In the Barents Sea, phytoplankton is the main primary producer sustaining the rest of the food web. Within the phytoplankton community there is a competition for light and dissolved nutrients. The phytoplankton species in the Barents Sea are either pelagic, or linked to the ice edge in a way similar to the ice algae. Phytoplankton blooms in spring and summer and attracts concentrations of intensively feeding secondary producers and their predators. The phytoplankton is both consumed by pelagic zooplankton and sink to the seafloor and sustain benthic feeders there.
Arctic shelf systems, and the Barents Sea in particular, have been shown to exhibit a tight pelagic-benthic coupling, i.e. stocks and processes of benthic organisms seem to be highly dependent on food inputs from pelagic sources (e.g. Piepenburg, 1997, Renaud et al., 2008, Tamelander et al., 2008). Until recently it was unclear how important production from the ice algae was to either zooplankton or benthic systems. Recent studies, however, have shown that zooplankton actively graze on ice algae where they co-occur, and that ice algae can be critical to completion of zooplankton life-cycles (Søreide et al., 2008). In addition, rapidly sinking ice algae can be tracked to the seafloor (Morata and Renaud, 2008, Tamelander et al., 2008), where it is readily assimilated by both filter-feeding and surface deposit-feeding benthos (McMahon et al., 2006). Finally, correlative evidence also exists that further suggests the importance of direct input of ice algae and other phytoplankton, forming detritus for benthic communities. High density aggregations of benthic filter feeders are found on shallow banks of the Barents Sea in areas characterised by both high pelagic production and strong near-bottom currents (e.g. Wassmann et al., 2006).