Summer phytoplankton of the northern Barents Sea (75–80º N)

2019 ◽  
pp. 8-19
Author(s):  
Larisa A. Pautova ◽  
Vladimir A. Silkin ◽  
Marina D. Kravchishina ◽  
Valeriy G. Yakubenko ◽  
Anna L. Chultsova
Keyword(s):  
Barents Sea ◽  
Weighted Average ◽  
Arctic Basin ◽  
High Arctic ◽  
Alexandrium Tamarense ◽  
Warm Water ◽  
The Arctic ◽  
Absolute Maximum ◽  
Deep Trench ◽  
Maximum Biomass

The structure of the summer planktonic communities of the Northern part of the Barents sea in the first half of August 2017 were studied. In the sea-ice melting area, the average phytoplankton biomass producing upper 50-meter layer of water reached values levels of eutrophic waters (up to 2.1 g/m3). Phytoplankton was presented by diatoms of the genera Thalassiosira and Eucampia. Maximum biomass recorded at depths of 22–52 m, the absolute maximum biomass community (5,0 g/m3) marked on the horizon of 45 m (station 5558), located at the outlet of the deep trench Franz Victoria near the West coast of the archipelago Franz Josef Land. In ice-free waters, phytoplankton abundance was low, and the weighted average biomass (8.0 mg/m3 – 123.1 mg/m3) corresponded to oligotrophic waters and lower mesotrophic waters. In the upper layers of the water population abundance was dominated by small flagellates and picoplankton from, biomass – Arctic dinoflagellates (Gymnodinium spp.) and cold Atlantic complexes (Gyrodinium lachryma, Alexandrium tamarense, Dinophysis norvegica). The proportion of Atlantic species in phytoplankton reached 75%. The representatives of warm-water Atlantic complex (Emiliania huxleyi, Rhizosolenia hebetata f. semispina, Ceratium horridum) were recorded up to 80º N, as indicators of the penetration of warm Atlantic waters into the Arctic basin. The presence of oceanic Atlantic species as warm-water and cold systems in the high Arctic indicates the strengthening of processes of “atlantificacion” in the region.

scholarly journals Low Abundance and Biodiversity of Top Predators -Seabirds and Marine Mammalsin High Arctic Seas

2020 ◽  
Vol 3 (3) ◽  
Keyword(s):  
Barents Sea ◽  
Chukchi Sea ◽  
Bird Species ◽  
Arctic Basin ◽  
High Arctic ◽  
The Arctic ◽  
Bering Strait ◽  
Arctic Seas ◽  
North East ◽  
The North

This article concerns the comparison of data collected in different high Arctic seas by the same team, mainly same platform (from the bridge of icebreaking RV Poarstern), and thus the same methodology. Drastic differences were noted, from high numbers in the Bering Strait and Chukchi Sea on the one hand, and Fram Strait and Barents Sea on the other. In contrast, abundance, mainly of seabirds, was very low in the Arctic Basin. Most numerous bird species varied in different areas, mainly fulmar, kittiwake, Brünnich’s guillemot and locally ivory gull. Biodiversity was low, as reflected by low numbers of species, a few of them representing the vast majority in numbers of individuals: between 85% and 95% of the total. Cetaceans were close to absent from the High Arctic Ocean, the Wandel Sea off North Greenland and the shallow seas along the North-East Passage; pinnipeds and polar bear were tallied on the Outer Marginal Zone OMIZ, basically absent in the Closed Pack Ice Zone CPI.

scholarly journals Influence of Atlantic inflow on the freshwater content in the upper layer of the Arctic basin

2019 ◽  
Vol 65 (4) ◽  
pp. 363-388
Author(s):  
G. V. Alekseev ◽  
A. V. Pnyushkov ◽  
A. V. Smirnov ◽  
A. E. Vyazilova ◽  
N. I. Glok
Keyword(s):  
Fresh Water ◽  
Large Scale ◽  
Barents Sea ◽  
Lower Boundary ◽  
Arctic Basin ◽  
Water Layer ◽  
Atlantic Water ◽  
Water Masses ◽  
The Arctic ◽  
The North

Inter-decadal changes in the water layer of Atlantic origin and freshwater content (FWC) in the upper 100 m layer were traced jointly to assess the influence of inflows from the Atlantic on FWC changes based on oceanographic observations in the Arctic Basin for the 1960s – 2010s. For this assessment, we used oceanographic data collected at the Arctic and Antarctic Research Institute (AARI) and the International Arctic Research Center (IARC). The AARI data for the decades of 1960s – 1990s were obtained mainly at the North Pole drifting ice camps, in high-latitude aerial surveys in the 1970s, as well as in ship-based expeditions in the 1990s. The IARC database contains oceanographic measurements acquired using modern CTD (Conductivity – Temperature – Depth) systems starting from the 2000s. For the reconstruction of decadal fields of the depths of the upper and lower 0 °С isotherms and FWC in the 0–100 m layer in the periods with a relatively small number of observations (1970s – 1990s), we used a climatic regression method based on the conservativeness of the large-scale structure of water masses in the Arctic Basin. Decadal fields with higher data coverage were built using the DIVAnd algorithm. Both methods showed almost identical results when compared.  The results demonstrated that the upper boundary of the Atlantic water (AW) layer, identified with the depth of zero isotherm, raised everywhere by several tens of meters in 1990s – 2010s, when compared to its position before the start of warming in the 1970s. The lower boundary of the AW layer, also determined by the depth of zero isotherm, became deeper. Such displacements of the layer boundaries indicate an increase in the volume of water in the Arctic Basin coming not only through the Fram Strait, but also through the Barents Sea. As a result, the balance of water masses was disturbed and its restoration had to occur due to the reduction of the volume of the upper most dynamic freshened layer. Accordingly, the content of fresh water in this layer should decrease. Our results confirmed that FWC in the 0–100 m layer has decreased to 2 m in the Eurasian part of the Arctic Basin to the west of 180° E in the 1990s. In contrast, the FWC to the east of 180° E and closer to the shores of Alaska and the Canadian archipelago has increased. These opposite tendencies have been intensified in the 2000s and the 2010s. A spatial correlation between distributions of the FWC and the positions of the upper AW boundary over different decades confirms a close relationship between both distributions. The influence of fresh water inflow is manifested as an increase in water storage in the Canadian Basin and the Beaufort Gyre in the 1990s – 2010s. The response of water temperature changes from the tropical Atlantic to the Arctic Basin was traced, suggesting not only the influence of SST at low latitudes on changes in FWC, but indicating the distant tropical impact on Arctic processes. 

scholarly journals Causes and features of long-term variability of the ice extent in the Barents Sea

2019 ◽  
Vol 59 (1) ◽  
pp. 112-122 ◽  
Author(s):  
S. B. Krasheninnikova ◽  
M. A. Krasheninnikova
Keyword(s):  
North Atlantic ◽  
Barents Sea ◽  
Arctic Basin ◽  
Atlantic Multidecadal Oscillation ◽  
Ice Cover ◽  
The Arctic ◽  
Model Calculations ◽  
The North ◽  
The Barents Sea ◽  
Cross Correlation Analysis

Based on the spectral analysis of a number of estimates of the ice extent of the Barents Sea, obtained from instrumental observational data for 1900–2014, and for the selected CMIP5 project models (MPI-ESM-LR, MPI-ESMMR and GFDL-CM3) for 1900–2005, a typical period of ~60‑year inter-annual variability associated with the Atlantic multidecadal oscillation (AMO) in conditions of a general significant decrease in the ice extent of the Barents Sea, which, according to observations and model calculations, was 20 and 15%, respectively, which confirms global warming. The maximum contribution to the total dispersion of temperature, ice cover of the Barents Sea, AMO, introduces variability with periods of more than 20 years and trends that are 47, 20, 51% and 33, 57, 30%, respectively. On the basis of the cross correlation analysis,  significant links have been established between the ice extent of the Barents Sea, AMO, and North Atlantic Oscillation (NAO) for the  period 1900–2014. A significant negative connection (R = −0.8) of ice cover and Atlantic multi-decadal oscillations was revealed at periods of more than 20 years with a shift of 1–2 years; NAO and ice cover (R = −0.6) with a shift of 1–2 years for periods of 10–20 years; AMO and NAO (R = −0.4 ÷ −0.5) with a 3‑year shift with AMO leading at 3–4, 6–8 and more than 20 years. The periods of the ice cover growth are specified: 1950–1980 and the reduction of the ice cover: the 1920–1950 and the 1980–2010 in the Barents Sea. Intensification of the transfer of warm waters from the North Atlantic to the Arctic basin, under the atmospheric influence caused by the NAO, accompanied by the growth of AMO leads to an increase in temperature, salinity and a decrease of ice cover in the Barents Sea. During periods of ice cover growth, opposite tendencies appear. The decrease in the ice cover area of the entire Northern Hemisphere by 1.5 × 106 km2 since the mid-1980s. to the beginning of the 2010, identified in the present work on NOAA satellite data, confirms the results obtained on the change in ice extent in the Barents Sea.

Ciliates and heterotrophic dinoflagellates in the marginal ice zone of the central Barents Sea during spring

2000 ◽  
Vol 80 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Frank Jensen ◽  
Benni Winding Hansen
Keyword(s):  
Sea Ice ◽  
Barents Sea ◽  
Prey Availability ◽  
Diversity Index ◽  
Open Water ◽  
Food Concentration ◽  
The Arctic ◽  
Maximum Biomass ◽  
Peak Biomass ◽  
Protozoan Community

Diversity and biomass of ciliates and heterotrophic dinoflagellates were analysed at six stations on a south–north transect (mimicking a time span of months in the biological succession during the Arctic spring–summer) from open water through drift ice and into fast ice (72°30′N 76°32′N) during spring 1993 in the open Barents Sea. A pycnocline was observed beneath the sea ice at 40–50 m. A diatom spring bloom beneath the ice with chlorophyll-a maximum >10 μg l−1 and a diverse protozoan community with a peak biomass of 34 μg C l−1 was associated with this bloom. Maximum biomass of tintinnids (1 μg C l−1), athecate dinoflagellates (8 μg C l−1) and thecate dinoflagellates (26 μg C l−1) were found associated with the chlorophyll-a maximum in the upper 10 m of the water column beneath the sea ice at the northern stations. In contrast, the protozooplankton community was dominated by naked ciliates at the southern open water stations. Here chlorophyll-a was low (<1 μg l−1) and the maximum biomass of protozooplankton was 10 μg C l−1 of which naked ciliates accounted for >50%.Cell sizes and estimated carbon content of cells >11 μm, as well as depth by depth biomass of 12 species/types of naked ciliates, 12 tintinnids, 12 athecate dinoflagellates and 24 thecate dinoflagellates, are presented. The community of naked ciliates was dominated by Strombidium spp. and Strobilidium spp., the tintinnids were dominated by Parafavella spp., Ptychocylis, Leprotintinnus, Acanthostomella and Tintinnopsis. The very small gyro-/gymnodinoid cells and Gyrodinium cf. spirale dominated the athecate dinoflagellates and the thecate dinoflagellates by the heterotroph Protoperidinium spp. generally accounted for the major part of the protozooplankton biomass along the transect. The Margalef diversity index revealed lowest diversity of ciliates and heterotrophic dinoflagellates in the open water and higher at ice-associated stations. The overall diversity was coupled with prey availability in terms of food concentration, but already saturated at 0.1 μg chlorophyll-a l−1.

First assessment of biomass and abundance of cephalopods Rossia palpebrosa and Gonatus fabricii in the Barents Sea

2016 ◽  
Vol 97 (8) ◽  
pp. 1605-1616 ◽  
Author(s):  
Alexey V. Golikov ◽  
Rushan M. Sabirov ◽  
Pavel A. Lubin
Keyword(s):  
Deep Water ◽  
Barents Sea ◽  
World Ocean ◽  
The Arctic ◽  
Arctic Ecosystems ◽  
Climate Conditions ◽  
Quantitative Distribution ◽  
Maximum Biomass ◽  
The Barents Sea ◽  
The Impact

Studies on the quantitative distribution of cephalopods in the Arctic are limited, and almost completely absent for the Barents Sea. It is known that the most abundant cephalopods in the Arctic are Rossia palpebrosa and Gonatus fabricii. Their biomass and abundance have been assessed for the first time in the Barents Sea and adjacent waters. The maximum biomass of R. palpebrosa in the Barents Sea was 6.216–6.454 thousand tonnes with an abundance of 521.5 million specimens. Increased densities of biomass were annually registered in the north-eastern parts of the Barents Sea. The maximum biomass of G. fabricii in the Barents Sea was 24.797 thousand tonnes with an abundance of 1.705 billion specimens. The areas with increased density of biomass (higher than 100 kg km−2) and abundance (more than 10,000 specimens km−2) were concentrated in deep-water troughs in the marginal parts of the Barents Sea and in adjacent deep-water areas. The biomass and abundance of R. palpebrosa and G. fabricii in the Barents Sea were much lower than those of major taxa of invertebrates and fish and than those of cephalopods in other parts of the World Ocean. It has been suggested that the importance of cephalopods in the Arctic ecosystems, at least in terms of quantitative distribution, could be somewhat lower than in the Antarctic or the tropics. Despite the impact of ongoing warming of the Arctic on the distribution of cephalopods being described repeatedly already, no impact of the current year's climate on the studied species was found. The only exception was the abundance of R. palpebrosa, which correlated with the current year's climate conditions.

scholarly journals Interannual characteristics of an 80 km resolution diagnostic Arctic ice–ocean model

1991 ◽  
Vol 15 ◽  
pp. 155-162 ◽  
Author(s):  
John E. Ries ◽  
William D. Hibler
Keyword(s):  
Ocean Circulation ◽  
Large Scale ◽  
Eddy Viscosity ◽  
Barents Sea ◽  
Arctic Basin ◽  
Ocean Model ◽  
The Arctic ◽  
Atmospheric Forcing ◽  
Ice Edge ◽  
Arctic Ice

Seasonal simulations with large-scale coupled ice–ocean models have reproduced many features of the ice and ocean circulation of the Arctic Ocean and the Greenland and Norwegian seas (e.g. Hibler and Bryan, 1987; Semtner, 1987). However, the crude resolution and high lateral eddy viscosity used by these models prevent the simulation of many of the smaller-scale seasonal features and tend to produce sluggish circulation. Similarly, the use of a single year’s atmospheric forcing prevents the simulation of features on an interannual time-scale. As an initial step towards addressing these issues, an 80 km diagnostic Arctic ice–ocean model is constructed and integrated over a three-year period using daily atmospheric forcing to drive the model. To examine the effect of topographic resolution and eddy viscosity on model results, similar simulations were performed with a 160 km-resolution model. The results of these simulations are compared with one another, with buoy drift in the Arctic Basin, and with observed ice-edge variations. The model results proved most sensitive to changes in horizontal resolution. The 80 km results provided a more realistic and robust circulation in most areas of the Arctic and improved the modelled ice edge in the Barents Sea, while also successfully simulating the interannual variation in the region. Although it performed better than the 160 km model, the 80 km model still produced too large an ice extent in the Greenland Sea. No significant improvement in the ice-edge prediction was observed by varying the lateral eddy viscosity. The results indicate that problems remain in the vertical resolution in shallow regions, in treating penetrative convection, and in the simulation of inflow into the Arctic Basin through the Fram Strait.

Atlantic influence on content of freshwater in upper layer of the Arctic Ocean

2020 ◽  
Author(s):  
Genrikh Alekseev ◽  
Andrey Pnyushkov ◽  
Alexander Smirnov ◽  
Anastasia Vyazilova ◽  
Natalia Glok
Keyword(s):  
Barents Sea ◽  
Lower Boundary ◽  
Arctic Basin ◽  
Atlantic Water ◽  
The Arctic ◽  
Tropical Region ◽  
Close Relationship ◽  
Rfbr Grant ◽  
The 1960S ◽  
Upper Boundary

&lt;p&gt;The interdecadal changes in layer of the Atlantic water (AW) and the fresh water content (FWC)&amp;#160; in the&amp;#160; Arctic Basin&amp;#160; (AB) are traced for the 1960s - 2010s&amp;#160; in order to assess the influence of the influx from the Atlantic on the FWC changes. The results showed that the upper boundary of the AB layer, identified on zero isotherm, everywhere rose in the 1990s - 2010s by several tens of meters relative to its position before the start of the warming in the 1970s. The lower boundary of the layer, also determined by the depth of the zero isotherm, fell. Such displacements of the layer boundaries indicate an increase in the volume of the AW in the AB. A reduction in the volume of the upper freshened layer it is necessary to maintain balance. Our calculations confirmed that in the 1990s, the FWC in the layer 0&amp;#8211;100 m decreased to 2 m or more in the Eurasian part of the Arctic Basin west of 180 &amp;#176;E and increased to east of 180 &amp;#176;E closer to the shores of Alaska and the Canadian archipelago,. This trend intensified in the 2000s and in the 2010s. A comparison of the distributions of the FWC and the position of the upper boundary of the AB layer over different decades by the method of spatial correlation confirmed a close relationship between both distributions. The response on changes of water temperature in the tropical region of the Atlantic is traced in the Barents Sea and in the Arctic basin.&amp;#160; That indicates the influence of low latitude SST on changes in AW layer and serves as an indicator of tropical effect on the Arctic processes. The study is supported by the RFBR grant 18-05-60107.&lt;/p&gt;

scholarly journals Sea ice phenology and primary productivity pulses shape breeding success in Arctic seabirds

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Francisco Ramírez ◽  
Arnaud Tarroux ◽  
Johanna Hovinen ◽  
Joan Navarro ◽  
Isabel Afán ◽  
...  
Keyword(s):  
Sea Ice ◽  
Barents Sea ◽  
Regional Scale ◽  
High Arctic ◽  
Trophic Levels ◽  
The Arctic ◽  
Ice Melt ◽  
Circumpolar Arctic ◽  
Suitable Framework ◽  
Ice Phenology

Abstract Spring sea ice phenology regulates the timing of the two consecutive pulses of marine autotrophs that form the base of the Arctic marine food webs. This timing has been suggested to be the single most essential driver of secondary production and the efficiency with which biomass and energy are transferred to higher trophic levels. We investigated the chronological sequence of productivity pulses and its potential cascading impacts on the reproductive performance of the High Arctic seabird community from Svalbard, Norway. We provide evidence that interannual changes in the seasonal patterns of marine productivity may impact the breeding performance of little auks and Brünnich’s guillemots. These results may be of particular interest given that current global warming trends in the Barents Sea region predict one of the highest rates of sea ice loss within the circumpolar Arctic. However, local- to regional-scale heterogeneity in sea ice melting phenology may add uncertainty to predictions of climate-driven environmental impacts on seabirds. Indeed, our fine-scale analysis reveals that the inshore Brünnich’s guillemots are facing a slower advancement in the timing of ice melt compared to the offshore-foraging little auks. We provide a suitable framework for analyzing the effects of climate-driven sea ice disappearance on seabird fitness.

Oil exploration in Spitsbergen

Polar Record ◽  
1965 ◽  
Vol 12 (81) ◽  
pp. 703-708 ◽  
Author(s):  
Jenö Nagy
Keyword(s):  
Continental Shelf ◽  
Barents Sea ◽  
Arctic Basin ◽  
The Arctic ◽  
Shallow Waters ◽  
Northwestern Part ◽  
Oil Exploration ◽  
Greenland Sea ◽  
The North ◽  
The Barents Sea

Svalbard comprises the islands between longs 10 to 35° E and between lats 74 to 81° N. The largest of these islands is Vestpitsbergen, followed by Nordaustlandet, Edgeøya, Barentsøya and Bjørnøya. The archipelago lies in the northwestern part of the Barents-Kara shelf. To south and east the continental shelf is covered by the shallow waters of the Barents Sea, whilst to the north and west the shelf falls away rapidly into the Arctic Basin and the Greenland Sea.

scholarly journals Sea-Ice Indicators of Polar Bear Habitat

2016 ◽  
Author(s):  
Harry L. Stern ◽  
Kristin L. Laidre
Keyword(s):  
Sea Ice ◽  
Polar Bear ◽  
Barents Sea ◽  
Arctic Basin ◽  
The Arctic ◽  
Sea Ice Concentration ◽  
The Barents Sea ◽  
Ice Concentration ◽  
Ice Retreat ◽  
Sea Ice Retreat

Abstract. Abstract. Nineteen distinct subpopulations of polar bears (Ursus maritimus) are found throughout the Arctic, and in all regions they depend on sea ice as a platform for traveling, hunting, and breeding. Therefore polar bear phenology – the cycle of biological events – is tied to the timing of sea-ice retreat in spring and advance in fall. We analyzed the dates of sea-ice retreat and advance in all 19 polar bear subpopulation regions from 1979 to 2014, using daily sea-ice concentration data from satellite passive microwave instruments. We define the dates of sea-ice retreat and advance in a region as the dates when the area of sea ice drops below a certain threshold (retreat) on its way to the summer minimum, or rises above the threshold (advance) on its way to the winter maximum. The threshold is chosen to be halfway between the historical (1979–2014) mean September and mean March sea-ice areas. In all 19 regions there is a trend toward earlier sea-ice retreat and later sea-ice advance. Trends generally range from −3 to −9 days decade−1 in spring, and from +3 to +9 days decade−1 in fall, with larger trends in the Barents Sea and central Arctic Basin. The trends are not sensitive to the threshold. We also calculated the number of days per year that the sea-ice area exceeded the threshold (termed ice-covered days), and the average sea-ice concentration from 1 June through 31 October. The number of ice-covered days is declining in all regions at the rate of −7 to −19 days decade−1, with larger trends in the Barents Sea and central Arctic Basin. The June–October sea-ice concentration is declining in all regions at rates ranging from −1 to −9 percent decade−1. These sea-ice metrics (or indicators of change in marine mammal habitat) were designed to be useful for management agencies. We recommend that the National Climate Assessment include the timing of sea-ice retreat and advance in future reports.

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