Trophic Ecology of Sharks in the Mid-East Pacific Ocean Inferred from Stable Isotopes  

作　　者：LI Yunkai GONG Yi CHEN Xinjun DAI Xiaojie ZHU Jiangfeng 

机构地区：[1]College of Marine Science,Shanghai Ocean University [2]Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources,Ministry of Education,Shanghai Ocean University

出　　处：《Journal of Ocean University of China》2014年第2期278-282,共5页中国海洋大学学报（英文版）

基　　金：Li Yunkai was supported by the National Natural Science Foundation of China (No.41206124);Ph.D.Programs Foundation of Ministry of Education of China (No.201 23104120001);the ‘Chen Guang’ Project of Shanghai Municipal Education Commission (No.D8004-10-0206);the Shanghai Education Development Foundation (No.B-8102-10-0084);Zhu Jiangfeng and Dai Xiaojie were supported by the National Natural Science Foundation of China (No.41106118);the Scientific Observing and Experimental Station of Oceanic Fishery Resources, Ministry of Agriculture, China

摘　　要：As apex predators, sharks are of ecological and conservation importance in marine ecosystems. In this study, trophic positions of sharks were estimated using stable isotope ratios of carbon and nitrogen for five representative species caught by the Chinese longline fleet in the mid-east Pacific, i.e., the blue shark （Prionace glauca）, the bigeye thresher shark （Alopias superciliosus）, the silky shark （Carcharhinus falciformis）, the scalloped hammerhead （Sphyrna lewini）, and the oceanic whitetip shark （Car-charhinus longimanus）. Of these species, oceanic whitetip shark has the lowest trophic level and mean 815N value （3.9 and 14.93%o± 0.84%o）, whereas bigeye thresher shark has the highest level/values （4.5 and 17.02%o±1.21%o, respectively）. The bigeye thresher shark has significantly higher 515N value than other shark species, indicating its higher trophic position. The blue shark and oceanic whitetip shark has significantly higher 813C values than bigeye thresher shark, silky shark and scalloped hammerhead, possibly due to different diets and/or living habitats. The stable isotope data and stomach content data are highly consistent, suggesting that sta-ble isotope analysis supplements traditional feeding ecology study of sharks, and thus contributes to understanding their trophic linkage.As apex predators, sharks are of ecological and conservation importance in marine ecosystems. In this study, trophic positions of sharks were estimated using stable isotope ratios of carbon and nitrogen for five representative species caught by the Chinese longline fleet in the mid-east Pacific, i.e., the blue shark(Prionace glauca), the bigeye thresher shark(Alopias superciliosus), the silky shark(Carcharhinus falciformis), the scalloped hammerhead(Sphyrna lewini), and the oceanic whitetip shark(Carcharhinus longimanus). Of these species, oceanic whitetip shark has the lowest trophic level and mean δ15N value(3.9 and 14.93‰± 0.84‰), whereas bigeye thresher shark has the highest level/values(4.5 and 17.02‰± 1.21‰, respectively). The bigeye thresher shark has significantly higher δ15N value than other shark species, indicating its higher trophic position. The blue shark and oceanic whitetip shark has significantly higher δ13C values than bigeye thresher shark, silky shark and scalloped hammerhead, possibly due to different diets and/or living habitats. The stable isotope data and stomach content data are highly consistent, suggesting that stable isotope analysis supplements traditional feeding ecology study of sharks, and thus contributes to understanding their trophic linkage.

关 键 词：trophic level stable isotope analysis mid-east Pacific SHARK 

分 类 号：S917.4[农业科学—水产科学]