Sub-ice algal assemblages of the Barents Sea: Species composition, chemical composition, and growth rates

Polar Biology ◽  
1992 ◽  
Vol 12 (5) ◽  
Author(s):  
ElseN�st Hegseth
Keyword(s):  
Chemical Composition ◽  
Species Composition ◽  
Growth Rates ◽  
Barents Sea ◽  
The Barents Sea ◽  
Algal Assemblages

Do abiotic mechanisms determine interannual variability in length-at-age of juvenile Arcto-Norwegian cod?

2002 ◽  
Vol 59 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Geir Ottersen ◽  
Kristin Helle ◽  
Bjarte Bogstad
Keyword(s):  
Growth Rates ◽  
Gadus Morhua ◽  
Barents Sea ◽  
Water Masses ◽  
Inverse Relation ◽  
Lower Growth ◽  
Density Dependent ◽  
The Barents Sea ◽  
The Mean ◽  
Dependent Growth

For the large Arcto-Norwegian stock of cod (Gadus morhua L.) in the Barents Sea, year-to-year variability in growth is well documented. Here three hypotheses for the observed inverse relation between abundance and the mean length-at-age of juveniles (ages 1–4) are suggested and evaluated. Based on comprehensive data, we conclude that year-to-year differences in length-at-age are mainly determined by density-independent mechanisms during the pelagic first half year of the fishes' life. Enhanced inflow from the southwest leads to an abundant cohort at the 0-group stage being distributed farther east into colder water masses, causing lower postsettlement growth rates. We can not reject density-dependent growth effects related to variability in food rations, but our data do not suggest this to be the main mechanism. Another hypothesis suggests that lower growth rates during periods of high abundance are a result of density-dependent mechanisms causing the geographic range of juveniles to extend eastwards into colder water masses. This is rejected mainly because year-to-year differences in mean length are established by age 2, which is too early for movements over large distances.

scholarly journals Spatial Distribution of Atmospheric Aerosol Physicochemical Characteristics in the Russian Sector of the Arctic Ocean

Atmosphere ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1170
Author(s):  
Sergey Sakerin ◽  
Dmitry Kabanov ◽  
Valery Makarov ◽  
Viktor Pol’kin ◽  
Svetlana Popova ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Chemical Composition ◽  
Arctic Ocean ◽  
Black Carbon ◽  
Forest Fires ◽  
Barents Sea ◽  
The Arctic ◽  
The North ◽  
The Barents Sea ◽  
The Arctic Ocean

The results from studies of aerosol in the Arctic atmosphere are presented: the aerosol optical depth (AOD), the concentrations of aerosol and black carbon, as well as the chemical composition of the aerosol. The average aerosol characteristics, measured during nine expeditions (2007–2018) in the Eurasian sector of the Arctic Ocean, had been 0.068 for AOD (0.5 µm); 2.95 cm−3 for particle number concentrations; 32.1 ng/m3 for black carbon mass concentrations. Approximately two–fold decrease of the average characteristics in the eastern direction (from the Barents Sea to Chukchi Sea) is revealed in aerosol spatial distribution. The average aerosol characteristics over the Barents Sea decrease in the northern direction: black carbon concentrations by a factor of 1.5; particle concentrations by a factor of 3.7. These features of the spatial distribution are caused mainly by changes in the content of fine aerosol, namely: by outflows of smokes from forest fires and anthropogenic aerosol. We considered separately the measurements of aerosol characteristics during two expeditions in 2019: in the north of the Barents Sea (April) and along the Northern Sea Route (July–September). In the second expedition the average aerosol characteristics turned out to be larger than multiyear values: AOD reached 0.36, particle concentration up to 8.6 cm−3, and black carbon concentration up to 179 ng/m3. The increased aerosol content was affected by frequent outflows of smoke from forest fires. The main (99%) contribution to the elemental composition of aerosol in the study regions was due to Ca, K, Fe, Zn, Br, Ni, Cu, Mn, and Sr. The spatial distribution of the chemical composition of aerosols was analogous to that of microphysical characteristics. The lowest concentrations of organic and elemental carbon (OC, EC) and of most elements are observed in April in the north of the Barents Sea, and the maximal concentrations in Far East seas and in the south of the Barents Sea. The average contents of carbon in aerosol over seas of the Asian sector of the Arctic Ocean are OC = 629 ng/m3, EC = 47 ng/m3.

scholarly journals Microzooplankton Growth Rates Examined across a Temperature Gradient in the Barents Sea

PLoS ONE ◽  
2014 ◽  
Vol 9 (1) ◽  
pp. e86429 ◽  
Author(s):  
Gayantonia Franzè ◽  
Peter J. Lavrentyev
Keyword(s):  
Temperature Gradient ◽  
Growth Rates ◽  
Barents Sea ◽  
The Barents Sea

scholarly journals Distribution of Polychaeta Communities in the Western and Northern Part of the Barents Sea

2020 ◽  
Author(s):  
Dinara Dikaeva ◽  
Elena Frolova
Keyword(s):  
Species Composition ◽  
Bottom Sediments ◽  
Barents Sea ◽  
Bottom Topography ◽  
Silty Clay ◽  
The Barents Sea ◽  
Structure Of Communities ◽  
Composition And Structure ◽  
Quantitative Characteristics ◽  
Hard Soils

Species composition and quantitative characteristics of polychaetes in the western and northern parts of the Barents Sea were analyzed on the basis of the material collected in July and November 2017 on MMBI expeditions aboard the RV “Dalniye Zelentsy”. Three faunistic polychaete complexes were revealed, depending on environmental conditions in the study area. A change in species composition and structure of communities from the bottom topography, structure of bottom sediments and bottom hydrodynamics were noted. An increase in biomass and density of polychaetes settlement was revealed in deep-water areas of the Barents Sea, on soft silty-clay soils, where the dominant species is Spiochaetopterus typicus. A decrease in quantitative characteristics of polychaetes was observed in shallow areas, on hard soils, in the zone of intensive erosion of bottom sediments as a result of warm and cold currents interaction, where the polychaete Nothria hyperborea dominated.

scholarly journals Dynamics of the Spatial Chlorophyll-A Distribution at the Polar Front in the Marginal Ice Zone of the Barents Sea during Spring

Water ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 101
Author(s):  
Pavel R. Makarevich ◽  
Veronika V. Vodopianova ◽  
Aleksandra S. Bulavina
Keyword(s):  
Species Composition ◽  
Sea Ice ◽  
Chlorophyll A ◽  
Phytoplankton Community ◽  
Barents Sea ◽  
Sea Water ◽  
Polar Front ◽  
Ice Melting ◽  
The Barents Sea ◽  
Ice Edge

Effects of the sea-ice edge and the Polar Frontal Zone on the distribution of chlorophyll-a levels in the pelagic were investigated during multi-year observations in insufficiently studied and rarely navigable regions of the Barents Sea. Samples were collected at 52 sampling stations combined into 11 oceanographic transects over a Barents Sea water area north of the latitude 75° N during spring 2016, 2018, and 2019. The species composition, abundance and biomass of the phytoplankton community, chlorophyll-a concentrations, hydrological and hydrochemical parameters were analyzed. The annual phytoplankton evolution phase, defined as an early-spring one, was determined throughout the transects. The species composition of the phytoplankton community and low chlorophyll-a levels suggested no phytoplankton blooming in April 2016 and 2019. Not yet started sea-ice melting prevented sympagic (sea-ice-associated) algae from being released into the seawater. In May 2018, ice melting began in the eastern Barents Sea and elevated chlorophyll-a levels were recorded near the ice edge. Chlorophyll-a concentrations substantially differed in waters of different genesis, especially in areas influenced by the Polar Front. The Polar Front separated the more productive Arctic waters with a chlorophyll-a concentration of 1–5 mg/m3 on average from the Atlantic waters where the chlorophyll-a content was an order of magnitude lower.

scholarly journals Bryozoa of the northern part of Barents Sea: species composition, distribution, ecology (based on the materials of expeditions MMBI 2016–2017).

2020 ◽  
Vol 11 (5-2020) ◽  
pp. 50-67
Author(s):  
O.Yu. Evseeva ◽  
Keyword(s):  
Species Composition ◽  
Environmental Conditions ◽  
Barents Sea ◽  
Water Masses ◽  
Bottom Relief ◽  
Composition Distribution ◽  
Related Factors ◽  
The Barents Sea ◽  
Distribution Features ◽  
Quantitative Indicators

The modern data about fauna of Bryozoa in the northern part of Barents Sea are obtained. The taxonomic and biogeographic composition, distribution features of bryozoan communities, and their quantitative indicators are analyzed. 124 Bryozoa species are identified in the samples, one of which (Uschakovia gorbunoviKluge, 1946) is a new for the Barents Sea fauna. It was found that the richness of the bryozoan fauna is determined by the variety of environmental conditions and depends on the bottom relief (and related factors: soil, hydrodynamic intensity and sedimentation) and the parameters of water masses.

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