Abstract
Under carbon emission reduction constraints, accurately assessing the spatial–temporal patterns and drivers of mariculture carbon emissions and sinks is critical for promoting marine economic development and achieving carbon neutrality. This study reviews key components of China’s mariculture carbon and analyzes provincial data from 2008 to 2023 using econometric models to estimate emissions, sinks, and net carbon values. Spatial heterogeneity and spillover effects are examined through geographically weighted regression, Moran’s I, and spatial Durbin models. The findings indicate the following: (1) Both direct and indirect mariculture carbon emissions are rising, with indirect emissions growing faster, notably in Shandong, Fujian, and Guangdong. (2) Shellfish carbon sinks generally dominate; algal carbon sinks are growing rapidly, especially in Fujian, Zhejiang and Shandong. (3) Net carbon values vary by region—positive in Liaoning, Hebei, Shandong, and Hainan, and negative in Jiangsu, Zhejiang, Fujian, Guangdong, and Guangxi. (4) Energy intensity increases emissions; industrial upgrading reduces them. Technological innovation, energy intensity, and ecological constraints enhance sinks. (5) Emission spillovers are positive for energy and negative for structure; sink spillovers are positive for energy and negative for technology; ecological effects are insignificant. Overall, shellfish and algae mariculture play a key role in China’s marine carbon sequestration. Regionalized carbon governance is essential to balance emissions–sinks, and to advance low-carbon mariculture.