Compound-specific isotopes of fatty acids as indicators of trophic interactions in the East China Sea ecosystem

• Published in: Chinese journal of oceanology and limnology Vol. 34; no. 5; pp. 1085 - 1096
• Main Author: 吴莹 王娜 张经 万瑞景 戴芳群 金显仕
• Format: Journal Article
• Language: English
• Published: Heidelberg Science Press 01.09.2016; Springer Nature B.V
• Subjects: Acetes chinensis; Arachidonic acid; benthic organisms; Benthos; Biogeochemistry; carbon; Carbon isotopes; Carbon sources; Chemistry; Comparative analysis; Comparative studies; Complex systems; Composition; Correlation; Decapoda; diet; Docosahexaenoic acid; Earth and Environmental Science; Earth Sciences; East China Sea; ecosystems; Fatty acid composition; Fatty acids; Food chains; Food sources; Food webs; Isotopes; Lipids; Marine; Metapenaeus joyneri; Oceanography; Organic carbon; Pelagic fisheries; Sediment-water interface; shrimp; Shrimps; Solenocera crassicornis; Species; stable isotopes; Total organic carbon; Trophic levels; Trophic relationships; East China Sea; INW, Donghai Sea; fatty acid; stable isotope ratio; compound-specific isotope ratio; East China Sea
• ISSN: 0254-4059; 2096-5508; 1993-5005; 2523-3521
• DOI: 10.1007/s00343-016-4309-9

The composition and compound-specific isotopes of fatty acids were studied within food webs in the East China Sea. Lipid-normalized stable carbon isotopes of total organic carbon had a good correlation with trophic level. Variations in fatty acid compositions among different species were observed but were unclear. Different dietary structures could be traced from molecular isotopes of selected fatty acids in the Shiba shrimp （Matapenaeus joyneri）, the coastal mud shrimp （Solenocera crassicornis） and the northern Maoxia shrimp （Acetes chinensis）. Both M. joyneri and S. crassicornis are mainly benthos feeders, while A. chinensis is a pelagic species, although they have a similar fatty acid composition. There was a good correlation for isotopes of arachidonic acid （C20：4n6; ARA） and docosahexaenoic acid （C22：6n3; DHA） among pelagic species from higher trophic levels. The isotopic compositions of DHA in benthic species were more negative than those of pelagic species at the same trophic level. The fact that the diet of benthic species contains more degraded items, the carbon isotopes of which are derived from a large biochemical fraction, may be the reason for this variation. A comparative study of benthic and pelagic species demonstrated the different carbon sources in potential food items and the presence of a more complex system at the watersediment interface.