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
Quality
Ecological
Quality
Quantity
Structure
General Quality Assessment
Biology
Chemistry
Water
Quality
Nutrients
Aesthetics
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 consumption
3. 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 proportionally
E.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 Scale
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
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
Mesolveliidae Hydrometridae Gerridae Nepidae Naucoridae
Notonectidae Pleidae Corixidae
Haliplidae Hygrobiidae Dytiscidae Gyrinidae
Hydrophilidae Clambidae Scirtidae Dryopidae Eliminthidae
Chrysomelidae Curculionidae
Hydropsychidae
Tipulidae Simuliidae
Planariidae Dendrocoelidae
Baetidae
Sialidae
Piscicolidae
Valvatidae Hydrobiidae Lymnaeidae Physidae Planorbidae
Sphaeriidae
Glossiphoniidae Hirudidae Erpobdellidae
Asellidae
Chironomidae
Oligochaeta (whole class)
5
4
3
2
1
Data Interpretation
• Compare sampling stations, e.g. up
and downstream of potential
pollution source
• Compare with historical data
• Compare with Environment Agency
data
BMWP at sites along the Tory Brook & River Plym
BMWP Score
100
90
80
70
60
50
40
30
20
10
0
1
2
3
4
5
6
River Plym
Tory Brook
Site
Average score per Taxon at sites along the Tory Brook & River
Plym
10
9
Average Score per Taxon
8
7
6
5
4
3
2
1
0
1
2
3
Site
4
5
6
River Plym
Tory Brook
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
Suspended Solids at sites along the Tory Brook & River Plym
Suspended Solids (mg/l)
30
27.5
25
22.5
20
17.5
15
12.5
10
7.5
5
2.5
0
1
2
3
4
Site
5
6
River Plym
Tory Brook
Site one at the
River Plym
Site two at
the River
Plym
Site four at the
River Plym
Phosphate at sites along the Tory Brook & River Plym
0.7
Phosphate (mg/l)
0.6
0.5
0.4
0.3
0.2
0.1
0
1
2
3
Site
4
5
6
River Plym
Tory Brook
Nitrate at sites along the Tory Brook & River Plym
16
Nitrates (mg/l)
14
12
10
8
6
4
2
0
1
2
3
Site
4
5
6
River Plym
Tory Brook
References
Bourne 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.environmentagency.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.environmentagency.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]