Variability of epifauna and temperature in the northern North Sea

Benthic epifauna in three areas of the northern North Sea was studied from 1999 to 2007 to investigate the effect of temperature changes on community structure and species abundance and biomass. Abundance and/or biomass of 16 epifauna species was significantly correlated with temperature anomalies of the mean sea surface temperature (SST) from 1971 to 2000. The response of species to SST changes was different in the study areas depending on species life history and, most likely on food supply, which in turn is strongly influenced by the timing and duration of primary production and regional hydrographical conditions (e.g. stratification). Also, changes in community structure were obvious in the three areas between 2002 and 2003 coinciding with high temperature anomalies and SST. On the other hand, these changes were mainly caused by the variability in abundance of dominant species and altogether no clear trends in community structure were found. In contrast to epifauna communities in the shallow southern North Sea temperature changes in the northern North Sea affected only single epifauna species until now.