The purpose of this benthic survey in Loch Sween was to determine species composition, diversity and biotope. Sublittoral sediment sampling was undertaken by SEPA for SNH as part of SNH's review of existing and new benthic data to ascertain the current marine nature conservation value of Loch Sween and inform the need for new survey work. Grab sampling was undertaken at 24 sites on the 22nd and 23rd November down the length of the loch from Sailean Mhor to the Loch approaches to collect detailed biological information on the seabed species and habitat features present.The purpose of SNH contracting Precision Marine Survey Ltd to analyse the infaunal data obtained from this survey by SEPA was to improve knowledge of the occurrence and distribution of species and habitats of recognised conservation importance, particularly priority marine features (PMFs). Video was also taken at a limited number of sites but due to adverse weather conditions visibility was exceptionally poor so the footage provided little information on the biota present.