Temporal variability of three different macrofauna communities in the northern North Sea

Abstract

In 1999, 2003 and 2007 macrofauna communities were sampled in three different areas (“Boxes”) of 10 × 10 nautical miles in the northern North Sea in order to study the temporal changes in community structure in relation to changes in temperature or changes in hydrography. Box D which was influenced by the Fair Isle Current revealed an increase in abundance of sand-licking species between 1999, 2003 and 2007. Significant positive correlations between SST and abundance of characteristic species as well as different feeding types in this mixed water column area seemed to be related to enhanced primary production and SST resulting in higher food supply. Within the East Shetland Basin (Boxes L and M) temporal changes in the macrofaunal communities between 1999 and 2003 were caused by a strong decrease in abundance of surface deposit and suspension feeders which indicated a lower food supply. An increase in abundance of species known for a rapid response to sudden food supply was found in 2007. There is evidence that hydrographic conditions such as stratification and different water masses in this area influence the variability of food supply for the macrofauna and caused changes in community structure.