中国近海海藻养殖及碳汇强度估算

海藻养殖是渔业碳汇的重要形式,碳汇生态功能显著。本实验以1999—2012年《中国渔业统计年鉴》统计数据为基础,对中国及浙江近海藻类养殖的产量、结构进行了分析,并对其固碳强度进行了估算。中国近海海藻养殖以海带、裙带菜、紫菜、江蓠等为主,期间年均总产量为141.87万t,各类海藻养殖产量所占比例分别为海带(60.29%)、裙带菜(7.92%)、紫菜(5.67%)、江蓠(5.39%)。浙江近海海藻养殖以紫菜、海带、羊栖菜、苔菜等为主,各类海藻养殖产量所占比例分别为紫菜(51.83%)、海带(27.73%)、羊栖菜(12.72%)、苔菜(1.27%)。浙江近海海藻养殖总产量占全国总产量的份额不高(2.55%),但养殖结构独特,部分种类的海藻养殖产量在全国同种类海藻养殖量中占有较高份额,其中苔菜占83.00%,羊栖菜占68.29%,紫菜占23.53%。1999—2012年,全国海藻年均固碳量为41.85万t/a,固碳量在2012年最高达51.50万t,整体呈现上升趋势。其中,海带年均固碳量在各类海藻中最高达26.45万t/a,其次是裙带菜3.23万t/a、紫菜2.24万t/a、江蓠2.01万t/a。浙江近海养殖海藻年均固碳量为1.03万t/a,约占全国年均固碳量的2.47%。为满足低碳经济发展的需求,建议加强近海自然碳汇及其环境的保护和管理,大力发展以海水养殖为主体的碳汇渔业,开展碳汇渔业关键技术与产业示范工程研究及海洋生物碳汇功能与碳汇渔业潜力的基础科学研究。

Marine algae culture and the estimation of carbon sink capacity in the coastal areas of China

Seaweed farming is an important form of carbon sink fisheries, which plays a significant role in ecological functions of carbon sink.In this paper, the yields and structures of Chinese and Zhejiang coastal algae farming were analyzed, and their carbon sink capacity was also estimated, based on the data of "Chinese Fishery Statistical Yearbook" from 1999 to 2012.The average annual production of algae in China was about 1 418 700 t.Chinese main marine algae were kelp, undaria, laver and gracilaria, which accounted for 60.29%, 7.92%, 5.67% and 5.39% respectively.Zhejiang's main marine algae were laver, kelp, Sargassum fusiforme and Enteromorpha prolifra, and their proportion was about 51.83%(laver), 27.73%(kelp), 12.72%(Sargassum fusiforme), and 1.27%(Enteromorpha prolifra).Although the portion of Zhejiang's marine algae production was only 2.55% out of total national production, the breeding structure was unique.In comparing with national data, certain kinds of Zhejiang's algae showed a higher yield, which had percentages of 83.00%(Enteromorpha prolifra), 68.29%(Sargassum fusiforme), and 23.53%(laver).Overall, Chinese marine algae carbon sink capacity demonstrates upward trend from 1999 to 2012.The highest carbon sink was up to 515 000 t in 2012, while the annual carbon sink capacity was 418 500 t.The annual average carbon sink of Chinese kelp was 264 500 t/a, which took up the highest proportion within all kinds of algae, followed by undaria 32 300 t/a, laver 22 400 t/a, and gracilaria 20 100 t/a.The annual algae carbon sink capacity of Zhejiang marine culture was 10 300 t, 2.47% of the corresponding national data.In order to meet the needs of the development of the low carbon economy, we suggest that natural carbon sink and its environment protection and management should be strengthened, and carbon fisheries should also be developed.In addition, technology and industry demonstration projects on carbon sink fisheries, marine biological carbon sink function and more potential of carbon sink fisheries basic scientific research should be carried out.