scholarly journals Cephalopoda as prey of juvenile Southern elephant seals at Isla 25 de Mayo/King George, South Shetland Islands

2015 ◽  
Vol 105 (1) ◽  
pp. 12-19 ◽  
Author(s):  
Luciana Burdman ◽  
Gustavo A. Daneri ◽  
Javier Negrete ◽  
Jorge A. Mennucci ◽  
Maria E. I. Marquez
Keyword(s):  
Southern Oscillation ◽  
Feeding Habits ◽  
South Shetland Islands ◽  
Antarctic Polar Front ◽  
Mirounga Leonina ◽  
Elephant Seals ◽  
Shetland Islands ◽  
Numerical Abundance ◽  
Southern Elephant Seals ◽  
The Antarctic

The aim of the present study was to enhance the knowledge of the feeding habits of the juvenile component of the population of Southern elephant seals [Mirounga leonina (Linnaeus, 1758)] from Isla 25 de Mayo, South Shetland Islands, age class whose diet information is scarce. A total of 60 individuals were stomach lavaged in the spring - summer seasons of three consecutive years (2003, 2004 and 2005) of which 53.3 % (n = 32) presented food remnants. The Antarctic glacial squid Psychroteuthis glacialis Thiele, 1921 was the dominant prey taxon in terms of frequency of occurrence (68.7%), numerical abundance (60.1%) and biomass (51.5%), contributing 84.1% to the total relative importance index. Other squid prey species of importance were Slosarczykovia circumantartica Lipinski, 2001 in terms of occurrence (37.5%) and numerical abundance (14%) and Moroteuthis knipovitchi Filippova, 1972 in terms of biomass (16%). All identified cephalopod prey taxa are distributed south of the Antarctic Polar Front, except for the squid Martialia hyadesi Rochebrune & Mabille, 1889 which has a circumpolar distribution associated to the Polar Frontal Zone. No significant differences in the sizes of P. glacialis preyed upon by elephant seals were found between sexes and years. However, significant interannual differences were found in the taxonomical composition of their diet. This would be associated with temporal changes in food availability at the foraging areas of seals, which in turn may have been influenced by changes in oceanographic conditions as a result of the El Niño Southern Oscillation (ENSO) phenomenon that occurred during part of the study period. Furthermore, a differential response of males and females to this temporal variation was observed, with the former being also associated to a predation on octopods. This would suggest a sexual segregation in foraging habits of this species from the early stages of its life cycle.

Migrations and foraging of juvenile southern elephant seals from Macquarie Island within CCAMLR managed areas

2002 ◽  
Vol 14 (2) ◽  
pp. 134-145 ◽  
Author(s):  
John van den Hoff ◽  
Harry R. Burton ◽  
Mark A. Hindell ◽  
Michael D. Sumner ◽  
Clive R. McMahon
Keyword(s):  
Foraging Ecology ◽  
Polar Front ◽  
Commercial Fishing ◽  
Antarctic Polar Front ◽  
Mirounga Leonina ◽  
Elephant Seals ◽  
Macquarie Island ◽  
Location Data ◽  
Southern Elephant Seals ◽  
The Antarctic

Twenty-three juvenile (8–14 months of age) southern elephant seals (Mirounga leonina L.) from Macquarie Island were tracked during 1993 and 1995. Migratory tracks and ocean areas with concentrated activity, presumed to be foraging grounds, were established from location data gathered by attached geolocation-time depth recorders. The seals ranged widely (811–3258 km) and foraging activity centred on oceanographic frontal systems, especially the Antarctic Polar Front and bathymetric features such as the Campbell Plateau region. The seals spent 58.6% of their sea time within managed fishery areas while the remainder was spent on the high seas, an area of unregulated fishing. The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) areas 58.4.1, 88.2 and especially 88.1 were important and distant foraging areas for these juvenile elephant seals. From fisheries records, diet and the foraging ecology studies of the seals there appears to be little, if any, overlap or conflict between the seals and commercial fishing operations within the regulated commercial areas. However, attention is drawn to the possibility of future interactions if Southern Ocean fisheries expand or new ones commence.

Foraging areas of southern elephant seals, Mirounga leonina, as inferred from water temperature data

1991 ◽  
Vol 42 (2) ◽  
pp. 115 ◽  
Author(s):  
MA Hindell ◽  
HR Burton ◽  
DJ Slip
Keyword(s):  
Continental Shelf ◽  
Polar Front ◽  
Antarctic Polar Front ◽  
Mirounga Leonina ◽  
Elephant Seals ◽  
Antarctic Continental Shelf ◽  
Southern Elephant Seals ◽  
Water Temperature Data ◽  
The Antarctic ◽  
Temperature Depth

Fourteen time-depth-temperature recorders were recovered from adult southern elephant seals (Mirounga leonina) returning to Macquarie Island to breed or moult. The resulting temperature/depth profiles indicated that all four males spent most of their time in waters lying over the Antarctic Continental Shelf, whereas only one of the ten females spent any time there. Five of the females foraged just off the Antarctic Continental Shelf. and the other five remained near the Antarctic Polar Front.

scholarly journals Southern elephant seal movements and Antarctic sea ice

2000 ◽  
Vol 12 (1) ◽  
pp. 3-15 ◽  
Author(s):  
H. Bornemann ◽  
M. Kreyscher ◽  
S. Ramdohr ◽  
T. Martin ◽  
A. Carlini ◽  
...  
Keyword(s):  
Sea Ice ◽  
Antarctic Peninsula ◽  
South Shetland Islands ◽  
Mirounga Leonina ◽  
King George Island ◽  
The South ◽  
Elephant Seals ◽  
Shetland Islands ◽  
Pack Ice ◽  
The Antarctic

Weaned pups and post-moult female elephant seals (Mirounga leonina) were fitted with satellite transmitters at King George Island (South Shetland Islands) between December 1996 and February 1997. Of the nine adult females tracked for more than two months, three stayed in a localized area between the South Shetland Islands and the South Orkney Islands. The other six females travelled south-west along the coast of the Antarctic Peninsula up to the Bellingshausen Sea. Two of them then moved north-east and hauled out on South Georgia in October. One female was last located north of the South Shetland Islands in March 1998. In total, eight females were again sighted on King George Island and six of the transmitters removed. The tracks of the weaners contrasted with those of the adults. In January, five juveniles left King George Island for the Pacific sector spending about four weeks in the open sea west of the De Gerlache Seamounts. Three of them returned to the tip of the Antarctic Peninsula in June, of which one was last located on the Patagonian Shelf in November 1997. The juveniles avoided sea ice while the adults did not. The latter displayed behavioural differences in using the pack ice habitat during winter. Some females adjusted their movement patterns to the pulsating sea ice fringe in distant foraging areas while others ranged in closed pack ice of up to 100%. The feeding grounds of adult female elephant seals are more closely associated with the pack ice zone than previously assumed. The significance of the midwater fish Pleuragramma antarcticum as a potential food resource is discussed.

Cephalopod diet of the southern elephant seal, Mirounga leonina, at King George Island, South Shetland Islands

2000 ◽  
Vol 12 (1) ◽  
pp. 16-19 ◽  
Author(s):  
G.A. Daneri ◽  
A.R. Carlini ◽  
P.G.K. Rodhouse
Keyword(s):  
Stomach Contents ◽  
Elephant Seal ◽  
South Shetland Islands ◽  
Southern Elephant Seal ◽  
Mirounga Leonina ◽  
King George Island ◽  
Elephant Seals ◽  
Shetland Islands ◽  
Important Prey ◽  
Southern Elephant Seals

In the summer of 1995/96, 25 southern elephant seals, Mirounga leonina, were stomach lavaged at Stranger Point, King George Island, South Shetland Islands. Cephalopod remains were present in 72% of the individuals sampled (n = 18). Seven species of squid and three of octopus were identified. The squid Psychroteuthis glacialis was the most important prey in terms of numbers (77%), biomass (80.8%) and frequency of occurrence (94.4%). Next in importance in terms of mass was the squid Alluroteuthis antarcticus (7.8%) in the diet of females and the octopodid Pareledone ?charcoti in the diet of males (13.2%). Females preyed on a wider variety of squid taxa than males (7 vs 3) but octopodids occurred only in stomach contents from males. The predominance of P. glacialis in the prey of the South Shetland Islands elephant seals can be explained by the southerly location of the foraging areas of this population compared to South Georgia, Heard and Macquarie islands, where the diet of southern elephant seals has previously been analysed. Psychroteuthis glacialis is the predominant squid in waters close to the Antarctic continent.

Weaning mass variation of southern elephant seals at King George Island and its possible relationship with “El Niño” and “La Niña” Events

2001 ◽  
Vol 13 (1) ◽  
pp. 37-40 ◽  
Author(s):  
D.F. Vergani ◽  
Z.B. Stanganelli ◽  
D. Bilenca
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
La Niña ◽  
South Shetland Islands ◽  
Mirounga Leonina ◽  
King George Island ◽  
Elephant Seals ◽  
La Nina ◽  
Southern Elephant Seals

Possible effects of “El Niño” Southern Oscillation (ENSO) components “El Niño”and “La Niña“ on populations of southern elephant seals, Mirounga leonina L., are considered in this study. Information on pup weaning mass, collected at King George Island, South Shetland Islands, over a ten-year period (1985–94) was analysed with respect to the occurrence of ENSO and recent research in feeding ecology of this population in the Bellinghausen Sea. Weaning mass of elephant seals was found to be higher during “La Niña” and a lower during “El Niño”. Differences in weaning mass between sexes varied in different proportions during El Niño and La Niña. The teleconnection between tropical Pacific anomalies and the Bellinghausen Sea deserves further research, and our results suggest a way to study this phenomenon using data of elephant seal pups weaning mass as indicators of changes in food availability.

The dynamics of male harem dominance in southern elephant seals (Mirounga leonina) at the South Shetland Islands

Polar Biology ◽  
2006 ◽  
Vol 29 (9) ◽  
pp. 796-805 ◽  
Author(s):  
Alejandro R. Carlini ◽  
Sebastián Poljak ◽  
Gustavo A. Daneri ◽  
María E. I. Márquez ◽  
Javier Negrete
Keyword(s):  
South Shetland Islands ◽  
Mirounga Leonina ◽  
The South ◽  
Elephant Seals ◽  
Shetland Islands ◽  
Southern Elephant Seals

Cephalopod prey of the southern elephant seal, Mirounga leonina L.

1992 ◽  
Vol 70 (5) ◽  
pp. 1007-1015 ◽  
Author(s):  
P. G. Rodhouse ◽  
T. R. Arnbom ◽  
M. A. Fedak ◽  
J. Yeatman ◽  
A. W. A. Murray
Keyword(s):  
Elephant Seal ◽  
Southern Elephant Seal ◽  
Antarctic Polar Front ◽  
Mirounga Leonina ◽  
Important Species ◽  
Elephant Seals ◽  
South Georgia ◽  
Cephalopod Species ◽  
Southern Elephant Seals ◽  
The Antarctic

In the austral summers of 1986 and 1988–1989, 51 southern elephant seals (Mirounga leonina) at Husvik, South Georgia (54°10′S; 36°43′W), were stomach lavaged after chemical immobilization. Only cephalopod remains were retrieved, including 1070 lower beaks that were identified and measured. In total these were estimated to represent a wet weight of 187.8 kg. Fourteen species of squid from 11 families and 2 species of octopod from 1 family were present. The most important species overall were the squids Psychroteuthis glacialis in terms of numerical abundance (33.7%) and Moroteuthis knipovitchi in terms of estimated biomass (31.2%). The remaining biomass was mainly comprised of the five large muscular squids, Kondakovia longimana (24.0%), P. glacialis (15.4%), Martialia hyadesi (11.2%), Alluroteuthis antarcticus (10.8%), and Gonatus antarcticus (3.6%). Larger seals of both sexes fed on a wider variety of cephalopod species than smaller seals, with large males taking the greatest diversity. Between the two summers of the study there were some changes in the relative importance of the various cephalopod species consumed; in particular, in 1988–1989 M. knipovitchi and M. hyadesi were less important and P. glacialis was more important. The taxa and size of cephalopods taken by southern elephant seals at South Georgia are almost identical to those taken by the grey-headed albatross (Diomedea chrysostoma), but the relative proportions are quite different. The biogeography of the cephalopods eaten suggests that southern elephant seals sampled at South Georgia do not forage to the north of the Antarctic Polar Front but probably travel southwards towards the Antarctic continent or Peninsula.

Serological screening for Brucella spp. and Leptospira spp. antibodies in southern elephant seals Mirounga leonina from Elephant Island, Antarctica, in 2003 and 2004

2020 ◽  
Vol 142 ◽  
pp. 161-170
Author(s):  
AM Sánchez-Sarmiento ◽  
V Ruoppolo ◽  
MMC Muelbert ◽  
JS Ferreira Neto ◽  
JL Catão-Dias
Keyword(s):  
Austral Summer ◽  
Agglutination Test ◽  
South Shetland Islands ◽  
Climate Change Scenarios ◽  
Mirounga Leonina ◽  
Serological Screening ◽  
Elephant Seals ◽  
Southern Elephant Seals ◽  
Monitoring And Surveillance ◽  
Elephant Island

Brucella spp. and Leptospira spp. antibodies were surveyed in 35 southern elephant seals (SESs) Mirounga leonina at Elephant Island (South Shetland Islands), western Antarctic peninsula, in the Austral summer of 2003 and 2004. The rose Bengal test and a commercial competitive ELISA (c-ELISA) were used to detect Brucella spp. exposure, and the microscopic agglutination test (MAT) with 22 live serovars was used to determine anti-Leptospira spp. antibodies. We found evidence of Brucella spp. exposure in 3 of 35 (8.6%) SESs tested via the c-ELISA displaying high percentage inhibition (PI), similar to other studies in pinnipeds in which Brucella spp. antibodies have been determined. Two of the 3 positives were pups (PI = 70.4 and 86.6%), while the third was an adult female (PI = 48.8%). The 3 c-ELISA positive SESs were additionally tested via the serum agglutination test but were found to be negative. All individuals were negative for antibodies against 22 Leptospira spp. serovars by MAT. These results contribute to the knowledge and monitoring of zoonotic pathogens with epizootic potential in Southern Ocean pinnipeds. Given the potential impact that pathogens may have on the abundance of wild (sometimes threatened and endangered) populations, constant monitoring and surveillance are required to prevent pathogen spread, particularly under forecast climate change scenarios.

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