areas that may be marginal for otters, and which otters appear not to have exploited as yet. This is by no means certain but this pattern of mink moving to the headwaters appears to have occurred on the upper Trent catchment as well (N. Mott, pers. comm.).

5.0 Otter sightings reported to the People’s Trust for Endangered Species As an addition to the field survey work, the PTES posted a request on their website for their members to report otter sightings in order to get an idea of the number of otters now being seen by members of the public. The table below shows a summary of the results: Region Reports Reports deemed

authentic Yorkshire 2 2 Severn 1 (spraint, not sighting) 0 Trent 1 (dead otter) 1 Anglian 3 3 Thames 2 (one probably a mink) 1 South West 5 5 Wessex 2 2 Southern 2 (one otter tracks) 1 Wales/Scotland 6 6 Total 24 21 A total of 24 reports were sent to PTES by their members and members of the public between August 2009 and June 2010. Six of these reports were from Wales or Scotland, and the rest from England. It is difficult to authenticate such data but one report had to be discarded as it was almost certainly of a mink (the animal was too small to be an otter) and two others were discarded because they were of otter signs rather than sightings. This left 21 sightings of otters by members of the public in an 11 month period, of which 15 were in England. Unsurprisingly the majority of sightings were in areas with higher than average otter populations. These reports are only from a small targeted sector of the population. However when considered with other recent otter sightings reported to the Environment Agency and Wildlife Trusts they illustrate that otters are now more commonly seen by anglers, conservationists and the general public. This is perhaps not surprising given the considerable expansion in range. It may also indicate that otters are becoming somewhat more habituated to human activity in the absence of significant persecution. Most otters however appear to be extremely wary of people. 6.0 Discussion 6.1 National trends The fifth Otter Survey of England provides the first opportunity to assess the current status of the otter in the whole of England against the predicted recovery trend and specific BAP targets for the species. The recovery of the otter population in England has continued in all areas except the south east. Otter range, and by implication the otter population, has increased in every region in England. Even in Southern Region, where the small isolated population in Kent/East Sussex has probably become extinct, this has been more than balanced by the increase in range in the west of the region. The UK BAP target was for otters to have returned to at least 997 10km squares in England by 2010 and 1084 by 2015 (HMSO, 1995). This has been achieved with otter signs being found in 1085 10km squares, 533/704 10km squares in the main survey and 552/718 10km squares in the alternate squares survey.

Of the 3327 sites surveyed during 2009-10, 1874 (56%) were found to be positive (i.e. to have signs of otters present). Of the 2940 sites surveyed in all five surveys, 1726 (59%) were positive. This represents an increase of 62 per cent since the 2000-02 survey and a 915 per cent increase since the first survey in 1977-79. The percentage of positive sites has increased in all of the regions into which England was divided for this survey except the Wye but the increase varies considerably between individual regions/catchments (Table 1). In some of the regions and catchments such as Thames, Anglian, Yorkshire and Wessex there have been major increases in the percentage of positive sites. In others such as South West, Southern and Wye there have been small or no increases. The reasons for these small increases vary. In South West region and the Wye catchment, otters had more or less reached carrying capacity by 2000-02 and no further increase would be expected, while in Southern Region the small otter populations in the east of the region have been lost and the increase in the west was from a very low level. The increase in positive sites from 34 to 56 per cent of all sites surveyed in the main survey demonstrates a real and continuing recovery of the otter population of England. Two regions, the South West and Wye are now probably at carrying capacity (see below) and two other regions, Wessex and Northumbria, and part of a third, the northern part of North West, are probably close to this point. The 2009-10 survey shows that the overall increase has not been quite as great as predicted by Strachan & Jefferies (1996) who calculated a recovery curve for the otter based on the eight ‘snapshots’ of status in the form of the three surveys of England, three of Wales and two of Scotland which had been completed when the report was written. The prediction was for 43 percent of the sites surveyed in all surveys to be positive by 1999 increasing to 56 percent by 2006, equating to approximately 60.5 percent in 2010. The actual results have fallen slightly below this at 36 percent in 2000-02 and 59 percent in 2009-10. The difference is small and may be due to the fact that the main survey in England differs from the other UK national surveys in only covering alternate 50km squares. In some regions, for example North West Region and the Trent catchment, the alternate squares spot-checks clearly show that there have been major increases in otter range in areas outside the main survey squares. This needs to be remembered when interpreting the results. Of the 115 catchments within the survey in England otter signs were found in 102 (88%) but it is very unlikely that breeding will have occurred in all of these. In some catchments such as the Roch, Irk and Medlock (12) in North West Region, otter signs were only found at one site so breeding is extremely unlikely there. However breeding has been confirmed in some catchments with otters found at only a small number of sites. An example of this is the Dove catchment (36) where breeding was confirmed in 2010 (C. Horsford, pers. comm.) but otter signs were only found at three sites in the main survey and at six sites in the alternate squares spot-checks. 6.2 Population expansion and connectivity The biggest change since the 2000-02 survey has been the expansion of previously discrete otter populations leading to these populations becoming contiguous. Otters in England now effectively form a single population. Of particular importance has been the expansion of range in Wessex Region. This has meant that there is no longer a gap between the populations of South Wales, the lower Wye, the lower Severn, the Thames, the South West and Southern Region. The expanding Wessex population has almost certainly made a contribution to the population of the upper Thames, the tributaries of

which rise close to those of the Bristol Avon which is also linked to the Kennet via the Kennet and Avon Canal, and to the western part of Southern Region. The otter population in the western end of Southern Region is now effectively part of a meta-population linked to the Wessex population. The increase in otter range in the Thames and Cherwell means that these populations are now contiguous to the east with the populations of the upper Ouse and Nene and to the west with the populations of the Bristol Avon. The increases in range in the Nene and Witham catchments of Anglian Region, on the Soar catchment of the Trent and the upper Avon catchment of the Severn have resulted in all these populations being contiguous. Otters are able to cross the watersheds between these catchments by small streams and possibly by the Grand Union Canal or even travelling overland. An example of this is the otter found dead on a road equidistant between the Great Ouse (Anglian) and Ray (Thames) catchments in September 2006. It was about 600m from the nearest watercourse (G. Scholey, pers. comm.). Similarly the extension of range in the northern part of Anglian Region has linked the otter population there to the population on the lower reaches and tributaries of the Trent and to the population in Yorkshire and through that to the very strong population in Northumbria. The otter population of the eastern side of England is now continuous from the Scottish border to Essex and along the coast from Berwick on Tweed to Felixstowe with otters using much of this coastline as well as the rivers. However they appear to be present at low levels in much of this area. The otter population of North West Region is now contiguous with the Northumbrian population in the north where the headwaters of the South Tyne and the Tees catchments rise very close to those of the Eden and its tributaries, and otter movement across the watershed is to be expected. Further south many of the headwaters of the Ure, Wharfe and Aire arise close to the headwaters of the Lune and Ribble. There are even some indications (see above) that otters may be beginning to cross from the Calder (Yorkshire) into the Roch (North West) catchment. Apart from the very south east of England and the area around London there are now few gaps in this continuous population although in many areas the population would appear to be small. The next largest gap is in the Liverpool - Warrington - Manchester area. At present this extends into the southern Pennines. It will be interesting to see if otters can pass through the urban area to link the otter population in Cheshire with the population of central and northern North West region. The southern Pennines have probably not yet been re-colonised because they are still remote from strong otter populations and it is almost certain that this area will be re-colonised in time. 6.3 Changes in use of habitats by otters The first Otter Survey of England in 1977-79 (Lenton et al., 1980) was carried out when the otter population was at a minimum and signs were only found at 170 sites. Since then the increase in range and population has led to otter signs being found on a greater range of habitats. In particular both coastal habitats and canals appear to be exploited far more now than at the nadir in otter numbers in the late 1970s and there are reports of otters taking fish from garden ponds. However it appears that the majority of otter territories in England are, as expected, on rivers and lakes.

6.3.1 Coastal habitats In the 1977-79 survey otter signs were found at only seven estuarine or coastal sites, six on the north Norfolk coast and one in Cornwall. Since the 2000-02 survey there has been a considerable increase in reports of coastal use by otters. This is perhaps not surprising as otters regularly use the coast in Scotland and are known to have done so in England in the past (Stephens, 1957). The Eurasian otter has no physiological adaptations for the marine environment and research in Scotland (Kruuk, 1995) has shown that while otters readily exploit coastal environments they are dependant upon freshwater for drinking and to wash the salt from their fur. The survey data shows that in Northumbria, Anglian and South West regions otters are using coastal streams that are too small to have sufficient fish biomass to support an otter. Otters using such small coastal streams are probably doing most of their foraging along the coast while using small streams as a source of freshwater and lying up areas. Increased coastal use by otters would also allow more connectivity between populations. Along the east coast where otters are already found either on or very near the coast from Berwick-on-Tweed to Felixstowe this is probably already the case. In North West Region, otters are spreading from the north and as yet appear to be using the coast only from the Solway Firth to the Lune estuary. They do, however, use the Ribble estuary further south and the area between was only surveyed as part of the alternate squares spot-checks so it is possible that otters are already using the coast in that area. It is likely that if they have not already done so they will re-colonise this part of the coast in the near future. Further south the coastal areas between the Ribble, Mersey and Dee estuaries provide some good habitat for otters and it is likely that they will also re-colonise the coast in this area in time. Otters now use many of the small streams along the coast and the larger estuaries from the Severn around the south west to Southampton Water. No signs of otters were detected near the coast from Southampton Water, around the south east coast to Felixstowe. Much of this coast is heavily urbanised but there are large areas of coastal wetland including Romney Marshes and the Thames estuary marshes which appear to provide good habitat for otters. If present trends continue they would be expected to re-colonise these areas in time. 6.3.2 Canals It is probable that otters have always used canals where these were within their range but at the time of the first Otter Survey of England in 1977-79 (Lenton et al., 1980), when the otter population was at a minimum, none of the 170 positive sites were on canals. This is not surprising as otter populations at that time had a very restricted geographical range which barely included areas within the main canal network. The results of the 2009-10 survey show that otters are now making extensive use of canals. They have been reported on canals in all parts of the country from the Bude Canal in Cornwall to the Llangollen Canal in Cheshire, the Lancaster Canal at Garstang and the Grand Union Canal at Aylesbury. Many canals hold good fish stocks and this is a resource that otters are certain to exploit. Anecdotal reports suggest that otters may move from rivers onto canals during floods but there is very little hard evidence to support this hypothesis. Some canals appear to offer links between catchments which could allow otters to move over watersheds. For example otters are known to make extensive use of the Grand Union Canal in Leicestershire in an area where it crosses catchment boundaries between

the Soar (Trent), the Welland (Anglian), the Avon (Severn) and the Nene (Anglian). In North Shropshire and Cheshire otters use the Shropshire Union canal, which crosses the Tern catchment (Severn) and the Weaver catchment (North West), and the Llangollen Canal which crosses the Dee catchment, the Perry catchment (Severn) and the Weaver catchment. Despite the apparent ease of access along these canals from catchments which have had good otter populations for many years the re-colonisation of Cheshire has been and continues to be slow. It is therefore difficult to be confident that otters use the opportunities for movements between catchments that canals appear to offer under all circumstances. As with rivers, any work on canals, including restoration, should take the possibility of otter use into account. This is particularly relevant where canals cross watersheds and could provide a link from one catchment to another such as the Wey and Arun Canal. Most of the possible issues should have been identified in the Environmental Impact Assessment that is legally required for a canal restoration. Issues to be considered include for example provision for young waterbirds and animals, including otters, to get out of the canal where the sides are vertical and the avoidance of excessive tidying up of scrub on the offside. Otters will of course lie up in scrub and it is an offence to “damage or destroy…any structure” [which an otter] “uses for shelter or protection” ( Wildlife and Countryside Act, 1981) so work parties undertaking work on canals or rivers must take this into account. There are records of individuals from many animal species drowning in canals (Hartwig, 2000, Howes, 1991) particularly where both sides are vertical sheet piling The numbers of deaths can be very significant and may even have impacts at a population level for species like roe deer and badgers (Howes, 1994). Adult otters are unlikely to drown in canals but the provision of access structures would almost certainly enable otters to use canals more easily and is known to reduce drowning in many species (Howes, 2003). Provision of such access points should in any case be the norm for animal welfare reasons and should be considered wherever new piling is installed or canals are being restored. 6.3.3 Garden ponds None of the survey sites in either the main survey or the alternate squares spot-checks were at garden ponds but there have been reports of otters taking fish from ornamental ponds in many parts of the country, including Devon (M-R Lane, pers. comm.), West Midlands (A. Crawford, pers. obs.), Oxfordshire (G. Scholey, pers. comm.), Cumbria (G. Butterill, pers. comm.) and Norfolk (Levy, 2010). Otters in natural situations often cross from rivers to ponds and in most, but not all, cases the garden ponds from which otters have taken fish are close to rivers, streams or canals which are known to be used by otters. While many people welcome the opportunity to see wildlife close to their homes in this way, many garden ponds are stocked with Koi carp and other fish which can be very valuable and the loss of family pets in this way can be distressing. Fencing is probably advisable if valuable fish are to be kept in ponds near watercourses. These precautions may in any case be needed to prevent access by other predators such as herons. 6.4 Population density and carrying capacity

Surveys of otter signs can only measure otter occurrence and not population size. While it is clear that there must be a relationship between the numbers of spraints found and the otter population, the relationship is obscure and is certainly not linear. Some authors (Mason & Macdonald, 1993; Strachan & Jefferies, 1996) have sought to devise indices to relate spraint numbers per unit length of river to population size but there is currently no

objective way of verifying these. For the 2009-10 survey report, as with the 2000-02 survey report, the only assumptions made are that the presence of otter signs indicates that an otter has recently been present at that site and that the number of sites in a catchment at which otter signs were found gives some measure of the length of river occupied by otters. In addition where several ages of spraint are present it can be assumed that otters are not merely transient. It can be assumed that where there is a high frequency of positive sites in an area and a large number of spraints that otters are present in larger numbers than in areas where spraints are infrequent and in small numbers. However it is not possible to link otter numbers to numbers and distribution of spraints. For the purposes of this report, full carrying capacity is defined as over 80 per cent of sites positive for two successive surveys at least five years apart. As otters spread into an area they may territorially mark all rivers but be present at a low density. It is assumed that if the level of positive sites has remained at over 80 per cent for five years or more then otter numbers will have increased to a level where otter numbers will be largely self-regulating and there will be few if any unoccupied territories. Otter territories will of course vary in size in response to the available food supply and habitat quality. In England only South West region and the Wye catchment could be said to be fully occupied and at carrying capacity by this definition. Wessex and Northumbrian regions, Cumbria and the upper Severn catchment all show a high percentage of positive sites. However it is likely that in most of these areas some watercourses are still only occasionally used by otters and some further consolidation of populations will occur in the next few years. All these areas either had a viable population in 1977-79 at the lowest point of otter populations in England or were adjacent to and had good links to areas which had a viable population at that time. The south west was arguably the only area of England where a viable otter population was detected in 1977-79 (Lenton et al., 1980). Surveys on the English part of the Wye catchment in 1977-79 only found otter signs on the Lugg and Arrow and their tributaries (Lenton et al., 1980; Crawford, 1979), but there was a viable population upstream in Wales. On the Severn catchment in England in 1977-79, otter signs were confined to the Teme catchment but as with the Wye there was a viable population further upstream in Wales. Wessex is adjacent to South West region and Northumbria and Cumbria are both adjacent to Scotland where otters survived in better numbers than in England. 6.5 Factors affecting otter populations There are a number of direct and indirect anthropogenic factors which have the potential to impact on otter populations although the scale of the population recovery suggests that these are not sufficient to prevent re-colonisation although they may be having an impact upon the speed of the recovery and the local attainment of carrying capacity. 6.5.1 Non-natural deaths It has long been recognised that dead otters provide an important potential source of material for study. Since the early 1980s a programme of collection and post mortem and chemical analysis of otter carcasses has been undertaken (Jefferies & Hanson, 1987, Simpson, 1998; Bradshaw & Slater, 1999; Chadwick 2007; Chadwick & Sherard-Smith, 2008; Chadwick & Deakin, 2009). In the mid 1980s this was expanded by the Vincent Wildlife Trust and since 1992 it has been part funded by the Environment Agency, in partnership with MAFF and Defra, the then Veterinary Investigation Centre (for southern and south west England) and Cardiff University (for Wales and the rest of England).

Currently all the otter post-mortem work supported by the Environment Agency is undertaken in partnership with the Cardiff University Otter Project. The number of otter carcasses retrieved for the post mortem programmes has increased from less than five in 1985 to 218 in 2009. However this can only be a small proportion of the total otter deaths and is of course heavily skewed towards otter carcasses that are easily found by the public. In the last three years (2007-09) at least 589 dead otters were collected of which approximately 425 were from England. All carcasses are given a post mortem to establish the cause of death and to determine health at the time of death. The livers are sent to the Environment Agency laboratory in Llanelli for ecotoxicological analysis for organochlorines, a suite of other pesticides, polychlorinated biphenyls (PCBs) and heavy metals. Other material from the otters is used in a number of academic studies. Together the post mortems and tissue analyses provide a great deal of information on the health of the otter population and the relationship between pathology of individual otters and the accumulation of persistent toxins. This provides valuable ecotoxicological surveillance of a top predator in the aquatic environment and thus of aquatic ecosystems as a whole. It is this that provides the rationale for Environment Agency funding. 6.5.1.1 Road casualties Roads have long been recognised as a potential threat to otters. Green (1991) identified road traffic as the largest and most rapidly expanding cause of otter mortality. Since then the number of otters known to be killed on the roads in England and Wales has risen very substantially. Between 2000 and 2009 1080 otters were found dead on roads and sent to Cardiff University for post mortem. Of the dead otters retrieved in 2007-09 the vast majority (86%) were road casualties and since it can be assumed that many carcasses were not collected, this must represent a significant level of mortality from a population that has still not recovered from its low point in the mid 1970s. The majority of these deaths were, as would be expected, in the areas where otter numbers are highest and where they will have a smaller impact at the population level. It is likely that in most areas otter road deaths replace, rather than add to, natural mortality. However in the very south east of England the loss of even a small number of individuals would have been serious and it is possible that this is one of the factors that pushed the population in the south east to extinction. The last record we have of otters in that area is of an otter found dead next to the A22. 6.5.1.2 Persecution Direct and indirect persecution including hunting and trapping were responsible for a large number of otter deaths in the past. In 1978 the otter was given full legal protection in England and Wales under the Conservation of Wild Creatures and Wild Plants Act 1975 and direct persecution largely ceased. In 1982 protection was extended to otter holts under the Wildlife and Countryside Act 1981. The otter is also protected under European law being listed in Annexes IIa and IVa of EC Directive 92/43 Conservation of Natural Habitats and Wild Fauna and Flora (the Habitats Directive). This was passed into national legislation by the Conservation (Natural Habitats, &c.) Regulations 1994, now replaced by the Conservation of Habitats and Species Regulations 2010. In addition the otter is listed in Appendix II of the Berne Convention to which the UK is a signatory and in Appendix II of The Convention on International trade in Endangered Species 1973 (CITES). Illegal killing of otters undoubtedly still occurs. Of the 589 otters sent to Cardiff University for post mortem examination in the three year period 2007 to 2009, four showed signs of

being shot, not all fatally, (Chadwick & Sherrard-Smith 2008; Chadwick & Deakin 2009; E. Chadwick, pers. comm.) but this must greatly underestimate the number of attempts at deliberate killing. Such killings could delay recovery in the south east and other areas where otter populations are weak but in areas where otters are well established it is unlikely that this will have an influence at a population level. 6.5.1.3 Accidental deaths in fish and crustacean traps In the 1980s serious concerns were raised over the level of accidental deaths in fyke nets set for eels (Jefferies et al., 1984). In response to this between 1989 and 1997 several Environment Agency regions passed bylaws prohibiting the use of a fyke net without an otter guard. In 2001 a national bylaw to this effect came into force. This threat to otters has thus largely been eliminated but enforcement action by fisheries staff is still needed because illegal traps are still being found without otter guards. In February 2010 an otter cub was found drowned in a fyke net fitted with an otter guard. It is believed the cub managed to get past the side of the guard thus demonstrating the need for correct fitting of guards. With the spread of American signal crayfish, and the promotion of their trapping on television, this has become more common and poses a similar problem for otters. In the three year period 2007-09 at least 15 otters were found dead in fyke nets and illegally set crayfish traps which exceeded the dimension restrictions required to prevent otter mortality. It is believed this seriously underestimates the level of deaths as carcasses are likely to be discarded and not reported under these circumstances. The increase in otter use of coastal habitats raises concerns about the possibility of otters drowning in crab and lobster pots. Since the early 1980s, this has been recognised as a serious problem in Scotland where otters have been found in lobster creels at depths of up to 15m (Jefferies et al., 1984). It is difficult to see how crab and lobster pots can be designed to exclude otters but some designs are more likely to catch otters (Jefferies et al., 1984). Work is probably required to design traps which will reduce this risk. The introduction of Marine Conservation Zones may allow the use of some types of traps to be limited in areas where otters are most at risk. 6.5.2 Pollution A major change since the first national otter surveys in 1977-79 has been the very significant improvement in water quality. Many rivers in the 1970s were so heavily impacted by industrial and sewage pollution that they were completely fishless. Rivers like the lower Thames, the Tame (flowing out of Birmingham) and the Tyne were fishless because of continual pollution most of which has now been controlled. Fish are still sometimes killed in very large numbers by serious pollution incidents such as the cyanide pollution of the Trent in September 2009 and a discharge of sodium hypochlorite (chlorine) into the R. Wandle in September 2007. Sewer overflows, urban runoff, diffuse pollution from farming, wrong connections to sewers and repeat smaller scale discharges from combined sewer overflows lower the water quality of many rivers and can impact upon fish stocks. There are however few rivers in England today where fish stocks are affected by continuous pollution to the extent that otters would be unable to find sufficient prey. The main factor in the decline of the otter population in England is believed to have been the impact of organochlorine pesticides (Chanin & Jefferies, 1978). Their concentration in the environment, and in otters submitted for post mortem and analysis, has declined significantly (Chadwick, 2007) and it is likely that they no longer pose a serious threat to otters. Concerns were also expressed about certain chemicals such as polychlorinated

biphenyls (PCBs) (Chadwick, 2007) and the possible impact of a range of endocrine disrupting compounds in sewage discharges on fish (Benstead, 2006) and through them on otters. The post-mortem and analysis work being done on otters by Cardiff University with the Environment Agency (Chadwick, 2007) is designed in part to ensure that the possible impacts of new chemicals upon the aquatic environment are detected before they become a serious problem. Further work is needed to identify which of these chemicals most require surveillance but the post mortem evidence to date suggests no serious pathological response from bioaccumulation of any of these, as yet unmeasured, compounds. The work also indicates that PCBs are not causing impacts upon otter reproductive performance and pathology. 6.5.3 Habitat quality Until recently background pollution levels and pollution incidents were the main factor limiting fish stocks on many watercourses but as background pollution levels have fallen and pollution incidents have reduced, the condition of in-stream habitat in watercourses may now be the major limiting factor for fish stocks as well as for populations of many other species from macrophytes to otters. It has become recognised that a range of habitat features in rivers provide the diversity of niches needed for different species and different life stages of these species and enable rivers both to ‘self clean’ and to recover more rapidly from pollution incidents. Since the Second World War there has been large-scale degradation of river and riparian habitats in England (Environment Agency, 2010) mainly due to agricultural intensification and the associated river engineering and drainage of wetlands. There has also been urban encroachment along river corridors and onto floodplains in many areas. The resulting impact on biodiversity has been significant and often devastating. A much more enlightened attitude to river management since the 1980s (Lewis & Williams, 1984; Ward, Holmes & Jose, 1994), led to the NRA (and later the Environment Agency) being given the duty to ‘further the conservation of natural beauty and….of flora and fauna associated with water’. Concerns about the state of the aquatic environment throughout Europe led to the passing of the Water Framework Directive (EC, 2000) which became part of UK law in 2003. The Directive requires member states to ensure that water bodies achieve ‘good ecological status’ with the exception of those water bodies classed, on strict criteria, as ‘heavily modified’ or ‘artificial’ which have to achieve ‘good ecological potential’. These targets are to be achieved by 2015 but where this is not possible they can be delayed until 2027 at the latest. ‘Good ecological status’ is defined as having biological, structural and chemical characteristics close to those expected under nearly undisturbed conditions while ‘good ecological potential’ is a recognition that changes to morphology or other factors as a result of society’s needs may make good ecological status uneconomic and/or technically very difficult to meet and a lower standard has to be the target. To implement the Water Framework Directive, the Environment Agency has drawn up River Basin Management Plans covering the whole country. These have identified the waterbodies which need to be improved and the measures needed to achieve this. In the first cycle of river basin planning good ecological potential may be defined in relation to the mitigation measures required to achieve it. In the last few decades, the Environment Agency and its predecessor bodies, Rivers Trusts and other organisations have undertaken a large number of small scale and a few large-scale riparian and wetland enhancement and creation schemes to re-create and

restore some of the lost river and riparian habitats. The greater recognition of the ecosystem function of wetlands in reducing flood risk and improving water quality seems likely to assist the move towards a more holistic approach to river catchment management. The adoption of some more environmentally-friendly farming practices, supported in many cases by agri-environment incentive scheme payments, has also slowed the rate of riparian habitat damage. 6.5.4 Factors affecting food supply A number of anthropogenic factors significantly affect the fish carrying capacity of rivers. This in turn will have an impact upon fish stocks and the food supply available to otters. 6.5.4.1 River structure Most of the main rivers in England have been modified and simplified by man (Environment Agency, 2010). Between the Second World War and the late 1980s many rivers, even smaller watercourses in rural areas, were deepened and straightened (re-sectioned) in order to allow improved land drainage and to reduce floodplain inundation from the norm in a ‘natural’ system of two or three times each winter to, on average, once every five years. Other rivers have been heavily modified for other purposes such as navigation. The consequent impact upon in-stream habitats, the fish they support and general water quality is often catastrophic. Environment Agency surveys show that three quarters of the river lengths in England and Wales have been modified (Raven et al., 1998). In 2007-8 more than 40 per cent of river length was classified as ‘severely modified’ (Environment Agency, 2010). In many cases this has seriously impacted upon the biomass of fish these rivers are able to support. In addition to the more obvious changes, the flow patterns in such rivers are radically different from those in a more natural river. As rivers rise towards bank full after rainfall, water velocities rise. In rivers that have been re-sectioned the volume of water at bank-full conditions is much higher with consequent major increases in velocity. As part of the re-sectioning process, engineers sought to create trapezoidal ‘self cleansing’ channels without slow flow areas where sediment could settle and in addition the dredged material was used to fill in backwaters and low areas next to the river which were used by fish as refuges in different flow conditions. Fish therefore experience flow velocities far in excess of the swimming speed of all but the largest fish and have no areas into which they can move to escape. This can lead to very distorted fish populations often with whole age classes missing where the small fish of that year have been lost. The increase in maximum flow speeds, combined with weirs and other obstructions to fish movement can cause fish populations in the upstream reaches of some rivers to be impoverished by the ‘export’ of fish and the prevention of natural re-colonisation from downstream. Re-sectioning also removes spawning gravels and other in-stream habitats and communities associated with gravel beds and compounds the effect by significantly reducing productivity and removing conditions essential for other life stages of fish and their food supply. Re-sectioning is also usually associated with more intensive agriculture with increased tillage and silt run-off. This can often lead to excessive deposition of silt, smothering the bed leading to further habitat degradation. 6.5.4.2 Barriers to fish movement Species such as salmon, sea trout and lamprey migrate up rivers to spawn and species such as eels migrate to the sea to spawn. Both types of fish require free access upstream

in order to complete their life-cycle. Although most species of coarse fish are not considered migratory, many species undertake considerable movement up and downstream. The numerous barriers on English rivers, including weirs, culverts and other artificial channels can have a serious impact upon the species composition and fish biomass as well as on their resilience to pollution incidents. Obstructions to fish passage also make pollution incidents more damaging as surviving fish often move downstream to escape pollutants and are unable to return. The Water Framework Directive (2000) introduced a general requirement for ecological protection of surface waters. Under the Eel Regulations 2009, eel passes may now be required on new structures and structures being repaired. Planned legislation, now postponed, will extend the requirement (under the Salmon and Freshwater Fisheries Act 1975) to provide fish passage for migratory salmonids, to other species. It is to be hoped that this will come into effect in the near future. In order to achieve the standard required for fish under the Water Framework Directive it is estimated that 2,500 man-made barriers to fish migration must be removed or mitigated in England and Wales. The Environment Agency uses its consenting powers to prevent new barriers to fish movement being created and is undertaking a programme of weir removal and/or lowering and fish pass construction. One example of this is the extensive programme of work on the Kennet and Lambourn in Thames Region. 6.6 Otter introductions The value and role of otter re-introductions and releases has been extensively debated by those involved in otter conservation (Mason, 1992; Jefferies, Wayre & Shuter, 2000; Green, 1997). Those supporting re-introductions and those opposing them felt that they had the best interests of the otter at heart. More recently re-introductions have become a point of debate in the angling press (Daily Mail, 2010; Stones, 2010) fuelled largely by erroneous assumptions that re-introductions are continuing and are causing an artificial increase in otter populations. The first Otter Survey of England in 1977-79 showed that in the previous 20 years otters had declined from being a widely distributed animal, ‘supporting’ 13 otter hunts in England and Wales, to remnant populations only in the south west, in some areas next to the Welsh border, in parts of the north of England and in north Norfolk. Over most of England the otter was already extinct and it seemed likely that if action was not taken the otter would become extinct in the whole of England. Two re-introduction programmes were therefore set up which between them released a total of about 170 otters. The Otter Trust released 116 captive-bred otters, starting in 1983 and concluding with the release of 17 otters, at three locations in the upper Thames catchment, in 1999. The Vincent Wildlife Trust released 49 rehabilitated otters (largely orphaned otter cubs), mainly in Yorkshire, between 1990 and 1996. Most of the re-introductions were in Anglian Region, at least 99 between 1983 and 1998, with 29 in Yorkshire region, 23 in Thames and small numbers in South West, Wessex and Southern regions and two each in the lower Trent and Wye catchments The re-introductions in England largely reinforced existing otter populations (Green, 1997). Remnants of the original otter population were usually present in the areas where releases were undertaken, though usually in low or very low numbers. In England most releases consisted of 2-4 otters (Jefferies et al., 2000; Green, 1997) which would have created very small populations vulnerable to chance losses except in those areas close to an existing

population (whether remnant or caused by releases) or where such populations were reinforced by subsequent releases. In Anglian Region the results of the 1977-79 Otter Survey of England (Lenton et al., 1980) showed that otters were present at that date with the main concentration being in north Norfolk. The population there suffered a major decline between 1978 and 1986 (Strachan et al., 1990; Spalton & Cripps, 1989) and it is likely that the Otter Trust re-introduction programme prevented the extinction of otters in Anglian Region. The main increases in otter activity in the region between 1994 and 2002 were in those areas where introductions took place between the two surveys indicating that a viable population had probably not been achieved before about 2000 (Strachan & Jefferies, 1996; Crawford, 2003). It is likely that the Otter Trust programme of releases speeded up the re-colonisation of Anglian Region by around 20 years. In Yorkshire the Vincent Wildlife Trust release programme between 1990 and 1996 strengthened the existing very low otter population. However the population remained small even in 2000. There was an increase between 1992 and 2000 but it was only from 11 to 19 per cent of positive sites. It is likely therefore that the introductions supported the otter population in Yorkshire and may even have helped it achieve the critical mass required for expansion. The results of the present survey show a major increase in positive sites but this increase is mainly concentrated in the northern part of the region near the expanding population of Northumbria. It is therefore likely that natural re-colonisation has been the main factor in Yorkshire although it is likely that re-introductions speeded up the development of a viable population by some years. In Thames Region, otters had started to re-colonise the west of the catchment, presumably having crossed the watershed from rivers in Wessex region, prior to 1992 (Strachan & Jefferies, 1996; G. Scholey, pers. comm.). Presumably this natural re-colonisation would have continued and the Thames would have been colonised naturally. However the introductions led to a significant increase in otter activity and must have speeded up re-colonisation by some years. It is impossible to know what would have happened without the introductions or what impact they had. It is also difficult to determine survival rates following release although some released otters were fitted with radio harnesses and the later releases were all fitted with microtransponders. Between five and seven per cent of released individuals are known to have died soon after release (Green, 1997), but this depends upon members of the public finding and reporting the corpses and must be a serious underestimate. In Anglian Region the level of introductions was probably sufficient, together with the very small remnant population, to have enabled a breeding population to develop. In Yorkshire the combination of the remnant population, introduced otters and animals naturally re-colonising from the north enabled a breeding population to develop although it is not possible to discover what role each of these factors played. In Thames otters would have re-colonised naturally but the releases probably speeded up the process. The releases in other catchments were all very small scale and were mainly in areas into which otters were already spreading. They may have had a small impact but this is very unlikely to be significant at a population level. The second and third otter surveys of England (1984-86 and 1991-94) showed that otter populations, although still very fragile, were starting to recover and by the mid 1990s it was becoming apparent that further releases were not required. In 1999 the final release by the Otter Trust of 17 otters at three locations in the upper Thames catchment including one location near a fish farm and carp fishery, brought to national prominence the possible

conflict between a returning otter population and certain sensitive fisheries such as specialist carp fisheries and trout farms. The Otter Trust had already decided, in agreement with the Otter BAP steering group, to phase out its breeding and release programme and the Vincent Wildlife Trust had already stopped its otter rehabilitation and release programme. It is significant that the areas where otters have reached, or are close to reaching, carrying capacity had no or very few otter introductions. No otters were introduced into the South West, Northumbria or Cumbria (although in Northumbria two orphaned otter cubs were released at the point they were found and some similar releases have been undertaken in South West). Only in Wessex did introductions take place with two otters being introduced onto the Hampshire Avon in 1989 (Jefferies et al., 2000). The only otters released since 1999 have been orphaned otter cubs and sick and injured otters, released by the RSPCA and other animal welfare organisations. The RSPCA and most of the other organisations have agreed only to release otters at the locations at which they were originally found. This is to allow otter cubs, which are released at the age they would leave their mother, to behave like ‘normal’ dispersing sub-adults and for adult otters to re-establish themselves in their previous territory - although in practice most adults which can be caught are too sick or injured to survive. Between 2000 and 2009 a total of 56 otters is known to have been released in England and Wales, mainly by the RSPCA (A. Grogan, pers. comm.). As would be expected these have nearly all come from areas with higher otter populations. Returning these animals to these same areas will therefore have little or no influence on population levels. The level of otter releases since 1999 should be compared to the 1,080 otters (nearly 20 times as many) which were killed on the roads in England and Wales and handed in to the Environment Agency for post-mortem within the same period (Chadwick & Sherrard-Smith 2008; Chadwick & Deakin 2009; E. Chadwick, pers. comm.). These otters are of course mainly from the same areas as the releases and in some cases may well include the mothers of the orphaned cubs. The figure for otter road kills must significantly underestimate the total death rate from this cause as it is known that many otters which are found are never handed in to the Environment Agency and others will not be found at all. The release of cubs as sub-adults at the location where they were found is not without controversy. Otter cubs normally remain with their mother for 12 months learning how to survive in and exploit their environment and it is obviously impossible to mimic this effectively in captivity. Since 1999 there have sometimes been suggestions that orphaned cubs should be released in areas where otters are less common. Simpson (2010) expressed concern that released otter cubs were less able to survive in the wild than cubs which have remained with their mother and suggested that it would be best to release these otters in south east England where there are few if any otters. However the general consensus within otter conservation is that this could seriously damage relationships between angling groups and otter conservation and for that reason it is best to continue with the present release protocol (G. Scholey, pers. comm.). Otters like all species have to survive within a largely man-created environment and the possible small benefits gained by otter populations as a result of releases away from the home area would be more than outweighed by the antagonism this would be certain to produce. When considering the possible impact of introduced otters it should be noted that less than 230 individuals of this native species are known ever to have been released in England and Wales. In contrast, in 2009 alone, fishery owners and managers applied to the Environment Agency for consent to introduce 13.6 million fish into waters in England and

Wales (C. Eade, pers. comm.) although not all of these will actually have been introduced. Many of these will be of non-native species. 6.7 Otters and fisheries The Eurasian otter is predominantly a fish predator. Studies based on spraint analysis across its range show that fish normally constitute 75-95 per cent of its diet (Woodroffe, 1994). Although non-fish prey can be seasonally important (such as amphibians) or may be selected by younger, less experienced animals (such as shore crabs by coastal sub-adults), fish generally predominate and reflect the otter’s physical adaptation for seeking food in the aquatic environment (Kruuk, 1995). It is almost inevitable that a freshwater fish predator is likely to come into conflict with human interests, either by impacts (real or perceived) on commercial fish-rearing facilities or on recreational angling activities. In the past otters were persecuted across their range in Europe, prior to, and even after, their significant decline in the late 1950s (Strachan & Jefferies, 1996). This sharp decline occurred at a time of growing understanding of man’s impact on the natural world and an increasing awareness of the requirement for responsible stewardship. This led to the introduction of legal protection measures in Britain and other countries (Strachan & Jefferies, 1996). In the UK, as otter numbers began to recover from the low point in the late 1970s, it was almost inevitable that conflicts with fisheries interests would occur. Many local otter projects of the 1980s and 1990s, set up by conservation groups and statutory agencies to encourage natural re-colonisation, engaged with local angling groups to gain their support in maintaining and improving good habitat and safe refuge areas. In 1993 the then NRA produced the booklet Otters and River Habitat Management (NRA, 1993) which drew together the methods for enhancing rivers for otters most of which involved habitat improvements which would also improve fish holding. The booklet was reprinted by the Environment Agency in 1999 (Environment Agency, 1999). In 1998 the Environment Agency produced a four-page leaflet, Otter predation - Is my fishery at risk? (Environment Agency, 1998) endorsed by a number of angling bodies. This was to alert owners of stillwater fisheries and fish farms to the possibility of otter predation on vulnerable waters. The leaflet advised owners to contact Wildlife Trust advisers or the Environment Agency for further advice on mitigation measures. By the time of the fourth national otter survey of England in 2000-02 the issue of stillwater fish predation had gained in prominence, and there had been much discussion between angling representatives, such as the Specialist Angler’s Alliance (SAA), and the members of the UK Otter BAP Steering Group to consider mitigation techniques. Research, funded by the Environment Agency and SAA, looked at the efficacy of different fencing designs in preventing access to food provided to captive Eurasian otters (Trout & Liles, 2005). This work, and other experience from around the country, informed the production of the publication Otters and Stillwater Fisheries, produced by the Wildlife Trusts and the Environment Agency and endorsed by the SAA (Jay et al., 2008). This publication provided background on otter biology and legislation and offered advice on planning and constructing otter-proof fencing. The growing concern among some fishery managers and anglers about impacts on stillwater fisheries (particularly specimen fisheries) has been matched since the publication of the 2000-02 otter survey by similar concerns from some anglers about impacts on river

fisheries. This has led to significant coverage in some of the angling press (Stones, 2010; Whitehead, 2010) and on websites, and promoted a debate about the impacts of otters on wild fish populations and calls for controls on otter numbers. The issue is clouded by considerable misinformation on the role and status of re-introductions. This has been perpetuated in parts of the angling press, both in respect to the numbers involved and whether a re-introduction programme is still under way (Daily Mail, 2010; Lemmon, 2010). The last release of captive-bred animals by the Otter Trust was in 1999. The proliferation of stillwaters as a result of sand and gravel extraction, reservoir construction and the creation of large numbers of purpose built fisheries in the past 50 years has created a very different water environment for the recovering otter population. The large number of stillwaters stocked with fish provides a considerable potential food supply in addition to that provided by rivers, streams and wetlands. Locally, this could increase the carrying capacity of some catchments for otters where a reliable and sustained food supply is available. For specimen fisheries, in particular stillwater carp fisheries, the loss of cherished and much-sought-after individual fish with a high market value is an unpalatable experience for club members and fishery managers. Although fencing has been put up at some fisheries this can be prohibitively expensive and in some sites is impractical. Fencing can also cause adverse landscape impacts and potential barriers to other wildlife. Only the most robust fencing can guarantee to exclude otters completely but it is likely that cheaper fencing options can reduce losses and be cost effective in some circumstances and perhaps ought to be considered more often as a pragmatic alternative. The impact of otter predation remains a very topical issue with discussions taking place between the Environment Agency, Natural England and representatives of the Angling Trust to address the concerns, explore the facts and identify the underlying factors which may be affecting river fisheries. It is clear that the concerns about possible otter impacts on river fisheries differ from those about stillwaters and require a different set of responses. For river fisheries, the focus has primarily been on impacts on specimen fish, particularly chub and barbel which are vulnerable to otter predation. On a number of lowland rivers in England there has been a trend over the last two decades towards increasing size and dominance of specimen fish combined with some evidence of poor recruitment and a skewed age structure of fish populations as a result. An increase in large specimen fish may be symptomatic of a wider problem of poor recruitment caused by factors such as poor habitat (often a result of past river engineering), the impact of water quality on egg survival and in some areas the impact of signal crayfish. The absence of otters for 30-50 years from some rivers may have contributed to the change in fish communities; once fish become a certain size they have few if any effective predators in England other than otters. Without otters they continue to grow subject to other environmental and biological constraints. The presence of large specimen fish may also be a factor in poor recruitment and subsequent senility of fish populations, due to suppression of con-specifics. The complexity of the relationships and ecological responses is increased by major improvements in water quality, more sensitive river management, and the manipulation of fish stocks by introductions, removals and artificial feeding. It is quite likely that in skewed fish populations dominated by large specimen fish, predation by otters may initiate a return to a more balanced and sustainable age structure. There is a clear link between those rivers which were without otters for a long period and those generating concerns about impacts on specimen fish. Those rivers which had otters present throughout the period of decline or where otters returned quickly, generate few, if

any, complaints and many have thriving and diverse fisheries. An example is the River Wye in Herefordshire where the otter population appears to have reached carrying capacity but the river is regarded as one of the ‘finest pleasure fishing destinations’ in England (Anglers Mail, 2010; Angling Times, 2010 A; Angling Times, 2010 B). Clearly good pleasure or match fishing is not incompatible with good otter population. Of ‘the top 50 rivers to fish’ listed in Angling Times (Angling Times 2010 A), 42 have otters present, many, as on the Wye, with otters at or close to carrying capacity. Similarly in both Ireland and large areas of Scotland otter populations remained at carrying capacity throughout the period of decline and recovery in England but the rivers in these countries have remained prime fishing destinations (Jones, 2009; Jones, 2010; Grigorjevs, 2010). The return of otters to many rivers raises the issue of their influence on fish population dynamics in lowland river systems, and also how fish behaviour may respond to the presence of otters to influence perceptions of abundance. It may be necessary to find measures to reduce or mitigate possible impacts on fisheries and to predict the likely responses and future structure of fish populations in response to a return to the historical norm of otter predation. We need to take a balanced approach to fishery management and to understand the important place that otters have in our freshwater environment and the special affection by the public in Britain. The most extreme response to the conflict of interest between otters and specimen anglers has been to call for culls and the translocation of problem otters (Whitehead, 2010; Stones, 2010). Many of these calls are based on a belief that otters somehow have exceeded ‘natural’ carrying capacity as a result of continuing introductions. In fact less than 250 otters have ever been released in Britain and the last introduction of captive bred otters was by the Otter Trust into the upper Thames in 1999. None of the introduced otters could still be alive and all otters in England today are the result of natural breeding in the wild, mainly from naturally recovering otter populations but also from the offspring of introduced individuals. It is important to remember that these concerns are mainly restricted to a sector of the angling community (stillwater and some river specimen fishermen) and only to a proportion of those. Many fishery managers, river keepers and anglers do not foresee the ultimate demise of fish populations (as it is often characterised) as a result of the recovery and strengthening of otter populations. Food supply, and its relative availability, will be the ultimate factor in determining otter density in England as elsewhere but territoriality will serve to limit numbers within the constraints of food supply. Other environmental requirements such as secure breeding sites are unlikely to be limiting given the wide range of habitats which otters are now exploiting. Mortality on roads and in illegally-set fish traps (both growing trends) might cause temporary lowering of otter populations but such mortality is likely to replace natural mortality rather than add to it. Otters have a catholic diet and will exploit whatever fish species are available. It is possible that the lack of eels on some of our rivers now provides them with a slightly narrower choice of prey than they would have had in the past but this may be compensated for by an increased biomass of other species (including non-native species such as common carp and signal crayfish). The biomass of fish available to them on English rivers may be no less than prior to their decline and is in any case far higher than that in some Scottish rivers which have retained good otter populations (Brazier & Mathias, 2001; Kruuk 1995). In some cases where signal crayfish have replaced the biomass of species previously unavailable (to otters) in the form of smaller invertebrates, the available biomass may have increased substantially. However the fish biomass on a number of rivers is now re-distributed into larger specimen fish which increases the likelihood of more

noticeable impacts in the short term until a more natural fish population is restored. New stillwaters have also increased the prey biomass available still further. However as top predators, otters will regulate their own density through territorial behaviour and the food resources available. The concept of ‘over-capacity’ would appear to have little ecological merit. This will not satisfy the concerns of those who see their specimen waters affected and their favourite fish partly eaten on the riverbank. We need a better understanding of what is influencing fish population structure on those rivers which appear to be ‘unbalanced’. There is also a significant challenge to both statutory agencies and conservationists on the one hand, and angling interests on the other, to consider what the future of specimen fisheries in the UK could and should be like in the future. Unless all parties accept that fish must take their chances in the environment like everything else, and that otters provide part of the backdrop of natural hazards with which any fish is faced, then we will see a constant state of claim and counter-claim and calls for action. Where practical, stillwater fisheries may need to be physically protected to guarantee longevity for specimen fish, otherwise some losses should be expected and allowed for. For rivers, it is likely that specimen fish will become more the exception rather than the norm with natural levels of predation restored. This suggests we should work for healthy balanced fish communities in our rivers, of which specimen fish comprise a small proportion as would be expected, and otters are part of that healthy and balanced environment. Otters have been part of the freshwater environment in Europe since the Pliocene, long before man came on the scene and this alone should serve to indicate that they do not pose a threat to the viability and future of the fish communities which evolved with them. 6.8 Priorities for future action There are several priority areas to enable a full understanding of the recovery of the otter population in England. 6.8.1 Survey work The results of the 2009-10 Otter Survey of England show that otter populations are recovering in every region and there are now few areas which can be regarded as the leading edge of the recovery. It would be desirable to survey these areas to determine the rate and pattern of recovery. These areas are:

• Essex. The yearly surveys carried out by Essex Wildlife Trust (Tansley, 2008, 2009, 2010) provide one of the few opportunities to monitor the movement of a leading edge in detail. Ideally these surveys should be continued so that the expected expansion into South Essex and the Lee valley can be monitored.

• Environment Agency staff in North West Region have carried out regular surveys of the previous leading edge in Cumbria for over 12 years (Bennett & Butterill, 2010). Ideally the new leading edge in the central/southern part of North West Region should be the subject of similar regular surveys.

• In Thames Region otters have colonised the west of the catchment and are also present in the north east of the catchment. The region thus has two important leading edges. Regular surveys should ideally be carried out on the Loddon, Wey and Colne to monitor the expected re-colonisation from the west and on the Lee, Roding, Beam and Ingreborne (at the eastern end of the region) to monitor the likely spread from Anglian Region. Surveys of the Loddon and Wey would also help to determine the spread of otters into Southern Region from the north. Ideally a

regular programme of surveys similar to that undertaken by Environment Agency staff in North West Region should be set up.

• Southern Region is likely to be the scene of an expansion from the west and possibly from the Thames catchment to the north. Surveys should ideally be carried out on the Arun, Adur and Ouse catchments to detect re-colonisation either from the west or from the Thames region to the north. Surveys in north Kent should ideally be carried out but these are probably only worth doing once otters have re-colonised south Essex and/or the lower Thames.

• The Isle of Wight. There is some evidence of otter presence on the Isle of Wight (M. Short, pers. comm.) but it is not clear whether this is simply a transient animal. It is likely that the Isle of Wight will be re-colonised within the next few years. Surveys should be carried out at three year intervals to determine this.

• The River Trent between Newark and Gainsborough is one of the apparent gaps in otter distribution in England. A boat based survey should be carried out to determine if otters are using this reach of the Trent.

• In the four westernmost catchments in Cornwall, 26 sites changed from positive to negative between 2000-02 and 2009-10. These were in part balanced by 13 sites which changed from negative to positive. It is likely that the change is the result of flooding in the period immediately preceding the survey and that it does not represent a change in otter activity. However a further survey would be desirable to confirm that this does not mark the start of a local decline.

• It is unclear whether otters do use canals as routes to cross watersheds, it would be useful to determine whether those canals linking key catchments are being used by otters. These would include, among others, the Kennet and Avon Canal between Trowbridge and Hungerford, the Rochdale Canal between Hebden Bridge and Rochdale and the Wey and Arun Canal (if this is restored) between Rowly and Ifold.

6.8.2 Other actions

• Preparations for the sixth Otter Survey of England in 2018 should be completed by the end of 2017.

• Continue funding for the post-mortem work undertaken at Cardiff University and the analysis of otter tissue at Environment Agency laboratories to maintain surveillance of the health of our otter populations and to identify the levels of bio-accumulating toxic chemicals which may be of concern. There is also a need to prioritise new suites of chemicals to test for to ensure early warning of new compounds of concern.

• The installation of otter ledges to reduce otter road casualties should be considered in all Flood Defence Consents (under the Land Drainage Act 1991) for new bridges or refurbishment of older structures.

• Canal restoration must include provision for the use of the canal by otters. The EIA for a canal restoration should state the measures that will be taken. It is unlikely that these will impose any additional burden as they should already be best practice. They include provision of ramps to allow animals, including otters, to get out of the canal where both sides are sheet piling, the provision of patches of cover on the offside of the canal and possibly the provision of artificial holts.

• Environment Agency fisheries and enforcement staff should ensure that all fyke nets for eels and other fisheries management are fitted with otter guards as required under fisheries bylaws and that all crayfish traps meet the legal maximum dimension requirements and are fitter with otter guards where required. Reports of illegally set nets and traps should be investigated and the nets and traps removed as soon as possible.

• All mink traps should be fitted with otter excluders as recommended by Game Conservancy Trust.

• Environment Agency fisheries staff should ensure that all licensed crayfish traps have an entrance of less than 90mm or are fitted with otter guards.

• Design work is needed to develop lobster and crab pots that pose less danger to otters.

• The Environment Agency should identify sensitive areas for otters in relation to crab/lobster pots. Where these pose a serious risk to otters consideration should be given to limiting the use of pots close inshore possibly through Marine Conservation Zones.

• Research to identify individual otters from spraint, including DNA and volatile compound research should be continued.

• All rehabilitation centres handling otters should follow the agreed RSPCA protocol for care procedures and ‘soft release’ back to the catchment of origin.

• Environment Agency work with angling representatives to provide advice and agree measures to minimise impacts of otter predation on vulnerable stillwaters should continue.

• Continue to work with angling representatives to understand the impact and implications of predation on those river fisheries which are vulnerable due to the structure of their fish communities and the presence of large numbers of specimen fish.

6.9 Conclusions The 2009-10 survey is the first otter survey of England to give complete coverage of the country. The results confirm that the increase in otter distribution, seen in every survey since the first in 1977-79, is continuing.

• Every one of the 12 regions and catchments into which England has been divided for the survey shows an increase in the number of positive sites.

• The pattern of the increase varies considerably. Previous surveys showed a ‘leading edge’ of otter distribution expanding to create large areas at low population density followed by consolidation some years later. The present survey shows that most of England now shows some signs of otters and that a leading edge can only be said to occur in the very south east of the country and in the Liverpool - Manchester area.

• Otters were shown to be present in 102 out of 115 subcatchments (88%) in England and in 36 of the 38 50km squares. An increase in otter distribution cannot be directly translated into an increase in otter numbers but such an increase in distribution must represent a significant increase in the number of otters on England’s rivers and wetlands.

• There have been major improvements in general water quality leading to more sustainable fish populations on many rivers. Serious pollution incidents, resulting in major fish kills, have also decreased markedly since the last survey. However such incidents do still occur and continued policing of water quality by the Environment Agency will be required for the foreseeable future.

• There are still concerns about the level of some environmental toxins, particularly those which can accumulate through the food chain. Environmental surveillance, partly through the programme of otter post-mortem and ecotoxicological analysis, needs to be maintained to address these concerns.

• The increases in otter range have taken place within the context of modified river habitat in England. There is still a considerable attrition of riparian habitat from intensive farming (and to a lesser extent from development). The requirement under the Water Framework Directive to bring all watercourses up to good ecological status (or full ecological potential for artificial and heavily modified watercourses) will create the conditions necessary to allow sustainable fish populations to develop. This in turn is a pre-requisite for a healthy otter population.

• The tolerance of otters to apparently high disturbance situations such as city centres is far higher than was thought. They appear to select low disturbance habitats where possible but at least some otters are willing to tolerate high levels of human disturbance under some circumstances. It is likely that there is a variation between individual otters in the tolerance of human disturbance.

• Accidental deaths of otters remain a cause for concern. Nearly 1000 otters are known to have been killed on the roads since the last survey in 2000-02 and this is certainly an underestimate. Deaths in fish and crustacean traps remain a concern and with higher numbers of otters using coastal habitats, deaths in lobster and crab pots may become a serious issue.

• The table below shows the percentage increase in the number of positive sites between the 2000-02 and 2009-10 surveys. (These have been calculated using only sites surveyed in both pairs of surveys). The figures for the 1977-79 to the 2009-10 surveys are shown for comparison.

Region Percentage increase

1977-79 to 2009-10 Percentage increase 2000-02 to 2009-10

Thames 2125* 411 Yorkshire 3500 163 Anglian 1650 120 Wessex 5650 91 North West 1978 77 Southern 360 77 Trent 667* 69 Northumbria 864 56 Severn 1392 53 Dee 700§ 33 South West 264 3 Wye 383 0

* No otter signs were found during the 1977-79 survey. Figures refer to 1984-86 to 2009-10 surveys § No otter signs were found during the 77-79 or 1984-86 surveys. Figures refer to 1991-94 to 2009-10 surveys

• There was a very high percentage increase in the Thames catchment where there

has been both consolidation of the population in the upper part of the catchment as well as re-colonisation eastwards.

• The expansion in Yorkshire, Wessex and Severn regions has been a consolidation of the population in the core areas combined with re-colonisation of areas which were previously without otters. There are now few parts of these regions which are wholly without otters but the population is probably low in some areas.

• In Anglian Region the increase has mainly come from consolidation of areas which in 2000-02 had a sparse or very sparse otter population. Otters are present in nearly all areas, only southern Essex still remains without otters.

• In North West Region there has been a major consolidation in the core areas in the north and the southern fringe combined with re-colonisation of much of the centre of

the region. The otter population in the centre of the region remains very small and scattered.

• Southern Region showed a small but significant increase in positive sites between 2000-02 and 2009-10. The increase was entirely in the western end of the region where there has been considerable expansion in range and an increase from nine to 25 positive sites (64%). This was partly balanced by the complete loss of the population(s) in the Eastern end of the region. Southern is the only region in which there has been a loss of range of the otter between the two surveys. The small otter population(s) in the eastern end of the region had clearly been in decline for some time. Between 1994-6 and 2000-02 otters appear to have been lost from north Kent and between 2000-02 and 2009-10 the population in Kent and East Sussex also appears to have been lost. The reasons are not clear but it is likely that the population(s) were too small to be self sustaining and they were too far from other populations to be sustained by immigration. The future of the population at the western end of the region looks secure and further eastward expansion would be expected.

• The Trent catchment has shown a disappointing level of increase since 2000-02. There has however been considerable consolidation and re-colonisation. It is possible that the main increase in this catchment was in square SK s/w which was not included in the main survey. The alternate squares spot-check survey revealed that otters were present in 22 of the 25 10km squares in that 50km square.

• In Northumbrian Region the increase in percentage terms has been fairly low but this is because otters were very widely distributed by 2000-02 and the increase has largely been as a result of consolidation within an existing range. Otters are now present throughout the region.

• The increase in positive sites in the Dee catchment has been small. However otters are now present across most of the catchment.

• The increase in positive sites in South West Region has been very small and on the Wye catchment there was no increase. In both cases this is due to the high level of positive sites in 2000-02. It is likely that both these catchments have reached carrying capacity.

• The return of the otter to most of England is one of the major conservation success stories of the last 30 years. The majority of this increase has been due to the otters themselves but the general improvements in water quality and consequent increase in fish stocks must have played a significant part.

6.10 Funding The Fifth National Otter Survey of England was funded by the Environment Agency and several partner organisations. We are very grateful to the People's Trust for Endangered Species, Thames Water, Wessex Water and Anglian Water for supporting the project. 6.11 Acknowledgements A project of this magnitude is inevitably a collaborative effort and very many people have contributed time, effort and data to make it as complete as possible. I have tried to include all those involved but I must apologise to those whose names may inadvertently not have been included. I would like to thank the contract surveyors who carried out the main survey, Libby Andrews, Hilary Marshall, John Martin, Robin Roper and Andy Rothwell. It is their hard

work and dedication which enabled the survey work to be carried out in only seven months. There are many other people who deserve my thanks. In particular, Graham Scholey chairman of the UK Otter BAP Steering Group who obtained the funding for the survey, helped with the survey preparation, gave me support throughout, co-wrote some sections of the report and helped to correct the final report. Frances Horsford assisted with the design of the survey, helped to develop the electronic survey maps, prepared many of these, assisted with the data preparation, carried out much of the data preparation and presentation and gave me much needed support in all these fields. Rob Ellis worked on the GIS system to enable the electronic maps to be created and Gerard Lenagan, Shelley Howard, Rob Ellis and Brian Wilson created all the maps which make the report intelligible. Libby Andrews provided support and help throughout the work. I would like to thank Tanya Houston and Tom Cousins who gave me an exciting two days of boat trips to carry out the otter surveys on the tidal Thames and Ruth Hannify who helped with the survey work there. Ben Wilson, Chris Rees, Rob Evans, Steve Chambers, Roger Handford, Charles Crundwell, Steve Powell, Guy Mawle, Lawrence Talks and Martin Williams who supplied information on fisheries. My colleagues in Environment Agency headquarters at Bristol, Paul Raven, Kate Warr, Elaine Gibb Audrey Callaghan and Emma Churchill who gave me support and help including comments on drafts also Jan Williams and Steph Galliford who patiently guided me through the contracting, procurement and payment procedures of the Environment Agency. All my colleagues in Central Area of Midlands Environment Agency and particularly my biodiversity colleagues Kathryn Edwards, Chris Farmer, Giles Matthews and Helen Rutherford who took the strain of extra work while I carried out the survey. Dr. Liz Chadwick of Cardiff University who provided me with the data on otter deaths and Darren Tansley, James Williams, Sylvia Jay, Penny Hemphill, James Field, Colin Howes, Richard Lawrence, Graham Roberts, Fran Southgate, Jo Ratcliffe, Judith Bennett, Mary-Rose Lane, Gail Butterill, Adam Grogan, Charlotte Eade, Mike Short, Terry Coult, Rob Strachan, Stephan Bodnar, Charlie Horsford, Chris Farmer, Rebecca Brunt, Nick Mott, Nicky Loveday Katherine Seager and Rachel Janes, who provided other assistance and a wealth of background information. Anish Shah and Andy Tomczynski (Thames Water), Fiona Bowles (Wessex Water), Andy Brown (Anglian Water), Jill Nelson and Nida Al-Fulaij (PTES) all helped to ensure that the project had the resources to carry out the survey. I would like to thank all the people and organisations who carried out the alternate squares spot-checks. They include Louise Adams, Erica Adamson, Chris Addy, B. Alcock, Sean Allen, Catherine Anderson, Fiona Anderson, Anglian Water staff, Julia Archer, Julia Armstrong, Mr. Arnauld, Connie Atkins, Doug Atkins, Rowena Baker, Stuart Baker, Rowena Baker, Heather Ball, Alex Banks, Irene Bannister, Chris Barker, Richard Barnes, Tracey Barnes, Amanda Bassett, Amal Belaidi, A.J. Bellamy, Abbie Bengston, I. Bennett, J. Bennett, Jude Bennett, Sarah Bennett, Robert Bentley, Elizabeth Biott, Chris Blood, Pam Blood, Viv Booth, Carlos Boullon, John Bradbeer, P. Bradfield, Stewart Bradshaw, Paul Breslin, Liz Brooks, Bronwen Bruce, Rebecca Brunt, John Bryden, Geoff Buck, Ben Bullen, Paul Burnham, Ralph Butcher, Gail Butterill, Colin Byatt, Phoebe Carter, Sonia Cassau, Pippa Caswell, S. Cawthorne, Alan Caytor, Susan Chambers, Pauline Chandler, Janet Chapman, Andy Chick, Philip Clay, Graeme Clayton, Patricia Clegg, T. Cobbleigh, Graham Colbourne, Maranda Coleman-Cooke, Catherine Collop, Katrina Coulson, Terry Coult, Debbie Cousins, Les Cousins, Peter Cowling, Nicky Cozens, Andrew Crawford, Alison Cross, Kanchan Dasgupta, Liz Dawson, Claire Denard, Rachel Dobie, Steve Docker, Dorset Otter Group, David Dowson, Briony Doyle, Mike Drew, Robert Dryden,

EcoRecord, Norman Edney, Mike Edwards, Cathy Ellis, Geoff Empson, Su Eyles, Tim Eyles, Chris Farmer, Roger Featherstone, James Field, James Fisher, Tanya Fletcher, Philippa Fortescue, Heather Fowle, Sue French, Liz Fricker, Phil Froud, Richard Gardner, Steve Garner, Jemma Gaskin, B. Gibson, Matt Gooch, John Gorst, R.E. Gould, Peter Goulding, Chris Govus, Vicky Gowers, Jo Green, John Green, Adam Grogan, Paddy Grove, S. Guest, Duncan Hall, Claire Halpin, Paul Hannaby, Ruth Hanniffy, Joanne Harkness, Tim Haskell, Mark Hassall, Vicky Hassell, Dunia Hatuqa, Tony Hause, Ruth Hawkins, Ruth Hawksley, Alex Hazel, Joe Hearn, Andrew Heaton, Roy Heeler, Penny Hemphill, Steve Henson, Nigel Hicks, Neale Hider, Craig Higson, Tim Hill, Emily Hillman, Ian Hirst, Paul Hiscocks, Sue Holland, Tim Holzer, Kathy Hughes, Rod Hydes, Sue Iles, L. Illes, C. Jackson, Claire Jackson, Christina Jackson, Rachel Janes, Sylvia Jay, Amanda Jenkins, Bill Johnson, Don Johnstone, Jane Johnstone, Sue Johnstone, Caroline Jones, Christopher Jones, Shirley Jones, Sue Joyner, Jana Kahl, Ros Kaye, Eleanor Kean, Lorraine Kerrison, Ian Keymer, Janet Keymer, Peter King, Charlie Kitchen, Nick Kite, Christine Knight, Richard Knott, Richard Knott, Steve Kuorik, Helen Lacy, John Lamming, Mary-Rose Lane, Brian Lavelle, Richard Lawrence, Hing Lee, Paul Lee, Francesca Leslie, Debbie Lewis, Kevin Lewis, Sonya Lindsell, Dean Lines, Graham Littlewood, Karen Lloyd, Nikki Loveday, Tim Love, John Macaulay, Paul Madgett, Ro Madgett, David Mallon, Carole Mander, William Mann, John Martin, Theresa Mason, Julia Massey, Chris Matcham, Giles Matthews, Rachael McFarlane, E. McSwan, Lucy Mead, Jude Merchant, Ian Metcalfe, Jon Middleton, Jasper Mitchie, Rolf Moebius, Nick Mott, Peter Murphy, Janet Negal, Jackie Nicholson, Beth Nightingale, Ian Nixon, Katie Noorlander, North Somerset Otter Group, Northumbria Mammal Group, Kevin O'Hara, Nick Oliver, N. Oliver, Rebecca O'Shea, Anthony Page, Jason Palmer, Jon Panter, Helen Parish, Tony Parker, Jeremy Parkinson-Smith, S. Parsons, Jools Partridge, Robert Partridge, James Pearce, Jane Pearman, Sue Penn, Fiona Percival, Mitch Perkins, Christa Perry, B.R. Petty, Jane Phillips, Peter Pilbeam, Gary Pilkington, Bob Platt, Lisa Prickett, John Pring, Amanda Proud, Anita Quigley, Nick Quintrell, Kevin Radley, Alison Rainer, Chris Rainer, John Randall, Jo Ratcliffe, Bob Reed, Tracey Reekie, Ian Rees, Duncan Revell, A. Richards, Geoff Richardson, Sally Richardson, Graham Roberts, Mr. Roberts, Miles Robinson, Romney Marsh Countryside Project, Robin Roper, Andy Rothwell, Ged Ryan, Mark Satinet, Helen Scarborough, Steve Scawthon, Graham Scholey, Carol Seddon, Chris Seward, Natasha Seward, Nigel Sharpe, David Shearing, Ian Shepherd, Ruth Simons, Graeme Simpson, Christine Singfield, Ann Skinner, Sue Slamon, Martin Slater, Hilary Smith, Phil Smith, Eleanor Smith, Ruth Snelson, Somerset Otter Group, Fran Southgate, Dave Spiby, Graham Stafford, Brian Stanley, Claire Sterling, Chris Stewart, Kate Stokes, Rob Strachan, Geoff Stratford, Rod Strawson, Peter Strickland, Ben Sykes, Tim Sykes, Darren Tansley, Sue Tatman, Caroline Tero, Emma Thompson, Jon Traill, Alison Turpin, Paul Vincent, Don Vine, Barbara Wager, Kat Walton, Anna Warburton, John Warre, Sarah Warrener, David Watt, Ernie Wells, Nick Whatley, David Wheeler, Mr. White, Stephen Wilkinson, Gareth Williams, James Williams, Ian Wilson, Michael Wilson, Tim Wojcik, Chris Wood, Sarah Yarwood-Lovett, Daphne Young, James Young, Sonya Young and Sarah Young. I would like to thank the people who contributed reports of otter sightings to PTES during the course of the survey; David Barton, Winnie Courtene-Jones, Michael Elder, Mark Gluckstein, Sheila Grundy, James Hoskins, Martin Hughes, Nisha Keshav, Maria Louise Lock, Simon Mason, Anthony Palmer, Stephen Powles, Lee Rees, David Roebuck, Keith Seaton, Susanna Selman, Richard Stranks, Sarah Threapleton, Josie Walter, Lexi Webber, Elizabeth Wheat, Michael Wilson, Andrew Wright and Rodney Wright.

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CRAWFORD, A., EVANS, D., JONES, A. & McNULTY, J., 1979. Otter survey of Wales 1977-78. Society for the Promotion of Nature Conservation, Nettleham. CRAWFORD, A.K., 1979. Otter Survey of the Wye and Dee Catchments in England 1979. Unpublished report for Welsh Water Authority. CRAWFORD, A.K., 1984. River Wye Otter Survey. Unpublished report for Welsh Water Authority. CRAWFORD, A.K., 2003. Fourth Otter Survey of England 2000-02. Environment Agency, Bristol. DAILY MAIL, 2010., He otter know better: Labour MP blames cute, furry predator for ruining Britain’s angling industry. Daily Mail, 29 April 2010 ENVIRONMENT AGENCY, 1999. Otters and river habitat management. Environment Agency, Bristol. ENVIRONMENT AGENCY, 1998. Otter predation - is my fishery at risk? Environment Agency. Bristol ENVIRONMENT AGENCY. 2010. Our river habitats, river habitats in England and Wales: current state and changes since 1995-96. Environment Agency. Bristol. EC. 2000. Council Directive 2000/60/EC. Establishing a framework for Community action in the field of water policy (Water Framework Directive). FARMER, C., 2005. A study of otter (Lutra lutra) in selected canals adjacent to rivers in the English Midlands. Unpublished B.Sc. dissertation. Nottingham Trent University. FARMER, C., 2007. Otter surveys south east of Leicester. Unpublished Environment Agency data. GASKIN, J., 2005. Watercourses within the Wirral, Cheshire, Greater Manchester and Derbyshire. Otter Surveys. Middlemarch Environmental. Unpublished report for the Environment Agency. GREEN, J., 1991. The impact of hunting, poaching and accidents on otter survival and measures to protect individual animals. Habitat 6, 171-190. GREEN, J. & GREEN, R., 1980. Otter Survey of Scotland 1977-79. Vincent Wildlife Trust, London. GREEN, J. & GREEN, R., 1997. Otter Survey of Scotland 1991-94. Vincent Wildlife Trust, London. GREEN, R., 1997. Re-introduction of otters – a successful conservation strategy? IUCN Otter Spec. Group Bull. 14(2). GRIGORJEVS, T., 2010. 900lbs-plus of roach in a match. Angling Times 9 February 2010: 5

HARTWIG, D., 2000. Game and domestic animal losses in canals in Northrhine Westfalia from 1988-1997. Zeitschrift fur Jagdwissenschaft 46: 2: 120-125. Blackwell. HMSO. 1995. The UK steering group report volume 2: Action plans. (as modified by Otter BAP group) Biodiversity Steering Group, London. HOWELL, P., 1990. Otter and mink survey of the Sow and Penk catchment. Unpublished report for the NRA. HOWES, C.A. 1976. The decline of the otter in South Yorkshire and adjacent areas. Naturalist, 936, 3-12. HOWES, C.A., 1991. Canals – a death trap for deer. Imprint 16: 8-9. HOWES, C.A., 1994. Wild animals drowning in Yorkshire canals. Bulletin of the Y.N.U. 21: 21-22. HOWES, C.A., 2003. Canals: linear pitfall traps for deer: Bulletin of the Y.N.U. 40: 55-58. JAY, S., LANE, M-R., O’HARA, K, PRECEY, P & SCHOLEY, G., 2008. Otters and stillwater fisheries. The Wildlife Trusts, Newark & Environment Agency, Bristol. JEFFERIES, D. J., WAYRE, P. & SHUTER, R., 2000. A brief history of the Otter Trust’s successful programme of repopulating lowland England with otters bred in captivity with a special emphasis on East Anglia. Otters, Journal of the Otter Trust, 2000 3 (4): 105-117. JONES, T., 2004. Otter Survey of Wales 2002. Environment Agency, Bristol. JONES, P., 2009. Ireland’s top 10 waters. Angling Times, 1st December 2010: 34. JONES, P., 2010. Leitrim: Fab fishing and perfect B & Bs. Angling Times, 9 February 2010: 40-41. KRUUK, H., 1995. Wild otters, predation and populations. Oxford University Press, Oxford, UK. LEMMON, D., 2010. Angling: Otters are not so cute and cuddly, believe me. Yorkshire Evening Post, 28 July 2010. LENTON, E.J., CHANIN, P.R.F. & JEFFERIES, D.J., 1980. Otter Survey of England 1977-79. Nature Conservancy Council, London. LEVY, A., 2010. The cuddly killer: otters caught sneaking into gardens to wipe out family fishponds. Daily Mail, 21 July 2010. LEWIS, G. & WILLIAMS, G., 1984. The rivers and wildlife handbook. RSPB/RSNC. LLOYD, J.L., 1962. Where are the otters? Gamekeeper and Countryside 65: 299-300. MACDONALD, S. & MASON, C., 2003. Essex Otters – struggling in a hostile environment? British Wildlife Feb 2003: 153-158.

MASON, C.F., 1992. Do otter releases make sense? The experience in Great Britain. In Reuther, C. (ed.): Otterschutz in Deutschland. Habitat 7. 157-161. MASON, C. & MACDONALD, S., 1993. Impact of organochlorine residues and PCBs on otters (Lutra lutra) in eastern England. Science of the Total Environment 138: 147-160. NRA, 1993. Otters and river habitat management. NRA, Bristol. O’CONNOR, F.B., BARWICK, D., CHANIN, PRF., FRAZER, J.F.D., JEFFERIES, D.J., JENKINS, D., NEAL, E. & SANDS, T.S., 1977. Otters 1977: First report of the Joint Otter Group. Nature Conservancy Council and Society for the Promotion of Nature Conservation, London and Nettleham, Lincoln. O’CONNOR, F.B., CHANIN, PRF., JEFFERIES, D.J., JENKINS, D., NEAL, E., SANDS, T.S. WEIR, V. & WOODS, M.S., 1979. Otters 1979: A second report of the Joint Otter Group. Nature Conservancy Council and Society for the Promotion of Nature Conservation, London and Nettleham, Lincoln. RATCLIFFE, J., 2008. Eden catchment otter survey May 2007. Technical Report NB882 (05/08). Environment Agency. RAVEN, P.J., HOLMES, N.T.H., DAWSON, F.H., FOX, P.J.A., EVERARD, M., FOZZARD, I.R. & ROUEN, K.J., 1998. River habitat quality: the physical character of rivers and streams and streams in the UK and Isle of Man. Environment Agency, Bristol. SIMPSON, V.R., 1998. A post-mortem study of otters (Lutra lutra) found dead in south west England. Environment Agency R & D Technical Report W148. SPALTON, J.A. & CRIPPS, S.J., 1989. The Report of the North Norfolk Otter Project 1986-87. Vincent Wildlife Trust, London. SPIBY, D., 2007. Survey to record and assess the distribution of otters in South Cumbria 2006. Technical Note: NB 847 (04/07). Environment Agency, Bristol. STEPHENS, M.N., 1957. The natural history of the otter. Universities Federation for Animal Welfare, London. STONES, S., 2010. It’s time for action says Trust. Angling Times 16 February 2010: 3. STRACHAN, R., in prep. Otter Survey of Wales 2009. Environment Agency Wales, Cardiff. STRACHAN, R., BIRKS, J.D.S., CHANIN, P.R.F. & JEFFERIES, D.J., 1990. Otter Survey of England 1984-86. Nature Conservancy Council, Peterborough. STRACHAN, R. & JEFFERIES, D.J., 1996. Otter survey of England 1991-1994. Vincent Wildlife Trust, London. TANSLEY, D., 2008. Essex otter survey 2007. Essex Wildlife Trust, Gt. Wigborough. TANSLEY, D., 2009. Essex otter survey 2008. Essex Wildlife Trust, Gt. Wigborough. TANSLEY, D., 2010. Essex otter survey 2009. Essex Wildlife Trust, Gt. Wigborough.

TROUT, R.C. & LILES , G., 2005. The use of fencing to prevent access by otters to fisheries. Specialist Anglers Alliance and Environment Agency. WALKER, C.W., 1970. The otter in Radnorshire. In: W.S. Lacey (ed.) Welsh Wildlife in Trust, 109-113. North Wales Naturalists’ Trust, Bangor. WARD, D., HOLMES, N. & JOSE, P., 1994. The new rivers and wildlife handbook, RSPB. WHITEHEAD, G., 2010. Otters eat £30k of fish in a week. Angling Times 2 February 2010: 2. WOODWARD, P., 2009. The best two miles of river in the country. Angling Times 1

December 2009: 22-23. WOODROFFE, G., 1994. The Otter. The Mammal Society. London. Appendix 1

Appendix 2

Site No Region Grid Ref GPS Grid Ref Start RecorderSite Name Date

Distance surveyed

Otter (and (Y/N) details)

600m, c200m d/s on shore and 400m u/s on river with gaps,

0122 SY128873

Sidmouth River Sid SW SY128873 SY12894 87335 HM 20/11/09 Y

0123 SY142933

Cotford River Sid

600m u/s mostly RB SW SY142933 SY14084 93252 HM 10/12/09 N

0124 SY121911 SW SY121911 SY12117 91148 HM

Burscombe Farm River Sid Trib 10/12/09 N

600m, c200m u/s, c 400m d/s RB, some in channel, both banks 600m. 150m d/s both banks, 300m u/s RB.

Budleigh Salterton River Otter

0125 SY074830 SW SY074830 SY07515 83040 HM 01/12/09 N

Perran Wharfe River Kennal

600m d/s RB, including island

0126 SW777385 SW SW777385 SW77762 38549 HM 22/07/09 N

Bissoe River Carnon

0128 SW782407

600m u/s LB SW SW782407 SW78321 40828 HM 21/07/09 N

Kennal Vale River Kennal

0129 SW745369

600m u/s RB SW SW745369 SW74525 37001 HM 06/08/09 N

Stithians Reservoir Kennal 0130 didn't get to startpoint

Site No Region Grid Ref GPS Grid Ref Start RecorderSite Name Date

Distance surveyed

Otter (and (Y/N) details)

600m, c200m d/s on shore and 400m u/s on river with gaps,

0122 SY128873

Sidmouth River Sid SW SY128873 SY12894 87335 HM 20/11/09 Y

0123 SY142933

Cotford River Sid

600m u/s mostly RB SW SY142933 SY14084 93252 HM 10/12/09 N

0124 SY121911 SW SY121911 SY12117 91148 HM

Burscombe Farm River Sid Trib 10/12/09 N

600m, c200m u/s, c 400m d/s RB, some in channel, both banks 600m. 150m d/s both banks, 300m u/s RB.

Budleigh Salterton River Otter

0125 SY074830 SW SY074830 SY07515 83040 HM 01/12/09 N

Perran Wharfe River Kennal

600m d/s RB, including island

0126 SW777385 SW SW777385 SW77762 38549 HM 22/07/09 N

Bissoe River Carnon

0128 SW782407

600m u/s LB SW SW782407 SW78321 40828 HM 21/07/09 N

Kennal Vale River Kennal

0129 SW745369

600m u/s RB SW SW745369 SW74525 37001 HM 06/08/09 N

Stithians Reservoir Kennal River

0130 SW703373

didn't get to startpoint arrowed on map SW SW703373 HM 06/08/09 Y 2m

Porkellis Moor

Appendix 3 Otter Survey of England 2009-10 Surveyor(s)

Fiona Percival Biodiversity Officer EA Carol Seddon Biodiversity Officer EA

Previously un-surveyed squares 50 km Square 10 km Square Site Grid Reference Date Otter

signs Y/N Mink signs Y/N

Notes

S J 7 8 6 7 0 5 27/11/09 N N Arley Brook. River very high. Sandbars checked for prints

S J 7 8 4 7 0 3 27/11/09 N N Arley Brook. No ledges. Sandbars under water S J 7 1 1 7 6 1 27/11/09 N N Arley Brook. No ledges. Water very high. Large box culvert S J 7 0 2 7 5 9 27/11/09 Y N Smoker Brook. Two spraints found at base of a large

riparian tree.

fifth otter survey of england 2009 - 2010 -...

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