Ecological shifts in polar shelf bottom habitats in response to climate change:
Bottom communities (benthos) of Arctic and Antarctic shelf seas differ pronouncedly in composition, diversity, and ecosystem functioning, reflecting the major evolutionary and ecological disparities between the two polar regions.
Though polar systems are in general thought to be particularly sensitive to climate-induced environmental changes, it is likely that Arctic and Antarctic bottom assemblages will respond differently to the external forcing.
In the Arctic, higher water temperatures, increased fluvial run-off and reduced ice cover are assumed to give rise to severe ecosystem changes propagating through all trophic levels, ultimately resulting in a shift in the relative importance of sea-ice, pelagic and benthic biota in the overall marine carbon and energy fluxes and a switch from a ‘sea-ice algae–benthos’ to a ‘phytoplankton–zooplankton’ dominance.
In contrast, circumpolar significant shifts in the Antarctic benthos as a direct response to sea-temperature rise are not likely for the near future. Instead, a continuing disintegration of ice shelves and shrinking of the sea-ice will impact bottom communities at a regional scale. Acidification might become a major problem for marine organisms in both polar areas.