Studying species associations from commercial catch data: a Baltic Sea application

Finland has 1100 km coast line with relatively strong environmental gradients. Finland has also gathered exceptionally comprehensive data on commercial catches of several fish species along the coast in relatively small units. Multidimensional scaling was applied to these data to test the hypothesis that the effects of the environmental gradients to the abundance and species composition of fish can be seen in the catches. This analysis divided the species into three groups: marine species, salmonid species and coastal species groups, the reproduction biology being the connecting factor between the species in each group. This implies that the reproduction success in a given environment is the main factor affecting the productivity and distribution of species along the coast of Finland. The commercial catch data proved informative in regard to the ecological similarity of the species.