Winfield, I.J., R. Rosch, M. Appelberg, A. Kinnerback, and M. Rask, 1997.  Recent Introductions of the Ruffe (Gymnocephalus cernuus) to Coregonus and Perca Lakes in Europe, and an Analysis of Their Allopatric and Sympatric Natural Distributions in Northern Europe, NERC Institute of Freshwater Ecology,Fischereiforschungstelle Baden-Wurttemberg, Institute of Freshwater Research, Finnish Game and Fisheries Research Institute

Abstract
Although the ruffe (Gymnocephalus cernuus) is native to many parts of Europe, its distribution has recently increased through a series of uncontrolled introductions. This three-part synthesis begins by reviewing these introductions and their perceived possible consequences for other fish species, particularly Coregonus spp. and Eurasian perch (Perca fluviatilis). The second part presents two contrasting European case histories from Lake Constance and Bassenthwaite Lake. Lake Constance is a large mesotrophic lake on the borders of Germany, Switzerland and Austria that supports fisheries for whitefish (Coregonus lavaretus) and Eurasian perch. Ruffe were first recorded in this lake in 1987 and have been the subject of study with respect to whitefish egg predation and possible competition with Eurasian perch. In contrast, Bassenthwaite Lake is a small eutrophic lake in the U.K. that does not support any commercial fisheries, but which in addition to Eurasian perch, holds one of only two U.K. populations of vendace (Coregonus albula). Ruffe were first recorded in this lake in 1991 and their potential effects on vendace through egg predation and on vendace and Eurasian perch through food competition have subsequently been studied. In the final component of this synthesis, allopatric and sympatric natural distributions of ruffe, Coregonus spp. and Eurasian perch in northern Europe are explored to examine the conditions under which native populations do and do not coexist. This is achieved through analyses using a database of nearly 800 lake fish communities in Sweden and similar data from approximately 200 small Finnish lakes.

Contact: Ian J. Winfield, NERC Institute of Freshwater Ecology, The Windermere Laboratory, Far Sawrey, Ambleside, Cumbria LA22 0LP, U.K. or ijw@wpo.nerc.ac.uk
Keywords: Ruffe, Ecological_interactions, Inland_lakes/rivers
Product Type: Publications, Conference_proceedings
User Type: General