Yuan Junji, Dong Yanhong, Li Junjie, Liu Deyan, Xiang Jian, He Tiehu, Kang Hojeong, Ding Weixin
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.
University of Chinese Academy of Sciences, Beijing, China.
Nat Food. 2025 Apr 3. doi: 10.1038/s43016-025-01156-5.
Coastal wetlands offer large carbon sequestration benefits but their conversion to aquaculture systems could result in substantial carbon losses. Here we show that the conversion of Spartina alterniflora salt marsh to mariculture ponds in China generated a greenhouse gas (GHG) footprint of 20.3 Mg CO equivalent per ha per year. Around two-thirds of the footprint can be attributed to foregone salt marsh GHG mitigation capacity, whereas direct carbon dioxide, methane and nitrous oxide emissions in mariculture ponds account for only ~10%, with the remaining ~20% arising from feed, fertilizer and energy consumption. Aquaculture can offer comparatively lower GHG footprints than other animal protein sources, such as terrestrial beef and small ruminants' production on a kg CO equivalent per kg protein basis, but this assumption may not be accurate when considering landscape-scale changes in GHG budgets, particularly in relation to the expansion of aquaculture within blue carbon ecosystems.
沿海湿地具有巨大的碳固存效益，但其转变为水产养殖系统可能会导致大量碳损失。我们在此表明，中国互花米草盐沼转变为海水养殖池塘产生的温室气体足迹为每年每公顷20.3 公吨二氧化碳当量。该足迹约三分之二可归因于丧失的盐沼温室气体减排能力，而海水养殖池塘中直接的二氧化碳、甲烷和氧化亚氮排放仅占约10%，其余约20%来自饲料、肥料和能源消耗。以每千克蛋白质的二氧化碳当量计算，水产养殖的温室气体足迹可能比其他动物蛋白来源（如陆地牛肉和小反刍动物养殖）相对较低，但在考虑温室气体预算的景观尺度变化时，尤其是与蓝碳生态系统内水产养殖的扩张相关时，这一假设可能并不准确。
