Abstract:Based on the Intergovernmental Panel on Climate Change interpretation of carbon sink and carbon source, and the characteristics of carbon sequestration by aquatic plants, this review revises the definition of fisheries carbon sink and carbon sink fisheries proposed in 2010. We emphasize the basic expression of the function of fisheries carbon sink and the important role of aquatic plants in them. We further explain the process and mechanism of promoting aquatic organisms to "remove and store" greenhouse gases (such as carbon dioxide) through algae culture, filter-feeding shellfish and fish aquaculture, fishing and enhancement of fishery stock, and other means. We analyzed the process and mechanism of carbon dioxide use by non-fed shellfish aquaculture by filtering phytoplankton and particulate organic matter, such as organic debris. Further, the characteristics of carbon usage, removal, storage, and release, and their quantitative relationships with energy budget are discussed. The analyses confirmed that shellfish aquaculture enhances the carbon sink capacity of aquatic ecosystem, and is a carbon sink rather than a carbon source. Our results revealed that with the continuous development of mariculture production, the carbon sink of shellfish mariculture in the coastal ocean of China has substantially increased in the past 20 years. The total carbon sink increased from 3.94 million tons in 2001 to 6.59 million tons in 2020. This included an average of 6.48 million tons/year in the past three years (2018—2020), equivalent to 870 000 hectares of compulsory afforestation per year. The net carbon sink increased from 2.55 million tons to 4.3 million tons in 2020, with an average of 4.22 million tons/year in the last three years (2018—2020), equivalent to 560 000 hectares of compulsory afforestation per year. Finally, relevant suggestions for sustainable and further development of carbon sink fishery are proposed.
