Abstract
In the period since 1945, Slapton Ley, a small, coastal lake in Southwest England, has been eutrophccated by nutrient inputs generated both by the intensification of agriculture, and the discharge of sewage effluent. Two simple models have been used to identify the main sources of catchment outputs, and to evaluate historical changes in land use, and their likely effect on lake trophic status.
Restoration strategies may also be evaluated using the same models. They suggest that in order to reduce loads upon the Ley to within OECD permissible limits, not only will all sewage and phosphate detergent inputs need to be prevented, but also losses from agricultural land must be reduced. This could take the form of the zoning of the catchment so that riparian zones are used, not as at present, for the grazing of livestock, but are converted to woodland, and more particularly eg to buffer strips sensu Mander (1985, 1992).
This policy, if implemented comprehensively, would reduce external phosphorus loads to within permissible limits. Eventually, however, some kind of internal control, such as manipulation of the fish populations, may also have to be attempted, in order to remove the ‘memory’ of five decades of eutrophication.
Similar content being viewed by others
References
Acott, T. G., 1989. An investigation into nitrogen and phosphorus loading on Slapton Ley, 1905–1985. BSc dissertation, University of Plymouth, 193 pp.
Burt., T. P., B. P. Arkell, S. T. Trudgill & D. E. Walling, 1988. Stream nitrate levels in a small catchment in Southwest England over a period of fifteen years. Hydrolog. Proe. 2: 267–284.
Countryside Commission. 1989. Countryside Information Grants for Landscape Conservation. Countryside Commission leaflet no CCP207, Great Britain: Countryside Commission, London, 4 pp.
Crabtree, K. & F. E. Round, 1967. Analysis of a core from Slapton Ley. New Phytol. 66: 255–270.
Department of the Environment, 1990. Our Common Inheritance. HMSO, London, 296 pp.
Edmondson, W. T. (1991). The Uses of Ecology: Lake Washington and beyond. Seattle, 329 pp.
Engstrom, D. A. & H. E. Wright, jr., 1984 Chemical stratigraphy of lake sediments as a record of environmental change. In E. Y. Haworth & J. W. G. Lund (eds), Lake Sediments and Environmental History. Leicester University Press: 11–69.
Glendinning, J. M, 1991. An investigation into an alternative land use strategy for the alleviation of eutrophication in Slapton Ley, South Devon. BSc dissertation, University of Plymouth, 88 pp.
Gulati, R. D., E. H. R. R. Lammens, M.-L. Meijer & E. van Donk (eds), 1990. Biomanipulation — Tool for Water Management. Developments in Hydrobiology 61. Kluwer Academic Publishers, Dordrecht, 628 pp. Reprinted from Hydrobiologia 200/201.
Heathwaite, A. L. & P. E. O'Sullivan, 1991. Sequential inorganic chemical analysis of a core from Slapton Ley, Devon, U.K. In J. P. Smith, P. G. Appleby, R. W. Battarbee, J. A. Dearing, R. Flower, E. Y. Haworth, F. Oldfield & P. E. O'Sullivan (eds), Environmental History and Palaeolimnology. Developments in Hydrobiology 67. Kluwer Academic Publishers, Dordrecht: 125–135. Reprinted from Hydrobiologia 214.
Johnes, P. J. & P. E. O'Sullivan, 1989. The natural history of Slapton Ley Nature Reserve. XVIII-Nitrogen and phosphorus losses from the catchment — an export coefficient approach. Field Studies 7: 285–309.
Jørgensen, S. E., 1980. Lake Management. Pergamon, 167 pp.
Mackereth, F. J. H., 1969. A short-core sampler for lake deposits. Limnol. Oceanogr. 14: 145–151.
Ministry of Agriculture, Fisheries and Food (MAFF), 1988 Set-Aside. MAFF leaflet no SA1, HMSO, London, 20 pp.
Ministry of Agriculture, Fisheries & Food (MAFF), 1991. Code of Food Agricultural Practice for the Protection of Water. HMSO, London, 80 pp.
Mander, Ü., 1985. The renovation of polluted surface flow in vegetated buffer strips. Acta et Comm. Univ. Tartuensis 675: 77–81 (in Russian, with English summary).
Mercer, I. D., 1966. The Natural History of Slapton Ley Nature Reserve. I — Introduction and morphological description. Field Studies 2: 385–405.
Morey, C., 1976. The Natural History of Slapton Ley Nature Reserve. IX — The morphology and history of the lake basins. Field Studies 4: 353–368.
Moss, B., 1983. The Norfolk Broadland: experiments in the restoration of a complex wetland. Biol. Rev 58: 521–561.
O'Sullivan, P. E., A. L. Heathwaite, K. M. Farr & J. P. Smith, 1989. South West England and the ShropshireCheshire meres. Guide to Excursion A, Vth International Symposium on Paleolimnology, Ambleside, Cumbria, UK, 1–6 September 1989, University of Plymouth, 122 pp.
O'Sullivan, P. E., A. L. Heathwaite, P. G. Appleby, D. Brookfield, M. I. Crick, C. J. Moscrop, T. B. Mulder, N. J. Vernon & J. M. Wilmshurst, 1991. Palaeolimnology of Slapton Ley, Devon, UK. In J. P. Smith, P. G. Appleby, R. W. Battarbee, J. A. Dearing, R. Flower, E. Y. Haworth, F. Oldfield & P. E. O'Sullivan (eds), Environmental History and Palaeolimnology. Developments in Hydrobiology 67. Kluwer Academic Publishers, Dordrecht: 115–124. Reprinted from Hydrobiologia 214.
Rast, W. & G.F. Lee. 1983. Nutrient loading estimates for lakes. J. Envir. Engin. 109: 502–517.
Ryding, S-O. & C. Forsberg, 1980. Short-term, load-response relationships in shallow, polluted lakes. In J. Barica & L. R. Mur (eds), Hypertrophic Ecosystems. Developments in Hydrobiology 2. Dr W. Junk Publishers, The Hague: 95–103.
Ryding, S-O., & W. Rast (eds), 1989. The Control of Eutrophication of Lakes and Reservoirs UNESCO, Paris, 314 pp.
Troake, R. P. L. M. Troake, & D. E. Walling, 1976. Nitrate loads of South Devon streams. In Agriculture and Water Quality HMSO, London, 340–355.
Trudgill, S. T., 1983. The Natural History of Slapton Ley Nature Reserve XVI — The soils of Slapton Wood. Field Studies 5: 833–840.
Van Vlymen, C. D., 1979. The Natural History of Slapton Ley Nature Reserve. XIII — The water balance of Slapton Ley. Field Studies 5: 59–84.
Van Vlymen, C. D., 1980. The water-balance, physicochemical environment, and phytoplankton studies of Slapton Ley, Devon. unpublished PhD thesis, University of Exeter, 248 pp.
Vollenweider, R. A., 1975. Input-output models with special reference to the phosphorus-loading concept. Schweiz. Z. Hydrol 37: 58–83.
Wilson, H. M., 1991. The effects of eutrophication on the submerged macrophyte community of Slapton Ley, South Devon BSc dissertation. University of Plymouth, 118 pp.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
O'Sullivan, P.E. Modelling the effects of alternative nutrient control policies — the example of Slapton Ley, Devon, UK. Hydrobiologia 251, 351–361 (1993). https://doi.org/10.1007/BF00007194
Issue Date:
DOI: https://doi.org/10.1007/BF00007194