A review of blue carbon credit projects' socio-economic activities

Coastal ‘blue carbon’ ecosystems (mangroves, seagrasses and saltmarshes) are critical for climate regulation and biodiversity, yet significant funding gaps persist in marine conservation. While blue carbon credits are increasingly used to bridge these gaps, concerns remain regarding their efficacy in delivering socio-economic benefits. Based on lessons from terrestrial carbon markets, failing to prioritise local community needs can lead to inequitable outcomes and externally mandated constraints, which undermine the legitimacy of nature-based solutions. This research seeks to add to the centralised understanding of the social dimension of blue carbon by delivering a comprehensive review of 77 publicly listed projects from global and regional carbon registries. We employed a thematic domain analysis to categorise intended socio-economic activities and used the Sustainable Development Goal (SDG) framework to evaluate their alignment with international sustainability targets. We found that blue carbon project proponents, that is the organisations responsible for developing and implementing these projects, target a diverse array of SDGs far beyond ‘Life Below Water’ (SDG 14). We identified a shift towards integrating broader international development activities, such as infrastructure improvement, cultural heritage preservation and water, sanitation and hygiene (WASH) services. Quantitative mapping demonstrates that these non-carbon activities relate most strongly to SDG 8 (Decent Work and Economic Growth), SDG 2 (Zero Hunger) and SDG 5 (Gender Equality). However, the study identifies a systemic lack of transparency regarding how activities are selected, the role of community co-design and the mechanisms for long-term monitoring and evaluation. We provide a baseline analysis of how blue carbon project proponents embed sustainable development principles. Addressing these procedural, distributive and evaluative gaps is essential to ensure that blue carbon markets are developed equitably, fostering social and ecological co-benefits while supporting international sustainability targets. To ensure blue carbon markets are developed equitably, practitioners and policymakers must move beyond participatory gestures towards robust procedural equity and enhancing project accountability. By integrating clear socio-economic baselines and measurable social impact criteria, blue carbon project proponents can transition projects from simply carbon-offsetting tools into trusted, holistic investments that foster resilient coastal communities and secure the long-term integrity of global marine ecosystems. Read the free Plain Language Summary for this article on the Journal blog.