ECN site code: L07
ECN monitoring by: UK Upland Waters Monitoring Network
Scoat Tarn in the English Lake District is a typical mountain corrie lake, being small and deep with an area of 5.2 ha and a maximum depth of 20 m. The lake lies in a west facing valley at an altitude of 602 m, and drains into Wastwater via the Nether Beck. The catchment comprises a small corrie (95 ha) with steeply sloping walls and three summits in excess of 825 m. The bedrock is Ordivician tuff (undifferentiated) of the Borrowdale Volcanic series and the local soils are mainly shallow, peaty rankers. The eastern slopes are mainly of rock and boulders while to the north are less steep and covered in rough grass and Sphagnum moss. Land use is confined to low intensity sheep grazing. Scoat Tarn has been shown by palaeoecological assessment to have acidified severely as a direct result of human-induced acid deposition. Monitoring by the UK Upland Waters Monitoring Network shows the site is now in the process of chemical recovery, with a substantial decline in inorganic aluminium and a slight increase in pH over the last two decades.