Chemistry and fish status of 67 acidified lakes at the coast of Aust-Agder, Southern Norway, in relation to post-glacial marine deposits

Abstract

67 lakes in a 0-15 km wide coastal zone within Aust-Agder County in Southern Norway have been investigated. The area receives 1,5 g S/m² and, 1,7 g N/m² as wet deposition. All lakes had about the same concentration of non-marine sulphate. Lakes in southwest were significantly less influenced by post-glacial marine deposits and markedly more acidified than lakes in the northeastern part of the region. Twentyone, probably 23, of the lakes were barren of fish. Lakes with pH higher than 5,5 in May had a broad spectrum of year classes. These fish populations represent a valuable resource in the region.