Long-term patterns of rocky bottom macrobenthic community structure in an Arctic fjord (Kongsfjorden, Svalbard) in relation to climate variability (1980–2003)

We investigated temporal variations in marine macrobenthic community structure from 1980 to 2003 in high-arctic Kongsfjorden (Svalbard) based on analysis of annual photographs at a permanent rocky bottom station. Abundance and area covered by macrobenthic organisms were estimated based on image analysis of high-resolution photographs, and community summary parameters were calculated as the basis for examination of interannual patterns. Interannual variability in abundance and species diversity were related to climate variability. 45% of the variability of the benthic community in Kongsfjorden could be attributed to environmental factors linked to the North Atlantic Oscillation Index (NAOI) and its local manifestations. The temperature of the West Spitzbergen Current (WSC) was a link between the NAOI and the benthic community. Biodiversity was negatively correlated to the NAOI. Severe changes in the benthic community were observed between 1994 and 1996 coinciding with a shift of the NAOI from a positive to a negative mode. The increase in biodiversity during this period was accompanied by a decline of actinarians and the appearance of dense carpets of brown algae.