Bottendjur i Storvänern 2021

The deep bottom fauna in both basins of Lake Väner were in 2021 at comparatively high abundances. The dominant taxonomic groups where as usual the comparatively large amphipod Monoporeia affinis, and the much smaller oligochaetes. The average size of the amphipods varies considerably between the two main lake basins, with in general much larger mean size in the Southwestern basin resulting inconsiderably higher total biomass in that basin. In 2021 the mean weight of the amphipod in this basinwas the highest noted so far for the whole lake.