The summer diet of demersal fish at the South Shetland Islands

1997 ◽  
Vol 9 (4) ◽  
pp. 407-413 ◽  
Author(s):  
Masanori Takahashi ◽  
Tetsuo Iwami
Keyword(s):  
Marine Ecosystem ◽  
Stomach Contents ◽  
Demersal Fish ◽  
South Shetland Islands ◽  
Fish Prey ◽  
Shetland Islands ◽  
Antarctic Marine ◽  
Dietary Component ◽  
Gobionotothen Gibberifrons ◽  
The Antarctic

The stomach contents of demersal fish in late January 1982 were analysed. Samples were taken at 100, 300 and 500 m depth south of Elephant Island, Bransfield Strait and north of Livingston Island, and at 800 m to the east of Smith Island. Fifty four taxa of fish belonging to 11 families were collected. The diets of 2101 fish representing 38 taxa were examined. These were classified into three categories, fish feeders, krill feeders and benthos feeders. Fish prey species fed on krill and/or benthos. Krill was a major dietary component for 32 (84.2%) out of 38 taxa. Gobionotothen gibberifrons was distributed at all 10 stations (100–800 m in depth) and its diet comprised krill and benthos. The present findings verify the importance of krill in the Antarctic marine ecosystem and indicate that krill is consumed by benthic fish at greater depths than previously reported.

Spatial patterns of summer demersal fish assemblages around the Antarctic Peninsula and South Shetland Islands

2014 ◽  
Vol 27 (2) ◽  
pp. 109-117 ◽  
Author(s):  
Facundo Llompart ◽  
Matías Delpiani ◽  
Eugenia Lattuca ◽  
Gabriela Delpiani ◽  
Adriana Cruz-Jiménez ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Fish Assemblages ◽  
Geographical Location ◽  
Research Programme ◽  
Demersal Fish ◽  
South Shetland Islands ◽  
Species Number ◽  
Shetland Islands ◽  
North East ◽  
The Antarctic

AbstractDuring the research programme conducted on the OV Puerto Deseado in the summers of 2011 and 2013, 36 stations were sampled using a demersal net at depths between 53–590 m in the Antarctic Peninsula and South Shetland Islands. A total 3378 fish specimens belonging to 36 species were recorded. Notothenidae was the best-represented family in species number, with Lepidonotothen nudifrons, L. larseni and Trematomus scotti being the most numerous species. Of the fish assemblages, 20% of the species were considered as dominant, 10% as common, 13% as occasional and 57% as rare. Six groups (and two sub-groups) were obtained by the ordination diagram based on geographical location: group 1=Gerlache Strait, group 2=Deception Islands, group 3=Biscoe Island, group 4=between Elephant and King George islands, group 5=northern Antarctic Peninsula, and group 6=South Shetland Islands, with sub-groups 6a shallower South Shetland Islands and 6b deeper South Shetland Islands. Sampling depth and water temperature significantly explained the spatial pattern. A latitudinal pattern of decreasing abundance from north-east to south-west was found in L. larseni and the opposite in T. scotti. The predictability of fish composition in the assemblages’ areas could be a useful tool for ecosystem-based management.

Fish in the diet of the Antarctic shag at four colonies on the Danco Coast, Antarctic Peninsula

2002 ◽  
Vol 14 (1) ◽  
pp. 32-36 ◽  
Author(s):  
R. Casaux ◽  
A. Baroni ◽  
E. Barrera-Oro
Keyword(s):  
Antarctic Peninsula ◽  
Fish Species ◽  
South Shetland Islands ◽  
The South ◽  
Coastal Fish ◽  
Shetland Islands ◽  
Important Prey ◽  
Inshore Waters ◽  
Gobionotothen Gibberifrons ◽  
The Antarctic

The diet of breeding Antarctic shags (Phalacrocorax bransfieldensis) was investigated at four colonies on the Danco Coast, Antarctic Peninsula, by the analysis of 616 pellets (regurgitated casts) collected from December 1997 to February 1998. Overall, demersal-benthic fish were the most frequent and important prey at all the colonies, followed by octopods and gastropods. Amongst fish, Notothenia coriiceps was the main prey in all of the sampling sites, followed in similar importance by Gobionotothen gibberifrons at Cape Herschel, Primavera Island and Midas Island and in less importance by Harpagifer antarcticus at Py Point. There were marked differences among colonies in the size of the fish consumed. The largest and the smallest specimens were eaten by shags from Midas Island and Py Point respectively. This was mainly influenced by the number of specimens of the smallest fish species, H. antarcticus, consumed at Py Point. The differences in the diet composition may be related to the different foraging areas used by the shags. Results from this study differ from previous studies around the Antarctic Peninsula. The shags at the Danco Coast preyed markedly more intensively than those at the South Shetland Islands on G. gibberifrons. This finding reflects the low abundance of this fish species in inshore waters (< 100 m depth) at the South Shetland Islands and supports the use of the Antarctic shags to monitor trends in local populations of coastal fish species.

Short Note: A method for sexing the chicks of Antarctic shags

2007 ◽  
Vol 20 (2) ◽  
pp. 147-148 ◽  
Author(s):  
R. Casaux ◽  
A. Ramón ◽  
A. Baroni
Keyword(s):  
Prey Availability ◽  
Short Note ◽  
Morphological Characters ◽  
Adult Mortality ◽  
South Shetland Islands ◽  
The South ◽  
Fish Prey ◽  
Shetland Islands ◽  
Age At First Breeding ◽  
Gobionotothen Gibberifrons

Several studies have been carried out during the last fifteen years on reproduction, population dynamics and diet of the Antarctic shag, Phalacrocorax bransfieldensis Murphy, at different localities in the South Shetland Islands (reviewed in Casaux & Barrera-Oro 2006). In both the colonies studied and in other colonies counted we observed that the number of breeding pairs was steadily decreasing (Casaux & Barrera-Oro 2006). Casaux & Baroni (2002) had earlier suggested that such a decreasing trend might be related, at least partially, to a marked decrease in the inshore populations of two fish prey species, the marbled notothen Notothenia rossii Richardson and the humphead notothen Gobionotothen gibberifrons Lönnberg (Barrera-Oro et al. 2000), which had been studied over a period of 19 years in coastal waters of the South Shetland Islands. Exactly how a reduction in prey availability affects the shag populations (e.g. migration of breeders to other colonies in the area or to new breeding areas, a decrease in the rate of recruitment, an increase in adult mortality, variation in the age at first breeding, etc) is not clear. To investigate this, we started a banding programme at Nelson Island, South Shetland Islands. We postulated that the processes might operate with different intensities on individuals of different sexes, so all individuals in each population studied needed to be sexed. This posed problems for chicks which have monomorphic plumage and no differences in vocalisations (Casaux & Baroni 2000), so that the normal methods for sexing in the field would not work. As most of the external morphological characters in the chicks of Antarctic shags have stabilized by 45–50 days old (Casaux 1998), Casaux & Baroni (2000) had suggested that the use of discriminant functions originally developed for adults could be an appropriate method to sex chicks more than 50 days old.

Fur seals, whales and tourists: a commercial history of Deception Island, Antarctica

Polar Record ◽  
2009 ◽  
Vol 46 (3) ◽  
pp. 210-221 ◽  
Author(s):  
J. Stephen Dibbern
Keyword(s):  
South Shetland Islands ◽  
Deception Island ◽  
Commercial Activity ◽  
Early 19Th Century ◽  
Cruise Industry ◽  
Shetland Islands ◽  
Fur Seals ◽  
History Of ◽  
The Antarctic ◽  
Antarctic Fur Seals

ABSTRACTDeception Island in the South Shetland Islands was the site of some of the earliest commercial activity to be carried out in the Antarctic with the early 19th century hunting of Antarctic fur seals. Nearly a century later it was the site of the most extensive anchorage for the reconstructed ships and ocean liners used as non-pelagic whale processing factories. Deception was also the site of what is the only successful land based commercial activity in Antarctic history. The Hektor whaling station operated in Whalers Bay from 1912 until 1931. Most of the remains of the station have now been obliterated by the volcanic activity that occurred in the late 1960s and 1970. By the later part of the twentieth century Deception Island had become a regular stop for the growing Antarctic tourist cruise industry. No other place in Antarctica has been so thoroughly identified with commercial activity.

The role of fish in the Antarctic marine food web: differences between inshore and offshore waters in the southern Scotia Arc and west Antarctic Peninsula

2002 ◽  
Vol 14 (4) ◽  
pp. 293-309 ◽  
Author(s):  
ESTEBAN BARRERA-ORO
Keyword(s):  
Food Web ◽  
Antarctic Peninsula ◽  
Demersal Fish ◽  
Pelagic Fish ◽  
West Antarctic ◽  
Antarctic Marine ◽  
Scotia Arc ◽  
West Antarctic Peninsula ◽  
The Antarctic

The role of fish in the Antarctic food web in inshore and offshore waters is analysed, taking as an example the coastal marine communities of the southern Scotia Arc (South Orkney Islands and South Shetland Islands) and the west Antarctic Peninsula. Inshore, the ecological role of demersal fish is more important than that of krill. There, demersal fish are major consumers of benthos and also feed on zooplankton (mainly krill in summer). They are links between lower and upper levels of the food web and are common prey of other fish, birds and seals. Offshore, demersal fish depend less on benthos and feed more on zooplankton (mainly krill) and nekton, and are less accessible as prey of birds and seals. There, pelagic fish (especially lantern fish) are more abundant than inshore and play an important role in the energy flow from macrozooplankton to higher trophic levels (seabirds and seals). Through the higher fish predators, energy is transferred to land in the form of fish remains, pellets (birds), regurgitation and faeces (birds and seals). However, in the general context of the Antarctic marine ecosystem, krill (Euphausia superba) plays the central role in the food web because it is the main food source in terms of biomass for most of the high level predators from demersal fish up to whales. This has no obvious equivalent in other marine ecosystems. In Antarctic offshore coastal and oceanic waters the greatest proportion of energy from the ecosystem is transferred to land directly through krill consumers, such as flying birds, penguins, and seals. Beside krill, the populations of fish in the Antarctic Ocean are the second most important element for higher predators, in particular the energy-rich pelagic Myctophidae in open waters and the pelagic Antarctic silver fish (Pleuragramma antarcticum) in the high Antarctic zone. Although the occurrence of these pelagic fish inshore has been poorly documented, their abundance in neritic waters could be higher than previously believed.

New trigonioid bivalves from the Early Jurassic to earliest Cretaceous of the Antarctic Peninsula region: systematics and austral paleobiogeography

1995 ◽  
Vol 69 (1) ◽  
pp. 66-84 ◽  
Author(s):  
Simon R. A. Kelly
Keyword(s):  
New Zealand ◽  
Antarctic Peninsula ◽  
Southern Africa ◽  
Late Jurassic ◽  
Early Jurassic ◽  
South Shetland Islands ◽  
Shetland Islands ◽  
Livingston Island ◽  
History Of ◽  
The Antarctic

New discoveries of trigonioid bivalves are documented from three areas in the Antartic Peninsula: the Fossil Bluff Group of Alexander Island, the Latady Formation of the Orville Coast, and the Byers Group of Livingston Island, South Shetland Islands. Eleven taxa are described, representing six genera or subgenera. The faunas are characterized by genera including Vaugonia (Vaugonia), the first Early Jurassic trigonioid recognized on the continent; Vaugonia (V.) and V. (Orthotrigonia?) in the Late Jurassic; and Iotrigonia (Iotrigonia), Myophorella (Scaphogonia), and Pterotrigonia (Pterotrigonia), which span the Jurassic–Cretaceous boundary, reaching the Berriasian stage. The following species are new: Pterotrigonia (P.) cramei n. sp., Pterotrigonia (P.) thomsoni n. sp., Vaugonia (V.) orvillensis n. sp., and V. (Orthotrigonia?) quiltyi n. sp. The faunas show affinities with those of New Zealand and southern Africa. Trigonioids characterize the shallower marine biofacies in the Jurassic of the Antarctic and reflect the principal shallowing events in the history of the region.

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