Water quality in chronically nutrient-rich lakes: the example of the Shropshire-Cheshire meres

摘要

The Shropshire and Cheshire meres of north-west England are characterised by high phosphorus concentrations. This review assesses the importance of phosphorus and nitrogen concentrations in determining the water and ecological quality of the meres. Palaeolimno-logical evidence indicates that the meres may be naturally eutrophic, but that phosphorus concentrations have increased in the past century. Results show that nitrogen concentrations have also increased and support the hypothesis that high concentrations of nitrogen contribute to reduced macrophyte species richness. In light of the evident significance of nitrogen, the potential role of nitrogen concentrations in driving eutrophication in the meres is discussed.