Macrofaunal community inside and outside of the Darwin Mounds Special Area of Conservation, NE Atlantic

摘要

Spatial distribution and patchiness of deep sea macrofaunalcommunities were studied from samples collected in the Rockall Trough, NEAtlantic. In June 2011, two areas, located outside and within the DarwinMound Special Area of Conservation (SAC), were sampled. Three megacores weredeployed in each area at approximately 900 m depth. The two areas,~ 18 km apart, did not differ in terms of sediment organic matter andpercentage of mud content, but small significant differences were found insediment median grain size and depth. Macrofaunal communities were found todiffer significantly, with the difference mostly driven by changes in theabundance of polychaetes, crustaceans and nematodes whilst no significantdifferences were seen for the other phyla. Whereas overall macrofaunalabundance was higher outside the SAC compared to within, this pattern variesconsiderably between phyla. Diversity indices showed no significantdifferences between protected and unprotected sites. Deep-water trawlingregularly take place outside the Darwin Mounds SAC whilst the area inside theSAC has been closed to bottom trawling since 2004, and the above distributionpatterns are discussed in the context of both environmental and anthropogeniccauses.