scholarly journals Cetaceans of the Barents Sea: Fauna and population status at the beginning of the XXI century

2021 ◽  
Vol 6 (2) ◽  
pp. 52-68
Author(s):  
T. V. Mishin

The Polar branch of Russian Federal Research Institute of Fisheries and Oceanography (VNIRO) carries out annually comprehensive surveys in the Barents Sea. This allows obtaining relevant data on distribution and occurrence of marine mammals, in particular cetaceans – the key link in the World Ocean ecosystem. In recent years, marine mammals monitoring has become increasingly important due to climate change and temperature rise in seas and oceans, that can result in habitat displacement and even possible extinction of certain species. This article summarizes the results of the vessel surveys of cetaceans carried out by the Polar branch of VNIRO in the Barents Sea in 2010–2019, as well as provides retrospective data on baleen whales (Mysticeti) and toothed whales (Odontoceti). Based on vessel survey material and taking into account data from literature sources, the current composition of the Barents Sea cetacean fauna is presented; at the beginning of the XXI century, it may include up to 16 species of 7 families. The analysis of vessel survey data made it possible to determine the status of marine mammals of this water area and to identify the frequency of their occurrence. The article presents population abundance for most species of baleen and toothed whales and shows the most likely spots of cetacean occurrence. According to the data obtained, white-beaked dolphin Lagenorhynchus albirostris is the most abundant, frequently sighted, and a year-round species: it accounts for more than 80 % of the total number of surveyed animals and about 50 % of all sighted cetaceans. Beluga whale Delphinapterus leucas and harbor porpoise Phocoena phocoena are also classified as permanent residents of the water area, and their localization is mainly confined to the Kola Peninsula coastal zone. May to October, the Barents Sea is regularly visited by species arriving from other Atlantic Ocean areas for feeding: minke whale Balaenoptera acutorostrata, fin whale Balaenoptera physalus, and humpback whale Megaptera novaeangliae. Narwhal Monodon monoceros and northern bottlenose whale Hyperoodon ampullatus are rarely sighted in the Russian Arctic western area.

2019 ◽  
Vol 76 (Supplement_1) ◽  
pp. i37-i53 ◽  
Author(s):  
Marie-Anne Blanchet ◽  
Raul Primicerio ◽  
André Frainer ◽  
Susanne Kortsch ◽  
Mette Skern-Mauritzen ◽  
...  

Abstract Marine mammals are important players in the Barents Sea ecosystem but their structural role in the foodweb has been little explored. We compare foodweb-related characteristics within and between phylogenetic groups for 19 marine mammals. As a group, they directly connect to the most central species (i.e cod and haddock) in the Barents Sea (i.e. cod and haddock) and consume over half of the available species. Pinnipeds are the most homogenous phylogenetic group with high omnivory and high prey richness. Mysticetes are split between well-connected species with high omnivory like the humpback whale, and peripheral specialists like the blue whale. Based on foodweb-derived indices some species consistently cluster together forming two groups, suggesting topological redundancy within them. One is dominated by Arctic seals and the other includes most of the baleen whales. Marine mammals generally contribute to network modularity as their trophic links are mainly within their own module. However, Atlantic species such as the grey seal act as a module connector decreasing modularity. This might negatively affect ecosystem robustness with perturbation effects spreading further and quicker in the foodweb. In the Arctic reaches of the Barents Sea, climate warming is likely to bring about extensive changes in the foodweb structure through a redistribution of species.


2009 ◽  
Vol 5 (2) ◽  
pp. 204-206 ◽  
Author(s):  
Peter J Corkeron

Some interpretations of ecosystem-based fishery management include culling marine mammals as an integral component. The current Norwegian policy on marine mammal management is one example. Scientific support for this policy includes the Scenario Barents Sea (SBS) models. These modelled interactions between cod, Gadus morhua , herring, Clupea harengus , capelin, Mallotus villosus and northern minke whales, Balaenoptera acutorostrata . Adding harp seals Phoca groenlandica into this top-down modelling approach resulted in unrealistic model outputs. Another set of models of the Barents Sea fish–fisheries system focused on interactions within and between the three fish populations, fisheries and climate. These model key processes of the system successfully. Continuing calls to support the SBS models despite their failure suggest a belief that marine mammal predation must be a problem for fisheries. The best available scientific evidence provides no justification for marine mammal culls as a primary component of an ecosystem-based approach to managing the fisheries of the Barents Sea.


Waterbirds ◽  
2000 ◽  
Vol 23 (3) ◽  
pp. 525
Author(s):  
David N. Nettleship ◽  
T. Anker-Nilssen ◽  
V. Bakken ◽  
H. Strøm ◽  
A. N. Golovkin ◽  
...  

2021 ◽  
Vol 12 (3-2021) ◽  
pp. 36-45
Author(s):  
A.V. Vashchenko ◽  

The paper presents the results of microbiological studies carried out in the Motovsky Bay (2017) and the northeastern part of the Barents Sea (2020) in October. It was shown that, with comparable values of abundance, the biomass of bacterioplankton in open waters was slightly higher than in coastal waters. The quantity was 148–717 thousand cells/ml in Motovsky Bay and 170–957 thousand cells/ml in the open water area. The biomass was 7.26–29.07 mg/m3 in Motovsky Bay and 9.71–51.39 mg/m3 in the open water area. The maximum values were in the 0–50 m layer,the minimum – in the bottom layer in both areas. Those results supplement the existing understanding of bacterioplanktons development and distribution in the Barents Sea in the autumn season.


2020 ◽  
Author(s):  
Anna Kursheva ◽  
Inna Morgunova ◽  
Vera Petrova ◽  
Galina Batova ◽  
Ivan Litvinenko ◽  
...  

<p>Information about hydrocarbons (HCs) distribution in components of geological environment (including aromatic (Ar) compounds) allows to estimate relative amounts of both natural and anthropogenic components and reveal sources of contamination. HCs are widely spread in lithosphere and create stable geochemical background. Variations in their composition attest to the specificity of initial organic matter, conditions of its accumulation and transformation.<br>The studied samples of soils and surface bottom sediments were collected during the research expedition in July, 2019 (supported by RFBR №18-54-20001 and NFR №280724). On the Norwegian coast of the Barents Sea the area of study included: salt marshes of Tana and Varanger fjords, littoral zone of rocky shores around Kiberg. In the Russian part of the Barents Sea samples were taken from the shallow water area of the Eastern coast of the Kola Bay. All samples were taken along the sublittoral – littoral – supralittoral transects appropriate for a detailed study of the organic matter (OM) spatial distribution. Study of the group composition of ArHCs in the extractable part of soil and sedimentary OM were performed using spectrofluorimetry.<br> The method is based on the ability of ArHCs to fluoresce under the influence of ultraviolet emitting in narrow spectral ranges determined by their molecular structure. This allows us to characterize the nature of ArHCs and determine possible sources of their input.<br>The spectrum characteristics of samples from intertidal zone of the Tana fjord salt marshes reflect the input of fresh unoxidized petroleum products such as diesel fuels and engine oils. The significant increase of ArHCs fluorescence intensity in surface sediments may testify to recent pollution accidents.<br>The spectrum traditionally associated with the estuarine-delta and lacustrine and swampy facies and characteristic for the post-sedimentation and early diagenetic stage of OM transformation was detected in samples from the salt marshes of Varanger fjord. <br>ArHCs of mixed origin (natural and anthropogenic) are identified in samples from the littoral zone of rocky shores of Kiberg. The spectral data of littoral sediments are typical for the polluted areas with high input of petroleum products. The specific maxima in the long wavelength region of spectrum that is characteristic for the high molecular weight aromatic compounds from the land plants is also detected in these samples. <br>Spectral characteristics of ArHCs of bottom sediments and soils collected from the shallow water area of the Russian part of the Barents Sea point to the presence of both low molecular weight benzene HCs (high volatile components of flammable liquids) and high molecular weight compounds (oil fuel, gas oil). The detailed study of these anthropogenic HC components seems to be very important given the fact of their detection in all littoral samples.<br>The further detailed study of the molecular markers and biomarkers (n-alkanes, isoprenoids, cyclanes, terpanes, PAHs) will increase our knowledge about HC sources, efficiency of their microbial and chemical degradation, allow to estimate human impacts on the environment of the region and draw up the regional “geochemical passport”.</p>


2021 ◽  
Vol 8 ◽  
Author(s):  
Torstein Pedersen ◽  
Nina Mikkelsen ◽  
Ulf Lindstrøm ◽  
Paul E. Renaud ◽  
Marcela C. Nascimento ◽  
...  

The Barents Sea (BS) is a high-latitude shelf ecosystem with important fisheries, high and historically variable harvesting pressure, and ongoing high variability in climatic conditions. To quantify carbon flow pathways and assess if changes in harvesting intensity and climate variability have affected the BS ecosystem, we modeled the ecosystem for the period 1950–2013 using a highly trophically resolved mass-balanced food web model (Ecopath with Ecosim). Ecosim models were fitted to time series of biomasses and catches, and were forced by environmental variables and fisheries mortality. The effects on ecosystem dynamics by the drivers fishing mortality, primary production proxies related to open-water area and capelin-larvae mortality proxy, were evaluated. During the period 1970–1990, the ecosystem was in a phase of overexploitation with low top-predators’ biomasses and some trophic cascade effects and increases in prey stocks. Despite heavy exploitation of some groups, the basic ecosystem structure seems to have been preserved. After 1990, when the harvesting pressure was relaxed, most exploited boreal groups recovered with increased biomass, well-captured by the fitted Ecosim model. These biomass increases were likely driven by an increase in primary production resulting from warming and a decrease in ice-coverage. During the warm period that started about 1995, some unexploited Arctic groups decreased whereas krill and jellyfish groups increased. Only the latter trend was successfully predicted by the Ecosim model. The krill flow pathway was identified as especially important as it supplied both medium and high trophic level compartments, and this pathway became even more important after ca. 2000. The modeling results revealed complex interplay between fishery and variability of lower trophic level groups that differs between the boreal and arctic functional groups and has importance for ecosystem management.


Author(s):  
Marie-Anne Blanchet ◽  
Raul Primicerio ◽  
André Frainer ◽  
Susanne Kortsch ◽  
Mette Skern-Mauritzen ◽  
...  

2021 ◽  
pp. 270-277
Author(s):  
D.P. Starodymova ◽  
◽  
A.I. Kochenkova ◽  
M.D. Kravchishina ◽  
◽  
...  

The elemental composition of suspended particulate matter (SPM) in the Barents Sea was studied based on the materials of the 68th cruise of the RV Akademik Mstislav Keldysh, August 2017, using ICP-MS and AAS methods. SPM of the sea surface layer is characterized by significant heterogeneity in the elemental composition, which is due to differences in the course of biogeochemical processes over the water area (for example, high differences in the level of primary production) and different compositions of terrigenous matter from the sources. Biophilic elements significantly enrich the SPM of the surface water layer and fluffy layer relative to the average composition of the earth's crust (the degree of enrichment of the surface SPM is higher than the fluffy layer).


2016 ◽  
Vol 97 (8) ◽  
pp. 1605-1616 ◽  
Author(s):  
Alexey V. Golikov ◽  
Rushan M. Sabirov ◽  
Pavel A. Lubin

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.


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