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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.
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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
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: • To achieve “Good Status” for all waters by set deadlines (2015) • To promote sustainable water consumption • 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
Why Sample Aquatic Invertebrates? • 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. ? • 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 • Sampling aquatic invertebrates is more meaningful than chemical monitoring 5. Aquatic invertebrates are relatively easy to collect
Collecting Samples Health and Safety first! • Prepare necessary methods statement and risk assessment
Collecting Samples • 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 • Together with co-worker, identify point(s) of entrance and exit • Use ranging pole to test substrate and provide support • 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
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
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 ? RIVPACS In this system the different river types are taken into account
Data Interpretation • Compare sampling stations, e.g. up and downstream of potential pollution source • Compare with historical data • Compare with Environment Agency data
Evidence of china clay in the water Site two at the Tory Brook Evidence that channel may have be altered Site six at the Tory Brook
Site one at the River Plym Site two at the River Plym Site four at the River Plym