Fish Species Richness in Polish Lakes

Global warming, eutrophication, fisheries overexploitation, species invasions, and habitat loss are the major threats to freshwater biodiversity. The aim of this study was determine richness diversity fish in 535 Polish lakes different morphometry (area more than 50 ha a maximum depth ranging from 0.4 108.5 m) trophic status (from oligotrophy hypereutrophy). A total 39 were found studied lakes, among which eight alien invasive. Shannon index varied between 0 2.04.The most common frequent Rutilus rutilus (99.8% frequency) Perca fluviatilis (99.6% frequency). Ten species, including five ones, characterized by very low frequency (<1%). number single ranged 1 19. In 11 12 (104 108 respectively) caught. richest taxonomic composition (19 species) recorded meso-eutrophic lake with an area 80 34.4 m, slightly poorer (18 hypereutrophic 168 2.7 m. poorest (one conductivity circumneutral pH. Statistical analysis showed that decreased increasing eutrophication conditions while it increased these lakes.