A blue carbon model for the European flat oyster (Ostrea edulis) 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.

Sounding out horse mussel sediment thickness: an integrated data approach

“…The integrated approach of horse mussel bed analysis through core, SBP, DDV, and abiotic data is also framed within an eco-social economics framework for climate change mitigation and adaptation (Sheehy et al, 2024a). A robust dataset, including respiration and calcification processes (Lee et al, 2024), of horse mussel bed sediments supports carbon accreditation processes and inclusion in blue carbon policy frameworks. In turn these can provide tangible benefits and incentives for policy makers and local communities to take a pro-active approach to blue carbon protection and restoration.…”

“…This SEM approach can link a wider range of abiotic data that might be suitable at large scale, to a multitude of biotic data, ecosystem service value, accreditation criteria, and carbon credit value based on tier level assessment. Alternatively, latent variables could be structured to include calcification and respiration processes (Lee et al, 2024) determine whether the horse mussel bed acts as a carbon source or sink (Fodrie et al, 2017).…”