At-sea distribution and prey selection of Antarctic petrels and commercial krill fisheries

International audience Commercial fisheries may impact marine ecosystems and affect populations of predatorslike seabirds. In the Southern Ocean, there is an extensive fishery for Antarctic krill Euphausiasuperba that is projected to increase further. Comparing distribution and prey selectionof fish...

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Published in:PLOS ONE
Main Authors: Descamps, Sébastien, Tarroux, Arnaud, Cherel, Yves, Delord, Karine, Godø, Olaf Rune, Kato, Akiko, Krafft, Bjørn A., Lorentsen, Svein-Hakon, Ropert‐coudert, Yan, Skaret, Georg, Varpe, Øystein
Other Authors: Norvegian Polar Research Institute (NPRI), Norwegian Polar Institute, Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), Institut National de la Recherche Agronomique (INRA)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Institute of Marine Research Bergen (IMR), University of Bergen (UiB), Département Ecologie, Physiologie et Ethologie (DEPE-IPHC), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Norwegian Institute for Nature Research (NINA), Akvaplan-Niva Tromsø, Norwegian Institute for Water Research (NIVA), The University Centre in Svalbard (UNIS)
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2016
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Online Access:https://hal.science/hal-01386700
https://doi.org/10.1371/journal.pone.0156968
Description
Summary:International audience Commercial fisheries may impact marine ecosystems and affect populations of predatorslike seabirds. In the Southern Ocean, there is an extensive fishery for Antarctic krill Euphausiasuperba that is projected to increase further. Comparing distribution and prey selectionof fishing operations versus predators is needed to predict fishery-related impacts on krilldependentpredators. In this context, it is important to consider not only predators breedingnear the fishing grounds but also the ones breeding far away and that disperse during thenon-breeding season where they may interact with fisheries. In this study, we first quantifiedthe overlap between the distribution of the Antarctic krill fisheries and the distribution of akrill dependent seabird, the Antarctic petrel Thalassoica antarctica, during both the breedingand non-breeding season. We tracked birds from the world biggest Antarctic petrel colony(Svarthamaren, Dronning Maud Land), located >1000 km from the main fishing areas, duringthree consecutive seasons. The overall spatial overlap between krill fisheries and Antarcticpetrels was limited but varied greatly among and within years, and was high in someperiods during the non-breeding season. In a second step, we described the length frequencydistribution of Antarctic krill consumed by Antarctic petrels, and compared thiswith results from fisheries, as well as from diet studies in other krill predators. Krill taken byAntarctic petrels did not differ in size from that taken by trawls or from krill taken by most Antarctickrill predators. Selectivity for specific Antarctic krill stages seems generally low in Antarcticpredators. Overall, our results show that competition between Antarctic petrels andkrill fisheries is currently likely negligible. However, if krill fisheries are to increase in thefuture, competition with the Antarctic petrel may occur, even with birds breeding thousandsof kilometers away.