Assessment of carbon sink capacity and potential of marine fisheries in China under the carbon neutrality target

Abstract

Increasing carbon sequestration and sink through marine fisheries is an important way to achieve“carbon neutrality”, in which the key lies in the scientific, accurate, and systematic calculation of the carbon sink capacity of marine fisheries. In this study, some carbon without carbon sink function in the classical“removable carbon sink”model was removed, and the carbon sink formed by shellfish and algae by releasing particulate organic carbon (POC) and dissolved organic carbon (DOC) was included. Using the panel data of production of shellfish and algae in nine coastal provinces of China’s mainland from 2006 to 2020, the carbon sink capacity of China’s marine fisheries was evaluated, and the contributing factors to the improvement of China’s marine fishery carbon sink capacity were deconstructed based on the Logarithmic Mean Divisia Index (LMDI) decomposition method. Then we predicted the potential of China’s marine fishery carbon sequestration by 2030 under different scenarios. The results show that: (1) The carbon sink capacity of China’s marine fisheries will reach 3.03 million tons in 2020, with significant regional differences; (2) Including carbon without carbon sink function will overestimate the carbon sink of marine shellfish fishery by 24.24%, while ignoring the carbon sink formed by shellfish and algae by releasing POC and DOC will underestimate the carbon sink of marine fishery by 50.70%; (3) Under the current development model that relies on scale effect, the carbon sink capacity of marine fisheries will reach 3.36~4.00 million t by 2030, and the growth potential of carbon sink is very limited. Based on this, China should promote its marine fishery carbon sequestration growth to a technology- driven and high- quality development model to continuously improve the coastal provinces’marine fishery carbon sequestration capacity and contribute to the realization of the target of carbon neutrality.