Positive tipping points for the sustainable growth of bivalve shellfish mariculture in England and Wales

Shellfish mariculture, the farming of marine bivalve shellfish, is a highly sustainable form of food production, which contributes significantly to the rural, coastal economies of England and Wales, and has considerable potential for growth. To unlock this potential, we explored the application of the positive tipping points (PTP) framework in an invited stakeholder workshop comprising key policy makers, regulators, industry representatives and academic researchers. Stakeholders mapped environmental and socio-economic factors constraining shellfish mariculture and identified key opportunities (leverage points) for positive intervention. The workshop focused on five case studies from southwest England addressing key constraints identified for the shellfish industry, including "licencing", "spatial planning" and/or "classification" of shellfish sites and cultured species. These case studies presented new data on the effectiveness of a range of interventions: i) catchment scale, and ii) nature -based, solutions for water quality management in the Exe estuary; iii) risk -based methods for assuring shellfish quality/safety in the Camel estuary; iv) evidence gathering on ecosystem services (habitat provisioning) by shellfish mariculture in Lyme Bay and, v) policy developments on licencing of Pacific oysters in England. Stakeholders highlighted opportunities for new guidance, innovative tools and technology to aid environmental monitoring, regulation and quality assurance for shellfish mariculture and for tradeable ecosystem services beyond food production (including nutrient regulation, coastal protection and habitat provisioning). These and other interventions identified by stakeholders (including product diversification and market development) were then prioritised and sequenced for optimal implementation. Actions, actors and enabling conditions were identified using the PTP framework to realise prioritised opportunities.