Bottendjur i Storvänern 2022

The population density on lake Vänern's deep bottoms was at a normal level at Tärnan in Värmlandssjön, while at Megrundet in Dalbosjön the density was higher than the long-term average. As usual, the dominant groups were the amphipod Monoporeia affinis, and the much smaller oligochaetes, which applies both in terms of density and biomass. At Tärnan, the total biomass was at a comparatively normal level, while at Megrundet it was lower than normal despite comparatively high densities. This is mainly because the amphipods were generally small specimens, making the average weight the second lowest recorded for the site