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bioRxiv · 10.1101/2023.01.25.524777

One marine protected area is not enough: The trophic ecology of the broadnose sevengill shark (Notorynchus cepedianus) in the Southwest Atlantic

Funes, M.·De Wysiecki, A. M.·Bovcon, N. D.·Jaureguizar, A. J.·Irigoyen, A. J.
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Abstract

O_LIThe broadnose sevengill shark (Notorynchus cepedianus) has been categorized as Vulnerable by the IUCN and shows a declining population trend in the Southwest Atlantic. Bycatch and poaching are the major threats in the region. C_LIO_LIAlthough some ecological requirements have been described, there are still several information gaps regarding its ecology. Important aspects of its trophic ecology, like main prey items or key feeding grounds, remain uncertain and are essential to design effective conservation strategies. C_LIO_LIWe applied stable isotope and stomach content analyses to describe the trophic ecology of sevengill shark within a marine protected area of Peninsula Valdes in Patagonia, Argentina. C_LIO_LIThe stomach content analysis determined the southern elephant seal, Mirounga leonina, as the most frequently regurgitated prey item (70%F) during abundance peaks of both species in Peninsula Valdes. The stable isotope analysis indicated that the overall contribution of the elephant seal to the diet of the sevengill shark was around 30% and that this percentage varied with the size of individuals. C_LIO_LIPresent results strengthen the current understanding of the trophic ecology of the sevengill shark. This study confirmed the use of the marine protected area as an essential foraging ground and identified its main prey items. Also, it reinforced the critical need to expand conservation tools beyond this particular coastal protection. C_LI

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Funes, M., De Wysiecki, A. M., Bovcon, N. D., Jaureguizar, A. J., Irigoyen, A. J.. 2023-01-26. One marine protected area is not enough: The trophic ecology of the broadnose sevengill shark (Notorynchus cepedianus) in the Southwest Atlantic. https://doi.org/10.1101/2023.01.25.524777

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