scholarly journals Heavy metals in surface water of the Atlantic sector of the Antarctic during the 79th cruise of the research vessel “Akademik Mstislav Keldysh”

2020 ◽  
Vol 5 (4) ◽  
pp. 56-68
Author(s):  
N. Yu. Mirzoeva ◽  
N. N. Tereshchenko ◽  
A. A. Paraskiv ◽  
V. Yu. Proskurnin ◽  
E. G. Morozov
Keyword(s):  
Heavy Metals ◽  
Trace Elements ◽  
Surface Water ◽  
Maximum Permissible Concentration ◽  
Drake Passage ◽  
Weddell Sea ◽  
Tierra Del Fuego ◽  
Atlantic Sector ◽  
Bransfield Strait ◽  
The Antarctic

Relevance of monitoring heavy metals content in the water of the Atlantic sector of the Antarctic is due to the need for a current assessment of quality of the marine environment for making responsible decisions on the conservation of marine living resources in this unique area of the World Ocean. The aim of the study was to obtain new data on levels and spatial distribution of concentrations of trace elements, mainly heavy metals, in surface water. Sampling of surface seawater was carried out during the Antarctic expedition of the 79th cruise of the RV “Akademik Mstislav Keldysh” at 21 stations in the area of the Drake Passage, the Bransfield Strait, and the Antarctic Sound, as well as in Weddell and Scotia seas. Extracting and concentrating of dissolved form of 13 trace elements (Be, Se, Sb, Tl, V, Pb, Cd, Cu, Zn, Ni, Mo, Co, and Fe) were performed using sodium diethyldithiocarbamate and carbon tetrachloride (CCl4). The elements were measured by mass spectrometry. Among all trace elements content, only Mo concentration in seawater at 9 stations, located in the Drake Passage, the Bransfield Strait, northern Weddell Sea, and off the southern coast of Tierra del Fuego Island, exceeded 1.2–2.8 times maximum permissible concentration of trace elements in fishery water bodies of the Russian Federation (MPCF). According to international regulatory legal acts, such as “Dutch sheets”, there were single cases of exceeding MPC (maximum permissible concentration under short-term exposure) for Cd and Zn, as well as exceeding TV (target value under chronic exposure) for Cu, Pb, Cd, Zn, Se, and Co at several stations. The research has shown as follows: despite limited anthropogenic pressure on this area of the Southern Ocean, in seawater of some regions of the Atlantic sector of the Antarctic, increased concentrations of several trace elements, inter alia heavy metals, are recorded. Further study of the sources of trace elements intake and the peculiarities of their distribution in seawater of the Atlantic sector of the Antarctic is required in order to account for ongoing processes, take measures for rational management, and provide ecologically acceptable use of natural resources in the Antarctic.

scholarly journals Natural iron enrichment around the Antarctic Peninsula in the Southern Ocean

2009 ◽  
Vol 6 (4) ◽  
pp. 7481-7515 ◽  
Author(s):  
M. V. Ardelan ◽  
O. Holm-Hansen ◽  
C. D. Hewes ◽  
C. S. Reiss ◽  
N. S. Silva ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Weddell Sea ◽  
South Shetland Islands ◽  
The South ◽  
Total Acid ◽  
Shetland Islands ◽  
Iron Enrichment ◽  
Bransfield Strait ◽  
Natural Iron ◽  
The Antarctic

Abstract. As part of the US-AMLR program that occupied 99 hydrographic stations in the South Shetland Islands-Antarctic Peninsula region in January–February of 2006, concentrations of dissolved iron (DFe) and total acid-leachable iron (TaLFe) were measured in the upper 150 m at 16 stations (both coastal and pelagic waters). The concentrations in the upper mixed layer (UML) of DFe and TaLFe were relatively high in Weddell Sea Shelf Waters (~0.6 nM and 15 nM, respectively) and lowest in Drake Passage waters (~0.2 nM and 0.9 nM, respectively). In the Bransfield Strait, representing a mixture of waters from the Weddell Sea and the Antarctic Circumpolar Current (ACC), concentrations of DFe were ~0.4 nM and of TaLFe ~1.7 nM. The highest concentrations of DFe and TaLFe in the UML were found at shallow coastal stations close to Livingston Island (~1.6 nM and 100 nM, respectively). The ratio of TaLFe:DFe varied with the distance to land: ~45 at the shallow coastal stations, ~15 in the high-salinity waters of Bransfield Strait, and ~4 in ACC waters. Concentrations of DFe increased slightly with depth in the water column, while that of TaLFe did not show any consistent trend with depth. Our data are consistent with the hypothesis that the relatively high rates of primary production known from the central regions of the Scotia Sea are partially sustained by natural iron enrichment resulting from a northeasterly flow of iron-rich coastal waters originating in the South Shetland Islands-Antarctic Peninsula region.

scholarly journals Spatial Structure and Intra-Annual Variability of Weddell Sea Front based on the Data of NOAA OISST Reanalysis

2020 ◽  
Author(s):  
Yu. V. Artamonov ◽  
E. A. Skripaleva ◽  
N. V. Nikolsky ◽  
◽  
◽  
...  
Keyword(s):  
Spatial Structure ◽  
Antarctic Peninsula ◽  
Time Lag ◽  
Water Area ◽  
Weddell Sea ◽  
The South ◽  
Orkney Islands ◽  
Bransfield Strait ◽  
South Orkney Islands ◽  
The Antarctic

Based on the NOAA OISST reanalysis data, the spatial structure of the Weddell Sea Front in the climatic field of the sea surface temperature was analyzed and the seasonal variability of front’s characteristics was estimated. The spatial position of the frontal zone in the Weddell Sea was analyzed using distributions of the total horizontal temperature gradient. The characteristics of the front (the position of the gradients' extrema corresponding to the front, their magnitude and temperature on the front axis) were determined for each month on the profiles of meridional and zonal temperature gradients along meridians and parallels with a discreteness of 2.5° of longitude and 0.25° of latitude. It is shown that the interaction of Weddell Sea cold waters, which are transported by currents northward along the Antarctic Peninsula coasts, with the warmer waters of the eastern shelf of the Antarctic Peninsula and the Bransfield Strait surface water causes formation of two branches of the Weddell Sea Front. These branches round from a vast shelf at the Antarctic Peninsula tip and the Joinville archipelago the south and north and are traced further east along the boundaries of the bottom rise located approximately between 62.5S and 64.5S. To the south of the South Orkney Islands shelf, the two branches merge into one front, which follows to the east along the depth dump of the relative shallow between the South Orkney and South Sandwich Islands. In the seasonal cycle of the Weddell Sea Front intensity, a time lag was revealed of the front intensification period in the direction from west to east. In Bransfield Strait the front is most intense in February, between the Antarctic Peninsula tip and the South Orkney Islands – in March, east of the South Orkney Islands – in April. The branch of the Weddell Sea Front off the northeastern of the Antarctic Peninsula coasts intensifies in November – January, in the western part of the water area east of the James Ross and Snow Hill Islands – in January – February.

scholarly journals Cryptophyte and Photosynthetic Picoeukaryote Abundances in the Bransfield Strait during Austral Summer

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 185
Author(s):  
Vladimir Mukhanov ◽  
Evgeny Sakhon ◽  
Alexander Polukhin ◽  
Vladimir Artemiev ◽  
Eugene Morozov ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Austral Summer ◽  
Weddell Sea ◽  
Significant Shift ◽  
Bransfield Strait ◽  
Bellingshausen Sea ◽  
Diverse Community ◽  
Physical And Chemical ◽  
The Antarctic ◽  
And Chemical Properties

A remarkable shift in the species composition and size distribution of the phytoplankton community have been observed in coastal waters along the Antarctic Peninsula over the last three decades. Smaller photoautotrophs such as cryptophytes are becoming more abundant and important for the regional ecosystems. In this study, flow cytometry was used to quantify the smallest phytoplankton in the central Bransfield Strait and explore their distribution across the strait in relation to physical and chemical properties of the two major water masses: the warmer and less saline Transitional Zonal Water with Bellingshausen Sea influence (TBW), and the cold and salty Transitional Zonal Water with Weddell Sea influence (TWW). Pico- and nano-phytoplankton clusters were distinguished and enumerated in the cytograms: photosynthetic picoeukaryotes, cryptophytes (about 9 µm in size), and smaller (3 µm) nanophytoplankton. It was shown that nanophytoplankton developed higher abundances and biomasses in the warmer and less saline TBW. This biotope was characterized by a more diverse community with a pronounced dominance of Cryptophyta in terms of biomass. The results support the hypothesis that increasing melt-water input can potentially support spatial and temporal extent of cryptophytes. The replacement of large diatoms with small cryptophytes leads to a significant shift in trophic processes in favor of the consumers such as salps, which able to graze on smaller prey.

scholarly journals Comparison of warming trends predicted over the next century around Antarctica from two coupled models

1998 ◽  
Vol 27 ◽  
pp. 576-582 ◽  
Author(s):  
Siobhan P. O'Farrell ◽  
William M. Connolley
Keyword(s):  
Climate Models ◽  
Winter Season ◽  
Drake Passage ◽  
Weddell Sea ◽  
Coupled Models ◽  
Coupled Climate Models ◽  
Temperature Signal ◽  
Antarctic Continent ◽  
Definition Of ◽  
The Antarctic

This paper investigales the climate change in two atmosphere ice-ocean coupled climate models — the UKMO and the CSIRO— in the Antarctic region over the next century. The objectives were to sec if an enhanced level of greenhouse-gas forcing results in a surface temperature signal above background variability, and to see if this pattern of change resembles the change seen to date in Antarctica, especially the warming around the Peninsula. The models show that although reduced sea-ice compactness is responsible for regions of enhanced air-temperature anomalies, these ice-compactness anomalies are determined by different mechanisms in the respective models. The pattern of warming in both models does not match the differential rates of warming seen in the observations of temperature change over the Antarctic continent in the lait few decades. Also the level of background ocean variability in the Drake Passage and Weddell Sea region hampers the clear definition of a signal over the Antarctic Peninsula in the coupled models. Although no winter enhancement in warming over the Peninsula region IS found, an autumn anomaly is seen in one of the models. The mechanism for this feature IS documented, and an explanation of why it does not persist throughout the winter season is presented.

Trace element speciation in water and bottom sediments of the Pirogov water reservoir

2020 ◽  
pp. 59-68
Author(s):  
O. A. Lipatnikova ◽  
T. N. Lubkova ◽  
N. A. Korobova
Keyword(s):  
Trace Elements ◽  
Surface Water ◽  
Bottom Sediments ◽  
Manganese Oxides ◽  
Maximum Permissible Concentration ◽  
Solid Phase ◽  
Metal Speciation ◽  
Water Reservoir ◽  
Element Speciation ◽  
Iron And Manganese

The composition and speciation of trace elements (Cu, Pb, Zn, Cd, Ni, Co, Mn, Fe, Ba, and Sr) in surface water and bottom sediments of the Pirogov water reservoir have been studied. It was found that the metal content in surface water does not exceed the maximum permissible concentration (MPC) for fishery water reservoir excluded Zn (2–9 MPC) and Cu (up to 2 MPC). According to results of thermodynamic calculations, the predominant metal speciation in water is the free ion (Sr, Ba, Zn, Ni, Co, Cd), fulvate (Cu) and carbonate (Pb) complex. The interstitial water is characterized by an increase in the content of sulfate complex of trace elements in loams, the solid phase of which is also characterized by slightly anomalous contents of Zn, Cd, Co, and Ni. According to data of sequential selective procedure, metals are predominantly immobilized in solid phase of bottom sediments in the crystal structure of silicates or bounded to iron and manganese oxides. Only for Cd and Mn exchangeable and bound to carbonates fractions are characterized by considerable relative contents.

scholarly journals Decadal Freshening of the Antarctic Bottom Water Exported from the Weddell Sea

2013 ◽  
Vol 26 (20) ◽  
pp. 8111-8125 ◽  
Author(s):  
Loïc Jullion ◽  
Alberto C. Naveira Garabato ◽  
Michael P. Meredith ◽  
Paul R. Holland ◽  
Peggy Courtois ◽  
...  
Keyword(s):  
Bottom Water ◽  
Weddell Sea ◽  
Antarctic Bottom Water ◽  
Atlantic Sector ◽  
Ice Shelves ◽  
Anthropogenic Component ◽  
Deep Layers ◽  
Bottom Waters ◽  
Circumpolar Current ◽  
The Antarctic

Abstract Recent decadal changes in Southern Hemisphere climate have driven strong responses from the cryosphere. Concurrently, there has been a marked freshening of the shelf and bottom waters across a wide sector of the Southern Ocean, hypothesized to be caused by accelerated glacial melt in response to a greater flux of warm waters from the Antarctic Circumpolar Current onto the shelves of West Antarctica. However, the circumpolar pattern of changes has been incomplete: no decadal freshening in the deep layers of the Atlantic sector has been observed. In this study, the authors document a significant freshening of the Antarctic Bottom Water exported from the Weddell Sea, which is the source for the abyssal layer of the Atlantic overturning circulation, and trace its possible origin to atmospheric-forced changes in the ice shelves and sea ice on the eastern flank of the Antarctic Peninsula that include an anthropogenic component. These findings suggest that the expansive and relatively cool Weddell gyre does not insulate the bottom water formation regions in the Atlantic sector from the ongoing changes in climatic forcing over the Antarctic region.

A new species of Orbiniella (Polychaeta: Orbiniidae) from deep basins of Antarctica

2005 ◽  
Vol 85 (4) ◽  
pp. 843-846
Author(s):  
Bhavani E. Narayanaswamy ◽  
James A. Blake
Keyword(s):  
Deep Water ◽  
Drake Passage ◽  
Geographic Range ◽  
Weddell Sea ◽  
The Third ◽  
Deep Water Species ◽  
The Antarctic ◽  
Setal Structure ◽  
A New Species ◽  
Water Species

During the 2002 Antarctic Deep-sea Biodiversity (ANDEEP) programme to the Drake Passage, Weddell Sea Basin and South Sandwich Slope and trench, a new deep-water species of orbiniid polychaete was collected: Orbiniella andeepia sp. nov. Orbiniella andeepia appears to be most closely related to O. marionensis but differs in capillary setal structure, the type and number of acicular spines found in each podial lobe. Orbiniella andeepia is only the third deep-water species of Orbiniella to be discovered. It exhibits both a wide depth- and geographic-range within the Antarctic slope and abyssal sediments.

Sponges of the Lazarev and Weddell Sea, Antarctica: explanations for their patchy occurrence

1995 ◽  
Vol 7 (3) ◽  
pp. 227-234 ◽  
Author(s):  
Julian Gutt ◽  
Vladimir M. Koltun
Keyword(s):  
Continental Shelf ◽  
Weddell Sea ◽  
Small Scale ◽  
Atlantic Sector ◽  
Investigation Area ◽  
Antarctic Continental Shelf ◽  
The Individual ◽  
Environmental Events ◽  
The Antarctic ◽  
First Time

Seventy-three sponge species were caught at 23 stations on the continental shelf of the Lazarev and Weddell Sea (Atlantic sector of the Southern Ocean). Tedania tantula was the most often found species amongst the 63 demosponge species caught and among the five hexactinellid species Rossella racovitzae was most common. The stations were classified according to their species inventory, and so the individual stations of the resulting four groups were rather uniformly dispersed over the entire investigation area. The species composition of adjacent stations varied considerably. There was no discernible relationship between the biological set of data and any combination of the available environmental characteristics of the stations. The sponge fauna of the, so far very poorly investigated, Lazarev Sea did not differ considerably from that of the adjacent Weddell Sea. The only species to be recorded for the first time on the Antarctic continental shelf were Homaxinella flagelliformis and Hyrtios arenosa. Small scale environmental events such as iceberg scouring, or biological characteristics such as extremely slow growth and budding reproduction are thought to generate the patchy distribution pattern.

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