August 2009 - 2013

Broads Authority Natural Environment Research and Monitoring Register

Contents

Page number

1. Introduction 1

2. Research Reviews: 2 - 24

Breydon Water Hydromorphic and Engineering Study 2

Broads Fen Condition Assessments 2011 3

Broads Authority Peat Resource Contract 2010 4

Trinity Broads Fen Margin Survey 2012 5

The impact of recreational boating on habitat use of water birds in the Norfolk Broads- A case study of the Trinity Broads 2011

5

Trinity Broads Breeding Bird Survey 6

Broads Fen Invertebrate Survey 2012 7

Biodiversity Audit and Tolerance Sensitivity Mapping for the Broads 7

Biomanipulation through zebra mussel propagation in the Norfolk Broads 8

The Effect of Motorboat Activity on Turbidity in the Norfolk Broads 11

The Ecological Status of Ditch Systems 12

New Opportunities for the Sustainable Management of Fens: Reed Pelleting, Composting and the Productive use of Fen Harvests.

13

Site Hydrology Assessment and WETMEC Development 14

Changes in Rare Plant Populations of Broadland Fens 1994-2009 15

Intraspecific patterns in Corbicula metal levels – influence of microhabitat and size

16

An Investigation of Polycyclic Aromatic Hydrocarbon Contamination in Sediments of the Norfolk Broads

17

Palaeoecological Investigation of the Past Biological Structure and Function of the Trinity Broads.

18

Reconstructing the Past Submerged Macrophyte Flora of Martham South, Burntfen, Sotshole and Nortons Broads, Fritton Lake and Mautby Decoy.

19

The influence of salinity on the distribution and survival of the Hawker dragonfly (Aeshna isosceles) in the Norfolk Broads.

20

The Effectiveness of Biomanipulation of the Trinity Broads, Norfolk 21

Septic Tanks and Pollution to Watercourses in the Norfolk Broads 22

An Exploratory Survey of Invertebrates of Wet Woodland in the Bure Valley and the Muckfleet Valley

23

3. Monitoring List 25 - 33

4. Future Broads Authority research and monitoring topic areas 34 - 40

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1. Introduction

The Broads Authority maintains an evidence-based approach to managing the

Broads ecosystem. The findings of monitoring and research since 2009 are

summarised in this register, which contains details of 22 research projects. A certain

amount of this research is relevant to specific questions in The Broads whilst some of

it is relevant to management in other wetlands across the UK and the world.

This review is complimentary to previous research reviews (1988, 1989-94, 2009)

along with various Broads Research Advisory Panel seminars, and topic based

workshops and conferences which have brought together the wide range of research

in the Broads.

The purpose of this document is to provide an overview of key research and

monitoring that has been undertaken or supported by the Broads Authority over

approximately the past three to four year period. Research projects undertaken by

partner organisations in the Broads area are not included in this report.

This Register outlines the key research results, with ongoing and special monitoring

projects listed. This information is fed into the English National Park Research data

base.

The programme and priorities for future research for 2013/14 are outlined in the final

section. This research programme will be updated annually. Longer-term research

and monitoring aspirations are summarised in workshop outputs, habitat strategies

(fens, drained marshes, lakes) and Action Plans (Broads Biodiversity, Sediment

Management, Lakes, Trinities, Lound, Barton and Upper Thurne) and are not

necessarily duplicated within this document, but serve to inform the annual research

programme.

Many of the reports can be found at www.broads-authority.gov.uk/authority/publications/conservation-

publications.html or can be gained by emailing andrea.kelly@broads-authority.gov.uk

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2. Research Reviews Title Breydon Water Hydromorphic and Engineering Study

Author JBA Consulting in conjunction with Deltares and Bright Angel Coastal Consultants

Type Research

Aim The aim of the project was to evaluate the current hydrodynamic and sediment transport processes occurring within the estuary and to investigate how these might change under various estuary management options. The options assessed have included the removal of the Turntide Jetty, the alteration of the Turntide Jetty and an investigation of the Dickey Works training structure. A capital dredging programme has also been investigated that would restore the channel to navigable depths.

Method Numerical modelling of the estuary has been undertaken using Delft3D, allowing a greater understanding of the flow and sediment transport processes. The model has been calibrated and validated against recorded water level, velocity and suspended sediment concentrations respectively within the estuary for a two week spring-neap tidal cycle.

Key results The study included a historic trend analysis for the estuary which suggests that there have not been any major changes to its plan form in recent history, and that minimal changes have been observed to the tidal range. The modelling showed ebb-tide dominance in terms of faster current speeds and larger shear stress, suggesting outgoing tides and fluvial processes will transport sediment downstream to the lower estuary. These processes would supply the Breydon Water mudflats with sediment, which will also be discharged into the sea. During the flood tide, remobilised sediment within the nearshore zone can be transported into the estuary due to the strong currents through the GYPA canalised watercourse. As such, the Breydon Water mudflats are believed to be formed by multiple processes, both related to the ebb and flood tide. The modelling indicated that if the existing Turntide Jetty was to be removed, a change to the velocity and flow direction adjacent to the structure may occur, of the order of 0.1 m/s. The shift in flow direction, while not major, presents a scenario which had some similarity to the anecdotal information that prior to the construction of the Turntide Jetty the River Yare swept across the Waveney channel. As such it has been recommended that a scaled-down, half sized structure be used to replace the existing Jetty to minimise the potential for channel migration. It is felt that this will assist in deflecting the Rive Yare flows whilst providing additional bank protection against erosion. Modelling of the Dickey Works suggests the remnant structure beneath the water level is having little effect on the estuary, and could likely be removed without having any major consequences.

Limitations Long-term predictions in sediment deposition and resultant variation in the hydromorphic processes operating in Breydon Water, would require a detailed historic analysis coupled with sediment sampling, which has not been available for this report.

Future Research Several recommendations have been provided as a result of this study, prioritised as either short or medium term options. Recommendations have been developed for four broad categories covering 'sampling, monitoring and data collection', modifications to the Turntide Jetty, modification to the Dickey Works, and proposed dredging. In summary these recommendations consist of the following:

Dive assessment and removal of Dickey Works piles (short term);

Additional hazard markers at Turntide Jetty/Dickey Works (short term);

Erosion assessment adjacent to Turntide Jetty (short term);

Full topographic survey (short term)

Sediment monitoring (short term);

Sediment sampling (short term);

Investigating of capital dredging (medium term);

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Detailed historic analysis (medium term);

Incorporation of amenity and landscaping at Turntide Jetty (medium term);

Replacement of Turntide Jetty with half-sized structure (medium term).

Title Broads Fen Condition Assessments 2011

Author OHES

Type Research

Aim To provide a site by site summary of the ecological condition of Broadland fen sites using vegetation data from the Fen Ecological Survey (ELP 2010), including the supplementary invertebrate data (Lott, Drake and Lee 2010), and the Fen Audit Review (Stephenson et al 2004). The site summaries are used to derive proposals for the restoration and enhancement of the fen sites.

Method In order to determine the management required for each site, this report needs to refer to two baseline statements of condition:

1. An assessment of current condition and 2. An overview of desired condition.

The broad approaches to management should then progress the site from the first to the second state. Both determinations of condition need to be evidence based, fit the aims of the project and be based on up to date and easily accessible information. Whilst the habitat-based framework provided as the template for assessing the current and desired condition of each site provides a first approximation, it is anticipated that the framework should subsequently be populated by further information enhancing and refining our understanding of ecological condition and desirable approaches to maximising the potential of the Broads Special Area of Conservation (SAC).

Key results The results are site specific and summarised in separate reports categorized by the Broads main river valleys, the Ant, Thurne, Bure, Yare and Waveney. The proposals in the reports can be taken forward by project staff and landowners to derive agreed and costed projects ready for funding and implementation. The reports can be found at www.broads-authority.gov.uk/authority/publications/conservation-publications.html

Limitations Limitations relate to comparing past vegetation data to present day NVC surveys. This includes Wheeler’s plot data which is at a different scale to that used in undertaking NVC surveys today. This may give a false impression of the species richness of fen vegetation samples in the Classification and is based on data from Broadland fens that is now over 30 years old. Similarly earlier vegetation studies, e.g. Pallis (1911) and Lambert (1951), can also be difficult to relate to the characters of modern fen vegetation, and vegetation samples can only be compared directly with great caution. Parmenter’s work to the character and condition of the fen sites today have been related to limitations in mapping accuracy of her plots1, and in the consequence of her classification being developed at a time when accounts of fenland vegetation were being prepared for publication within the NVC. Without a detailed reworking of Parmenter’s database in line with the NVC, and careful location of each sample plot, only rather broad comparisons can be made between the open fen habitat characters at the time of her survey and that provided by the Fen Ecological Survey (OHES 2013).

Future Research Hydrological studies being undertaken in parallel: In parallel with this report, Broads Authority commissioned OHES to develop a set of tools to undertake preliminary hydrological assessments of sites, employing existing hydrological, hydrometrical and hydrogeological data, within the Wetland Mechanisms (WetMecs) framework (Wheeler, Shaw and Tanner, 2009). Through the last decade, Bryan Wheeler and Sue Shaw have undertaken the development of this approach to providing a typology of hydrogeological situations and relating them to sites, and also providing eco-hydrological linkages to fen vegetation. This approach has broadened considerably in recent years, being applied to several other water-dependent habitats, particularly following the work of Owen Mountford (CEH) and David Gowing (Open University), amongst others. In Broadland, a series of short

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hydrogeological accounts have already been published on many key fens, and the application of the WetMecs framework to other sites in the Broads is being assessed (The report can be found at www.broads-authority.gov.uk/authority/publications/conservation-publications.html).

Title Broads Authority Peat Resource Contract 2010

Author ELP a Division of OHES Environmental

Type Research

Aim 1. To provide an assessment of the presence and disposition of peat materials and associated sediments of the valley floors.

2. Characterise the peat in terms of its degree of decomposition and indicators of degradation.

3. Record associated hydrological features and vegetation evident at the time of survey.

4. Provide a database of survey cores to supplement the Broads Authority’s records.

5. Indicate relevent management issues in relation to peat conservation.

Method Target areas for peat surveys were identified in the headwaters of the Ant, Bure, Thurne and Waveney valley within the Executive Boundary of the Broads Authority and which represent the range of landscape and management situations within these areas of the Broads. The Authority sought access from landowners within the target area, and provided base maps, existing peat survey data from the British Geological Survey, and habitat accounts from the Phase I Fen Meadow Survey. The field surveys were conducted over the period December 2009 to March 2010. A hand auger was used to core to depths of up to 4.25 metres to characterize the peat. A database of 290 mapped cores was developed, to add to the Authority’s existing peat database. A subjective assessment of the condition of the peat body was made at each survey area, using field evidence of peat condition and groundwater level.

Key results The survey concluded that active peat formation is not present in any of the survey areas and that the ground surface lacks evidence of freshly formed fen peat. Instead, well-decomposed peat has been subject to drainage and frequently cultivation. The survey demonstrated the variability of peat conditions at sites within the Ant, Bure, Thurne and Waveney valleys. Areas of peat were found to be in good conditions in each valley, but some parts of peat bodies, most noticeably adjacent to arterial drains and watercourses, were assessed to be in poor condition. It is concluded that there is a need for site scale assessments of the condition of Broadland peats, and peat condition surveys provide a useful means by which to inform landowners and agri-environment advisors of the potential for peat restoration, and reasonable targets for success.

Limitations

Future Research In particular, the Authority’s Broad Peat Resource project may develop its role in:

Providing an assessment of the characterics of the peat resource, and identifying peat bodies that may hold potential for restoration through agri-environment schemes undertaken by land managers and administered by Natural England.

Providing a framework within which opportunities to restore peat bodies under more than one ownership can be assessed, and by which common issues relating to water control affecting several land parcels can be explored.

Promoting positive management of peat soils BA_Peat Carbon Management.pdf

By identifying and developing opportunities for sustainable forms of peatland management, including concepts such as ‘carbon credits’.

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Title Trinity Broads Fen Margin Survey 2012

Author Norfolk Wildlife Services Ltd

Type Research

Aim To survey the marginal fen vegetation at the Trinity Broads to provide an up-to-date picture of the condition of this important wetland following management work, including significant broadside scrub removal. The survey results will be used to assess management results and to provide a baseline dataset to allow any changes from impacts such as climate change.

Method Eleven sampling sections of marginal fen vegetation at Ormesby Broad, Ormesby Little Broad, Rollesby Broad, Lily Broad and Filby Broad were identified prior to field surveys taking place. Within each section, at least five quadrats recording the fen and swamp vegetation were taken, with the exception of section C on Rollesby Broad and section B on Ormesby Broad, where the strip of fen was so narrow that only one homogenous stand of fen could be sampled before Phragmites, Typha and Schoenoplectus swamp transitions began. Quadrats used were 10 x 10m. All species of higher plant, liverwort and moss were recorded and rated for abundance on the DOMIN scale. Information on vegetation structure was recorded for each quadrat including bryophyte cover, open water cover, bare ground cover, average sward height and total vegetation cover. Grid references of the centre point of each quadrat were taken.

Key results A total of 51 quadrats were sampled across the entirety of the Trinity Broads from which eight NVC communities were identified. Overall, the quadrats sampled had a reasonable fit with the NVC communities, although there were variances in terms of the relative abundances and frequencies of some of the key features of the communities A number of samples showed a strong correlation with new communities and variants of communities proposed by Harding et al 2010 from the Broads Fen Ecological Survey, particularly S24 and S4. The report summarises the broad NVC communities and species present across the Trinity Broads. The results provide a strong baseline against which future monitoring can be compared, to identify and assess potential vegetative changes which may occur in response to climate change.

Limitations Vegetation on the margins of fens could only be surveyed from the boat. The narrowness of these strips and their inaccessibility by foot meant that no quadrat measurements could be accurately taken. Instead, the length and width of each community type was noted, and a GPS reading was taken from as close to the centre of each stand as could be completed from boat.

Future Research Future surveys could focus on the spread or decline of fen areas in response to climate change, as well as monitoring the distribution and abundances of the rare and scarce species identified in this survey, and those which were notably absent. Monitoring of sites where scrub clearance has occurred is necessary to report on the effectiveness of the investment of scrub removal undertaken by the Trinity Broads Partnership. Also whilst sites show a greater floristic diversity than non-managed areas, there is some indication that negative indicator species such as Rubus fruticosus agg. may be becoming dominant.

Title The impact of recreational boating on habitat use of water birds in the

Norfolk Broads- A case study of the Trinity Broads 2011

Author Almut Jenke, MSc UCL

Type Research

Aim This study aims to assess the influence of recreational boating on the habitat choice of waterbirds during the breeding season in the Trinity Broads.

Method To assess relative importance, analysis needs to raise results on effect size of predictors, which allows comparison of disturbance and environmental variables on the basis of percentage of explained variation. During a 3-weeks field study, corresponding to the breeding season, bird and boat data was acquired. Habitat variables were extracted from secondary sources using ArcGIS. Pearson

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established correlations between continuous variables. Further, ordination techniques such as Principal Component Analysis (PCA) and Canonical Correspondence Analysis (CCA) characterised survey sites in terms of site-specific disturbance and established requirements of bird species. Analysis of continuous predictors concluded with Multi Linear Regression Models (MLR) establishing significance and effect size of disturbance versus environmental variables in shoreline and open water habitats respectively. These results were the basis for comparison of the two types of habitats and for establishing relative importance of disturbance.

Key results Results showed disturbance parameters had a subordinate influence on habitat choice when contrasted to environmental variables. Boat numbers, access rights and accumulative distance to operators had no conspicuous effect on occupation of either habitat. Moreover, neither boating intensity or bird abundance were significantly correlated to daytime or day of week. Although disturbance represented by intensity of protection did influence bird abundance, effect size was overruled by the environmental variables. Out of these, most important were habitat type and environmental status. Accordingly, most birds favoured shoreline habitats and areas in recovering environmental condition. In general, it was primarily environmental qualities that influenced habitat choice. Hence it was to conclude that the threat of disturbance was outweighed by environmental benefits in most cases, a process analogous to the concept of adaptation. However, there were exceptions. In open water habitats disturbance was an important threat and the primary criteria for habitat choice. Especially sailing activity affected populations negatively. On the species level further trends indicated that moorhen were threatened by disturbance in shoreline habitats. Bigger species however, such as swan and geese which favoured extensive water surfaces were endangered by boating in open-water habitats.

Limitations Although we can say that assessed birds were adapted to disturbance we cannot assume that this is equally true for other species. For instance, the bittern and the kingfisher (Alecedo atthis), species which are known to have occupied the Trinity Broads before (Taylor et.al.,2000), were not recorded. In theory, these and other birds might have been more abundant if there was no disturbance. Especially most vulnerable birds are the first to leave a site in response to medium level disturbance (Hockin et.al., 1992), hence due to rarity these birds are at great risk of neglect in disturbance studies.

Future Research Crucial conclusions on the most vulnerable species can only be made by before-after studies comparing the state of an undisturbed environment with conditions of a disturbed one. These studies could provide information on the impact of disturbance on nearly all species that can potentially use these habitats. Although comparison with an undisturbed state was impossible, this study’s strength was a comparison of highly disturbed sites with least disturbed ones. Hence, it could draw conclusions on a sufficiently wide range of species.

Title Trinity Broads Breeding Bird Survey

Author Broads Authority

Type Survey

Aim To carry out a systematic survey of breeding birds of the Trinity Broads in order to carry out a comparison with past data, particularly that for 1983/84.

Method In 2011 it was decided to replicate the 1983/84 survey to produce more comparable results. The margins of each broad were surveyed from a boat with an electric outboard in April, May and June, with two observers recording breeding pairs of birds. The locations of the breeding pairs were then mapped. The estimated totals for each broad were summarised in tabular form for comparison with the 1983/84 results. A table was also compiled for the maximum numbers of birds present on each broad during the spring, derived from survey date counts and the monthly WEBS data. The survey will be repeated for a second year in 2012 to give a more direct and accurate comparison with 1983/84, and a full report and analysis produced.

Key results The survey highlighted some striking differences between 1983/84 and 2011.

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In general breeding numbers of Great Crested Grebe, Mute Swan and Coot were broadly comparable or increasing (and all had good productivity), while breeding duck numbers were significantly lower. Reed Warbler numbers had increased but Sedge Warbler and Reed Bunting numbers were greatly reduced.

Limitations None Identified

Future Research To repeat the survey in future years.

Title Broads Fen Invertebrate Survey 2012

Author P LEE, C M DRAKE & G NOBES

Type Research

Aim To assess the invertebrate assemblages of some fens and fen meadows which have few records but are likely to support a wider variety of species;

To provide more baseline information on some fen habitat creation / restoration projects.

Method A range of invertebrate groups were sampled in 10 wetland compartments in the Norfolk Broads. Three compartments were part of the Buttle Marsh habitat creation project, two compartments were within the South Fen rewetting project and the remaining five compartments were in established areas of fen. The reported work adopted the statistically robust methods for site selection, sampling and analysis as used in the Broads Fen Invertebrate Survey (Lott et al., 2010). A total of 30 samples of each of the target groups from ten fen or fen meadow compartments, i.e. three samples per target group per compartment, were taken. The invertebrate groups targeted are listed in tables 1 and 2 of the report. Time-standardised methods of ground-searching, pond-netting, sweep-netting and suction sampling were used for sampling assemblages of each of the target groups (for details of techniques see Drake et al. (2007). Adoption of these fieldwork methods yielded the comparable samples required for statistical analysis and also fulfiled the requirements of baseline data for further monitoring. The use of these methods in 2012 is summarised in table 1 of the report.

Key results 549 species were recorded including two Red Listed species and 18 others of conservation concern. Eight were Broadland speciality species. As in the original Broads Fen Invertebrate Survey (Lott et al., 2010), two main invertebrate communities were identified. The true fen community is dominated by the permanent wet mire assemblage type (ISIS code W3) and is found in mires, where free water is retained in moss, tussocks and the peat surface. Aquatic, open water species (mainly ISIS code W2 but also some species with code W1) constitute a separate ecological group and are associated with boundary ditches. Both communities have conservation value.

Limitations The timing of sampling visits was generally later in the year than the visits undertaken by Lott et al. (2010) due to the poor weather in 2012.

Future Research The results of the current project can be used as a baseline for a future monitoring programme at Buttle Marsh and South Fen, but only by following the same sampling protocol and using the same target taxa. It is recommended that the ISIS representation and rarity scores be used to monitor the conservation value of true fen invertebrate assemblages. It is also recommended that the open water community of boundary ditches be monitored separately using the same methodology.

Title Biodiversity Audit and Tolerance Sensitivity Mapping for the Broads

Author C. Panter, H. Mossman & P. Dolman

Type Research

Aim To examine and quantify biodiversity in differing habitats within the Broads Authority Biodiversity Action Plan area. This will provide an evidence-base to underpin conservation priorities and strategic adaptive planning. The report will also analyse species sensitivity to salinity, flooding and drying - defining species tolerance assemblages, which can then be mapped and linked to saline incursions and climate change scenarios. This research will then be utilised to

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support adaptive management.

Method Available species records were collated for the Broads Action Plan area, which capture and combine significant systematic surveys and previously un-collated records. This work provided an electronic database of 1, 507, 648 biological records spanning from 1670 to 2011. Contemporary distributions for priority species are based upon 174, 931 records post-1988.

Key results 11,067 taxa have been recorded in the Broads, of which 1,519 are priorities for conservation. This includes 403 species of beetle, 251 true flies and 179 species of moth. This constitutes 26% of all UK BAP species, 13% of all UK RDB species and 17% of all nationally notable or scarce species.

The Broads offer habitat for 85% of the UK Bird Red species and 94% of the UK Bird Amber species.

66 species are defined as Broads Specialities, of which 31 are entirely or largely restricted to the Broads within the UK.

Analysis shows priority species are greatly associated with peat fen. However, other important habitats were discovered. In order of relative importance; fen, wet grassland, dry grassland, wood pasture, woodland, small standing waterbodies, heathland, littoral and lake margins, coastal, sand dune, brown field, reedbed and arable.

Broads Specialities were concentrated in fen habitats, particularly those of the Ant and Bure valleys.

No post-1988 record was found for 423 of the 1,519 priority species. 67 of which have been reported as locally/nationally extinct and the status of the remaining 356 species is unknown.

Extinct or extirpated species are primarily associated with dry grassland, brown field or arable habitats.

Developed methodologies allowed classification of tolerance ranges to salinity, flooding and drying. Of the 1,096 priority species, 1,053 were successfully classified for their hydrological and salinity tolerance. 63% of priority species, including 79% of Broads Speciality invertebrates require fully freshwater conditions. 13% of priority species were classified as tolerating mild to moderately brackish conditions (all vertebrates).

52% of priority species in the Broads are associated with dry or damp conditions, and are vulnerable to flooding and have a high tolerance of drought. This though only includes 3 Broad’s speciality species. Most Broad specialities (59%) are associated with wet habitats. Fully aquatic species only comprised 10% of priority species, but 25% of all Broad’s specialities.

Limitations Cannot quantify the proportion of species depleted by infrequent or ephermal saline incursions. Moreover, depletion as a result of hydrological change is inferred from best evidence but the true loss will be very dependent upon many variables, such as season, life cycle stage or water quality.

Future Research 1. Develop strategic priorities to strengthen biological recording coverage in the Broads, and increase our understanding of the status of priority species with no recent observations.

2. Communicate and increase recognition of The Broads biodiversity importance.

3. Improve site networks and strategic planning for non-wetland habitats within the Broads to address the documented loss of biodiversity.

4. Increase understanding and monitoring of appropriate indicators of biodiversity

5. Assess the utility of axiophytes as indicators of habitat quality and environmental change.

6. Develop the priority species vulnerability and risk alongside potential mitigation and adaptation activities.

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Title Biomanipulation through zebra mussel propagation in the Norfolk Broads

Authors David Aldridge & Claire McLaughlan

Type Literature review

Aim To assess whether propagated Dreissena polymorpha can improve the water quality of the Norfolk Broads.

The Problem Historically the Broads was characterised by clear water, submerged macrophytes and low nutrients. However, run-off from agricultural land and sewage inputs have increased nitrogen (N) and phosphorous (P) levels, leading to eutrophication. This has pushed the system into an algal dominated state, which has resulted in macrophyte reduction, turbid waters and low oxygen levels, which has dramatically reduced biodiversity.

How can this help? D. polymorpha is a prolific filter feeder and has been shown to push eutrophic systems back towards an oligotrophic state, characterised by clear water. This allows bottom rooting macrophytes to establish, leading to higher biodiversity and more valued ecosystem services, which assist in conservation, recreation and tourism. This results by zebra mussels ingesting suspended nutrients in the water column, reducing nutrient load and increasing competition for resources. This lowers algal numbers as they are no longer able to access the necessary nutrients for algal blooms. The concentration of Chlorophyll a can be utilised to measure algal content in a water body. Research at Barton Broad has shown chlorophyll a content to fall from a peak value of over 550 mgL

-1 in summer 1993, to below 100mgL

-1 in the

summer of 2005 (D. Aldridge 2008). This demonstrates a negative correlation between zebra mussel numbers and chlorophyll a concentration, as the period stretching from 1993 to 2005 witnessed an exponential growth in the zebra mussel population. It is estimated that Barton Broad contains 44,444,000 zebra mussels, which cover an estimated area of 50000m

2. Prior studies have shown zebra mussels

to have a clearance rate of between 30 and 300 ml mussel-1

hr-1

. If multiplied by the population size at Barton Broad, this equates to 4-40% of Barton Broads water volume being filtered every day.

Biomanipulation through zebra mussel propagation, and its applicability in the Broads

The population of zebra mussels in Barton Broad is currently constrained by a lack of appropriate substrate for byssal attachment. As such, numbers can be increased via the provision of an artificial substrate. This “farming” of zebra mussels is best facilitated in the Norfolk Broads by a matrix of wire mesh cages filled with flotation material, with nets being suspended for mussel attachment. As zebra mussels are susceptible to UV damage they do not usually settle in the upper 1m of the water column, which poses an issue in the Norfolk Broads as they are on average 1.4m deep. This can be overcome by selecting positions for rigs that are shaded, or by incorporating vegetation in to the rig which will shade the mussels below. Estimations based on 5 rigs, incorporating 1000 linear meters of netting at Barton Broad, would yield a minimum of 20,000,000 mussels. If a filtration rate of 300ml mussel

-1 hr

-1 was achieved for 12 hours per day, then the propagated

mussels would filter the Broad every 11.6 days. This filtration rate is dependent upon water temperatures above 12˚C. On average zebra mussels remove 50% of suspended chlorophyll a when water flow is 10 000 l h

-1. This equates to 4% of Barton Broads chlorophyll a

content being removed per day. However, this removal rate is dependent upon the rate of algal replenishment and nutrient levels. On average zebra mussels will grow up to 20mm in length, within a 12 month period at East Anglian locations. Typically a 20mm individual will contain 0.2mg of P, which is the limiting nutrient in aquatic systems. Currently, the annual load of P in Barton Broad is 58kg. As such, the current population of mussels in Barton Broad is a sink for 15% of the total P. If propagation is utilised, then total suspended P will further decline by 0.2mg per individual.

Limitations Public perception – Propagation of a species known to the public as invasive, with a view that it is ecologically and economically a pest, may need managing. However, the important issue here is that the Broads Authority will not be introducing this species but rather maximising its positive attributes in locations where it is present.

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Biogeochemistry and the Benthic Ecosystem – Deposition of faecal and pseudo-faecal material from zebra mussels to the benthos will influence biogeochemistry and the benthic ecosystem. The increased load of organic material may cause sediments to become reduced, with low oxygen levels as a result of decomposition. This may result in lower biodiversity at rig sites, but this negative point must be judged in relation to the overall positive effect on the whole ecosystem. Furthermore, if aerobic conditions are maintained below the rigs, then denitrification by bacteria will also lower N levels through N2 gas release. As such, site specific management and sediment assessment is needed, as benefits below the rigs are dependent upon aerobic conditions.

Cyanobacteria – The preferential removal of algae by zebra mussels may lead to increased populations of cyanobacteria. As reduced algal load will reduce competition for resources, thus expanding the niche of cyanobacteria. However, even if cyanobacteria become more abundant, it is predicted that in absolute terms their numbers will fall as a result of reduced nutrient load. To date no UK water body has witnessed a marked increase in cyanobacteria, as a result of zebra mussel arrival and establishment.

Increase in Zebra mussel biomass – May impact the ecosystem as molluscivorous fish and birds will have increased food availability.

Non-Native Shrimp – Zebra mussels provide a refuge to invasive shrimp species with the propagation of mussels possibly facilitating their spread to other locations within the Broads. This is of great concern, with management at Barton Broad looking in to zebra mussel removal to hinder D. villosus range expansion. However, zebra mussels will only facilitate spread if no other hard substrate is available. Also, in Port Talbot zebra mussels are not present but D.villosus has reached high densities. This illustrates the relationship to not be obligatory in D. villosus invasion and establishment.

Fouling – Farming zebra mussels may lead to an increase in the fouling of boats, navigational structures, abstraction pipes etc.

Further Research Investigate the effect of increased deposition of organic matter and nutrients to the benthos, to ascertain biogeochemical implications upon the benthic community. Moreover, if increased nutrient load is detrimental, what management procedures will best ameliorate the problem.

Investigate the effect of falling algal numbers upon cyanobacteria populations, whilst assessing whether a decrease in nutrients is sufficient to limit cyanobacteria population growth.

Survey and monitor the population of the invasive D.villosus species, whilst investigating whether zebra mussels are facilitating the colonisation of new areas in the Norfolk Broads.

Zebra Mussel Survey – Where are the populations?

River Ant & Barton Broad; Mud pumping in the 1990’s at Barton Broad has exposed the bedrock, yielding a hard surface for the attachment of zebra mussels. In 2003 research revealed change in the zebra mussel population (P. Pearson 2003), with further research by D.Aldridge in 2008 and S.Lambert in 2010 showing the population to be increasing. In 2008 zebra mussels were confined to the eastern shore of the broad but by 2010, 30 out of 35 collection sites across the broad yielded zebra mussels. The river Ant near to Barton Broad and Sutton Broad show no signs of Zebra mussel invasion. However, on the river Ant near Irstead, where the substratum is sandy and stony, zebra mussels have colonised. Numbers here have exponentially increased, with a single trawl yielding 1500+ individuals. Moreover, reed beds in How Hill have also witnessed increases, with numbers in the 90’s being estimated in the hundreds but in the millions by 2009. This research revealed zebra mussels to be attaching to the basal stems and rhizomes of reed beds. River Bure; Zebra mussels have been recorded for over 70 years in the river Bure, with numbers being highest above Wroxham bridge through to the River Ant mouth. Numbers have fluctuated over the years, with highest densities

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being observed in Horning. Recent years have witnessed numbers in the Bure increase, with a single trawl in Wroxham Broad yielding 656 individuals, juxtaposed to trawls in the 1990’s when only a few were caught. Populations in the River Ant seaward of the river Thurne junction are low, which coincides with salinity. Malthouse Broad in 2009 also yielded only a small population River Thurne; Zebra mussel populations have been recorded since the 1990’s and remain low. There is no record of populations above Potter Heigham Bridge, with salinity levels being viewed as the controlling factor. River Yare; The river Yare has only been recently colonised, which is attributed to historically high pollution levels. In 2009 research showed numbers to be low, with populations persisting on the shells of unionid species. The seaward distribution limit of the zebra mussel reflects tidal incursions, which increases the salinity of the freshwater above Cantley. However, Rockland Short Dyke experienced a zebra mussel population explosion in 1995 but further research shows numbers to have drastically declined. This decline may be attributed to the effect of Corophium curvispinum upon zebra mussel colonisation. River Chet; Zebra mussel populations are low and sparse, which is attributed to the tidal nature of this river. In 2009 no zebra mussels were recorded following a trawl of the river. River Waveney-Oulton Dyke; Zebra mussels first appeared in 1973, and by 1992 populations appeared sporadically below Beccles and Oulton Dyke. This range has extended, with individuals being collected near Herringfleet Mill and Blundeston Marsh in 1995.At this time salinity levels were recorded between 300-420 mg/l Cl

-1. By 2003 populations had increased, with numbers high in

the river near Burgh St Peter, and the distal end of Oulton Dyke. However, this was short lived as following a tidal influx in the winters of 2006 and 2007, densities fell sharply. Research in 1996 at Oulton Broad showed the zebra mussel population to be low.

Title The Effect of Motorboat Activity on Turbidity in the Norfolk Broads

Author J. Barrie (2011)

Type BSc Research

Aim The main aim of this report is to investigate the effect of motor boat activity on turbidity in the Broads. However, the report will also look in to the temporal variability in turbidity and motorboat activity and whether this differs between sites. Moreover, it will establish whether regulations on motorboat speed have reduced turbidity as a result of its implementation.

Method Of the four investigation sites selected, three possess a high and low motorboat activity test site. This results as three sites have a major bridge, restricting boat access. Thus high activity (Site 1) occurs on one side, with the other experiencing low activity (Site 2). High and low activity will be investigated at Wroxham, Wayford and Potter Heigham, with Bishopgate acting as a control with no activity. Turbidity will be measured by two methods, firstly via the Secchi disk and secondly by a portable turbidity meter. All locations have a 3mph speed limit, which is the lowest in the Broads area. Motorboat activity will be measured at 15 minute intervals, with turbidity measurements being taken every 45 minutes.

Key Results Statistical analysis of the results reveals motorboat activity to significantly increase turbidity. If an anomaly reading is removed from the Potter Heigham result then all test sites support this hypothesis.

Variations from baseline turbidity are greatest in areas of intense motorboat activity (Wroxham 11.11 and Potter Heigham 12.70 NTU). The lowest turbidity averages were found in Bishopgate (3.91 NTU) and Wayford site 2 (2.96 NTU), which are non-navigable.

Utilising sediment data shows Potter Heigham to have the highest clay and silt sediment composition, which may explain the high turbidity results of 29.36 and 27.07 NTU.

Statistical analysis via ANOVA shows significant differences in turbidity

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between sites one and two, thus correlating with higher turbidity as a result of increased motorboat activity.

Utilising results from Hilton & Phillips (1982) it can be concluded that speed limit restriction has little effect on motorboat induced turbidity.

Phosphate (P) stripping in the Broads has considerably lowered P levels in the sediment and it is thought that motorboat phosphate re-suspension is not contributing to eutrophication.

Turbidity is mainly attributed to algal blooms not sediment re-suspension.

Future Research 1. Link the duration and severity of motorboat induced turbidity on macrophyte growth and establishment, and investigate whether this hinders restoration attempts.

2. Analyse the conclusion that motorboat sediment re-suspension does not add to P levels in the water column and is not linked to eutrophication.

Title The Ecological Status of Ditch Systems

Author M. Palmer & V. Kindemba

Type Survey/Research

Aim To investigate the current status of aquatic invertebrate and plant communities of grazing marsh ditch systems in England and Wales, with reference to site management and future monitoring.

Method 75 sites within the Bure and Yare valleys were surveyed for invertebrates and plants. One pre-requisite for selection was previous research in the area, allowing for comparisons to be made on ecological state between the previous research date and 2009. Invertebrates were sampled between late April and early June each year between 2007 and 2009. Samples were taken from a 50m section of ditch, which encompassed a wide variety of vegetation. Plants were recorded in detail along a 20m stretch, with observations on extra species being recorded from the remaining area.

Key Results The following species of invertebrate were found along the river Bure and possess a high conservation status; Norfolk hawker dragonfly, Little whirlpool ram’s-horn snail and Shining ram’s-horn snail.

The following species of plant were found along the rivers Yare and Bure and possess high conservation status; Frogbit, Whorled water-milfoil, Tubular water-dropwort, Sharp-leaved pondweed, Greater water-parsnip and the Water-soldier.

Species Conservation Status (SCS) scores and Species Richness in the marshes of the Yare and Bure are well above the national average, with Habitat Quality close to average.

Plant survey results indicate a fall in Species Richness and Naturalness from 1988 to 2009. Conversely, SCS scores and Habitat Quality have significantly increased.

The Plant Salinity Index shows salinity to have markedly decreased from 1988 to 2009. This is attributed to Flood Prevention Schemes for the Yare and Bure valleys.

Algal species have markedly decreased between 1989 and 2009, with frogbit increasing. This is attributed to a decline in salinity but may also be indicative of improved water quality.

Invasive species have increased, with Elodea Canadensis being 50% more prevalent, with Elodea nuttalli being discovered for the first time.

Mesoeutrophic frogbit and water-soldier dominated groups have increased, with eutrophic groups declining. Moreover, some saline environments have reverted to freshwater conditions.

Results show that aquatic flora has improved from 1988 to 2009 and it is attributed to management with conservation targets.

Research in to mollusc assemblages reveals a significant increase in Species Richness between the 1970’s and 2009.

ANOVA statistical analysis shows no significant difference between fauna inside SSSIs and outside of SSSIs.

Limitations Sampling effort may vary, giving rise to different values in 2009 and

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thus falsifying the results.

The Norfolk Broads does not have sufficient historical research to enable a full invertebrate comparison, with comparisons between the 1970’s and 2009 being wholly based on mollusc assemblages.

Title: New Opportunities for the Sustainable Management of Fens: Reed

Pelleting, Composting and the Productive use of Fen Harvests

Author: Nick Ash (Ecology, Land and People)

Type: Literature review / Research

Aim: Sustainable management of open fen in the Norfolk Broads is compromised. The days of high produce value, cheap labour and absence of competition have passed, which has resulted in decreased fen harvesting. This lack of management has resulted in changes to the Broads ecology and is negatively affecting species. As a result, this report will evaluate potential end uses for fen products with the view of identifying a long-term sustainable management solution.

Results: A European Union Life Funded Project engineered the Fen Harvester and Blower. This has greatly increased the area accessible for harvest, allowing for higher yields. This though is limited by demand for soil improver grade compost, which is the current management tool for sustainably utilising fen arisings. However, the long term sustainability of this approach is questioned.

If the process of composting is better organised, in terms of processing, disposal and licensing then composting represents one of the most cost effective solutions for disposal at the small to medium scale.

Compost quality could be improved by mixing fen cuttings with other products, such as wood-chips, silt or peat. This may result in compost of agricultural quality, which possesses a higher economic value. However, it is likely for soil conditioning grade compost to prevail.

A larger scale and commercial composting operation could subsidise the harvester operation, relieving the burden on the Broads Authority budget, whilst increasing the habitat quality for inhabitant species. Moreover, for the first time fen management would be integrated with the agricultural system.

Other viable end-products include;

Thatching – Commercial reed and sedge cutting is core to sustainably managing the Broads. However, yield quality and cheap imports from Eastern Europe and China undermines long term sustainability.

Stock feed – For a small number of sites of high conservation value, the cutting, baling and sale of marsh hay is viable.

Biodiesel / Biochar – All fen products can be pyrolysed, but the technology is in its infancy.

Combustion fuels – Reed pellets

The production of reed pellets requires moisture content below 16%, and only reed is suitable (Harvest between January and April to reduce moisture content)

Small to medium mills process 3000 tonnes of reed per year. However, production will be constrained by supply, as current yields are 50 tonnes/ha with only 200ha available for harvest. This could be increased by sourcing new areas.

Currently, there are no pellet burners in East Anglia. Demand would have to be stimulated through developing user partnerships.

It is suggested that power plants licensed to burn hay may be able to utilise reed pellets, due to similar combustion characteristics.

Reed pellet CO2 emissions are low comparative to fossil fuel combustion, even when CO2 release from transport to the power station is considered.

Limitations 1. Mixed fen does not pelletise easily and a pure reed harvest is required. 2. A medium sized mill requires 3000 tonnes of reed/year, but reed beds

in the Broads only produce 50 tonnes/ha with only 200 ha available for harvest. (This excludes commercial reed beds.)

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3. Currently there is no demand for reed pellets in the Broads area. 4. To establish infrastructure for reed pellet production a large initial

investment is required.

Recommendations 1. At the current harvest scale composting offers the most cost effective disposal option.

2. Any expansion or move to true sustainability in fen harvesting requires development of alternative end-products.

3. An enhanced and commercial composting operation will accommodate a range of harvested material, including woodchip, peat and dredging silt.

4. Reed pellets provide an end-product for pure reed harvests, with moisture contents below 16%. Although considerable constraints are apparent, the report suggests pursuing this option.

5. Harvested material with moisture content between 16 and 35% can yield biodiesel and biochar end products. Investigation in to the new pyrolysing technology is required.

6. Continued support for commercial reed and sedge cutting is needed.

Title Site Hydrology Assessment and WETMEC Development

Author Kirsty Spencer, Jonny Stone & Mike Hill

Type Review

Aim A number of studies are being commissioned by the Broads Authority to assess current and future hydrological function of the Broadlands fen habitat. This report will assess;

1) The usefulness of existing data held by the Broads Authority relating to water quality, water levels and other hydrological studies pertinent to fen hydrology.

2) Produce a site-based spreadsheet listing hydrological data. 3) Assess three selected sites using a WETMECS* approach. 4) Document the process used during WETMECS trial and the uses of

data available. (*WETMECS – Allow a baseline for predicting the effects of change to a given water resource. This is achieved via analysing the importance of variables, such as groundwater, rainwater, flooding, adjacent land use etc.)

Key points The hydrological datasets utilised are limited to the Broads Authority and those easily accessed from the Environment Agency. The hydrological datasets analysed relate to; Review of Consents (RoC) data, regional and site specific conductivity monitoring, water quality and tidal data. With supporting data relevant to hydrological function coming from; The Fen Vegetation Survey, The Fen Audit, The Fen Invertebrate Survey and Appendix 3a of the report written by Wheeler, Shaw and Turner (2009) on sites where WETMEC types are identified. The above datasets were analysed with the following four end uses in mind;

1) The formation of a conceptual hydrological model (WETMEC). 2) Assessment of fen condition and whether water levels and quality are

appropriate for maintaining features of high ecological importance. 3) To predict future environmental changes, such as the effects of climate

change or water abstraction. 4) The measurement of changes to site management.

The report then compiles all data for each site producing a site-based spreadsheet that lists all hydrological data. Three sites are then chosen for WETMEC assessment, with the selection being based on the data available whilst ensuring the sites vary in river catchment and landscape. The resulting three sites are; 1) Ebb and Flow Marshes 2) Hall Fen 3) Mrs Myhills Marsh, Catfield Common and Lings Hill. All available Broads Authority data is utilised to allow site characteristics to be known, with uncertainties about these highlighted. Described methodologies (Wheeler, Shaw & Tanners 2009) are employed, allowing the WETMEC unit of classification to be ascertained at each site.

Limitations Dependent on existing Broads Authority data, and easily accessible data held by the Environment Agency.

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Soil and marsh surface details absent in data collection.

Conclusions In terms of WETMEC classification the report concludes the Broads Authority and partners hold sufficient data to classify a large area of the Broadlands area.

The WETMEC classification requires data on at least water level and vegetation at any given site.

Title Changes in Rare Plant Populations of Broadland Fens 1994-2009

Author John Wilde

Type BSc

Aim To identify the changes in abundances of rare/important fen plants between 1994 and 2009.

Method 22 species examined, chosen for their nationally rare or important status, to see if there was an increase or decrease in abundance between the two fen survey dates of 1994 and 2005-2009. Fen compartments surveyed in both 1994 and 2005-2009 were analysed where any of the 22 species were present. Species abundance was calculated for each species on a valley basis based on the abundance of each species in 10ths divided by the number of quadrats. Relationships were looked at with soil type and water level data. GIS was used to create maps in the Northern Broads to find areas that could be targeted for fen creation which, in theory, could act as new areas to colonise declining species.

Key Results Only 23% of fen compartments were able to be used for comparison.

None of the 22 species decreased in abundance in every river valley.

Dryopteris cristata and Potomogeton coloratus increased in abundance in valleys where they were found, Ant/Bure/Thurne and Ant/Bure respectively.

No species had significant changes in Waveney Valley (little usable data as not many compartments surveyed in 1994).

In the Yare and Muckfleet there were more species with a significant increase than decrease, in the Ant, Bure and Thurne it was the opposite.

Ant: Lythrum salicaria, Myrica gale, P. coloratus significant increase. Peucedanum palustre significant decrease (still found in 98 of 100 compartments surveyed but in significantly lower abundance). Viola paulustris rarely found (<5% of compartments).

Bure: Eupatorium cannabinum, L.salicaria, M.gale, P.coloratus significant increases. Sonchus palustris significant decrease. Carex diandra, Epilbium obscurum, Sagina nodosa all had a small presence.

Muckfleet: Potentilla palustris significant increase.

Thurne: P.palustre, S.palustris, L.salicaria significant decreases.

Yare: E.cannabinum, L.salicaria significant increases.

E.cannabinum, L.salicaria, M.gale all had significant statistical increases on peat soils. There were no significant changes in non-peat soils.

E.cannabinum, M.gale increased with a decrease in water levels.

P.palustre, S.palustris decreased with a decrease in water levels.

Publications

Supported by Broads Authority

Further research potential

Further investigation into the decreases in abundances of species of interest.

Repeat of the 2005-2009 survey on a more frequent basis to assess changes. Re-survey same quadrat locations.

Only 22 of 459 species were analysed – use methodology to examine other species of interest.

Examine Sagina nodosa and Viola palustris in more detail because due to their rarity they were not suitable for statistical analysis.

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Title Intraspecific patterns in Corbicula metal levels – influence of microhabitat and size

Author Nicole Spann

Type Under-graduate (BSc)

Aim Variability in the concentration of heavy metals in the soft tissue of C. fluminea may reflect differing microhabitats, metal loading, or differences between individual metal accumulation, which can stem from clam size. As such, the aim of this study is to identify whether sediment load or C. fluminea size is attributed to individual differences in bioaccumulation of heavy metals.

Method 8 different sites were sampled along a 1 km section of the river Yare. These sites were about 100m apart, with sediment cores (upper 10cm) and grab samples of C. fluminea being taken. These samples were then analysed for the following heavy metals; Cadmium (Cd), Chromium (Cr), Copper (Cu), Nickel (Ni), Lead (Pb), Mercury (Hg), Tin (Sn) and Zinc (Zn). The soft tissue was then analysed in C.fluminea, with the clams being divided in to 4 size categories (10-15, 15-20, 20-25 & 25-30mm). At each site at least one clam from each size bracket was collected and analysed. Furthermore, the sediment from each site will be sieved to a grain size of <63µm and analysed for the above mentioned metals. Moreover, the sediments water content, organic matter content and distribution of grain size will be measured.

Key Results Only sites 3 and 8 possessed different sediment types. Site 3 possessed coarse particulate matter, where as site 8 was fine and clayey, which is thought to represent the bedrock.

Sediment analysis shows the microhabitat to be diverse, thus affecting the exposure risk of C.fluminea to heavy metals.

Metal load is affected by the sediment type, with site 8 being classified as unpolluted and site 7 and 2 being most polluted.

Site 7 and 2 possess high levels of Cu, Pb and Zn, with Hg concentrations being high at all sites, ranging from 83-117 mg/kg.

C. fluminea tissue analysis shows Cd, Cr and Zn to be negatively correlated to clam size.

Levels of Cr found within the soft tissue of C.fluminea positively correlated with the metal concentration of the corresponding collection site. However, this is the only metal to show this result. This demonstrates the importance of body size in bioacummulation of heavy metals in C. fluminea.

Limitations This report concludes that heavy metal accumulation in C. fluminea is not correlated with site concentration. However, this may not be indicative of a relationship. Bivalves are sedentary, suspension feeders who feed upon suspended particulate matter within the water column. As such, the particles ingested by an individual may not originate from their given location, resulting in their accumulated metal levels being representative of another section of the river. Furthermore, certain individuals may have a genetic disposition to accumulate particular metals at differing rates, thus differences in accumulation rate may be a product of an individual’s genetics.

Further Research Potential

If the relationship between heavy metal accumulation and sediment concentration is to be fully understood, then an element of control over the particulate matter received by an individual is needed. With regards to bivalves, sediment within rivers will only become of significance in terms of bioaccumulation if it is re-suspended in to the water column. As such, sediment re-suspension rates and an average travelling distance of the re-suspended material may be a better methodology to assess the relationship. However, the probability of successfully investigating this is low. As a result, it may be better to undertake a literature review, researching the relationship between the concentration of metals within the particles ingested and the rate of bioaccumulation within the individual. Furthermore, if body size is negatively correlated with C. fluminea metal accumulation, then the life history of this species needs to be assessed. As if the results are correct, juvenile individuals are accumulating heavy metals at a faster rate.

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Title: An Investigation of Polycyclic Aromatic Hydrocarbon Contamination in Sediments of the Norfolk Broads

Author: Eoin Hurst

Type: MSc research

Aim: The primary aim of this report is to establish the current levels of polycyclic aromatic hydrocarbon (PAH) contamination in sediment samples taken throughout the Norfolk Broads. The secondary aim is to determine the potential ecological hazard posed by the accumulation of PAHs in the benthic community. Tertiary aims;

Develop a conceptual model to highlight sources, pathways and receptors of PAH contamination at the catchment level.

Determine PAH levels and physico-chemical properties of the sediment.

Assess the spatial distribution of current PAH contamination.

Identify impacts for the Broad Authority’s sediment management policies and the implications in terms of achieving good ecological and chemical status as set by the Water Framework Directive.

Methodology: Literature informed the development of a conceptual model to detail the sources and pathways of PAHs in the Broads, which assisted in determining the 16 sampling sites. These sites encompass shallow lakes, rivers and brackish habitats, which are agreed to be representative of the catchment as a whole. At each site surficial sediments were collected using a Ponar bottom grab, lowered from the side of the boat. Microwave-assisted extraction was used to separate PAHs from the sediment, with the PAH concentration quantified using a gas chromatograph mass spectrometer. These levels were then compared with the Flemish government’s consensus-based sediment quality guidelines. This was utilised as a benchmark to determine the ecological hazard posed by PAH compounds.

Key results: PAH levels varied between sites, from 118-36400 µg kg-1

, with a mean value for all sites being 6745µg kg

-1.

Fluorene had the lowest mean concentration of 45 µg kg-1

, with the highest mean concentration being pyrene at 1117 µg kg

-1.

The highest individual sample concentration of PAHs was 36400 µg kg-

1 found on the river Bure at Cow Tower.

The lowest individual sample concentrations were found at rural locations in Cockshoot and South Walsham Broads.

A pyrogenic source of PAHs was strongly indicated at 15 out of 16 sites, which were evenly spread between the combustion of petrol/diesel and solid fuels (wood, coal etc). One site was shown to have a petrogenic source, which entered the system via runoff from the main road.

No significant difference was found between total PAH between sites with high or low boat traffic. However, 90% of sample sites with a boat yard had significantly higher PAH concentrations than those without.

An ecological hazard assessment using the Flemish sediment quality guidelines found 4 sites where PAH levels were high enough to negatively affect biota. A further 11 sites were assessed as being above the limit required for good ecological status, as set out by the Water Framework Directive.

Analysis of sediment shows the Norfolk Broads to be moderately polluted by PAHs.

Comparisons between 4 sites common to a study undertaken in 2007, shows a large decrease in PAH at these locations.

The study highlights the significant work needed by the Broads Authority to meet targets by 2015 set out by the Water Framework Directive.

Further research potential:

Boating activity was not found to positively correlate with total PAH. However, this report was based on a boat traffic census from 2010. Further site specific investigation is advised as the literature suggests

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PAH concentration to increase with increased traffic.

The high PAH level of 36400 µg kg-1

found on the river Bure justifies further investigation in to boatyards and PAH concentration. This should be undertaken within a short time frame as a preventative measure. Also, remediation may be warranted to prevent long term damage. It is suggested that boatyards and boat users should be made aware of the ecological damage caused by oil and fuel spills.

An ecological hazard assessment shows PAHs to be having a greater negative effect upon the benthic ecosystem than previously suspected. As such, the report suggests a more in-depth assessment of the threat to benthic species from PAHs.

The report suggests a routine PAH monitoring system, to allow for the impact of management to be assessed. Monitoring should be both chemical and biological to detect small scale ecological changes before harmful effects are observed.

Title: Palaeoecological Investigation of the Past Biological Structure and

Function of the Trinity Broads

Author: T. Davidson, G. Clarke, D. Morley, N. Rose, S. Turner & C. Sayer (UCL)

Type: Research

Aim: To investigate via sediment cores the past biological composition and function of the Trinity Broads. The report tracks changes in the composition of submerged macrophytes, and by assessing changes in cladoceran, fish and mollusc populations, inferences can be made about ecological function and how this may relate to macrophyte reduction.

Method: Sediment cores were taken from the semi-littoral zones of Ormesby, Rollesby, Lily, Ormesby Little and Filby Broads in March 2007. Stratigraphic changes were noted and the percentage dry weight and organic matter content of each core was determined in the laboratory. Sphaeroidal Carbonaceous Particles (SCPs) were analysed, allowing for core chronologies to be established. The cores were then further analysed for macrophyte and cladoceran remains, allowing for insights in to the submerged flora and ecological function of the Trinity Broads.

Results: Trinity Broad has witnessed profound alterations in flora and fauna since its formation.

The ancestral community was characterised by a diverse flora of Potamogeton species. Additionally, a diverse community of charophytes existed with cladoceran assemblages suggesting a system dominated by benthic species, reflecting a low nutrient level system with very low pelagic primary production. This is further enforced by analysis of the diatom community.

Cladoceran analysis identifies a relatively early change in ecosystem function. Macrophytes decline in diversity and abundance, with Potamogetan, Chara and Nitella species being majorly impacted. This change is associated with increased nutrient load. Sediment records show Ormesby Broad to be first affected by eutrophication in 1890. However, Filby Broad is not affected until the 1950s. In all Broads, the moment of change is reflected by a marked increase in pelagic zooplankton, showing a shift in primary production from the benthic to the pelagic zone.

Sediment analysis reveals submerged plants and phytoplankton blooms to coexist. This finding is contrary to contemporary thinking that shallow lakes are either macrophyte or plankton dominated.

Sediment analysis reveals a third change, which is contemporary and corresponds with a further shift towards phytoplankton production. This is reflected in all cores by a significant increase in Daphnia, especially D. pulex and D. magna. These species are large bodied and very effective grazers of phytoplankton and are vulnerable to fish predation. This indicates low levels of zooplanktivory and high phytoplankton abundance.

Fish data indicates a decline in the fishery, suggesting a reduction in

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the number of larger individuals, particularly perch and cyprinids.

Surface sediments reflect fine-leaved Potamogetan species dominance, which in Ormesby Broad could reflect partial recovery as a result of biomanipulation efforts. However, recent research highlights early season growth of fine-leaved Potamogetan species throughout the Norfolk Broads, with crashes in their populations by July. As such, the result could be symptomatic of how shallow lakes respond to moderate eutrophication.

Data shows eutrophication to affect the Trinity Broads system in sequence, from Ormesby through to Filby. The timing of change at each site reflects resistance by each Broad to nutrient enrichment by its neighbour. Data from Ormesby Broad suggests that in the mid-19

th

century the sediments of the Trinity system stopped acting as a phosphorous sink, and stopped the systems buffering capacity. This resulted in the effects of eutrophication, which cascaded down the system to the next site.

Management recommendations:

Reduce nutrients entering the site by identifying and reducing any remaining point sources, especially septic tanks.

Promotion of catchment sensitive farming, to reduce diffuse nutrient enrichment.

Monitor sites to allow for information on seasonal and inter-annual variation. This monitoring should include; monthly assessments of chemical and biological parameters – crucially phytoplankton crop and composition, zooplankton, and at least two macrophyte and fish surveys in early June and August.

Further research into the nature of phosphorus release from sediments.

Further research into the light requirements and germination conditions of formerly dominant species.

Further research into the viability of the seed bank across the system.

Investigate new restoration techniques to allow for the stabilisation of sediments, including breaks to water flow and organic binding materials.

Title Reconstructing the Past Submerged Macrophyte Flora of Martham South,

Burntfen, Sotshole and Nortons Broads, Fritton Lake and Mautby Decoy

Author T.A. Davidson, G.H. Clarke, R. Rawcliffe, K. Roe & N. Rose

Type Research

Aim To investigate the former macrophyte flora of six lakes within the Broads area. This will be established via the use of palaeolimnological techniques and by analysing the sedimentary remains for plant macrofossils. This will provide an insight in to the ancestral macrophyte community at each site and allow for a chronology of change to be established.

Method Sediment cores were extracted using an adapted Livingstone type fat piston corer with the location recorded via GPS. One core was taken from all 6 sites and dated by the analysis of Spheroidal Carbonaceous Particles (SCPs). The cores were then sieved at the 350 and 125 µm scales and examined under a stereo-microscope (x10-40) to allow for plant and animal fossils to be counted.

Results Martham South – Core Name: MARS1 Macrofossil analysis reveals large shifts in community composition with the core showing the water of this broad to be historically brackish. The presence of foraminifera and R.maritima demonstrates this salinity. The majority of species present in the core are tolerant to some level of salinity, such as M. Spicatum and P. Pectinatus. These more saline species gave way to freshwater Chara species, which dominated the Broad for several hundred years. Although this analysis is limited in its resolution it does show Martham Broad to have undergone large changes in its submerged macrophyte flora, with these changes being driven by changing salinity not eutrophication. Burntfen Broad – Core Name: BURF1 In 1700 and 1800 AD the diversity and abundance of plant species was high, in particular species of Potamogeton. In total 5 species of Potamogeton were recorded, including one broad-leaved species and the currently rare P.

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Compressus. In total 11 species of submerged macrophyte were identified and it is thought the community would have contained many more species, as rare species are very unlikely to be recorded in the sediment. Analysis of fauna shows multiple benthic habitats, which indicates a water body dominated by submerged macrophytes. However, this is followed by a dramatic decline in submerged macrophyte remains with a shift to floating-leaved vegetation. It is thought a shift from benthic to pelagic production then occurs, with zooplanktivorous fish increasing, resulting in a lowered light climate that is indicative of eutrophication. Sotshole Broad – Core Name: SOTS1 The lack of a good chronology for the SOTS1core means it is very difficult to identify the timing of any change in the sediment. However, plant macrofossil analysis shows a species rich Potamogeton and Chara dominated community to be replaced by floating-leaved species. The invertebrate fauna mirrors this change, with plant associated molluscs being replaced by pelagic cladoceran taxa and a general decline in abundance. Nortons Broad – Core Name: NORT1 No reliable chronology could be established and large riverine sediment inputs make remains within the core rare and difficult to find. However, the large riverine inputs would severely impact macrophyte establishment and growth and may be the reason as to why low abundance is found. However, results do show Nortons Broad to have changed over the cores time period. The ancestral community appears to be dominated by Ceratophyllum, several species of Potamogeton and water lily. At this time a diverse mollusc and cladoceran fauna was supported, with both benthic and pelagic taxa present. This however profoundly changes with submerged macrophytes being lost. It is not known whether this resulted from a high algal crop via nutrient enrichment, sediment deposition or a reduction in water depth. The lack of pelagic cladoceran taxa supports the latter but it may have resulted through a combination of factors. Mautby Decoy – Core Name: MAUT1 The plant fossil record shows Mautby Decoy to have changed from a Chara dominated community to a floating–leaved community dominated by N.alba, N. Lutea and associated Ceratophyllum. Fritton Decoy – Core Name: FRIT1 Macrophyte succession overtime shows all symptoms of being driven by eutrophication. The community was initially Chara dominated with benthic productivity being high. This was followed by a shift to canopy forming plants, including Potamogeton taxa. After this stage macrophytes become rare with animal remains showing an abundance of Daphnia taxa, suggesting phytoplankton blooms.

Further Research Potential:

Linking lake reconstruction research with restoration attempts, to observe if a community follows a predictive path back to a pre-disturbance community.

Title The influence of salinity on the distribution and survival of the Hawker

dragonfly (Aeshna isosceles) in the Norfolk Broads

Author Alex Pickwell – University of Lincoln

Type Post Graduate

Aim To investigate how physical and chemical differences of a water body can affect A. isosceles, especially in terms of reproduction. Research will also assess whether A. isosceles exists as a member of a climax community, and how water quality and community structure are related to A. isosceles persistence and reproductive potential. This will be tested at 8 different sites, which collectively incorporate fresh, brackish and fresh water environments that experience saline water inundation.

Method All following measurements will be taken in both the spring and summer; 1. A YS1-556 multi probe and a Palintest Photometer 5000 will measure

the dissolved oxygen content, electrical conductivity, pH, redox potential, temperature and phosphate and nitrate concentrations of a given water body.

2. Kick sampling for 3 minutes will assess the macroinvertebrate community of each site. The net aperture size is 670cm

2 with the mesh

21 | P a g e

being 1mm. Debris will be removed and sifting will allow for the community structure to be ascertained.

3. Floral composition and individual species percentage cover will be assessed through utilising a 20m stretch at each site.

Key Results Average Shannon-Wiener Index Scroes show Plant community diversity to fall with increasing salinity (Brackish sites = 0.79, confirmed breeding sites = 1.24 and non-breeding sites unaffected by salinity = 1.09.)

Shannon-Wiener Index scores show A. isosceles reproduction to be confined to areas of high biodiversity (breeding sites = 1.24 / non-breeding sites = 1.09.)

Average vegetation cover at breeding sites is 94%, compared to 63% at non-breeding sites unaffected by salinity.

Average Shannon-Wiener Index Scores show macroinvertebrate diversity to fall with increasing salinity, and to be highest at sites of reproduction. (Brackish sites = 1.34, breeding sites = 2.48 and non-breeding sites unaffected by salinity = 2.21.)

Average Community Conservation Scores are highest in areas of A. isosceles reproduction (Brackish sites = 13.3, non-breeding sites unaffected by salinity = 11.2 and breeding sites = 18.3.)

Canonical Correspondence Analysis shows a large percentage of floating vegetation, deep water availability and low water salinity to be key habitat requirements for A. isosceles.

Salinity levels remain similar in non-breeding and breeding sites at 0.56gL

-1 and 0.66gL

-1 respectively, thus attributing A. isosceles

reproduction to other factors. Results show percentage floating vegetation to be critical, with breeding sites possessing 42% coverage and non-breeding sites averaging 7%.

A. isosceles exclusion from brackish water habitat results from high salinity (7.60gL

-1) and low vegetation coverage (5%). Salinity remains

the main reason for exclusion as it dictates the plant community and composition.

Confirmed breeding sites have a salinity range of 0.66-1.94gL-1

, which is over 0.5gL

-1 which defines a fresh water environment. This result

suggests that A. isosceles may not be restricted entirely too freshwater environments.

Supported by University of Lincoln and the Broads Authority

Limitations Primarily this report focuses upon biodiversity levels, linking A. isosceles to climax communities. The report also links A. isosceles to particular species of flora, and how their presence within a community can predispose that area to A. isosceles presence and reproduction. Further data is also collected on macroinvertebrate number and diversity but the report does not state why this is of relevance to salinity. The data again was collected to further demonstrate A. isosceles existence as a climax community member.

Further Research potential

If the effect of salinity upon A. isosceles is to be researched, methodologies need to be different. One way in which the effect of salinity can be researched is via a literature review. Alternatively, a controlled stretch of water could be divided, with each compartment having known but different salt concentrations. This approach would minimise the importance of other variables, as the same location is utilised. However, limitations are apparent as A. isosceles may not be confined to a single compartment, thus yielding misleading results.

Title The Effectiveness of Biomanipulation of the Trinity Broads, Norfolk

Author David King

Type BSc research

Aim To assess whether biomanipulation has promoted macrophyte establishment and growth in Ormesby Broad. The effect of biomanipulation in Ormesby will also be assessed in neighbouring Broads which are connected.

Method A total of 198 sample sites across Ormesby, Rollesby, Ormesby Little, Lily and Filby Broads were sampled in 2009. Surveys were undertaken in both June and August across all sites to ensure both early and late emerging macrophytes

22 | P a g e

were recorded. The method utilised to quantify macrophyte abundance is outlined by Gray 2009a, which allows for continuity in results and enables comparisons to be made between years of investigation. Other variables investigated were water depth via an echo-sounder unit, and visibility which was measured through the utilisation of a Secchi disk.

Key Results Mean macrophyte abundance has increased each year since 1997 across all Broads, with the non-biomanipulated Broads of Rollesby, Lily and Ormesby Little showing steep increases in macrophyte abundance from 2005 onwards.

Pearson’s Correlation Coefficient statistically confirms no correlation between any Trinity Broad and Ormesby Broad in terms of macrophyte abundance. This highlights the parameters controlling macrophyte abundance and how they differ in Ormesby Broad as a result of the biomanipulation of the fish community.

Shannon’s Diversity Index shows macrophyte diversity to increase as a result of biomanipulation.

Survey results reveal macrophyte abundance to increase as a result of biomanipulation. This initial rise in Ormesby Broad filters through the connected system, triggering increases in macrophyte abundance in other localities. However, Ormesby Broad peaks in 2007 with neighbouring Broads peaking in 2008.

Results show macrophyte increases to abate after 10 years, meaning the top-down control utilised in Ormesby Broad needs to be applied repeatedly or the system returns to a turbid state.

Pearson’s Correlation Coefficient highlights a significant correlation between macrophyte and macroalgae abundance in Rollesby, Ormesby Little, Lily and Filby Broads, revealing a system which is stabilised by bottom-up nutrient controls.

Total Phosphorous (TP) has increased post 1997, with levels exceeding the Conservation Target set by Natural England of <100µgL

-

1.

Pearson’s Correlation Coefficient supports the assumption that TP and Total Oxidised Nitrogen (TON) fluctuate in unison across the Trinity Broads network, supporting a diffuse nutrient input.

Pearson’s Correlation Coefficient reveals a relationship between mean TP and chlorophyll a in Ormesby and Rollesby Broads. This is of importance, as biomanipulation in Ormesby should result from Daphnia control. This result shows biomanipulation via top-down methods to only temporarily increase water clarity and macrophyte abundance. Thus bottom-up factors are of significance in restoration efforts via biomanipulation.

Further Research 1. Research in to bottom-up biomanipulation techniques and whether both bottom-up and top-down techniques can be integrated to allow for The Broads restoration. Key bottom-up techniques include zebra mussels, sediment removal and reducing the nutrient load within the catchment area.

Title Septic Tanks and Pollution to Watercourses in the Norfolk Broads

Author William James

Type Literature Review

Aim To assess the risk of phosphorous pollution from septic tanks in the Norfolk Broads. This will be achieved by estimating the number of septic tanks within a given catchment area, with the variables affecting pollution risk being weighted. This will allow for the severity of risk to be assessed and visually illustrated per catchment area.

Factors affecting pollution risk.

Distance from water body: Septic tanks in close proximity to a water body, pose a greater risk.

Soil type: Soils filter and attenuate pollutants, with their ability to do so dependent upon soil structure and composition.

Septic Tank Maintenance: Maintenance is unregulated, with research in the US showing over 10% of all septic tanks to be inappropriately

23 | P a g e

maintained.

System age: Systems constructed over 25 years ago pose a greater risk.

Topography: The gradient of a catchment area will affect flow rate, with research suggesting that no system should be built on a gradient above 20%.

Density: A high septic tank density will reduce pollution absorption.

Modelling the risk in the Norfolk Broads

The variables utilised in this report are dependent upon available literature. As such, not all variables are incorporated in to the model. Furthermore, each variable is weighted per location, depending on the varying degree of pollution risk. Variables utilised

1. Distance from water body 2. Density – In calculating the density it is assumed that any household

over 30m from a mains sewer connection has a septic tank. 3. Gradient 4. Soil properties – Risk evaluated via soil permeability, measured by

hydraulic conductivity. Locations

1. Alderfen Broad 2. Burntfen Broad 3. Cockshoot Broad 4. Sotshole Broad

Results Alderfen Broad – Out of the 105 septic tanks in Alderfen Broad catchment area, 91 were situated in a high risk zone. Burntfen Broad – Out of the 88 septic tanks in Burntfen Broad catchment area, 13 were situated in a high risk zone. With another 45 posing a moderate to high risk of pollution. Cockshoot Broad – Out of the 5 septic tanks in Cockshoot Broad catchment area, only 1 posed a high risk, with 2 posing a moderate to high risk of pollution. Sotshole Broad – Out of the 138 septic tanks in Sotshole Broad catchment area, 22 posed a high risk, with a further 97 posing a moderate to high risk.

Limitations The weighting given to each septic tank at each location may not reflect its true impact, as pollution risk may not follow the quantified weight given. For example, if a particular septic tank is ranked 1 on distance and another is ranked 2, the latter may not pose double the risk.

The model is not applied, and the results cannot be tested, as there is no data available on phosphorous pollution from each septic tank. As such, the pollution risk of each septic tank is assumed and not evidentially based.

The density and location of each septic tank is assumed, and not reflective of the true density and location of septic tanks.

Due to a lack of research in this area important variables, such as septic tank maintenance and age are missing.

Title An Exploratory Survey of Invertebrates of Wet Woodland in the Bure

Valley and the Muckfleet Valley

Author P. Lee & C.M. Drake

Type Research

Aim A high conservation value is placed upon invertebrate fauna of the Broads. However, this is mostly attributed to open water, reed beds and fen habitat, with the conservation value of wet woodland being little studied. To improve management and planning within the Broads area, the invertebrate assemblages of wet-woodland must be investigated. As such, the aim of this report is to assess the invertebrate conservation value of unsurveyed wet-woodland in the Muckfleet and Bure Valley’s.

Method Invertebrate groups were sampled at 12 wet-woodland sites, equally divided between the Bure and Muckfleet Valley’s. Utilising the National Vegetation Classification (NVC), the sample sites fell in to one of two categories; W2 (Salix, Betula and Phragmites woodland) and W5 (Alnus and Carex woodland). Three of each category were sampled at the two valley locations. The results were

24 | P a g e

then analysed to investigate the species richness of NVC community type and river catchment. Moreover, similarity and multivariate analysis allows species assemblage response to NVC community type and river catchment to be understood. A computer application known as ISIS will also be utilised to ascertain the conservation value of Broads Assemblage Types (BATs) in each woodland site.

Key Results In total 361 species of invertebrate were recorded, including 3 species of fly with Red Data Book status and a further 17 nationally scarce species.

Whittaker’s measure shows between site diversity to be very low, ranging from 3.2 to 4.8.

Mann-Whitney U test analysis shows invertebrate richness to not significantly differ between successional stage. The exception was Diptera, which was more abundant in W5 woodland. The test further shows no significant difference in species richness between the Bure and Muckfleet valleys.

Analysis of Similarities reveals low similarity between invertebrate communities at each site, with variation being highest between the woodland sites of the Bure Valley.

The Global ANOSIM statistical test reveals the wet-woodland of the Muckfleet and Bure Valley’s to be significantly different from one another.

Ordination of community data from all sample sites clearly separates the Bure Valley and Muckfleet Valley invertebrate assemblages, but shows no difference between NVC grouping (W2 or W5).

ISIS Analysis - Utilises Broad Assemblage Types BATs (W3 = Wet Mire, A1 = Arboreal Canopy and F3 = Shaded field and ground layer)

No sample area showed a single BATs assemblage to be dominant in terms of invertebrate abundance. However, W3 was most important in the sample sites of the Bure Valley and for two sites in the Muckfield Valley.

F3 is most important for invertebrates in the Muckfield Valley sites, especially for the Trinity5 sample site.

Bure Valley W3 assemblages exceed the threshold for national importance.

Utilising rarity scores for the W3 assemblage, no significant difference was found between W2 and W5 NVC woodland types.

The Bure Valley woodland sites possessed a higher Rarity Score and Conservation Value than those of the Muckfleet Valley.

Limitations Arboreal research investment is lacking.

Some species could not be correctly identified and were not utilised in the statistical analysis. As such, the conservation value could be underestimated. Moreover, these species may mark the difference between successional stages.

Differences in conservation value were not linked to woodland type or environmental variables. As such, this report cannot conclude whether these links do exist or whether they are just symptomatic of the limitations in the survey.

Future research potential

Further research in to invertebrate assemblages of the arboreal habitat.

Measure environmental variables at each sample site.

Increase the sample site number and increase result reliability.

Attempt to identify all invertebrates collected.

25 | P a g e

Broads Authority Routine Monitoring March 2012

A key activity where the Authority’s coordination role is important includes research and monitoring. This is one of the organisations

Conservation Priorities. The Authority will continue to be research and evidence led in its management of land and water concentrating

on the application of the understanding gained. Agreed actions as part of the 2011 Conservation Priorities were to:

1. Produce a list of regular monitoring, research and the data available to others;

2. Continue to rationalise methodologies where it is sensible to do so, enabling it to be compatible with other data series;

3. Seek to build in appropriate monitoring with new funded projects.

This document lists the Authority’s routine monitoring programme along with the drivers, locations, timing and resource.

The priority areas for monitoring fall into the following areas:

1. Fens (including turf ponds, vegetation, water quality) 2. Lakes (including vegetation, water quality, fish) 3. Biodiversity recording and invasive species monitoring 4. Operational Impact Monitoring & Compliance

26 | P a g e

Broads Authority Routine & Project-based Monitoring

Fen Management

What Drivers Where When Frequency Who Questions Priority?

Turf pond restored

dyke vegetation

surveys

Protected species

monitoring;

impact of site

management

Filby Broad

(south) and Burgh

Common, How

Hill and other

older turf ponds

July Summer

following

digger works,

then

biannually

HMF every 5

years

Ecologist, EO Frequency of survey

needs confirming.

HMF

Long-term

monitoring fen

vegetation

Impact of site

management;

Climate change

research; Water

level trends;

Water quality

research; Species

recording

BA fen

management

sites

2012/13 How Hill

and Horning

Marsh Farm

June/July EO assist 2

survey days

per year.

Aimed for

repeat survey

at each site

once every 5

years

Ecologist

developing

method, site

selection,

prioritization.

Ecologist and EO

completing field

survey and data

management

Forward plan required

Fen site vegetation

/ management

activity mapping

Impact of site

management;

Guide future

management;

ensure cross

compliance;

All BA fen

management

sites

Initial

baseline;

annual

revision or

following

management,

1 day per site

for initial

baseline; 1

day per year

for each site

EO completing field

survey and data

management

Basic fen/scrub/other

habitat mapping. Notes

on cross-compliance

issues; GIS data stored

with fen management

27 | P a g e

provide records

for HLS

whichever is

shorter.

revision Ecologist

completing scrub

mapping via

contractors

events

Manage salinity

monitoring at

Reedham Marsh

Climate change

research; Water

quality research;

Reedham Marsh

(How Hill) and

other sites TBA

Fixed term

partnership

with EA

2012-14

Monthly

deployment as

required

Ecologist

developing

method, site

selection,

prioritization.

EO and Ecologist

completing field

survey and data

management

Sampling location TBC

Long-term survey

of fen dykes

Impact of site

management;

Water quality

research

How Hill

HMF

Summer Annually?

Every 5 years

TBC – may not be

required

Review results of

student research

project 2012

Lake Management

What Drivers Where When Frequency Who Questions Priority?

Long term

monitoring of water

plants

Impact of site

management;

Climate change

research; Water

quality research;

Species recording

Priority list of

Broads, including

long-term sites

and restoration

sites

Late July-

early Sept

(also June for

Trins)

20 days

survey per

year?

Ecologist

developing

method, site

selection,

prioritization.

Complete move to point

survey. Contract to

Nigel Wilby asap to

analyse 2011 data;

Plan for Trinities?

28 | P a g e

EO co-ordinating

other BA officers &

volunteers to

completing field

survey and data

management

Water plants in

rivers

Impact of site

management;

Climate change;

Water quality

Upper vegetated

reaches of main

navigable river

channels

June (or

responsive to

harvester

work plan)

2 survey days

per year; 1

river per year

Ecologist lead on

developing

method; site

selection &

prioritization.

EO lead on

completing field

survey and data

management

Requires methodology;

avoid EA site

duplication; develop

forward sampling plan;

EO to report data in

2012 water plant report

Hydroacoustic

survey of water

plants

Impact of site

management;

Water quality

research

Previous surveys

at Barton,

Trinities, Hickling

June-Aug 1 survey at

each site in

2012

EO lead on

completing field

survey and data

management

Requires forward plan;

EO to summarize

previous reported data

in 2012 water plant

report

Water quality

monitoring at

broads not

sampled by EA

Impact of site

management;

Climate change

research; Water

quality research

Mainly isolated

sites; Priority list

of Broads,

including long-

term sites and

restoration sites

Late July-

early Sept

Variable as

per annual

programme

Ecologist site

selection,

prioritization.

EO completing field

survey and data

Forward plan required.

29 | P a g e

management

Fish surveys at

active

biomanipulation

sites

To inform

removals; Impact

of site

management;

Water quality

research

Cockshoot,

Barton barrier

Trinity Broads

Winter Annually

(Ormesby

Broad

annually, rest

of Trinity

Broads

biannually)

EO lead on issuing

contract

Long-term fish

survey

Impact of site

management and

condition; Water

quality research

Alderfen,

Cromes,

Cockshoot, Upton

Gt

Winter Annually Ecologist issuing

contract

Landowner agreement

required at each site

Biodiversity recording and invasive species monitoring

What Drivers Where When Frequency Who Questions Priority?

As part of water

plant survey record

native and non-

native bivalve

species and

number captured

using the rake

survey method for

water plants

Impact of site

management;

Non-native

species impacts;

Protected species

recording

(Depressed river

mussel)

Priority list of

Broads, including

long-term sites

and restoration

sites

Late July-

early Sept

(June for

Trins)

As part of 20

days survey

per year?

EO field survey

and data

management.

Rangers and other

officers ad-hoc

records

ID sheet and recording

on Trimble required

Mink monitoring

via rafts set out in

Impact of site

management;

Non-native

BA fen

management

All year TBC EO completing field

survey and data

management

30 | P a g e

fen sites species impacts;

Protected species

recording (water

vole)

sites reporting back via

Ecologist to Mink

Management

Project

What Drivers Where When Frequency Who Questions Priority?

Bat surveys Protected species

monitoring;

success of bat

populations at

Ormesby WTW

Ormesby Broad

and Ormesby

WTW other sites

TBC

May, August,

October

Three times

per year

EO and ESW staff,

plus bat licence

holder contractor

for roost checks

Data under review

Breeding Bird

monitoring

Impact of site

management and

condition;

Protected species

recording

Buttle Marsh

Trinity Broads

Summer Annually

Trinity Broads

Annually

(once a month

from Apr-Aug)

Buttle Marsh

Ecologist liaising

with UEA on

method, prioritizing

sites and

coordinating

records

EO managing site

access &

agreement with

UEA

Trinity Broads EO

and volunteers

Ecologists to confirm

methods

31 | P a g e

Bittern – booming

and nesting at How

Hill and Buttle

Marsh

Climate change

research; Impact

of site

management and

condition;

Protected species

recording

Ormesby Broad

Little Broad How

Hill and Buttle

Marsh

Spring/

Summer

Annually Ecologist creating

method, prioritizing

sites and

coordinating

volunteers,

gamekeepers

officers records

and sending to

RSPB

Ecologists to confirm

method

Wetland Bird

Surveys (WeBS)

Impact of

recreation;

maintenance of

long term dataset,

Climate change

research; impact

of site condition;

NNR

management.

Cromes Broad,

Reedham Marsh

& Trinity Broads

Annually,

Nov to March

1 Sunday per

month; How

Hill & Trinity

sites takes 4

hours in total.

EO and volunteers

completing field

survey and data

management

Swallowtail

butterfly transects

and larval counts

Impact of site

management and

condition;

How Hill,

Trinity Broads

(Rollesby Charity

Lands, Filby

broad south and

west) and Burgh

Common

General butterfly

transects at

Ormesby WTW

Horning Marsh

Farm (includes all

June/July/Au

g

Annually

Trinity 3 days

per year

Ecologists,

Rangers &

Volunteers

completing field

survey and data

management;

Ecologists review

the data along with

other data from the

Broads

Ecologists to confirm

method

Hill,

General

butterfly

transects at

Ormesby

WTW is

ESW

priority for

monitoring

the WTW,

HMF

32 | P a g e

wildlife

observations)

Desmoulin whorl

snail surveys

Protected species

monitoring;

impact of water

abstraction

Trinity Broads (10

sample sites)

July and Oct Biannually? EO and volunteers.

EO to analyse data

and write up report,

comparing to

previous surveys.

Need to check whether

biannual frequency is

appropriate.

Operational Impact Monitoring & Compliance

What Drivers Where When Frequency Who Questions Priority?

Impacts of

dredging

techniques

PRISMA reporting PRISMA dredge

sites

Project

based; As

required

2012-14

During works EO lead on

completing field

survey and data

management

Impact of

operational works

on SAC/ SPA/

Protected Species

Conservation

Regulations;

Planning consent

Project based; As

required

Project

based; As

required

Project based;

As required

EO lead on

completing field

survey and data

management

a) Duck Broad island scheme

2012/13 Weekly water

sampling; Pre-

& during

works duck

impact study

EO lead on

completing field

survey and data

management

b) Bats in trees surveys on BA sites

Pre-works

surveys;

Dawn

emergence

2 dawn

surveys during

May-

September

EO lead on

completing field

survey and data

Process to be finalized

with Rangers which

identifies trees for

remedial work in

33 | P a g e

surveys

prior to works

on

autumn/winter

management following

autumn/winter, by end

April each year in

following

c) water vole mitigation in fen ditches

Pre-works as

required by

work

programme

Survey in

activity

season May-

Sept

EO lead on

completing field

survey and data

management

d) Pre works survey at dredging disposal sites

Pre works as

required by

work

programme

Survey in

optimal

season for

relevant

features

EO lead on

completing field

survey and data

management

Fen Harvester

arisings quality

analysis

Environmental

Permitting

requirement

Fen harvester

sites where

arisings used for

agricultural

benefit

Project

based; As

required

Prior to works EO lead on

completing field

survey and data

management

34 | P a g e

Future Broads Authority research and monitoring topic areas

Over the next 2 to 3 years (2013-15) the programme and priorities for Broads Authority led research will include the following areas

outlined in the table below.

MSc or PhD research into the impact of climate change scenarios on specific Broads species and associated habitat change.

Topic Project detail Project origin Resources and

timescale for

delivery

Cost to

Broads

Authority per

year (£)

Climate change

impact and

adaptation

General

Baseline ecological monitoring of wetland

creation and Local Nature Reserves to

determine biodiversity change in terms of

habitats and species response to climate

change.

Broads Biodiversity Group,

Species Action Plans (fen

orchid, swallowtail and

fens)

Broads Authority

2012-15

2,000

Climate change

impact and

adaptation -

Saline input into

wetland and river

habitats

Set up and support a monitoring and research

network throughout the Broads

Water Quality Partnership Broads Authority

NE, EA

2012-15

500

35 | P a g e

Climate change

impact and

adaptation -

Species impacts

Effect of salinity on stoneworts (chara

connivens and Nitellopsis obtusa)

Broads Authority/UEA

Climate change

impact and

adaptation -

Species impacts

Create research-led action plans for

translocating species of conservation concern

with strongholds in the Broads

Broads Authority Broads Authority

2014/15

5,000

Fen – Salinity /

climate change

Monitoring of saline events to determine the

penetration of salt water into selected fen sites

to link with future assessment of a potential

hydrological model to capable of predicting salt

concentrations in fens.

Recommendation of

partnership hydro-ecology

fen workshops.

Complimenting Review of

Consents.

Broads Authority

2012-15

1,000

Fen – Salinity /

climate change

PhD to assess the greenhouse gas emissions

from fens in relation to salinity and climate

change processes

Recommendation of the

Supplement to the Fen

Management Strategy.

Broads Authority

2012-2015

5,000

Fen – climate

change

MSc to assess carbon storage and recent carbon sequestration in floodplain fens Collecting cores for analysis of total carbon and stratigraphic dating (based on historical fly-ash deposition)

Linked to the PhD to

assess the greenhouse gas

emissions

Broads Authority

2012-2014

Fen - Scrub Mapping the change in distribution of scrub

within the fens using BA aerials

Broads Authority/ Broads

Biodiversity Group

Broads Authority

2015/16

Completed for

2004 and

2010

36 | P a g e

Required in

2015 (2,000)

Fen – Nitrogen

deposition

Literature study to assess the nitrogen

deposition within the Broadland fens plants

linked to the location of atmospheric nitrogen

sources

Broads Authority/ Broads

Biodiversity Group

2013/14

Unfunded

Fen - Long-term

monitoring

Survey BA owned sites and selective

management agreement sites as part of the

long-term monitoring of fens, commencing in

2011.

Recommendation of the

Supplement to the Fen

Management Strategy.

Broads Authority

Officers

2012-15

Ongoing

Fen - Long-term

monitoring

Longer term monitoring of areas that are scrub

cleared for the purpose of restoring open fen,

with idea of assessing positive vegetative and

invertebrate response to returning to an open

habitat, against the possible negative

vegetative and substrate response of clearance

techniques. Would need pre and post survey.

Recommendation of the

Fen Ecological Survey.

Broads Authority

Natural England

2013-2015

Unfunded

Fen - Long-term

monitoring

Repeat of the Fen Ecological Survey

(vegetation and invertebrates)

Broads Biodiversity Group Unfunded £200,000

(est.)

Fen – fen meadow

invertebrates

First-time survey of fen meadows for

invertebrates

Broads Biodiversity Group Unfunded £5,000 -

10,000

Fen – fen ditch

survey

First-time survey of fen ditches for water plants Broads Biodiversity Group Unfunded £5,000 -

10,000

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Fen - Harvesting Investigation of using fen material as soil

improver or biomass. Assessing the time to

compost, the composition and trialling

incorporating into commercial agriculture in

partnership with local landowner/s.

Fen Management Strategy

and its Supplement.

DECC industry

competition

2012-14 outside

of the Broads

Fen - Harvesting Investigation of sites and infrastructure required

for removal of material and compression of the

peat.

NE and BA BA

Fen – Turf ponds Assessment of turf ponds and invertebrates to

investigate the implication of succession and

connection

Broads Authority/ Broads

Biodiversity Group

Broads Authority

2013/14

5,000

Peat project

Assessing and mapping the peat stratigraphy at

sites in the Broads in relation to management

decisions

Linking to climate change

and fen and grazing marsh

management

Broads Authority

2012/13

Rivers and

Broads – Water

Quality

Monitor and review the application of Phoslock Biodiversity and Water

Strategy

Broads Authority

2013-15

3,000 per year

Rivers and

Broads – Water

Quality

Monitor water quality at sites which require

surveillance (Whitlingham, several small broads

that are not sampled by the EA)

Lake Restoration Strategy.

Catchment Sensitive

Farming.

Broads Authority

2012-15

500 per year

Rivers and

Broads – Habitats

& Species

Comparison of water plant survey method of

the Broads Authority and the national water

plant monitoring methods

Broads Authority Broads Authority

2013/14

Ongoing

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Rivers and

Broads – Pre-

disturbance

macrophyte

communities of the

Broads

Pre-disturbance macrophyte communities of

the Broads from existing basal peats to try and

capture more species and gain deeper insight.

This would complement the existing pollen

data. Combined with germination texts on these

basal sediments.

ECRC-UCL and SJL Unfunded

2014/15

5,000 (est)

Rivers and

Broads – mud

pumping

Assessment of pre- and post ecological, water

and sediment quality data for key mud pumped

broads e.g. Barton Broad against success

criteria. Assessing the reasons for success at

each site.

Broads Authority, Natural

England

Broads Authority

2013/14

5,000 (BA)

7,5000 (NE)

Rivers and

Broads –

Synthesis of

management

General assessment of all data for all lakes,

including a lake by lake assessment of

outcomes in terms of where we are today and

what we need to do in the future. Including an

assessment of all the information available and

the key learning points and the rate of change

through the current targets for WFD and SSSIs.

Broads Authority, Natural

England

Broads

Authority,

Natural England

2013/14

5,000 (BA)

7,5000 (NE)

Rivers and

Broads – Trinity

Broads recovery

Analysis of the macrophyte (structure,

abundance and diversity), fish populations and

nutrient chemistry.

Analysis of sediment and inflow P sources in

each basin to report on nutrient retention and

release.

Assessment of water plants recovering from

Trinity Broads Partnership Trinity Broads

Partnership

Trinity Broads

Partnership

Ongoing

Ongoing

39 | P a g e

dredged sediment. Broads Authority Ongoing

Rivers and

Broads - Non-

Native Invasive

Species

Foodweb isotope study of dikerogammerus

villosus (killer shrimp) to determine the impact

on the broads

Queen Mary

College London

Seeking

funding from

partners

Rivers and

Broads - Non-

Native Invasive

Species

Record native and non-native bivalve species

and number captured using the rake survey

method for water plants

Following on from several

non-native bivalve surveys

BA staff to

record info

during water

plant survey. ID

crib sheet

required.

Rivers and

Broads - Non-

Native Invasive

Species

Mesocosm studies to examine the independent

and synergistic impact of invasive gammarid

species on native biodiversity, ecosystem

processes and food web structure under

climate change scenarios.

Queen Mary College

London – Michelle Jackson

& Jonathan Grey

Requested

support from

EA, NE

Unfunded

Rivers and

Broads –

Sediment

Management

Impacts of hydrodynamic dredging in the

Broads.

Following on from

Ecological Assessment of

Water Injection Dredging in

the lower Yare

Potential MSc

student project

utilising BA, EA

and BESL data.

Requires

funding,

potential

partnership with

EA

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Species - Fen raft

spider

Fen raft spider – funding research and

translocation into the Broads

Broads Biodiversity Group BA contribution

to partnership of

NE, Zoos,

RSPB, NWT,

SWT

2,000

Species - Fen

orchid

Fen orchid – investigation of germination

conditions

Broads Biodiversity Group BA 1,000

Species -

Breeding water

birds

Breeding bird assessment in the Trinity Broads Trinity Partnership E&SW, BA In house

Species -

Molluscs

Survey of marsh dykes for snails, covering

areas with poor survey data

BA, NE BA funding 1,000