scholarly journals Benthic foraminifera from Pine Island and Ferrero bays, Amundsen Sea

2013 ◽  
Vol 34 (2) ◽  
pp. 169-200 ◽  
Author(s):  
Wojciech Majewski
Keyword(s):  
Deep Water ◽  
Ross Sea ◽  
Common Species ◽  
Species Level ◽  
South Shetland Islands ◽  
Amundsen Sea ◽  
Shetland Islands ◽  
Circumpolar Deep Water ◽  
Almost All ◽  
Water Depths

Abstract Twenty one core tops from the central part of Pine Island Bay and nearby Ferrero Bay were collected in early 2010. They originate from a poorly studied area of the Amundsen Sea influenced at greater depths by relatively warm Circumpolar Deep Water. Almost all samples came from water−depths between 550 and 900 m and yield benthic foraminiferal assemblages of moderate variability with a significant decrease in calcareous forms with increasing water−depth. In total, 93 benthic taxa, belonging to 71 genera, are identified at the species level. They share a greater percentage of common species with the Ross Sea than with South Shetland Islands, most likely due to stronger climatic dissimilar− ity with the latter. Interestingly, the assemblages from Pine Island Bay, share the greatest numbers of taxa with assemblages described from Lutzow−Holm Bay in East Antarctica, where the influence of Circumpolar Deep Water has been also recognized.

scholarly journals Changes in Digenean Infection of the Antarctic Fish Notothenia Coriiceps in Admiralty Bay, King George Island, Over Three Decades

2014 ◽  
Vol 35 (3) ◽  
pp. 513-520 ◽  
Author(s):  
Zdzisław Laskowski ◽  
Witold Jeżewski ◽  
Krzysztof Zdzitowiecki
Keyword(s):  
Dominant Species ◽  
Antarctic Fish ◽  
Common Species ◽  
South Shetland Islands ◽  
Admiralty Bay ◽  
Shetland Islands ◽  
Orkney Islands ◽  
Digenean Species ◽  
Notothenia Coriiceps ◽  
Almost All

AbstractThe infection of black rockcod,Notothenia coriiceps,with digeneans in Admiralty Bay (South Shetland Islands) within three months, from November 2007 to January 2008, is compared with the infection in the same three months in 1978/79, based on the examination of twenty fish collected in each month. Digenea found in 1978/1979 season were more numer-ous, and more diverse. Only five digenean species,Macvicaria georgiana,Neolebouria antarctica,Lepidapedon garrardi,Genolinea bowersiandLecithaster macrocotyle, were re-corded during both investigations, whereas three species,Neolepidapedon trematomi,Elytro-phalloides oatesiandGonocerca phycidis, only in 1978/79.M. georgianawas the dominant species in 1978/79 and sub-dominant in 2007/08. Other digeneans were found inN. coriicepsin 2007/08 invariably together withM. georgiana. G. bowersiwas the sub-dominant species in 1978/79 and the most common species in 2007/2008. Infections with Digenea belonging to other species were much less intense. Of the three rare or common species in 1978/79, the two,L. garrardiandL. macrocotyle, occurred in both seasons, whereasE. oatesioccurred only in 1978/79. Three remaining species were sporadic or absent. The overall results there-fore demonstrated that infections with almost all digenean species were less strong in 2007/08 than three decades earlier, in 1978/79. Only data onM. georgiana,G. bowersiandL.garrardiwere statistically significant (p <0.05). Data on the occurrence of 14 species of Digenea inN. coriicepsfrom South Shetland Islands, South Orkney Islands, South Georgia, Argentine Is-lands, Melchior Islands, Adelie Land and Heard Island are given.

A new Antarctic foraminiferal species for detecting climate change in sub-Recent glacier-proximal sediments

2009 ◽  
Vol 21 (5) ◽  
pp. 439-448 ◽  
Author(s):  
Wojciech Majewski ◽  
Andrzej Tatur
Keyword(s):  
Climate Change ◽  
Climate Warming ◽  
The Arctic ◽  
South Shetland Islands ◽  
King George Island ◽  
Tidewater Glaciers ◽  
Admiralty Bay ◽  
Shetland Islands ◽  
Foraminiferal Species ◽  
Water Depths

AbstractCribroelphidium webbi sp. nov. is the only adequately described sub-Recent elphidiid foraminifer from Antarctica. In Admiralty Bay (King George Island, South Shetland Islands), it is found at several locations within inner fiord setting at water depths between 33 and 165 m, but most commonly shallower than 100 m. In outer basins this foraminifer is absent. In the cores analysed, C. webbi sp. nov. is present in well-constrained sub-Recent horizons that are clearly related to climate warming and deglaciation. These horizons represent a diachronous facies marker rather than a single stratigraphic layer. Cribroelphidium webbi sp. nov. shows clear association with retreating tidewater glaciers, therefore it is an important sensitive glacier-proximal indicator. It appears that it shares similar ecologic affinities with Cribroelphidium excavatum clavatum, which is widely distributed throughout the Arctic.

scholarly journals Glacial Meltwater Identification in the Amundsen Sea

2017 ◽  
Vol 47 (4) ◽  
pp. 933-954 ◽  
Author(s):  
Louise C. Biddle ◽  
Karen J. Heywood ◽  
Jan Kaiser ◽  
Adrian Jenkins
Keyword(s):  
Dissolved Oxygen ◽  
Deep Water ◽  
Ocean Model ◽  
Water Type ◽  
Ice Shelf ◽  
Amundsen Sea ◽  
Glacial Meltwater ◽  
Circumpolar Deep Water ◽  
Water Characteristics ◽  
Multiparameter Analysis

AbstractPine Island Ice Shelf, in the Amundsen Sea, is losing mass because of warm ocean waters melting the ice from below. Tracing meltwater pathways from ice shelves is important for identifying the regions most affected by the increased input of this water type. Here, optimum multiparameter analysis is used to deduce glacial meltwater fractions from water mass characteristics (temperature, salinity, and dissolved oxygen concentrations), collected during a ship-based campaign in the eastern Amundsen Sea in February–March 2014. Using a one-dimensional ocean model, processes such as variability in the characteristics of the source water masses on shelf and biological productivity/respiration are shown to affect the calculated apparent meltwater fractions. These processes can result in a false meltwater signature, creating misleading apparent glacial meltwater pathways. An alternative glacial meltwater calculation is suggested, using a pseudo–Circumpolar Deep Water endpoint and using an artificial increase in uncertainty of the dissolved oxygen measurements. The pseudo–Circumpolar Deep Water characteristics are affected by the under ice shelf bathymetry. The glacial meltwater fractions reveal a pathway for 2014 meltwater leading to the west of Pine Island Ice Shelf, along the coastline.

scholarly journals Die Polychaeten der Amsterdam-Expedition nach der Insel Ascension (Zentral-Atlantik)

1992 ◽  
Vol 61 (4) ◽  
pp. 219-235 ◽  
Author(s):  
Gesa Hartmann-Schröder
Keyword(s):  
Atlantic Ocean ◽  
Persian Gulf ◽  
West Indies ◽  
Galapagos Islands ◽  
Species Level ◽  
South Shetland Islands ◽  
Galápagos Islands ◽  
Shetland Islands ◽  
Ascension Island ◽  
The Pacific

During the Amsterdam Expedition to Ascension Island in 1989 eighteen species of polychaetes were collected, fifteen of which were already known to science. One could not be identified to species level and two were new to science: Aricidea (Aedicira) ascensionensis n. sp. and Notodasus arenicola n. sp. Four of the known species are widely distributed, three are circumtropicalsubtropical and one has a tropical-subtropical distribution in the Pacific and in the Atlantic Ocean. Another species is recorded from different regions in the Atlantic Ocean. The rest of the species were –.until now –.only known from their type localities, viz. West Indies, Angola, Persian Gulf, Galapagos Islands, and South Shetland Islands.

scholarly journals Variability of Circumpolar Deep Water transport onto the Amundsen Sea Continental shelf through a shelf break trough

2013 ◽  
Vol 118 (12) ◽  
pp. 6603-6620 ◽  
Author(s):  
K. M. Assmann ◽  
A. Jenkins ◽  
D. R. Shoosmith ◽  
D. P. Walker ◽  
S. S. Jacobs ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Water Transport ◽  
Deep Water ◽  
Shelf Break ◽  
Amundsen Sea ◽  
Circumpolar Deep Water

scholarly journals Variation in the Distribution and Properties of Circumpolar Deep Water in the Eastern Amundsen Sea, on Seasonal Timescales, Using Seal-Borne Tags

2018 ◽  
Vol 45 (10) ◽  
pp. 4982-4990 ◽  
Author(s):  
Helen K. W. Mallett ◽  
Lars Boehme ◽  
Mike Fedak ◽  
Karen J. Heywood ◽  
David P. Stevens ◽  
...  
Keyword(s):  
Deep Water ◽  
Amundsen Sea ◽  
Circumpolar Deep Water

Molecular evolutionary relationships of the octopodid genus Thaumeledone (Cephalopoda: Octopodidae) from the Southern Ocean

2008 ◽  
Vol 20 (3) ◽  
pp. 245-251 ◽  
Author(s):  
J.M. Strugnell ◽  
M.A. Collins ◽  
A.L. Allcock
Keyword(s):  
Southern Ocean ◽  
Deep Water ◽  
Deep Sea ◽  
Nuclear Gene ◽  
Population Level ◽  
Molecular Study ◽  
South Shetland Islands ◽  
Evolutionary Relationships ◽  
Sequence Variability ◽  
Shetland Islands

AbstractRecent trawling in the Southern Ocean has yielded individuals of a number of species of the deep sea octopod genus Thaumeledone. This paper provides the first molecular study of the genus, employing molecular sequences from five mitochondrial (12S rDNA, 16S rDNA, COI, COIII, cytochrome oxidase b) and a single nuclear gene (rhodopsin) and includes representatives of each of the known Southern Ocean species. Thaumeledone rotunda, believed to be circumpolar in distribution and found in relatively deep water is the sister taxa to T. gunteri, known only from South Georgia. A notable level of sequence variability was evident between a T. peninsulae individual recently captured from the Powell Basin, and two T. peninsulae individuals captured from the continental slope, north of the South Shetland Islands. This is likely to represent population level intraspecific variation within this species.

scholarly journals Is Ekman pumping responsible for the seasonal variation of warm circumpolar deep water in the Amundsen Sea?

2017 ◽  
Vol 132 ◽  
pp. 38-48 ◽  
Author(s):  
T.W. Kim ◽  
H.K. Ha ◽  
A.K. Wåhlin ◽  
S.H. Lee ◽  
C.S. Kim ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Deep Water ◽  
Ekman Pumping ◽  
Amundsen Sea ◽  
Circumpolar Deep Water
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