The North Sea Benthos Project 2000 was initiated as a follow-up to the 1986 ICES North Sea Benthos Survey with the major aim to identify changes in the macrofauna species distribution and community structure in the North Sea and their likely causes.The results showed that the large-scale spatial distribution of macrofauna communities in the North Sea hardly changed between 1986 and 2000, with the main divisions at the 50 m and 100 m depth contours. Water temperature and salinity as well as wave exposure, tidal stress and primary production were influential environmental factors on a large (North Sea-wide) spatial scale.The increase in abundance and regional changes in distribution of various species with a southern distribution in the North Sea in 2000 were largely associated with an increase in sea surface temperature, primary production and, thus, food supply. This

No abstract

The present study investigates the species distribution patterns and macrofaunal assemblages along the English Channel and the environmental factors contributing to observed patterns. Seven distinct macrofaunal assemblages were identified based on Hamon grab samples. In the western Channel, an Echinocyamus/Nemertea assemblage dominated, giving way to an Abra/Scalibregma assemblage in inshore waters. A Verruca/Sabellaria assemblage was identified to occupy large regions of the mid-Channel while those of the east Channel were more spatially variable. While variations in depth, sediment particle size and wave and tidal stress were significantly related to variations in assemblage structure, temperature did not appear to be greatly influential. In addition, acoustic data obtained for each station sampled allowed us to determine how representative the observed biological communities are over spatial scales somewhat larger than the sampling points. In contrast to earlier comparable studies using anchor dredges, the biological communities sampled in this study did not exhibit a large east–west distinction; the most abundant species and key assemblages were found to be present along the length of the Channel. The possible reasons for these differences with earlier studies are discussed.

No abstract

No abstract