Comprehensive estimation and spatiotemporal differentiation of marine fishery carbon sinks in China's coastal provinces

Increasing the carbon sink capacity of marine fisheries is a key strategy toward achieving carbon neutrality. Comprehensive estimation of marine fishery carbon sinks and analysis of their spatiotemporal differentiation are essential to accurate assessments of their potential. However, previous studies have primarily focused on carbon sinks from marine shellfish and algal aquaculture, while overlooking those from marine capture fisheries. In this study, we developed a comprehensive estimation framework for carbon sinks associated with marine shellfish aquaculture, algal aquaculture, and capture fisheries. We also conducted a thorough assessment of marine fishery carbon sinks in China's coastal provinces from 2008 to 2022. Additionally, the spatiotemporal differentiation of China's marine fishery carbon sink was analyzed using the Dagum Gini coefficient and β-convergence model. The results indicate that China's marine fishery carbon sink has exhibited a slight downward trend, decreasing from 13.97 million tons in 2008 to 11.64 million tons in 2022. The distribution of the marine fishery carbon sink across China's coastal provinces is spatially uneven, with higher levels observed in eastern and southern coastal provinces and lower levels in northern coastal provinces. China's marine fishery carbon sinks exhibit a β-convergence characteristic and a catch-up trend in which regions with lower carbon sink levels experience faster growth. To further enhance the marine fishery carbon sink, it will be essential to implement additional protection and restoration projects, optimize regional development strategies for marine fishery carbon sinks, and establish incentive mechanisms to accelerate the improvement of these carbon sinks.