Transition zones in small lakes: the importance of dilution and biological uptake on lake-wide heterogeneity
Stream inflows are frequently the dominant route for nutrients from catchments to lakes. Studies on large, deep reservoirs and lakes have shown the importance of the fate of inflow plumes for nutrient accessibility to phytoplankton. However, few studies have considered shallow water transition zones between streams and lakes, often a feature of small lakes. This study examined the spatial and temporal dynamics of phosphorus in a shallow stream-lake transition in a small lake to improve our understanding of how phosphorus reaches the pelagic zone. Despite the high discharge levels, and the importance of dilution in explaining observed spatial gradients in soluble reactive phosphorus (SRP), total phosphorus (TP) and chlorophyll a, we found evidence for significant biological uptake of SRP in the inflow embayment during the growing season. This may represent an additional mechanism for the dispersal of phosphorus from the embayment into the lake. The length scale for the transition zone was short (~150 m) which indicated that the direct influence of the inflow on the wider lake was small. However, SRP measurements taken only from the pelagic site underestimated mean lake-wide concentrations when including transition zones by up to 18% during the growing season.
KeywordsInflows Transition zone SRP Chlorophyll a Nutrient delivery Esthwaite Water
- Aldridge, K. T., J. D. Brookes & G. G. Ganf, 2010. Changes in abiotic and biotic phosphorus uptake across a gradient of stream condition. Rivers Research and Applications 26: 636–649.Google Scholar
- Downing, J. A., Y. Prairie, J. J. Cole, C. M. Duarte, L. J. Tranvik, R. G. Striegl, W. H. McDowell, P. Kortelainen, N. F. Caraco, J. M. Melack & J. J. Middelburg, 2006. The global abundance and size distribution of lakes, ponds, and impoundments. Limnology and Oceanography 51: 2388–2397.CrossRefGoogle Scholar
- Fischer, H. B., J. E. List, R. C. Y. Koh, J. Imberger & N. H. Brooks, 1979. Mixing in inland and coastal waters. Academic Press, Inc., London.Google Scholar
- Ford, D. E., 1990. Reservoir transport processes. In Thornton, K. W., B. L. Kimmel & F. E. Payne (eds), Reservoir limnology: ecological perspectives. John Wiley & Sons Inc., New York.Google Scholar
- Hall, G. H., S. C. Maberly, C. S. Reynolds, I. J. Winfield, J. B. James, J. E. Parker, M. M. Dent, J. M. Fletcher, B. M. Simon & E. Smith, 2000. Feasibility study on the restoration of three Cumbrian lakes. Centre for Ecology and Hydrology, Ambleside.Google Scholar
- Hart, R. C. & P. D. Wragg, 2009. Recent blooms of the dinoflagellate Ceratium in Albert Falls Dam (KZN): history, causes, spatial features and impacts on a reservoir ecosystem and its zooplankton. Water SA 35: 455–468.Google Scholar
- Jirka, G. H. & M. Watanabe, 1980. Thermal structure of cooling ponds. Journal of the Hydraulics Division-ASCE 106: 701–715.Google Scholar
- Jones, I. D., T. Page, J. A. Elliott, S. J. Thackeray & A. L. Heathwaite, 2011. Increases in lake phytoplankton biomass caused by future climate-driven changes to seasonal river flow. Global Change Biology. doi:10.1111/j.1365-2486.2010.02332.x.
- Kimmel, B. L., O. T. Lind & L. J. Paulson, 1990. Reservior primary production. In Thornton, K. W., B. L. Kimmel & F. E. Payne (eds), Reservoir Limnology: Ecological Perspectives. John Wiley & Sons Inc., New York.Google Scholar
- Le Pape, O., F. Chauvet, Y. Désaunay & D. Guérault, 2003. Relationship between interannual variations of the river plume and the extent of nursery grounds for the common sole (Solea solea, L.) in Vilaine Bay. Effects on recruitment variability. Journal of Sea Research 50: 177–185.CrossRefGoogle Scholar
- Lihan, T., S. Z. Nurain, M. A. J. Amizam, A. R. Sahibin & A. M. Mustapha, 2010. Determination of spatial and temporal variability of Pahang River plume using remote sensing images. Map Asia 2010 and ISG 2010, Kuala Lumpur, Malaysia.Google Scholar
- Likens, G. E., 1972. Eutrophication and aquatic ecosystems. In Likens, G. E. (ed.), Nutrients and Eutrophication: The Limiting Nutrient Controversy. Proceedings of the Symposium on Nutrients and Eutrophication: The Limiting-Nutrient Controversy. American Society of Limnology and Oceanography, Lawrence, Kansas.Google Scholar
- Liu, Y., P. MacCready & B. M. Hickey, 2009. Columbia River plume patterns in summer 2004 as revealed by a hindcast coastal ocean circulation model. Geophysical Research Letters 36. doi:10.1029/2008GL036447.
- Lohman, K. & J. R. Jones, 2010. Longitudinal patterns in nutrient chemistry and algal chlorophyll below point sources in three northern Ozark streams. Verhandlungen der Internationalen Vereinigung fur Theoretische und Angewandte Limnologie 30: 1559–1566.Google Scholar
- Mackay, E. B., I. D. Jones, A. M. Folkard & P. A. Barker, 2011. Contribution of sediment focusing to heterogeneity of organic carbon and phosphorus burial in small lakes. Freshwater Biology. doi:10.1111/j.1365-2427.2011.02616.x.
- Miller, H. J., 2008. Investigation into Mechanisms for the Internal Supply of Phosphorus to the Epilimnion of a Eutrophic Lake. PhD Thesis, Geography Department, Lancaster University, Lancaster.Google Scholar
- Pacini, N. & R. Gächter, 1999. Speciation of riverine particulate phosphorus during rain events. Biogeochemistry 47: 87–109.Google Scholar
- Talling, J. F., 1974. Photosynthetic pigments: general outline of spectrophotmetric methods; specific procedures. In Vollenweider, R. A. (ed.), A Manual on Methods of Measuring Primary Production in Aquatic Environments. Blackwell, Oxford: 22–26.Google Scholar
- Thornton, K. W., 1990. Perspectives on reservoir limnology. In Thornton, K. W., B. L. Kimmel & F. E. Payne (eds), Reservoir Limnology: Ecological perspectives. John Wiley & Sons, New York.Google Scholar
- Twinch, A. J., 1984. The role of bottom sediments in modifying soluble phosphate loads to a dendritic, hypertrophic reservoir. In Eriksson, E. (ed.), Proceedings of the Uppsala Conference. IAHS-AISH Publication No. 150: 381–392.Google Scholar
- Vidal, J., 2006. Basin Scale Hydrodynamics in a Mediterranean Reservoir. Implications for the Phytoplankton Dynamics. PhD Thesis, University of Girona, Girona.Google Scholar
- von Westernhagen, N., 2010. Measurements and Modelling of Eutrophication Processes in Lake Rotoiti, New Zealand. PhD Thesis, Department of Biological Sciences, The University of Waikato, Hamilton.Google Scholar