2011 Scottish Natural Heritage (SNH) Lochs Linnhe, Etive, Leven and Eil broadscale validation benthic survey - part B

The purpose of this benthic survey of Lochs Linnhe, Etive, Leven and Eil was to carry out a broadscale validation survey of historical records and to assess the distribution and condition of beds of flameshells (Limaria hains), horse mussels (Modiolus modiolus), intertidal blue mussels (Mytilus edulis) and sea loch egg wrack (Ascophyllum nodosum ecad mackaii). Additional aims included assessment of the current condition of recorded instances of northern sea fan and intertidal tide-swept algal communities. Surveying in the Linnhe sea lochs system was split into two parts, A and B. Part A was a coarse grained characterisation of the search feature distribution, carried out by the Scottish Association for Marine Science (SAMS), that incorporated remote benthic sampling using a combination of grab and video (DDV and ROV). Part B (described here) was chiefly to examine discrete beds of specific PMFs, undertaken by Heriot-Watt University (HWU), using divers to provide detailed survey analyses on targeted high priority features, shore based survey methods and drop-down video. This study aimed to determine whether PMFs and MPA search features were still present at previously documented locations. A drop-down video and diver survey was conducted by HWU for SNH between the 18th June and 4th November 2011 to collect detailed biological information on the seabed species and habitat features present. Drop-down video drift tows were undertaken at 38 sites within the Linnhe sea lochs system study area from the RV Serpula, principally as a component of the localised dive surveys of flame shell and horse mussel beds. The images, analysed under SNH contract by HWU, were used to describe the nature of the seabed in terms of the physical structure and the species assemblages. Localised surveys (combination of DDV, dive and diver MNCR phase-two) were carried out at 9 sites to assess the distribution, extent and condition of the high priority PMF MPA search features. The vessels RV Seol Mara and RV Serpula were used for this survey. This work was funded by Marine Scotland as part of the Scottish MPA project.