Structure of Fish Communities in Lakes and Its Abiotic and Biotic Determinants

Abstract

We summarize the scientific knowledge about lake fish communities with respect to taxonomic and functional diversity, to patterns of abundance and biomass, and to size structure. The majority of studies have been conducted in temperate areas of the Palearctic and Nearctic, but we added more scarcely available data about fish communities from Arctic and Sub-Arctic lakes and from tropical and sub-tropical regions. We adopt the model of hierarchical filters to elucidate how regional and local factors and processes create the local community. The chapter is framed by a short overview on historical processes such as speciation and colonization that shaped regional species pools, and hence form the source for locally available species. Contemporary processes forming regional species pools are colonization by dispersal and extinction, the latter often caused by anthropogenic pressures on freshwaters. A major determinant of large-scale occurrence, abundance and size of fish species is the thermal structure of lakes. Lake morphometry determines the lake stratification type, the temperature gradients and the habitat diversity, and therefore affects both presence of species and their abundances and sizes. Lake productivity affects primarily species abundances and size distributions. Furthermore, biotic processes such as predator-prey interactions and competition may contribute to forming local lake fish communities, but their effects on species occurrences is less clear than their effects on abundances and size structure. We close the chapter by a final paragraph on research areas that are seen promising with respect to advancing the knowledge about lake fish communities in future.