亚热带养殖海湾皱瘤海鞘生物沉积的现场研究  

An in situ study on biodeposition of ascidian(Styela plicata) in a subtropical aquaculture bay,southern China

作　　者：闫家国[1,2] 齐占会[1] 田梓杨[1] 史荣君[1] 张汉华[1] 黄洪辉[1] 

机构地区：[1]农业部南海渔业资源开发利用重点实验室,广东省渔业生态环境重点实验室,中国水产科学研究院南海水产研究所,广州510300 [2]上海海洋大学水产与生命学院,上海201306

出　　处：《生态学报》2013年第6期1900-1906,共7页Acta Ecologica Sinica

基　　金：国家自然科学基金(41106088);“十二五”国家科技支撑计划(2011BAD13B02);863计划(2012AA052103);重点实验室开放课题(201104,MESE-2011-02;开-10-09)

摘　　要：皱瘤海鞘是亚热带海域分布最广和数量最多的附着生物种类之一。2012年1月—7月在典型的亚热带养殖海湾-大亚湾大鹏澳海域,利用沉积物捕集器现场测定了皱瘤海鞘(Styela plicata)的生物沉积速率,并测定了生物沉积物中有机物(OM)、总碳(TC)、总氮(TN)、有机碳(OC)和有机氮(ON)含量。结果显示:皱瘤海鞘的生物沉积速率变化范围为每天145.5—1011.8mg/个,平均每天516.0mg/个,海鞘的生物沉积速率变化范围为每天154.8—1065.8 mg/g干重,平均每天463.3 mg/g干重。海鞘生物沉积物中OM、TC、OC、TN和ON含量分别为14.38%、10.80%、2.87%、3.06%和0.86%,高于自然沉积物中的含量,分别为13.39%、7.36%、2.32%、2.29%和0.67%。其中TC和ON含量要显著高于自然沉积物(P<0.05)。皱瘤海鞘的OM、TC、OC、TN和ON的生物沉积速率分别为每天74.20,55.73,14.80,15.79和4.43 mg/个。实验期间附着在浮筏养殖设施和养殖牡蛎壳上的海鞘密度变化范围为54.9—222.1个/m2,平均147.5个/m2,养殖海域单位面积的海鞘生物沉积速率平均为每天76.1 g/m2,是自然沉积速率(平均每天62.7 g/m2)的1.21倍,其中OM、TC、OC、TN和ON的平均沉积速率分别为每天10.94,8.21,2.18,2.32和0.65 g/m2。据此可推算,大鹏澳筏式牡蛎养殖海区(约103 hm2)皱瘤海鞘的年生物沉积物负荷为29000 t,其中OM,TC,OC,TN和ON分别4100,3100,820,870和240 t。研究结果说明,海鞘等附着生物在大规模浅海贝类养殖中对养殖生态环境的影响也不容忽视。A worldwide increase in farming of filter feeding bivalves and a growing awareness of the likely environmental impacts stem from biodeposition lead to extensive and well recognized studies. Whereas the suspended longline culture with massive and intensive facilities built （e.g., buoys, anchors and ropes） and bivalve shells in the farming area supply the footstone for the fouling organisms such as the ascidians and large number of breeding depended on them, which can be extremely abundant in areas of large-scale bivalve culture. Therefore, the fouling organisms may also influence the environment by remarkably increasing their amounts. There is an urgent need to examine the possible effects of biodeposition from the fouling organisms. The ascidian Styela plicata is one of the most predominant fouling species in tropical and subtropical bays. S. plicata is a filter feeding species like the bivalves. However, untill recently, the biodeposition of S. plicata was unknown. In order to evaluate the influence of S. plicata on the coastal environment, the biodeposition rate of ascidian S. plicata was investigated in Dapeng Cove, located in the southwest of the Daya Bay, a subtropical bay in southern China. Intensive oyster Crassostrea gigas longline culture activities were conducted there. The ascidians were sampled from the culture facilities and shells of the oyster Crassostrea gigas. The biodeposition rate was measured in situ in suspended culture areas by sediment traps from January to July, 2012. The contents of organic matters （OM）, total carbon （TC）, total nitrogen （TN）, organic carbon （OC） and organic nitrogen （ON） in biodeposits and in natural sediments were analyzed and compared. Results showed that the biodeposition rate of S. plicata ranged from 145.5 to 1011.8 mg·ind-1·d-1, with an average of 516.0 mg·ind-1·d-1.The mean contents of OM, TC, OC, TN and ON in the biodeposits was 14.38%, 10.80%, 2.87%, 3.06% and 0.86%, respectively, and were higher than those of 13.39%, 7.36%, 2.32%, 2.

关 键 词：海鞘 皱瘤海鞘 附着生物 生物沉积 亚热带海湾 

分 类 号：S931.3[农业科学—渔业资源]