scholarly journals Distribution and diversity of cumacean assemblages in Admiralty Bay, King George Island

2011 ◽  
Vol 32 (4) ◽  
pp. 341-354 ◽  
Author(s):  
Krzysztof Pabis ◽  
Magdalena Błażewicz-paszkowycz
Keyword(s):  
Abundant Species ◽  
Silty Sand ◽  
Silty Clay ◽  
Central Basin ◽  
Depth Range ◽  
King George Island ◽  
Admiralty Bay ◽  
Core Species ◽  
Sandy Clay ◽  
Key Species

Distribution and diversity of cumacean assemblages in Admiralty Bay, King George IslandEleven species of cumaceans were found in 105 samples collected in Admiralty Bay (King George Island) in the summers of 1984/85 and 1985/86, from 20 to 500 m depth range. Four cumacean assemblages were distinguished using the multivariate analysis. They were characterized by the dominance of one or two species often with low density values. Two assemblages were found in open waters of Admiralty Bay. The first inhabited on sandy-clay-silt and silty-clay-sand bottom deposits in the depth range from 140 to 330 m, withCampylaspis maculata(1.6 ± 2.1 ind./0.1m2; F = 72.4%) andLeuconsp. (1.4 ± 1.6 ind./0.1m2; F = 68.9%) as key species. The second assemblage was found in the depth range from 50 to 120 m with silty-sand sediments, and it was characterized by the presence of Vauthompsonia inermis (6.5 ± 6.6 ind./0.1m2; F = 92.0%). A third assemblage was found in shallow waters influenced by glaciers in the bottom area of Ezcurra Inlet. It was characterized by sandy-clay-silt sediments and the presence ofEudorella splendida(14.6 ± 9.4 ind./0.1m2; F = 100.0%) as a core species. The last assemblage was found in the shallow sublittoral (50-100 m) of Ezcurra Inlet and the central basin, withDiastylis anderssoni armata(1.5 ± 1.1 ind./0.1m2; F = 85.7%) andDiastylopsis goekei(1.1 ± 1.0 ind./0.1m2; F = 71.4%) as the most frequent and abundant species.V. inermisis considered a eurytopic species with high frequency in the whole material, and was present in all four distinguished assemblages.E. splendidaandD. goekeiwere also recorded in each of the assemblages, but their total frequency was lower.

scholarly journals The use of Geoeletric Methods for Post-foundation Assessments of Distressed Buildings in Ebute-meta, Mainland Local Government Area of Lagos State

2021 ◽  
pp. 104-119
Author(s):  
O. J. Airen
Keyword(s):  
Soft Clay ◽  
Maximum Depth ◽  
Silty Sand ◽  
Silty Clay ◽  
Clayey Sand ◽  
Near Surface ◽  
Cone Resistance ◽  
Sandy Clay ◽  
Geotechnical Investigations ◽  
Support Engineering

Geophysical and geotechnical investigations were combined to investigate the immediate causes of the distresses and foundation failures of buildings in Ebute-Meta area of Lagos, south-west Nigeria. Six (6) traverses were mapped in the study area across which six (6) 2D Wenner ERI, and fourteen (14) VES geophysical data were acquired. One (1) boring and five (5) CPT geotechnical data were also acquired. 2D ERI results reveal that resistivity values vary from 4.62 – 293 Ωm across the study area. Three resistivity structures were identified which denoted peat/clay, sandy clay, clayey sand and sand. The resistivity of the peat/clay varies from 4.62 – 27.9 Ωm with thickness varying from 12 - 25 m. The sandy clay varies in resistivity and thickness values from 26 – 86 Ωm and 8 – 29 m respectively. The clayey sand from 84.4 – 182 Ωm and 10 -15 m, and sand, having resistivity and thickness values of 293 Ωm and 3 – 5 m. The VES reveals similar results to the 2D ERI, delineating six geoelectric layers which are the topsoil, peat, clay, sandy clay, clayey sand and sand at maximum depth of 35.8 m. The borehole (BH) reveals a maximum boring depth of 45 m with eight zones comprising dark grey sandy clay, firm to stiff silty clay, soft, dark organic silty peaty clay, grey silty sand, dark grey silty sandy clay, dark grey organic peaty clay, grey silty sandy clay and medium dense to dense grey sand with occasional gravels. The CPT, which penetrated a maximum depth 15.8 m reveal that the cone resistance values vary progressively from 0 – 162 kg/cm2indicating very soft clay to soft clay near-surface and medium dense to dense geologic material at deeper depth. The peat/clay delineated by the 2D ERI and VES at 5 – 25 m depth with resistivity value varying from 4.62 -17 Ωm in the study area, and also revealed in the BH at 5.75 – 27.75 m depth as soft, dark organic silty peaty clay, having cone resistance values varying from 0 – 20 kg/cm2 is laterally extensive and incompetent to support engineering foundation.

Soft bottom sublittoral amphipod fauna of Admiralty Bay, King George Island, Antarctic

2011 ◽  
Vol 40 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Anna Jażdżewska
Keyword(s):  
Dominant Species ◽  
Historical Data ◽  
Subtidal Zone ◽  
Central Basin ◽  
King George Island ◽  
Soft Bottom ◽  
Admiralty Bay ◽  
Ca 50 ◽  
Shallow Area ◽  
Different Depths

AbstractThe present analysis is based on 140 quantitative samples collected from depths of 20 to 500 m in the central basin of Admiralty Bay and its inner shallow area, Ezcurra Inlet. One hundred and twenty species were identified, of which 47 species were new for Admiralty Bay. Mean density of crustaceans decreased with depth. Highest species richness was observed at depths of 50–100 m. Historical data and present investigations revealed distinct differences in the amphipod assemblages at different depths. In the subtidal zone, Gondogeneia antarctica was the dominant species; in the shallow sublittoral (down to ca 50 m) Prostebbingia gracilis and Hippomedon kergueleni played an important role. Below 50 m, the importance of phoxocephalid species increased.

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 A new mini box corer for sampling muddy bottoms in antarctic shallow waters

2009 ◽  
Vol 52 (3) ◽  
pp. 629-636 ◽  
Author(s):  
Carlos Alejandro Echeverría ◽  
Helena Passeri Lavrado ◽  
Lúcia Campos ◽  
Paulo Cesar de Paiva
Keyword(s):  
Stainless Steel ◽  
Shallow Waters ◽  
King George Island ◽  
Sampling Area ◽  
Sampling Device ◽  
Admiralty Bay ◽  
Direct Sampling ◽  
External Frame ◽  
Bottom Sampling ◽  
Box Corer

A new Mini Box Corer (MBC-GEAMB) was developed for bottom sampling in Antarctic shallow waters down to 100 m depth from a small vessel. It consists of a detachable stainless steel box with a total sampling area of 0.0625 m², and a closing arm with a detachable blade without an external frame. MBC allowed stratified bottom sampling and good quality samples comparable to those obtained through diving. A comparison between the MBC-GEAMB and a 0.056 m²van Veen grab (VV) was undertaken for the benthic macrofaunal composition in Admiralty Bay, King George Island (Antarctica). MBC and VV samples were taken from three depths (20, 30 and 60m) in two sites. Total densities sampled with the MBC were up to 10 times higher than those obtained with van Veen grab. VV samples might lead to faunistic abundance underestimation compared to the MBC samples. Besides, MBC showed a higher performance on discriminating different sites as regards total macrofaunal density. It is suggested that MBC could be employed as an efficient remote sampling device for shallow-waters where direct sampling by SCUBA was not advisable.

scholarly journals Is polychaete diversity in the deep sublittoral of an Antarctic fiord related to habitat complexity?

2012 ◽  
Vol 33 (2) ◽  
pp. 181-197 ◽  
Author(s):  
Krzysztof Pabis ◽  
Jacek Siciński
Keyword(s):  
Species Richness ◽  
Habitat Complexity ◽  
Feeding Guilds ◽  
Depth Range ◽  
Soft Bottom ◽  
Admiralty Bay ◽  
Sea Floor ◽  
Species Richness And Diversity ◽  
South Shetlands ◽  
High Species Richness

Is polychaete diversity in the deep sublittoral of an Antarctic fiord related to habitat complexity?Seventy-six species of Polychaeta were found in 19 quantitative samples collected in the deep sublittoral (200-500 m) of Admiralty Bay (South Shetlands). Three assemblages were distinguished by similarity analysis (clustering, nMDS). The soft bottom in depths from 200 to 300m was strongly dominated byMaldane sarsi antarcticaand had very low species richness and diversity. The second assemblage was distinguished in the areas of the sea floor in the same depth range but with aggregations of Ascidiacea and Bryozoa. It was again characterized by high abundance ofMaldane sarsi antarctica, but showed significantly higher species richness and diversity. Diversity of polychaete feeding guilds was also high in these areas. This pattern was probably associated with an increased habitat complexity due to the presence of dense aggregations of large suspension feeders. High species richness and diversity was also noted in the third assemblage, associated with the deepest sublittoral (400-500 m) of Admiralty Bay. This is the area characterized by very stable environmental conditions, where the assemblage was dominated byTharyx cincinnatus, Sternaspissp.,Maldane sarsi antarctica, andAsychis amphiglypta.

scholarly journals Temporal Distribution of Arsenic and Metals in Soil From King George Island, Antarctica

2022 ◽  
Vol 8 ◽  
Author(s):  
Tailisi H. Trevizani ◽  
Rosalinda C. Montone ◽  
Rubens C. L. Figueira
Keyword(s):  
Human Activities ◽  
Temporal Distribution ◽  
Polar Regions ◽  
Control Points ◽  
King George Island ◽  
Admiralty Bay ◽  
Direct Exposure ◽  
Antarctic Continent ◽  
The Antarctic ◽  
Continue Monitoring

The polar regions are vulnerable to impacts caused by local and global pollution. The Antarctic continent has been considered an environment that has remained little affected by human activities. Direct exposure to contaminants may occur in areas continuously occupied by research stations for several decades. Admiralty Bay on the southeast coast of King George Island, has potential for being affected by human activities due research stations operating in the area, including the Brazilian Commandant Ferraz Antarctic Station (CFAS). The levels of metals and arsenic were determined in soils collected near CFAS (points 5, 6, 7, and 9), Base G and at two points distant from the CFAS: Refuge II and Hennequin. Samples were collected after the fire in CFAS occurred in February 2012, up to December 2018 to assess the environmental impacts in the area. Al and As were related with Base G. Refuge II and Hennequin can be considered as control points for this region. As a consequence of the accident, the increased levels for Cd, Cu, Pb, and Zn, especially at point 9 (inside the CFAS) and in the soil surrounding the CFAS in 2013. The results from 2016 to 2018 demonstrated a reduction in levels of all studied metals near CFAS, which may be related to the leaching of metals into Admiralty Bay; it is thus, being important the continue monitoring soil, sediments, and Antarctic biota.

scholarly journals Colonization by mites of glacier-free areas in King George Island, Antarctica

2009 ◽  
Vol 44 (8) ◽  
pp. 891-895 ◽  
Author(s):  
Grzegorz Gryziak
Keyword(s):  
West Coast ◽  
Protected Area ◽  
Soil Samples ◽  
Oribatid Mites ◽  
King George Island ◽  
Admiralty Bay ◽  
Near Shore ◽  
South Shetlands ◽  
Mite Communities ◽  
The Antarctic

This work aimed to investigate the ratio of colonization by terrestrial mites on ice-free areas created by the ongoing climate-induced melting of Antarctic glaciers. Glacier retreat opens new ice-free areas for the colonization by vegetation and animals. The study was undertaken on the Antarctic Specially Protected Area no. 128 (West Coast of the Admiralty Bay, King George Island, South Shetlands Islands). Transects marked between the Ecology, Baranowski and Windy Glaciers, and a sea shore were used to collect soil samples. Oribatid mites were found only on near-shore areas, on patches of vegetation of more than 30 years of age. The colonization by mite communities is strongly determined by the presence of plants.

scholarly journals Arsenic, copper and zinc in marine sediments from the proximity of the brazilian­antarctic base, Admiralty Bay, King George Island, ­Antartica

2010 ◽  
pp. 137-140 ◽  
Author(s):  
Andreza Portella Ribeiro ◽  
Rubens César Lopes Figueira ◽  
César de Castro Martins ◽  
Charles Roberto de Almeida Silva ◽  
Elvis Joacir de França ◽  
...  
Keyword(s):  
Marine Sediments ◽  
King George Island ◽  
Admiralty Bay ◽  
Copper And Zinc ◽  
Arsenic Copper
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