Selsey Bill and the Hounds MCZ DropDown Camera and Grab Surveys 2023.
Abstract
This report presents the survey of Selsey Bill and the Hounds Marine Conservation Zone (MCZ), with Seastar Survey Ltd. undertaking a drop-down camera and grab sampling survey of the MCZ. A total of 22 camera transects were completed, yielding 4 hours and 21 minutes of analysable footage and 376 still images. Grab sampling was attempted at 19 stations, with samples for macrobenthic invertebrate analysis successfully collected at 16 stations and samples for particle size analysis successfully collected at 17 stations. The underwater imagery data analysis results indicated that the seabed within the MCZ was fairly heterogenous, with a total of 16 biotopes identified. The grab samples were characterised by medium to very fine sands and gravels. Several habitats of conservation interest were identified. Subtidal sands and gravels were widespread throughout the MCZ. Blue mussel (Mytilus edulis) beds were identified at a single station in the inshore region of the MCZ, and patchy clay exposures were recorded at two stations. Annex I reef features were present either as flat bedrock or as areas of cobbles overlying soft sediments. Undulate skate, Raja undulata, a species of conservation interest, was identified from video footage at two sampling locations.