biological monitoring of water quality the totality of features and characteristics of water that...
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Biological Monitoring of Water Quality
“the totality of features and characteristics of water that bear upon
its ability to support an appropriate natural fauna, and to sustain legitimate
uses.” (Pugh, 1997)
The 3 components of management of ecological quality in rivers
General Quality Assessment
GQA Scheme for Biology
• A = Very Good– Biology similar (or better than) that expected for an average and
unpolluted river of this size, type and location. High diversity of taxa, usually with several species in each. Rare to find dominance of any one taxon.
• B = Good C = Fairly Good, D = Fair, E = Poor
• F = Poor– Biology limited to a small number of very tolerant taxa such as worms,
midge larvae, leeches and water hoglouse, present in very high
numbers.
Water Framework Directive (2000)
WFD looks at the whole system; seeks to manage water proactively on a catchment basis, using reference systems
Aims:1. To achieve “Good Status” for all waters by set deadlines
(2015)2. To promote sustainable water consumption3. To protect & enhance the status of aquatic ecosystems &
associated wetlands
Water management to be based on natural units not natural ones
Aquatic Invertebrates
Sampling
Identification
Using aquatic inverts as indicators of biological water quality
What are Aquatic Macro-invertebrates?
Aquatic Invertebrates - Examples
Why Sample Aquatic Invertebrates?
1. Aquatic inverts are ecologically important within the food chain –
- abundance
- species and ecological diversity
Functional roles include:•Algal grazers
•Consumers of bacteria & fungi
•Detritivores
•Predators
•Prey
Why Sample Aquatic Invertebrates cont. ?
2. Aquatic Invertebrates vary in their sensitivity to water pollution i.e. they are good biological indicators
3. Aquatic invertebrate data provides longer term information than chemical data
4. Sampling aquatic invertebrates is more meaningful than chemical monitoring
5. Aquatic invertebrates are relatively easy to collect
Collecting Samples
Health and Safety first!
1. Prepare necessary methods statement and risk assessment
Collecting Samples
2. Check mobile phone, put on life jacket
3. Review bank features including slope, vegetation, conditions underfoot, obstacles or special hazards
4. Review waterbody features including depth, turbidity, flow, substrate, channel profile, vegetation, obstacles or special hazards
Collecting Samples
5. Together with co-worker, identify point(s) of entrance and exit
6. Use ranging pole to test substrate and provide support
7. Go slowly
8. Common Sense Rule: Don’t get in if there is any doubt over safety
Collecting Samples
4 – Minute Combined Kick-sweep Sample
– 30 seconds collection of surface activity insects– 3 minute kicking and sweeping– 30 seconds collection of benthic invertebrates adherent
to stones, logs, car tyres and shopping trolleys
Key Point:
Important to divide time between component habitats or microhabitats proportionallyE.g. Open water, submerged vegetation, emergent vegetation, exposed substrate, overhanging vegetation, submerged wood
Sample Storage
Either a three stage process:• Firstly: apply a fixative, usually 4%
aqueous solution of formaldehyde
• Secondly: sort sample, i.e. pick out inverts
• Thirdly: store sorted sample in a preservative, usually 70% alcohol
Or; simply use 90% alcohol (IMS)
Sorting a Sample
• Wash out fixative
• ‘Dilute’ sample across a white tray
• Carefully pick out the invertebrates
Review of Aquatic Invertebrate Groups
Crustacea – Water Fleas
Crustacea – Freshwater Shrimp
Platyhelminthes - Flatworms
Annelida – Hirudinea - Leeches
Mollusca – Gastropoda - Snails
Insecta – Hemiptera – Water Bugs
Insecta – Coleoptera – Water Beetles
Insecta – Diptera – True Flies
Insecta – Megaloptera - Alderflies
Insecta – Tricoptera – Caseless Caddis Flies
Insecta – Tricoptera – Cased Caddis Flies
Insecta – Tricoptera - Adult Caddis Fly
Insecta – Plecoptera – Stone-flies
Insecta –Ephemeroptera - Mayflies
Insecta – Ephemeroptera – Adult Mayfly
Insecta – Odonata – Dragonflies & Damselflies
Data Interpretation
Calculate the Biotic Scores
• Taxon or species richness; the easiest measure of biodiversity
• BMWP score; the Biological Monitoring Working Party score
• ASPT index value; the Average Score Per Taxon
BMWP score Category Interpretation
0-10 Very poor Heavily polluted
11-40 Poor Polluted or impacted
41-70 Moderate Moderately impacted
71-100 Good Clean but slightly impacted
>100 Very good Unpolluted, unimpacted
BMWP Scale
BWMP – Score dependent on sample size, sampling efficiency and seasons
Different unpolluted rivers often generate very different BMWP scores due to natural variation in ecological communities eg.
silted lowland rivers with turbulent upland streams.
The solution ?
RIVPACSIn this system the different river types are taken into account
Mesolveliidae Hydrometridae Gerridae Nepidae NaucoridaeNotonectidae Pleidae CorixidaeHaliplidae Hygrobiidae Dytiscidae GyrinidaeHydrophilidae Clambidae Scirtidae Dryopidae EliminthidaeChrysomelidae CurculionidaeHydropsychidaeTipulidae SimuliidaePlanariidae Dendrocoelidae
BaetidaeSialidaePiscicolidae
Valvatidae Hydrobiidae Lymnaeidae Physidae PlanorbidaeSphaeriidaeGlossiphoniidae Hirudidae ErpobdellidaeAsellidae
Chironomidae
Oligochaeta (whole class) 1
3
2
4
5
Data Interpretation
• Compare sampling stations, e.g. up and downstream of potential pollution source
• Compare with historical data
• Compare with Environment Agency data
0102030405060708090
100
1 2 3 4 5 6
BM
WP
Sc
ore
Site
BMWP at sites along the Tory Brook & River Plym
River Plym
Tory Brook
0
1
2
3
4
5
6
7
8
9
10
1 2 3 4 5 6
Ave
rag
e S
core
per
Tax
on
Site
Average score per Taxon at sites along the Tory Brook & River Plym
River Plym
Tory Brook
Site two at the Tory Brook
Evidence of china clay in the water
Evidence that channel may have be altered
Site six at the Tory Brook
02.5
57.510
12.515
17.520
22.525
27.530
1 2 3 4 5 6Su
sp
en
de
d S
olid
s (m
g/l)
Site
Suspended Solids at sites along the Tory Brook & River Plym
River Plym
Tory Brook
Site one at the River Plym
Site two at the River
Plym
Site four at the River Plym
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
1 2 3 4 5 6
Ph
os
ph
ate
(mg
/l)
Site
Phosphate at sites along the Tory Brook & River Plym
River Plym
Tory Brook
ReferencesBourne Stream. 2008. BMWP Scoring – measuring Freshwater Quality [online] Available at
http://www.bournestreampartnership.org.uk/bmwpscoring.htm [Accessed 23rd March 2008]
Centre for Ecology & Hydrology. 2008. RIVPACS (River Invertebrate Prediction and Classification System): an introduction. [Online] Available at: http://www.ceh.ac.uk/sections/re/RIVPACS.html [Accessed 2nd April 2008]
DEFRA. 2006. Key Facts about: Inland Water Quality and Use, Phosphate Concentrations in rivers: 1995-2005. [Online]. Available at: http://www.defra.gov.uk/environment/statistics/inlwater/kf/iwkf09.htm [Accessed 4th April 2008]
Environmental Agency. ND. General Quality Assessment of rivers – biology, [Online] Available at: http://www.environment-agency.gov.uk/commondata/acrobat/bio_method_09_03_559881.pdf [Accessed 19th November 2007]
EPA, 2007. Biological Indicators of Watershed Health. [Online] (Updated 30th November 2007) Available at: http://www.epa.gov/bioindicators/html/indicator.html [Accessed 20th March 2008]
Gainey P. 2007. Cornish mineral company fined for polluting salmon river. [Online] Available at: http://www.environment-agency.gov.uk/news/1901125 [Accessed 4th April 2008]
Hawkes H. 1997. Technical Note, Origin and Development of the Biological Monitoring Working Party Score System, 32 (4) Pages 964-968
Martin R. 2004. Origin of the Biological Monitoring Working Party System, A brief summary, [Online] Available at http://www.cies.staffs.ac.uk/origbmwp.htm [Accessed 20th November 2007]