Upper trophic structure in the Atlantic Patagonian shelf break as inferred from stable isotope analysis
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The Patagonian Shelf is a very productive region with different ecosystem structures. A long history of fishing in the Southwestern Atlantic Ocean combined with a complex hydrographic structure, with a permanent front over the shelf-break and different coastal frontal regions, and a wide non-frontal area in between have made the food web in this area more complex and have resulted in changes to the spatialtemporal scale. Stable isotopes of carbon and nitrogen were used to determine the trophic structure of the Patagonian shelf break which was previously poorly understood. The results indicated that the average δ15N value of pelagic guild (Illex argentinus) was remarkable lower than those of the other guilds. The δ13C values of almost all species ranged from -17‰ to -18‰, but Stromateus brasiliensis had a significant lower δ13C value. Compared with the southern Patagonian shelf, short food chain length also occurred. The impact of complex oceanographic structures has resulted in food web structure change to the temporal-spatial scale on the Patagonian shelf. The Patagonian shelf break can be considered as a separated ecosystem structure with lower δ13C values.
Keyword13C 15N trophic structure Patagonian shelf break
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We would like to thank the fisheries observers, crew and the officers of the trawler Longfa, LIU Zijun, CHEN Lvfen, WANG Rui, SONG Qi and REN Zeqian at the College of Marine Sciences, Shanghai Ocean University for their helps in processing the samples. We acknowledge Mr Alan Coughtrey of the Shanghai Ocean University for his help in polishing the language. Finally, we would also like to thank two anonymous reviewers for their contributions to improve this manuscript.
- Agersted M D, Bode A, Nielsen T G. Trophic position of coexisting krill species: A stable isotope approach. Mar. Ecol. Progr. Ser., 516:139-151.Google Scholar
- Arkhipkin A, Brickle P, Laptikhovsky V. 2013. Links between marine fauna and oceanic fronts on the Patagonian Shelf and Slope. Arquipelago-Life Mar. Sci., 30: 19–37.Google Scholar
- Boltovskoy D. 2000. South Atlantic Zooplankton. Backhuys Publishers, Leiden. 1706p.Google Scholar
- Jackson G D, Bustamante P, Cherel Y, Fulton E A, Grist E P M, Jackson C H, Nichols P D, Pethybridge H, Phillips K, Ward R D, Xavier J C. 2007. Applying new tools to cephalopod trophic dynamics and ecology: perspectives from the Southern Ocean Cephalopod Workshop, February 2–3, 2006. Rev. Fish Biol. Fish., 17 (2–3): 79–99.CrossRefGoogle Scholar
- Leichter J J, Witman J D. 2009. Basin-scale oceanographic influences on marine macroecological patterns. In: Witman J D, Roy K eds. Marine Macroecology. University of Chicago Press, London. p. 205–226.Google Scholar
- Mann K H, Lazier J R N. 2006. Dynamics of Marine Ecosystems: Biological-Physical Interactions in the Oceans. 3 rd edn. Blackwell Publishing Ltd., Cambridge, USA. 512p.Google Scholar
- Nakamura I, Inada T, Takeda M, Hatanaka H. 1986. Important Fishes Trawled offPatagonia. Japan Marine Fishery Resource Research Centre, Tokyo. 369p.Google Scholar
- Olson D B. 2002. Biophysical dynamics of ocean fronts. In:Robinson A R, McCarthy J J, Rothschild B J eds. The Sea, Volume 12: Biological-Physical Interactions in the Sea. John Wiley & Sons, Inc., New York, USA. p.187-218.Google Scholar
- WoRMS Editorial Board. 2014. World register of marine species. www.marinespecies.org. Accessed on 2016-08-30.Google Scholar
- Zenteno L, Crespo E, Vales D, Silva L, Saporiti F, Oliveira L R, Secchi E R, Drago M, Aguilar A, Cardona L. 2015. Dietary consistency of male South American sea lions (Otaria flavescens) in southern Brazil during three decades inferred from stable isotope analysis. Mar. Bio l., 162 (2): 275–289.CrossRefGoogle Scholar