scholarly journals Appendicularia (Tunicata) in an Antarctic Glacial Fjord–Chaotic Fjordic Structure Community or Good Indicators of Oceanic Water Masses?

Diversity ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 675
Author(s):  
Anna Panasiuk ◽  
Marcin Kalarus
Keyword(s):  
Cold Water ◽  
Late Summer ◽  
Polar Regions ◽  
Oceanic Water ◽  
King George Island ◽  
Dynamic Changes ◽  
Abiotic Conditions ◽  
Long Period ◽  
Dominant Part ◽  
Water Community

Appendicularians are important but remain poorly studied groups of zooplankton in polar regions. The present research is based on samples collected in Admiralty Bay (King George Island) during a year-long period. Six larvacean species were noted, among which Fritillaria borealis and Oikopleura gaussica were found to be the most numerous, while the other species were relatively rare. Fritillaria borealis was a dominant part of the late summer (warm water) community, while O. gaussica had the highest presence in the winter (cold water) community. The abundance of appendicularians recorded in the bay was less numerous than that described by other authors. The most important factors influencing annual changes in the larvaceans in the bay was season, but only in the case of the two species. These facts were probably linked to the very dynamic changes in the abiotic conditions in the fjord, and the influx of specific masses of water.

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.

Monitoring snow and ice surfaces on King George Island, Antarctic Peninsula, with high-resolution TerraSAR-X time series

2015 ◽  
Vol 28 (2) ◽  
pp. 135-149 ◽  
Author(s):  
U. Falk ◽  
H. Gieseke ◽  
F. Kotzur ◽  
M. Braun
Keyword(s):  
Time Series ◽  
High Resolution ◽  
Snow Cover ◽  
Satellite Image ◽  
Polar Regions ◽  
King George Island ◽  
Differential Gps ◽  
Snow Cover Extent ◽  
Wide Range ◽  
Multi Temporal

AbstractChanges of glaciers and snow cover in polar regions affect a wide range of physical and ecosystem processes on land and in the adjacent marine environment. In this study, we investigated the potential of 11-day repeat high-resolution satellite image time series from the TerraSAR-X mission to derive glaciological and hydrological parameters on King George Island, Antarctica, between 25 October 2010 and 19 April 2011. The spatial pattern and temporal evolution of snow cover extent on ice-free areas can be monitored using multi-temporal coherence images. Synthetic aperture radar (SAR) coherence is used to map glacier extent of land-terminating glaciers with an average accuracy of 25 m. Multi-temporal SAR colour composites identify the position of the late summer snow line at ~220 m a.s.l. Glacier surface velocities are obtained from intensity feature-tracking. Surface velocities near the calving front of Fourcade Glacier were up to 1.8±0.01 m d-1. Using an intercept theorem based on fundamental geometric principles together with differential GPS field measurements, the ice discharge of Fourcade Glacier was estimated at 20 700±5500 m3 d-1 (corresponding to ~19±5 kt d-1). The rapidly changing surface conditions on King George Island and the lack of high-resolution digital elevation models for the region remain restrictions for the applicability of SAR data and the precision of derived products. Supplemental data are available at http://dx.doi.org/10.1594/PANGAEA.853954.

scholarly journals The effect of pulverising aeration on changes in the oxygen and nitrogen concentrations in water of Lake Starzyc

2015 ◽  
Vol 25 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Piotr Wesołowski ◽  
Adam Brysiewicz
Keyword(s):  
Dissolved Oxygen ◽  
Nitrate Nitrogen ◽  
Ecological Status ◽  
Ammonium Nitrogen ◽  
Abiotic Conditions ◽  
The Third ◽  
Long Period ◽  
Nitrogen Concentrations ◽  
Bottom Waters ◽  
Restoration Measures

Abstract Due to poor ecological status of Lake Starzyc, lake restoration measures were undertaken in 2003 to improve aerobic conditions of near-bottom waters and to decrease phosphorus concentrations. To do this, a wind-driven pulverising aerator was installed in the lake. The aim of this study was to analyse variability of oxygen and nitrogen concentrations in lake water near the aerator in the third year of its operation and later on in the three-year-long period of the years 2008–2010. It was found that concentrations of ammonium-nitrogen, nitrate-nitrogen and dissolved oxygen near the aerator did not differ from those in sites 4 and 5, which evidenced similar abiotic conditions in analysed waters. Higher concentrations of dissolved oxygen and lower concentrations of nitrate-nitrogen were found in the years 2008–2010 than in 2005.

scholarly journals Development of radar glacier zones on the King George Island ice cap, Antarctica, during austral summer 1996/97 as observed in ERS-2 SAR data

2000 ◽  
Vol 31 ◽  
pp. 357-363 ◽  
Author(s):  
Matthias Braun ◽  
Frank Rau ◽  
Helmut Saurer ◽  
Hermann Gobmann
Keyword(s):  
Meteorological Data ◽  
Austral Summer ◽  
Late Summer ◽  
Ground Truth ◽  
King George Island ◽  
Equilibrium Line Altitude ◽  
Sar Images ◽  
Ice Cap ◽  
Wet Snow ◽  
Frozen Percolation

AbstractBased on a time series of European remote-sensing satellite (ERS-2) synthetic-aperture radar (SAR) images from 1996/97, ablation on the King George Island (Antarctica) ice cap is documented. Snowmelt patterns were monitored by mapping the dynamic evolution of radar glacier zones and their boundaries. On the ice cap, all major radar glacier zones except the dry-snow radar zone were identified during the observed period While winter was characterized by a frozen-percolation radar zone, the ablation season was characterized by wet-snow and bare-ice radar zones. A striking bright backscatter signature indicated the presence of a highly reflective zone in the lower parts of the wet-snow zone. It was attributed to a phase 2 melt (P2) radar zone, which is characterized by a metamorphosed and roughened surface of a melting snow cover. Due to the absence of simultaneously acquired ground-truth information, concurrent meteorological data proved to be essential for interpreting the SAR images. Although the maximum elevation of the ice cap does not exceed 680 ma.s.L, ablation patterns obviously reflect altitudinal control. Melt onset up to 530 m a.s.l. was initiated by an advection event at the end of October 1996. A wet snowpack on the entire ice cap corresponds with a prolonged period of high temperatures in January 1997. However, the highest parts of the ice cap were affected by occasional melt-freeze cycles. The transient snowline at the end of February was determined as being at 250 m a i l. This late-summer snowline was regarded as an approximation of the equilibrium-line altitude for the 1996/97 ablation season.

scholarly journals Characterising terrestrial influences on Antarctic air masses using Radon-222 measurements at King George Island

2014 ◽  
Vol 14 (18) ◽  
pp. 9903-9916 ◽  
Author(s):  
S. D. Chambers ◽  
S.-B. Hong ◽  
A. G. Williams ◽  
J. Crawford ◽  
A. D. Griffiths ◽  
...  
Keyword(s):  
Late Summer ◽  
Early Spring ◽  
Late Winter ◽  
South American ◽  
King George Island ◽  
Air Masses ◽  
Diurnal Cycles ◽  
Baseline Values ◽  
One Year ◽  
Radon Measurements

Abstract. We report on one year of high-precision direct hourly radon observations at King Sejong Station (King George Island) beginning in February 2013. Findings are compared with historic and ongoing radon measurements from other Antarctic sites. Monthly median concentrations reduced from 72 mBq m−3 in late-summer to 44 mBq m−3 in late winter and early spring. Monthly 10th percentiles, ranging from 29 to 49 mBq m−3, were typical of oceanic baseline values. Diurnal cycles were rarely evident and local influences were minor, consistent with regional radon flux estimates one tenth of the global average for ice-free land. The predominant fetch region for terrestrially influenced air masses was South America (47–53° S), with minor influences also attributed to aged Australian air masses and local sources. Plume dilution factors of 2.8–4.0 were estimated for the most terrestrially influenced (South American) air masses, and a seasonal cycle in terrestrial influence on tropospheric air descending at the pole was identified and characterised.

Cephalopods as prey. III. Cetaceans

1996 ◽  
Vol 351 (1343) ◽  
pp. 1053-1065 ◽  
Keyword(s):  
Polar Regions ◽  
Oceanic Water ◽  
Cetacean Species ◽  
Commercial Fish ◽  
Cephalopod Species ◽  
The North ◽  
Continental Shelf Water ◽  
Continental Shelves ◽  
Regional Estimates ◽  
The North Pacific

Over 80 % of odontocete species and two balaen whale species include cephalopods in their diet regularly. In 28 odontocetes they comprise the main food. Predominently cephalopod-eating species are found in the Physeteridae, Ziphiidae, Phocaenidae and Delphinidae. By far the most important of the 28 families of cephalopods represented in the diet of cetaceans are the oceanic Ommastrephidae, Histioteuthidae and the Cranchiidae, with the neritic Loliginidae assuming most importance on the continental shelves. Onychoteuthidae and Gonatidae assume greater importance in polar regions and the North Pacific. The other 22 families form a reservoir from which various cetaceans eat opportunistically and as their sizes permit. There are probably less than 60 cephalopod species regularly in the diet of cetaceans. Species composition of the food varies regionally, seasonally and annually. Locally, the greatest difference is found between cetaceans that live in oceanic water and continental shelf water. There is a positive correlation between the size of the prey and both the size of pelagic feeding cetacean species and the growth stage within a species. This leads to some partitioning of the food and less competition. Broad estimates show that the biomass of oceanic cephalopods consumed annually by the largest odontocete, Physeter catodon , may be over twice the biomass of fish caught by man. Regional estimates show that consumption by cetaceans of little known cephalopod species may greatly exceed the local catches of commercial fish.

Contemporary Changes in Vegetation of Polar Regions

2011 ◽  
Vol 18 (1) ◽  
pp. 35-51 ◽  
Author(s):  
Maria Olech ◽  
Michał Węgrzyn ◽  
Maja Lisowska ◽  
Agnieszka Słaby ◽  
Piotr Angiel
Keyword(s):  
Vegetation Dynamics ◽  
Climate Changes ◽  
The Arctic ◽  
Original Research ◽  
Polar Regions ◽  
King George Island ◽  
Maritime Antarctic ◽  
The Earth

Contemporary Changes in Vegetation of Polar Regions Rapid climate changes which have been observed over the recent years in both polar regions of the Earth, directly or indirectly affect vegetation dynamics. This article presents the main directions of the changes taking place in the recent years in tundra communities of both polar regions, based on original research carried out in the Arctic in Spitsbergen and in the maritime Antarctic on King George Island.

Possible multiple introductions of Cladonia borealis to King George Island

2012 ◽  
Vol 24 (4) ◽  
pp. 359-366 ◽  
Author(s):  
Chae Haeng Park ◽  
Gajin Jeong ◽  
Soon Gyu Hong
Keyword(s):  
Haplotype Network ◽  
Rdna Locus ◽  
Rrna Genes ◽  
Lsu Rdna ◽  
Polar Regions ◽  
King George Island ◽  
Long Distance ◽  
Multiple Introductions ◽  
Network Analyses ◽  
Rdna Sequences

AbstractMany lichens have extensive distributional ranges covering several climatic zones and are able to colonize extreme habitats, including high alpine and polar regions. Cladonia borealis, one of the dominant lichen species on King George Island, is a cosmopolitan species inhabiting polar, subpolar, and alpine areas. It is usually found on soil, humus, and mosses, and is morphologically highly diverse. To understand the phylogeographic history of C. borealis on King George Island, we compared specimens from there with specimens from Norway and Chile. We conducted phylogenetic and haplotype network analyses of the partial SSU, ITS1-5.8S-ITS2, and partial LSU rDNA sequences including intron sequences in LSU rRNA genes. Nuclear rDNA locus of C. borealis from King George Island was separated into two monophyletic lineages. It is suggested that they originated in multiple independent introduction events after long-distance dispersal from other continents.

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