1. Eutrophication Material contributed by Martin Bloxham and Paul Worsfold, Eutrophication in the Sea of Azov. Source: SeaWiFS Project, NASA/Goddard Space Flight Center and ORBIMAG

2. 1. DEFINE eutrophicationDEFINE 2. Explain the CAUSES and SOURCES of eutrophicationCAUSES and SOURCES 3. Discuss the ENVIRONMENTAL IMPACTS of eutrophicationENVIRONMENTAL IMPACTS 4. Look at the SOCIO-ECONOMIC consequences of eutrophicationSOCIO-ECONOMIC 5. Look at POLICY/REMEDIATIONPOLICY/REMEDIATION 6. Explain how to MONITOR EutrophicationMONITOR 7. Examine 3 CASE STUDIESCASE STUDIES Case study 1: Black Sea Case study 2: Lough Neagh Case study 3: Irish Environmental Protection Agency 8. Present REFERENCES and LINKS to information sourcesREFERENCES and LINKS The lecture will:

3. 1. Defining Eutrophication Most limnologists consider eutrophication as an increase in the rate of supply of organic matter to an ecosystem. For marine scientists, eutrophication (GESAMP, 1990) is “used simply to mean ‘enhanced nourishment’ and refers to the stimulation of aquatic plant growth by mineral nutrients, particularly the combined forms of phosphorus or nitrogen”. For more information on defining eutrophication, click HereHere

4. 2. Causes of Eutrophication The immediate causes of eutrophication are listed below. For more detailed information on the underlying causes of eutrophication, click on the immediate cause of interest: 2.1 Enhanced nutrient inputs 2.2 Increased recycling/ mobilisation of nutrients 2.3 Trapping of nutrients (e.g. in river impoundments)

5. 3. Environmental Impacts of Eutrophication Here are some of the impacts of eutrophication. The consequences of each of these impacts will be explained in the lecture. For more information click on the impact of interest: 3.1 Decrease in the transparency of waterDecrease in the transparency of water 3.2 Development of anoxic conditions (low oxygen levels)Development of anoxic conditions (low oxygen levels) 3.3 Increased algal bloomsIncreased algal blooms 3.4 Loss of habitat (e.g. Sea grass beds)Loss of habitat (e.g. Sea grass beds) 3.5 Change in dominant biota (e.g. Changes in plankton and macrophyte community structure or changes in fish composition)Change in dominant biota (e.g. Changes in plankton and macrophyte community structure or changes in fish composition) 3.6 Decrease in species diversity 3.7 Change in the aesthetic value of the water body

6. 4. Socio-economic Consequences of Eutrophication Here are some of the main socio-economic consequences of eutrophication: 4.1 Increased vegetation may impede water flow and the movement of boats 4.2 The water may become unsuitable for drinking even after treatment 4.3 Decrease in the amenity value of the water (e.g. it may become unsuitable for water sports such as sailing) 4.4 Disappearance of commercially important species (such as trout) 4.5 Loss of tourism/recreation (swimming, boating) 4.6 Loss of aesthetic value: visual disamenity of algal blooms in lakes

7. 5. Remediation Measures A reduction in the extent of artificial eutrophication can (in principle) be achieved by: 5.1 Reduction in the use of phosphates as builders in detergentsReduction in the use of phosphates as builders in detergents 5.2 Reduction in the use of nitrate containing fertilisersReduction in the use of nitrate containing fertilisers 5.3 Implementation of tertiary sewage treatment methods which remove phosphate and nitrateImplementation of tertiary sewage treatment methods which remove phosphate and nitrate 5.4 Improvements in agricultural practices (economising on fertiliser use and improving land use) 5.5 Aeration of lakes and reservoirs to prevent oxygen depletion particularly during algal blooms 5.6 Restoration of natural wetlands, efficient in nutrient removal 5.7 Removing phosphate-rich plant material from affected lakes 5.8 Removing phosphate-rich sediments by dredging

8. 6. Monitoring of Nutrients This section looks at: The biogeochemistry of nutrients (nitrogen, phosphorus and silicon) Methods of nutrient sampling and storage handling Techniques for the determination of nutrients in aquatic environments Validation of nutrient data For more information on nutrient monitoring, click HereHere

9. 7. Case Study A case study is presented to illustrate eutrophication issues 7.1 Case Study : THE BLACK SEA by Professor L.D. Mee (University of PlymouthTHE BLACK SEA

10. 8. References Mee, LD, Bloxham, M, Glegg, GA, Hart, V, Beaumont, N and Payne, S (2000) Global International Waters Assessment; draft methodology, University of Plymouth. GESAMP (1990) (IMO/FAO/UNESCO-IOC/WMO/WHO/IAEA/UN/UNEP Joint Group of Experts on the Scientific Aspects of Marine Pollution) The State of the Marine Environment. GESAMP No. 39, 111pp, London. Anderson, N.J., Historical changes in epilimnetic phosphorus concentrations in six rural lakes in Northern Ireland, Freshwater Biology, 1997, 38, 427-440. Bloxham, M., Nixon, E., McGovern, E., Rowe, A., Smyth, M. and Duffy, C., Winter Nutrient Monitoring of the Western Irish Sea- 1990-2000, Irish Marine Environment and Health Series, 2001. Useful links are on the next page.....

11. 8. Useful Links Global International Waters Assessment (GIWA) Web site Oslo and Paris Commission (OSPAR) Quality Status Reports (QSR2000) Joint Group of Experts on the Scientific Aspects of Marine Pollution (GESAMP) European Statistics (EuroStat) Irish Marine Institute Water UK More useful links are on the next page.....

12. 8. Useful Links Helsinki Commission (HELCOM) Environment Agency (EA) Institute of Grassland and Environmental Research (IGER) Department of Agriculture and Rural Development Northern Ireland (DARDNI) Irish Environmental Protection Agency (EPA)