On the distribution of sympagic macro-fauna in the seasonally ice covered Barents Sea

摘要

The sympagic fauna (= sea ice fauna) of the Barents Sea was investigated on nine (2–5 weeks) cruises in the period 1983–1988. The amphipodsApherusa glacialis, Onisimussp. andGammarus wilkitzkiiwere the most conspicuous and abundant invertebrate species associated with the ice. Mean biomass-values ranged from 0 to about 2 g/m2, and were less than 0.001 g/m2in five of the nine cruises.Apherusa glacialis, Onisimussp. andGammarus wilkitzkiiare regarded as autochthonous sympagic species, and as such dependent upon a permanent ice cover. Allochthonous sympagic species were few and without significant importance. The variations in species abundance and biomass were believed to be closely connected to the age and drift-history of the ice. The density of the sympagic fauna increases as a result of increasing influx of ice into the Barents Sea from the Arctic Ocean. Density of the sympagic fauna were believed to increase with decreasing distance to the multiyear/first-year ice boundary.A. glacialiswas found further away from the spreading centers and in higher numbers than the other sympagic species due to its greater motility. No day-night variations in the occurrences of the sympagic fauna were recor