Water quality monitoring at Loch Leven 2008-2010: report of results

Long-term monitoring of the water quality in Loch Leven has been undertaken by the Natural Environment Research Council since the late 1960s. Over this period, the lake has suffered serious degradation due to the combined effects of eutrophication, pesticide pollution and climate change. However, following management intervention aimed at improving the water quality of the lake, the site has undergone a slow recovery. The recovery trajectory has, at times, seemed somewhat erratic. This is due to inter-annual variations in the in-lake processes that regulate the release of legacy phosphorus from the sediments following a reduction in catchment sources, although climatic variation and changes in biological interactions have also affected the recovery in the loch. This report summarises the findings of 40 years of research on Loch Leven and presents additional data from samples collected between 2008 and 2010. The more recent data are integrated into the longer term perspective to provide an indication of whether the recovery of Loch Leven is continuing. The implications of the findings from the Loch Leven Long Term Monitoring Project, in terms of achieving water quality targets and providing key ecosystem services, are discussed.