Ascidians (Tunicata, Ascidiacea) of Potter Cove, South Shetland Islands, Antarctica

1998 ◽  
Vol 10 (2) ◽  
pp. 147-152 ◽  
Author(s):  
M. Tatian ◽  
R.J. Sahade ◽  
M.E. Doucet ◽  
G.B. Esnal
Keyword(s):  
Abundant Species ◽  
South Shetland Islands ◽  
Physical Factors ◽  
Substrate Type ◽  
Patchy Distribution ◽  
Potter Cove ◽  
Shetland Islands ◽  
Soft Bottoms ◽  
Synoicum Adareanum ◽  
Main Factor

Certain physical factors, substrate type and ice action appear to be important determinants for ascidian distribution. Three different substrate types were sampled at depths between 0–30 m by SCUBA diving: soft bottoms, hard bottoms and moraine deposits. The species found were Aplidium radiatum, Synoicum adareanum, Distaplia cylindrica, Sycozoa gaimardi, Sycozoa sigillinoides, Tylobranchion speciosum, Corella eumyota, Ascidia challengeri, Cnemidocarpa verrucosa, Styela wandeli, Dicarpa insinuosa, Pyura bouvetensis, Pyura discoveryi, Pyura obesa, Pyura setosa, Molgula enodis and Molgula pedunculata. Highest diversity and patchy distribution was found in less stringent environments, where epibiosis is a commmon phenomenon on stolidobranch ascidians. Differences in stalk development were found in the most abundant species Molgula pedunculata and Cnemidocarpa verrucosa. Ice action may be the main factor that determines the absence of ascidians above 15 m in all the stations sampled.

scholarly journals Photosynthetic light requirements and vertical distribution of macroalgae in newly ice-free areas in Potter Cove, South Shetland Islands, Antarctica

Polar Biology ◽  
2015 ◽  
Vol 39 (1) ◽  
pp. 153-166 ◽  
Author(s):  
D. Deregibus ◽  
M. L. Quartino ◽  
G. L. Campana ◽  
F. R. Momo ◽  
C. Wiencke ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
South Shetland Islands ◽  
Potter Cove ◽  
Shetland Islands ◽  
Light Requirements

Succession of Antarctic benthic algae (Potter Cove, South Shetland Islands): structural patterns and glacial impact over a four-year period

Polar Biology ◽  
2017 ◽  
Vol 41 (2) ◽  
pp. 377-396 ◽  
Author(s):  
Gabriela L. Campana ◽  
Katharina Zacher ◽  
Dolores Deregibus ◽  
Fernando Roberto Momo ◽  
Christian Wiencke ◽  
...  
Keyword(s):  
Benthic Algae ◽  
South Shetland Islands ◽  
Potter Cove ◽  
Structural Patterns ◽  
Shetland Islands

A new species of Ammothea and other pycnogonids from around Livingston Island, South Shetland Islands, Antarctica

2000 ◽  
Vol 12 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Tomás Munilla León
Keyword(s):  
New Species ◽  
Abundant Species ◽  
South Shetland Islands ◽  
Similar Species ◽  
Shetland Islands ◽  
Livingston Island ◽  
The Family ◽  
A New Species

Specimens of 22 species of pycnogonids belonging to twelve genera and seven families were collected during a cruise near Livingston Island, South Shetland Islands. Twenty two of the 94 stations yielded pycnogonids: the new species Ammothea hesperidensis is described fully, illustrated, and compared with similar species. The family Nymphonidae provided both the greatest diversity of species (seven) and number of specimens (35). The most abundant species were Achelia hoekii and Nymphon australe.

Effect of a shore-based sampling programme on Notothenia coriiceps populations

2002 ◽  
Vol 14 (3) ◽  
pp. 221-224 ◽  
Author(s):  
R.J. CASAUX ◽  
E.R. BARRERA-ORO
Keyword(s):  
Random Error ◽  
South Shetland Islands ◽  
Sampling Effort ◽  
Potter Cove ◽  
Bottom Type ◽  
Shetland Islands ◽  
Notothenia Coriiceps ◽  
Alternative Hypotheses ◽  
Sampling Programme ◽  
Intensive Sampling

The effect of an intensive sampling programme on an inshore population of Notothenia coriiceps was studied at Potter Cove, South Shetland Islands, by comparing catch data taken in successive summers of 1992/93 to 1994/95 at one specific zone (site 1) with those taken in the 1994/95 summer at two close but not previously sampled zones (sites 2 and 3). The fish were caught with trammel nets under similar sampling conditions (depth, net measurements, bottom type). In site 1, a decline in length (TL) of the fish was observed throughout the whole period. The fish from sites 2 (mean = 32.4 cm) and 3 (mean = 31.8 cm) exhibited no significant differences in mean length. They were larger (P = 0.07) than those from site 1 caught in the summers of 1994/95 (mean = 28.8 cm) and 1993/94 (mean = 30.2 cm), but were similar in size to those sampled in the summer of 1992/93 (mean = 31.7 cm), just when the sampling programme started in site 1. Although alternative hypotheses to explain the results are discussed (e.g. random error, strong recruitment), it is suggested that the size variations of the fish sampled at site 1 are due to intensive sampling effort carried out throughout this study at that specific zone in Potter Cove.

Distribution of PAHs in the water column, sediments and biota of Potter Cove, South Shetland Islands, Antarctica

2009 ◽  
Vol 21 (04) ◽  
pp. 329 ◽  
Author(s):  
Antonio Curtosi ◽  
Emilien Pelletier ◽  
Cristian L. Vodopivez ◽  
Walter P. Mac Cormack
Keyword(s):  
Water Column ◽  
South Shetland Islands ◽  
Potter Cove ◽  
Shetland Islands

scholarly journals Multi-year analysis of distributed glacier mass balance modelling and equilibrium line altitude on King George Island, Antarctic Peninsula

2018 ◽  
Vol 12 (4) ◽  
pp. 1211-1232 ◽  
Author(s):  
Ulrike Falk ◽  
Damián A. López ◽  
Adrián Silva-Busso
Keyword(s):  
Mass Balance ◽  
Air Temperature ◽  
Surface Air Temperature ◽  
High Variability ◽  
South Shetland Islands ◽  
Glacier Mass Balance ◽  
Equilibrium Line Altitude ◽  
Potter Cove ◽  
Shetland Islands ◽  
Ice Cap

Abstract. The South Shetland Islands are located at the northern tip of the Antarctic Peninsula (AP). This region was subject to strong warming trends in the atmospheric surface layer. Surface air temperature increased about 3 K in 50 years, concurrent with retreating glacier fronts, an increase in melt areas, ice surface lowering and rapid break-up and disintegration of ice shelves. The positive trend in surface air temperature has currently come to a halt. Observed surface air temperature lapse rates show a high variability during winter months (standard deviations up to ±1.0K(100m)-1) and a distinct spatial heterogeneity reflecting the impact of synoptic weather patterns. The increased mesocyclonic activity during the wintertime over the past decades in the study area results in intensified advection of warm, moist air with high temperatures and rain and leads to melt conditions on the ice cap, fixating surface air temperatures to the melting point. Its impact on winter accumulation results in the observed negative mass balance estimates. Six years of continuous glaciological measurements on mass balance stake transects as well as 5 years of climatological data time series are presented and a spatially distributed glacier energy balance melt model adapted and run based on these multi-year data sets. The glaciological surface mass balance model is generally in good agreement with observations, except for atmospheric conditions promoting snow drift by high wind speeds, turbulence-driven snow deposition and snow layer erosion by rain. No drift in the difference between simulated mass balance and mass balance measurements can be seen over the course of the 5-year model run period. The winter accumulation does not suffice to compensate for the high variability in summer ablation. The results are analysed to assess changes in meltwater input to the coastal waters, specific glacier mass balance and the equilibrium line altitude (ELA). The Fourcade Glacier catchment drains into Potter cove, has an area of 23.6 km2 and is glacierized to 93.8 %. Annual discharge from Fourcade Glacier into Potter Cove is estimated to q¯=25±6hm3yr-1 with the standard deviation of 8 % annotating the high interannual variability. The average ELA calculated from our own glaciological observations on Fourcade Glacier over the time period 2010 to 2015 amounts to 260±20 m. Published studies suggest rather stable conditions of slightly negative glacier mass balance until the mid-1980s with an ELA of approx. 150 m. The calculated accumulation area ratio suggests dramatic changes in the future extent of the inland ice cap for the South Shetland Islands.

H2O2 accumulation from photochemical production and atmospheric wet deposition in Antarctic coastal and off-shore waters of Potter Cove, King George Island, South Shetland Islands

1999 ◽  
Vol 11 (2) ◽  
pp. 131-139 ◽  
Author(s):  
Doris Abele ◽  
Gustavo A. Ferreyra ◽  
Irene Schloss
Keyword(s):  
Hydrogen Peroxide ◽  
Surface Waters ◽  
Wet Deposition ◽  
High Energy ◽  
South Shetland Islands ◽  
King George Island ◽  
The South ◽  
Potter Cove ◽  
Shetland Islands ◽  
Snowfall Event

Temporal and spatial variations of the hydrogen peroxide accumulation were measured in off-shore waters and in intertidal rockpools near Jubany Station, King George Island, South Shetland Islands. As H2O2 photoformation is mainly driven by the short wavelength radiation in the UV-B and the UV-A range of the solar spectrum, the study was conducted between the beginning of October and the end of December 1995, the period of Antarctic spring ozone depletion. Wet deposition of H2O2 containing snow was identified as a major source of hydrogen peroxide in the surface waters of Potter Cove. As the concentrations of dissolved organic carbon (DOC) in Potter Cove surface waters were low (121 ± 59 μmol Cl−1), when compared to the highly eutrophicated waters on the German Wadden coast (6000–7000 μmol Cl−1), direct UV-induced DOC photo-oxidation was of only limited significance in the Antarctic sampling site. Nonetheless, under experimental conditions, H2O2 photoformation in Potter Cove surface waters amounted to 90 ± 40 nmol H2O2 h−1 l−1 under a UV-transparent quartz plate. When high energy UV-B photons were cut-off by a WG320 filter formation continued at a rate of 66 ± 29 nmol H2O2 h−1 l−1 due to UV-A and visible light photons. Samples from freshly deposited snow contained between 10 000 and 13 600 nmol H2O2 l−1, and a snowfall event in mid November resulted in a maximum concentration of 1450 nmol H2O2 l−1 in the upper 10 cm layer of Potter Cove surface waters. Maximal H2O2 concentrations in intertidal rockpools were even higher and reached up to 2000 nmol H2O2 l−1 after the snowfall event. During a grid survey on December 17 1995, H2O2 concentrations and salinity displayed a north to south gradient, with higher concentrations and PSU at the south coast of the cove. The reasons for this spatial inhomogenety are as yet unknown, but may relate to a minor local input of photo-reactive organic matter from creeks entering the cove in the south-east, as well as to waste water discharge from the station, located on the south beach.

A new species of Ammothea (Pycnogonida) and other pycnogonids from Livingston Island and surrounding waters (South Shetland Islands, Antarctica)

2001 ◽  
Vol 13 (2) ◽  
pp. 144-149 ◽  
Author(s):  
Tomás Munilla León
Keyword(s):  
New Species ◽  
Abundant Species ◽  
South Shetland Islands ◽  
Similar Species ◽  
Depth Range ◽  
Shetland Islands ◽  
West Antarctic ◽  
Livingston Island ◽  
The Family ◽  
A New Species

Fifty-nine species of pycnogonids belonging to sixteen genera and eight families were collected during a cruise near Livingston Island and surrounding waters, from depths between 0 and 1019 m. The new species Ammothea bentartica is described fully, illustrated and compared with similar species. The family Nymphonidae had both the greatest number of species (20) and number of specimens (67% of 1201). The most abundant species were Nymphon charcoti and N. australe. Nymphon paucidens and Pallenopsis buphtalmus were collected for a second time. The collections increased the geographical distribution of five species and the depth range of seven species. This collection appears typical of the West Antarctic zone.

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