The gross ecosystem product of oyster reefs

Abstract

Oyster reefs are critical interfacial habitats that underpin coastal and marine bio-diversity, and enhance multiple ecosystem services of blue carbon habitats, including water filtration and shoreline stabilization. However, despite this ecological value, oyster reefs have suffered dramatic global declines. The absence of a systemic economic valuation of oyster reef ecosystem services introduces deep uncertainty in the prioritization of restoration areas, thereby constraining coordinated large-scale transboundary conservation, restoration, eco-engineering efforts, and policy. Here, we novelly introduce and estimate the gross ecopotential , or Gross Ecosystem Product (GEP), as a systemic index of reef ecosystem services grounded in ecological fitness. Fitness is assessed by habitat suitability (HS) at a ∼9.2 km resolution globally. The ecopotential is calculated as a multicriteria socio-ecological value function combining potential oyster trade value with monetary scenarios for the quantified shell-carbon component, water filtration and nutrient removal. Potential effects on adjacent vegetated blue-carbon habitats are discussed as conceptual pathways but are not included in the numerical carbon valuation. We highlight ten hotspot countries – the USA, Australia, Chile, China, Japan, South Korea, Argentina, France, Germany, and Italy – where HS and restoration opportunities are the highest. Seabed light availability and minimum primary productivity, reflecting phytoplankton biomass, emerged as the dominant global drivers of oyster reef HS and GEP. At the reference threshold ( HS ≥ 0.65), approximately 23% of predicted high-HS habitat overlaps the evaluated marine and coastal protected-area network, and approximately 10% of high-HS cells in the hotspot analysis coincide with occurrence records. Because the presence-only archive is incomplete and unevenly sampled, high-HS cells without an occurrence record are interpreted as candidates for further survey rather than confirmed oyster absences. Hydrogeomorphic analyses indicate that ecosystem morphology drives GEP through distinct routing of ecological flows: ∼72% of reefs occur in estuaries, 21% in lagoons or inlets, and 7% in river deltas. Our findings highlight the considerable GEP of oyster reefs when conservation, restoration, and regeneration are interconnected actions with systemic and global impact. The proposed GEP approach integrates publicly available socio-ecological and economic data to generate decision-relevant priority insights for restoration planning. Digital Eco-Information layers, identifying existing and potential reef habitats with high GEP, are provided, including their hydrogeomorphic flows and cascading ecosystem services. The model is readily tunable to higher-quality data and broadly extensible to other biogenic species and habitats, providing a scalable baseline for blue-carbon ecosystem management and future scenario development.