The diet of the Antarctic fur seal Arctocephalus gazella at the South Orkney Islands in ten consecutive years

Casaux, Ricardo; Juáres, Mariana A.; Carlini, Alejandro R; Corbalán, A.

doi:10.1007/s00300-015-1836-3

Cited by 11 publications

(7 citation statements)

References 27 publications

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“…Sequences from cephalopod viruses were also detected, although were much scarcer than those from crustaceans. This also agrees with current knowledge about the diet of A. gazella in the Atlantic sector of the Southern Ocean, where octopuses and squids are regularly consumed, although in low numbers 44 – 46 . It is worth noting than not cephalopod beak was recovered from the scats analyzed here 48 .…”

Section: Resultssupporting

confidence: 91%

Viral metagenomics reveals persistent as well as dietary acquired viruses in Antarctic fur seals

Martínez-Puchol

Cardona

Drago

et al. 2022

Sci Rep

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Viruses linked to animals inhabiting Antarctic latitudes remain poorly studied. Remote environments hosting large pinniped populations may be prone to exposure of immunologically naïve animals to new infectious agents due to increasing human presence or introduction of new animal species. Antarctic fur seals (Arctocephalus gazella) inhabiting the Western Antarctic Peninsula and the South Shetland Islands are challenged because of climate change and increased anthropogenic activity. In the present study, the fecal and serum virome of A. gazella was characterized by applying target enrichment next generation sequencing. The resulting viromes were dominated by CRESS-DNA sequences. Viruses known to infect vertebrate and invertebrate hosts were also observed in fecal samples. Fur seal picornavirus was present in all the fecal pools studied suggesting it is a prevalent virus in these species. Six different viruses presenting similarities with previously described A. gazella viruses or other otariids and mammal viruses were identified as potential new A. gazella viruses. Also, diet-derived viruses such as crustacean viruses were present in fecal content. Penguin viruses, but not fish viruses, were also detected. Obtained results contribute to a better understanding of the viral community present in these species, which is relevant for its conservation.

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Section: Resultssupporting

confidence: 91%

Viral metagenomics reveals persistent as well as dietary acquired viruses in Antarctic fur seals

Martínez-Puchol

Cardona

Drago

et al. 2022

Sci Rep

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“…In excess of 32,000 adult and subadult male AFS arrive in late January at Signy and Laurie Islands in the South Orkney Islands with recorded numbers decreasing throughout April 29 , 30 . The diet of male AFS at the South Orkney Islands is dominated by krill 31 ; assuming an average age of 4 year 32 and using the estimated amount of Antarctic krill consumed for this age class at South Georgia (3 t/year) 33 , the number of male AFS recorded at just these two sites in two months would consume approximately 24,000 t or 70% of the total recorded catch in Subarea 48.2 in 2016 34 . Areas intensively used by both male AFS and the fishery around the South Orkney Islands overlap in space and time with the late stages of chinstrap penguin breeding 35 and numerous large penguin colonies occur along the western coastlines of the islands 36 .…”

Section: Discussionmentioning

confidence: 99%

“…Importantly though, in the context of interpreting penguin population demographic decline through reduced survival of a key life history stage, consideration should also be given to the likely nonlinear increase in potential competitive interactions, particularly given the rapid increase in male AFS abundance in recent decades 49 . Additional factors not directly related to this study should also be considered, such as the direct mortality of fledglings by male AFS with several studies highlighting the impact even a few penguin-eating seals can have 31 , 50 .…”

Section: Discussionmentioning

confidence: 99%

Male Antarctic fur seals: neglected food competitors of bioindicator species in the context of an increasing Antarctic krill fishery

Lowther

Staniland

Lydersen

et al. 2020

Sci Rep

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The fishery for Antarctic krill is currently managed using a precautionary, ecosystem-based approach to limiting catch, with performance indices from a long-term monitoring program focused on several krill-dependent predators that are used to track ecosystem health. Concerns over increased fishing in concentrated areas and ongoing efforts to establish a Marine Protected Area along the Peninsula, a key fishing region, is driving the development of an adaptive management system for the fishery. The cumulative effects of fishing effort and interactions among krill-dependent predators and their performance is at present neglected in the CCAMLR Ecosystem Monitoring Program. However, we show considerable overlap between male Antarctic fur seals and the krill fishery in a complex mosaic, suggesting potential for cumulative impacts on other krill dependent predators. A holistic view is required as part of future efforts to manage the krill fishery that incorporates various sources of potential impacts on the performance of bioindicator species, including the fishery and its interactions with various krill dependent predators.

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“…While the myctophids were not commercially exploited, the population of some notothenioid species, such as the mackerel ice sh Champsocephalus gunnari (Lonnberg 1905), the humped rock cod Gobionotothen gibberifrons (Longberg 1905) and the marbled Notothenia Notothenia rossii (Fischer 1885) were seriously depleted (Kock and Jones 2012; Marschoff et al 2012;Barrera-Oro et al 2017). The rst two species were reported as prey of the Antarctic fur seal at the South Shetland Islands and at other islands of the Scotia Arc (Reid et al 1995;Daneri et al 1996;North et al 1996;Casaux et al 2004Casaux et al , 2015Reid et al 2006), while N. rossii was registered as prey at South Georgia (Bonner 1968;North et al 1983). It has been suggested that the limited occurrence of this and other shelf sh species in the diet of fur seals at the South Shetland Islands could be the consequence of the impact of the commercial shery on notothenioid populations (Reid et al 2006).…”

Section: Introductionmentioning

confidence: 99%

The relevance of fish in the summer diet of the Antarctic fur seal (Arctocephalus gazella) at Hope Bay, Antarctic Peninsula and Stranger Point, South Shetland Islands

et al. 2023

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The sh incidence, particularly notothenioids and myctophids, in the diet of non-breeding male Arctocephalus gazella in the western Antarctic Peninsula (AP) region is scarcely known. We made a comparative diet analysis on 158 faecal samples collected in summer 2005 at Hope Bay (HB), AP and at Stranger Point (SP), South Shetland Islands (SSI). The occurrence of Antarctic krill Euphausia superba and sh as prey was similar at HB, whereas krill was predominant at SP. For each sh species identi ed based on the otoliths found, their relative importance in the diet was evaluated using the IRI index.Notothenioid sh prevailed at HB: Pleuragramma.antarctica was the most important prey followed by Chaenodraco wilsoni. Contrarily, myctophids predominated at SP: Gymnoscopelus nicholsiand Electrona antarctica were the dominant prey. Both benthopelagic and pelagic sh species were represented at HB, while the latter were more important at SP; we suggest that seals from SP are foraging in pelagic strata, while at HB their habitat includes benthic and pelagic environments. Demersal nototheniid species were scarcely represented and only at HB, which might be related to a preference of fur seals on the more abundant pelagic prey there. At SP, the absence of demersal nototheniid otoliths in the faeces could be linked to the historical n sh sheries that took place in the SSI area. On sh species consumption, there was a higher diversity at SP in comparison with HB but a low overlap between these sites. Our ndings are compared with studies from localities of the AP and the Scotia Arc.

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The diet of the Antarctic fur seal Arctocephalus gazella at the South Orkney Islands in ten consecutive years

Cited by 11 publications

References 27 publications

Viral metagenomics reveals persistent as well as dietary acquired viruses in Antarctic fur seals

Viral metagenomics reveals persistent as well as dietary acquired viruses in Antarctic fur seals

Male Antarctic fur seals: neglected food competitors of bioindicator species in the context of an increasing Antarctic krill fishery

The relevance of fish in the summer diet of the Antarctic fur seal (Arctocephalus gazella) at Hope Bay, Antarctic Peninsula and Stranger Point, South Shetland Islands

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