Carbon sink efficiency of Chinese mollusk mariculture.

Chinese mollusk mariculture plays a key role in boosting ocean carbon sink capacity through biological processes, supported by large-scale production. However, its full potential remains underutilized due to the absence of comprehensive efficiency evaluations. This interdisciplinary study applies a three-stage approach to assess the carbon sink efficiency of Chinese mollusk mariculture, with a focus on regional variations across nine coastal provinces from 2012 to 2022. The results show that environmental variables and statistical noise distort efficiency scores, leading to overestimation in six provinces and underestimation in three. After adjusting for these influences, regional disparities in efficiency become more apparent. High-production provinces such as Shandong, Fujian, and Guangdong exhibit higher efficiency, while low-production provinces like Hainan show diminished performance. Although there is a positive correlation between production volume and carbon sink efficiency, further improvements are constrained by the sector's low profitability. To address this, we propose two strategies: (1) reallocating subsidies from capture fisheries to mollusk mariculture, and (2) accelerating carbon trading between mollusk mariculture and other industries. These measures could enable the global mollusk mariculture to enhance both its carbon sink capacity and efficiency, contributing to food security and climate change mitigation. • A three-stage approach integrating DEA and DEA-Malmquist paradigms for quantitative evaluations. • Comparison on regional variations and evolutionary trends before and after eliminating the interference of external factors. • Strong positive correlation between carbon sink efficiency and mollusk mariculture production. • Fundamental constrains to efficiency enhancement and solutions for achieving both ecological and economic benefits. [ABSTRACT FROM AUTHOR]