2022 Cornwall Inshore Fisheries and Conservation Authority (IFCA) Fal and Helford SAC Drop Down Video Maerl Habitat and Classification Survey

Cornwall Inshore Fisheries and Conservation Authority (Cornwall IFCA) carried out a survey between May and July in 2022 of the maerl feature of the Fal and Helford Special Area of Conservation (SAC). The aim of the survey was to get a better understanding of the varying types of maerl habitats present including: dense maerl (live and dead or dead), maerl sediment (live and dead or dead), sparse maerl (live and dead), scattered maerl (live and dead), maerl veneer (live and dead, static or live and dead, mobile) and areas of potential maerl which lack detail, and to provide and updated extent and distribution map within the Fal and Helford SAC. There were two parts to this survey and the current report details the second part. The first part consisted of an initial side-scan sonar survey in the Fal and Helford SAC, which was carried out by Cornwall IFCA in 2020 and 2021 (Sturgeon et al., 2021). The initial survey gathered acoustic data within the SAC, focusing on Falmouth Bay and covered an area from Pendennis Point to the Helford River out to the Fal and Helford SAC boundary from Zone Point towards Manacle Point. This second part uses the acoustic data gathered in part one to identify transitions between different acoustic signatures, with the aim of verifying habitat types represented by the given acoustic signals, using drop down video and stills. The survey is reported on by Jenkin et al., 2023.