Study on ecosystem services of bivalve mollusc and fish farming in ponds and wetlands

This study synthesises evidence from a systematic literature review and stakeholder consultations to assess the positive environmental effects of marine bivalve aquaculture and finfish farming in ponds and wetlands.

Benefits are largely linked to ecosystem services, particularly regulation and maintenance functions involving bio- and physico-chemical water processes, nutrient cycling, improved water quality, sediment stabilization, benthic–pelagic coupling, nutrient sequestration and enhanced biodiversity.

Provisioning services relate to the production of nutritious, low-emissions food, while cultural services include socio-economic benefits. Risks and potential negative impacts are highlighted, stemming mainly from excessive nutrient accumulation which can degrade water quality, foster eutrophication, cause light attenuation, alter sediment geochemistry and change ecosystem configuration. Additional risks include invasive species introductions, disease and plastic pollution, though these are considered low severity.

Risks and potential negative impacts are not inherent to the farming systems but occur due to regulatory oversight and poor management practices, and the study identifies mitigation measures where negative impacts do occur.

Stakeholders generally viewed aquaculture-environment interactions positively, and opportunities for development centre on better promotion of their low-impact or positive environmental contributions, although significant environmental, regulatory and socioeconomic challenges still present barriers. Good-practice examples, including from terrestrial agriculture, highlight tools and pathways for sustainable expansion.