Boreal-arctic species dominate the biomass of benthos in the Barents Sea (as well as throughout the arctic shelf), and have an optimum temperature range lying within the long-term temperature mean of the region. According to this latter theory, any deviation from the long-term mean has a negative impact on boreal-arctic species reproduction, abundance, and biomass. Some studies suggest that the decline in total biomass of benthos from 1924-1935 to 1968-1979 (Antipova 1975b) is due to a change in faunal distribution during the cold period between the 1960s and 1980s (Figure 2.6.1; Bryazgin, 1973; Antipova, 1975b; Bochkov and Kudlo, 1973), while others invoke declining biomass of resident boreal-arctic species during the 1930s-1960 warm period (Galkin, 1987; Kiyko and Pogrebov, 1997a; Kiyko and Pogrebov, 1998).
One of the most consistent features found on Arctic continental shelves, including the Barents Sea, is the tight coupling between pelagic production and benthic abundance, biomass, and processes (e.g. Piepenburg, 2005, Renaud et al., 2008). Therefore, oceanographic factors influencing the spatial distribution of pelagic production (fronts, upwelling) will often be mirrored in distribution and biomass of benthic fauna (Grebmeier et al., 2006; Wassmann et al., 2006). One feature of the Barents Sea that has received some attention is the position of the Polar Front (i.e. the border between Atlantic and Arctic water masses). Due to enhanced sedimentation of fresh phytodetritus in this region (Carmack and Wassmann, 2006), infauna in this area generally has higher abundance and biomass, and different dominance patterns, than either north or south of the Front (Denisenko et al., 2003, Carroll et al., 2008). Where the Front becomes more diffuse to the east of the Barents Sea, however, this trend is somewhat reduced (Cochrane et al., 2009). Areas of strong bottom currents and presumed high resuspension/ advection of organic material (e.g. bank areas), suspension-feeding epifaunal organisms are found in high abundances, further indicating the dependence of benthic production on food input (Wassmann et al., 2006).
Whereas benthic stocks (abundance, biomass) reflect signals of delivery of pelagic production to the sea floor that are integrated over years to decades, respiration/remineralisation rates are determined by food delivery to the sediment surface on scales of days to a few weeks (Renaud et al., 2008). Abiotic processes influencing benthic rates, therefore, include those factors affecting phytoplankton production (see above), but also short-term events that affect water column stratification, and thus both mixing of nutrients and active downward transport of particulate material. These short-term processes include ice melt, wind/storm events, brine rejection during freeze-up, and tidal action.
