2022-2024 FISP: Ecosystem Benefits of UK Oyster Aquaculture Sites Mumbles 2023 Dredge Sampling Survey

As part of the Fisheries Industry Science Partnerships (FISP) project 'Ecosystem Benefits of UK Oyster Aquaculture Sites' project partners Tethys Oysters Ltd. / Atlantic Edge Oysters Ltd., Envision Marine Ltd. and the University of Essex have collaborated in a research project to determine ecosystem benefits provided by oyster aquaculture by measuring biodiversity and denitrification activity at a variety of sites in England and Wales. Surveys were undertaken by ENVISION in 2023 to measure the biodiversity associated with three oyster farms and one naturalised rock oyster reef in comparison to control sites with similar environmental conditions, as well as ecosystem function (nitrification/denitrification activity) at these sites. Recognising the importance of conservation and restoration of native oyster populations, surveys were also carried out in 2022 and 2023 to measure oyster abundance and associated biodiversity at an historic native oyster site, commercially restocked with native oysters in 2021. Survey works included recording of underwater imagery, sediment sampling, oyster dredging and ecosystem function sampling. Underwater camera systems were used to record the diversity of biota around the oysters during submersion. Sediment samples were taken for measurement of diversity of macrofauna, particle size distribution and total organic carbon, and the ecosystem function testing involved sampling of sediment and swabs of oysters/hard surfaces to determine the abundance and activity of denitrifying/nitrifying microorganisms on oyster site substrates, through genomic analysis. The results of the denitrification and biodiversity services provided by oyster aquaculture were communicated to consumers, industry and decision makers to increase understanding and promote awareness of the ecosystem benefits provided by aquaculture.