渔业碳汇与碳汇渔业定义及其相关问题的辨析

Clarification on the definitions and its relevant issues of fisheries carbon sink and carbon sink fisheries

中文关键词: 渔业碳汇  碳汇渔业  贝类养殖碳使用、移出、储存与释放  贝藻碳汇量评估  发展建议

英文关键词: Fisheries carbon sink  Carbon sink fisheries  Farmed shellfish carbon usage, removal, storage, and release  Carbon sink assessment for shellfish and macroalgae mariculture  Development suggestions

中文摘要:

      本文基于联合国政府间气候变化专门委员会(IPCC)关于碳汇和碳源的解释和水生植物固碳特点，对2010年提出的渔业碳汇和碳汇渔业的定义进行修订，强调了渔业碳汇功能和增汇的基本表达方式和水生植物在渔业碳汇中的重要作用，进一步解释了通过水生藻类养殖、滤食性贝类和鱼类等养殖、渔业生物群体捕捞和增殖等渔业生产活动促进水生生物“移出和储存”CO2等温室气体的过程和机制。分析了贝类养殖在不需要投放饵料的前提下，通过滤食浮游植物及有机碎屑等颗粒有机物大量使用水体中CO2的过程及机制，从能量收支层面论述了使用碳、移出碳、储存碳和释放碳4个碳库的特征及其数量关系，进而证实贝类养殖提升了水域生态系统碳汇能力，是碳汇而不是碳源。贝藻养殖碳汇评估结果表明，随着海水养殖生产持续发展，近20年我国近海贝藻养殖碳汇有较大幅度的增加，总碳汇量从2001年394万t增加到2020年659万t，其中近三年(2018—2020)平均总碳汇量为648万t (相当于每年义务造林87万hm2)；净碳汇量从2001年255万t增加到2020年430万t，近三年(2018—2020)平均净碳汇量为422万t (相当于每年义务造林56万hm2)。最后，提出了健康持续、深入发展碳汇渔业的相关建议。

英文摘要:

      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.