长江口牡蛎礁恢复及碳汇潜力评估

牡蛎礁是温带河口和滨海区一种特殊的海洋生境,它具有生物生产、净化水体、提供鱼类生境、维持生物多样性和防止海岸侵蚀等重要功能,根据对长江口牡蛎礁恢复工程的跟踪监测结果,分析和评估该人工牡蛎礁恢复及碳汇潜力。研究结果表明,在2004—2010年期间,该人工牡蛎礁牡蛎种群的增长迅速,2005年牡蛎平均密度和生物量达到最高,以后各年牡蛎生长过程中存在＂自疏＂现象和死亡,总密度下降,但个体增长。牡蛎礁上大型底栖动物物种数、总密度和总生物量呈快速的增长趋势,2004年至2010年共出现大型底栖动物47种,至2010年8月其密度和生物量分别达到941ind·m-2和44.51g·m-2。该人工牡蛎礁具有强大的固碳能力,通过牡蛎的钙化过程,单位面积年固碳量为2.70kg·m-2,年平均固定碳量达3.33×104t,直接产生的年平均固碳效益达837万元,相当于营造1110hm2热带森林。

Restoration and Assessment of Carbon Sink Potential for Aintertidal Oyster Reef in the Yangtze River Estuary,China

With the adoption of Kyoto Protocol to the United Nation Framework Convention of Climate Change in 2005,carbon sink fishery becomes the hotspot among the fishery science and technology of China.Oyster reefs are very important marine habitats in temperate estuaries and coasts,providing large number of services and goods such as fishery production,water purification,fish habitat,maintenance of biodiversity,erosion control etc.So far,little information is available on the carbon sink potential of oyster reefs.The present study aimed to assess the restoration and carbon sink potential of a created intertidal oyster reef was in the Yangtze River estuary,China.The oyster（Crassostrea sp.） population rapidly increases with reef development,and its mean density and biomass reached the highest at approximately one year after restoration（in June 2005）.Thereafter,the mean oyster density decreased with the increasing in the mean size of the oyster.The species richness,density and biomass of resident macrobenthos（exclusive of oyster and barnacles） in the restored oyster reef showed a gradually increasing trend.The study recordeda total of 47 macrobenthos species,the mean density of 941 ind·m-2 and biomass of 44.51 g·m-2 in 2010.The restored intertidal oyster reef has a strong carbon sink potential of about 2.70 kg·m-2,can lock up 3.33×104 t carbon per year through calcification process,and produced ecological value of approximately 8 370 000 RMB per year,which was equivalent to restore 1 110 hm2 tropical forest.