The distributional pattern of benthos from different periods shows considerable variability, but demonstrates a number of more consistent features (Figure 2.4.8).
The areas with low abundance (less than 1000 individuals/ m2) and biomass (less than 10-25 g/m2) are usually restricted to bottom depressions such as the western deep-water areas in the Bear Island Channel and Hopen Deep, deep-water areas between Franz Josef Land and the shallow waters of the Novaya Zemlya bank and the deep-water areas in Eastern Basin. The high biomass areas (biomass hotspots) are usually located in connection with considerable rises in sea-floor topography and generally typical for the areas with hard soil and strong currents (Kiyko and Pogrebov, 1997a).
The rich communities within these areas are dominated by epifauna, where the majority of species are suspension feeders. Biomass has also been found to be significantly elevated in Polar Front areas, where there is a tight coupling between primary production and the benthos (Carroll et al., 2008). Whereas the distribution of zoobenthos in the Barents Sea is related to depth, near-bottom temperature and sediment type (Dahle et. al, 1998; Denisenko, 2007), perhaps the most important factor determining the benthos biomass and distribution is the abundance and availability of food supply for benthic organisms (Zenkevich, 1961; 1970; Carmack and Wassmann, 2006; Wassmann et al., 2006; Denisenko, 2007; Carroll et al., 2008). Quantitative characteristic of benthos along the Kola section are depended not only on temperature but also on bottom fish trawling. Denisenko (2001) showed a decrease of more than 60 % in the benthos biomass (Figure 2.4.9 left) and concluded that there was a relation between decreased benthos biomass (Figure 2.4.9 right) and high intensity of bottom fish trawling in the main fishery areas.
In regions such as the Barents Sea, spatial variability in food abundance is linked to ice cover patterns. In heavily ice-influenced areas, with low annual primary production, the faunal abundance was significantly lower than that in the more productive southern waters (Cochrane et al., 2009; Figure 2.4.10).