A blue carbon model for the European flat oyster (<scp><i>Ostrea edulis</i></scp>) and its application in environmental restoration

Abstract Historically, considerations of the carbon budget of bivalve shellfish have disproportionately focused on the cycling of carbon in shell alone, overlooking respiratory release and the potential role of bivalve shellfish habitats in the stabilization of sediment, and therefore of carbon. Data on carbon cycling are key to providing essential evidence to inform evaluation of management strategies and the business case for restoration of European flat oyster ( Ostrea edulis ) habitats. The purpose of this study was to examine the flat oyster carbon budget at the scale of the individual and to set out a framework to enable future comparisons of carbon budgets between ecosystems. Through the combination of previously established work with measurements of calcification and respiration both in situ and ex situ , a carbon budget at the scale of a single oyster was determined. In consideration of the flat oyster carbon budget, the inclusion of the deposition of sedimentary carbon, as well as carbon stored in shell, balanced with the release of carbon through respiration and calcification suggests that these habitats are unlikely to be significant carbon sinks in the context of global climate change mitigation. However, the recovery of flat oyster beds is likely to facilitate the accretion of substantial carbon stocks that are nevertheless important in conservation management.