Macro-infaunal biodiversity and analysis of associated feeding guilds in the Greater Minch area, Scottish west coast

Abstract

Survey work was carried out in the Greater Minch area on the west coast of Scotland in 1997. The survey covered an area of 17,000 km2, extending from Kinlochbervie in the north-east to the Stanton Banks in the south-west. Acoustic and ground-truth surveys were conducted using the seabed discrimination system RoxAnn© and underwater television cameras. This paper examines the macro infaunal component of the benthic community from 28 stations sampled throughout the region. From these, 198 taxa were identified, while species per station ranged from 11 to 69 with a maximum abundance of 2100 individuals per m2. Biomass ranged from 2·3 g m−2 to 103·1 g m−2, with a mean value of 21·0 g m−2. Multivariate statistical analysis of the infaunal data revealed the presence of three benthic assemblages, which were closely related to habitat type. An investigation into the dominant feeding guilds or isotrophic groups from each assemblage revealed that surface deposit feeding dominated the very fine sand habitats while both surface and subsurface deposit feeding were very common in the silt communities. A combination of feeding types (namely carnivorous, suspension and surface-deposit feeding) was associated with the sand habitats. The findings of this study are discussed in relation to those in similar habitat types.