摘要
为了解三峡大坝蓄水后库区干流鱼类食物网结构及营养关系的构成,应用碳(δ13C)、氮(δ15N)稳定性同位素技术,分别于2010年夏季(7月份)和冬季(12月份)对三峡库区巫山至万州段干流鱼类食物网结构及营养关系的季节变化进行了探讨,并与2005年夏季该区域鱼类食物网结构和营养关系组成情况进行了比较。结果显示:本次(2010年)调查颗粒有机物(POM)和固着藻类样品δ13C值分别为-25.62‰～-23.72‰、-19.81‰～-19.47‰,且无显著性季节(夏季和冬季)差异。POM和固着藻类(内源性营养物质)是三峡库区巫山至万州段干流鱼类食物网基础能量的主要来源,但外源性营养物质输入也是其基础能量来源的重要补充途径。与2005年相比,2010年该区域鱼类食物网中消费者δ13C值富集度和食物网营养级长度均有所增加。该研究结果对三峡库区鱼类资源增殖放流和生态修复有重要指导意义。
The Three Gorges Dam is the largest hydroelectric power station project in the world. After the impounding of the Three Gorges Reservoir （TGR） , its hydrological characteristics （ water depth, water flow velocity and water temperature）markedly changed. Meanwhile, the external nutrients, e. g. terrestrial plant, debris, soil organic matter, come from the Yangtze River upstream and stagnate in the TGR after the impounding of the TGR. As no study was carried out investigating the comprehensive effects of the above factors on the fish community structure and their food web in the TGR, the stable carbon and nitrogen isotope （δ3C and δ5 N）technology was applied in this study to evaluate the food web of fish and nutrient relationship caused by the seasonal variation in the main stream of the TGR from Wushan to Wanzhou （summer,July 2010; winter, December 2010）, and the data of 2005 in summer were also provided to compare their changes. The results of δ3C indicated that the values of both particulate organic matter （POM） and periphytic algae samples were （ - 25.62‰） - （ - 23.72‰） and （ - 19. 81%o） - （ - 19.47‰）, respectively,and no significant variation of δ13C values was observed for primary producers （POM and periphytic algae）between summer and winter in 2010（P 〉 0.05 ）. However, as the POM and periphytic algae （ endogenous nutrients） were the main basal carbon origin for the webs of the fish food, and the input of the exogenous nutrient substance was an important supplementary way for the consumers in TGR. In summary, an increasing trend of the δ3C values for consumers and the chain length for the webs of the fish food were obtained from 2005 to 2010. Our findings will be helpful to the management of the fish resources and the protection of the ecological restoration in the TGR.
出处
《水产学报》
CAS
CSCD
北大核心
2013年第7期1015-1022,共8页
Journal of Fisheries of China
基金
公益性行业(农业)科研专项(200903048-08)
关键词
鱼类
食物网
颗粒有机物
碳氮稳定性同位素
三峡库区
fish
food webs
particulate organic matter
carbon and nitrogen stable isotopes
Three GorgesReservoir
