Carbon Sink Capacity and Its Value Evaluation of Mariculture in Fujian Province, China

【Background】Seawater aquaculture carbon sinks underpin marine carbon sequestration, with important scientific and practical implications. As a key mariculture region in China, Fujian still lacks a full-scale evaluation of its aquaculture carbon sink potential and economic value. This study adopts LMDI to quantitatively evaluate the carbon sequestration potential of local shellfish and macroalgae cultivation. It also employs carbon tax price mechanisms to conduct a systematic economic valuation of mariculture-based carbon sinks.

【Method】This study focuses on Fujian’s shellfish and macroalgae aquaculture. It first establishes biomass accounting models for carbon content and dry–wet ratio of shellfish and algae based on 2011–2025 data from the 《China Fishery Statistical Yearbook》. It then applies a Man–Kendall test and Theil–Sen estimator to analyze the spatiotemporal dynamics of carbon sink capacity. Finally, combined with 《Blue Carbon Accounting Protocol》, a custom economic valuation model is built to quantify the carbon sequestration economic value of these aquaculture systems.

【Results】From 2010 to 2024, Fujian’s shellfish carbon sink capacity rose by 54.04%, alongside a 133.52% growth in macroalgal carbon sequestration. Fujian possesses prominent sequestration potential for both species. Following the existing growth trajectory, the region’s overall carbon sink capacity is projected to hit 2.709 million tons by 2030. In economic valuation, SCE dominates Fujian’s shellfish and macroalgae carbon sinks at 97.61%, while STE merely constitutes 2.39%, revealing substantial scope for STE enhancement.

【Conclusion】This study addresses a core research gap by systematically evaluating Fujian’s seawater aquaculture in terms of its carbon sequestration potential and economic value. The findings strengthen the theoretical and methodological foundation for regional blue carbon research, facilitate the upgrading of local mariculture, and promote the green transition of seawater aquaculture in Fujian. This further supports the healthy development of the marine economy.