fish status survey of nordic lakes: effects of acidification, eutrophication and stocking activity on present fish species composition.the status of fish populations in 3821 lakes in norway, sweden and finland was assessed in 1995-1997. the survey lakes were chosen by stratified random sampling from all (126 482) fennoscandian lakes > or = 0.04 km2. the water chemistry of the lakes was analyzed and information on fish status was obtained by a postal inquiry. fish population losses were most frequent in the most highly acidified region of southern norway and least common in eastern fennoscandia. according to the inquiry results, ...200312733793
the interactions of abiotic and biotic factors influencing perch perca fluviatilis and roach rutilus rutilus populations in small acidified boreal lakes.four small, acidified boreal lakes, all sustaining populations of perch perca fluviatilis, roach rutilus rutilus and pike esox lucius, were studied in four successive years. three lakes were moderately acidified (mean ph of 5·61-5·83), while the fourth was more acidic (mean ph of 5·16) and had a sparse population of r. rutilus. perca fluviatilis density was higher in this lake (1004 ha(-1)) than in the other three (355-717 ha(-1)), where r. rutilus dominated in terms of numbers (981-2185 ha(-1)) ...201121781101
Displaying items 1 - 2 of 2