中国贝类养殖对海洋碳循环的贡献评估

Evaluation of contribution of shellfish culture to ocean carbon cycle in China

造成全球暖化的主要原因是温室气体的过量排放,其中CO2的贡献率达60%,贝类养殖具有碳沉积作用。依据农业部渔业局编制的《中国渔业统计年签》,以2001年到2010年的年平均产量计算贝类捕获和养殖的碳沉积能力,并评估其碳沉积潜力;计算牡蛎、蛤、扇贝与贻贝4种贝壳单位面积的碳沉积能力并与森林、珊瑚礁的碳沉积能力进行比较分析。分析表明中国近10年贝类总产量稳定在1100万t以上,并有增加的趋势,其中海水养殖贝类约占87.34%。贝类养殖和捕获总产量的碳沉积和海水养殖产量的碳沉积量分别为58.57、51.15万t/a,碳沉积能力分别相当于122.28、106.78万ha的造林,可分别减少大气CO2增加量的0.0125%、0.0109%。牡蛎、蛤、扇贝与贻贝的单位面积碳沉积速率分别为1.573、0.388、0.301、1.039t碳/(ha·a);牡蛎和贻贝高于森林的碳沉积能力0.479t碳/(ha·a);但低于珊瑚礁的碳沉积能力1.8t碳/(ha·a)。中国贝类淡、海水养殖产量可分别创造约268.4万元/a、12 711.2万元/a的碳权商机。

The excessive emission of greenhouse gases results in global warming, and CO2 contributes to this process by about 60%. Shellfish culture has effect of carbon deposition which was calculated and evaluated by the 10 year average yield of fishing shellfish and culturing shellfish production from 2001 year to 2010 year based on China Fishery Statistics Yearbook. The unit area carbon deposition capacity of oyster, clam, scallop and mussel was calculated and compared with the carbon deposition capacity of forests and coral reefs. Analysis shows that the total yield of shellfish is stable and more than 110 million tons with an increasing trend and the mariculture shellfish is account for about 87.34%. The total carbon deposition of shellfish aquaculture and capture and the amount of carbon deposition of the mariculture shellfish are approximately 585.7 and 511.5 thousand tons per year, respectively, which are equivalent to about 1222.8 and 1067.8 thousand hectares afforestation for carbon deposition and can reduce the increasing amount of CO2 in the atmosphere by approximately 0.0125 % and 0.0109 % respectively. Carbon deposition rates of oyster, clam, scallop and mussel are 1.573, 0.388, 0.301 and 1.039 t/（ha·a）, respectively. The carbon deposition rates of oyster and mussel with consumption of economic value are higher than the forest（0.479 tC/（ha·a））, but lower than the coral reefs（1.8 t/（ha·a））. The effect of using the shellfish for carbon deposition is superior to capture and archive CO2 directly into deep sea by carbon capture and storage engineering. Freshwater culture shellfish and mariculture shellfish can create carbon credit opportunities 2.684 million yuan and 127.112 million yuan per year respectively in China.