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Title: An assessment of changing nutrient inputs to Windermere and their influence on water quality and charr population dynamics
Author: S.I. Heaney
Author: C.A. Mills
Author: J.E. Corry
Document Type: Monograph
In the early eighties Windermere showed evidence of increasing nutrient enrichment. This was evident from regular summer blooms of the blue-green algae (cyanobacteria) Oscillatoria bourrellyi in the South Basin, followed by the development of anoxia in the deeper waters. In the light of this knowledge, North West Water (NWW) commissioned the Freshwater Biological Association to provide a general assessment of environmental and biological features of Windermere and their susceptibility to change (Atkinson et al., 1986). This Report showed that algal production is generally phosphorus limited. However, since 1945 there has been a c. 20-fold increase in the winter maximum of soluble reactive phosphorus (SRP) in the South Basin and a large estimated loading of SRP (0.9 g of Phosphorus per square metre and year) to this basin. The North Basin showed less phosphorus enrichment and an estimated annual loading one third that of the South Basin. There has also been a small change in maximal algal biomass as indicated by chlorophyll a concentration, but significant shifts of algal quality during summer to regular growths of blue-green algae. The Report also indicated that the charr population, one of the 8 in England, might be particularly sensitive to the development of deep water anoxia. Following this Report, NWW commissioned a two year study of Windermere to provide further information on its water quality, a more refined phosphorus budget, and an investigation of the biology and population structure of charr. The present report integrates these studies to provide an assessment of the nutrient status of the lake and its implications for the charr.
Publisher: Freshwater Biological Association
Publication Date: 1989
Publication Place: Ambleside
Subject Keywords: LakesNutrientsCyanophyceaeEnvironmental factorsBiological indicatorsPhosphorusSoluble reactive phosphorusChlorophyll aWater qualityHydrological measurementsLightChemical compoundsPhytoplanktonCharrPopulation structureParasitologyCatchesEutrophication
Geographic Keywords: EnglandCumbriaWindermere
Taxonomic Keywords: CyanobacteriaOscillatoria bourrellyiSalmonidaeSalvelinus alpinusBacillariophyceae
Extent: 38; + 5 tables, 32 figures
Total file downloads: 25

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