气候变化领域集成服务门户

High-latitude marine communities are dependent on sea ice patterns. Sea ice cover limits light, and hence primary production and food supply. Plankton, carried by currents from open water to areas under the sea ice, provides a transitory food resource that is spatially and temporally variable. We recorded epifaunal abundances at 17 sites in McMurdo Sound, Antarctica, over 12 yr, and found differences in communities based on location and time. The differences in location support patterns observed in long-term infaunal studies, which are primarily driven by currents, food availability, and larval supply. The temporal differences, highlighting 2004 and 2009 as years of change, match the altered persistence of sea ice in the region, caused by the appearance and disappearance of mega-icebergs. The temporal changes were driven by changes in abundance of species that filter feed on large particulates. The shift in current patterns that occurred due to mega-icebergs decreased the normal food supply in the region. In addition to the decrease in food availability, we suggest that the reduced light resulting from thicker-than-normal sea ice resulted in a shift to smaller phytoplankton. A change in food quality as well as quantity may have influenced the temporal change in epifaunal communities.