This report presents the environmental and ecological data acquired from a drop-down camera and benthic grab survey of the Plymouth Sound area of Plymouth Sound and Estuaries SAC in 2021. The report compares the features of the SAC in 2021 with those recorded in previous surveys.
Sample stations were selected to enable temporal comparison with 2011 and/or 2015 survey data. Grab samples were successfully collected at 43 stations, and triplicate infauna samples were obtained at 17 of these stations. Grab samples were analysed for biomass (of each major taxonomic group), macrofauna and particle size [analysis] (PSA) in accordance with NMBAQCS protocols.
Imagery data was collected at 15 stations. Deployment of the drop camera was in accordance with the relevant guidelines (Coggan, R. et al., 2007 & NMBAQCS, 2015).
The 2021 survey data showed no indication that the extent and distribution of habitat features had changed in comparison with the 2011 and 2015 sediment data or the 2017 to 2021 dive data. There was no evidence that there had been significant ecological changes in the biotope community structure, notable species, or ecological function within the SAC.
Recommendations for future surveying, interpretation and assessment of the SAC include aiming to maximise the resolution at which species are recorded, consideration of data analysis using different survey methods, and the identification of key structural and functional taxa in future monitoring.
This report will inform a later condition assessment and management activities for this site.