Depth distribution of Calanus finmarchicus and C. glacialis in relation to environmental conditions in the Barents Sea

1991 ◽  
Vol 10 (2) ◽  
pp. 409-420 ◽  
Author(s):  
KIM H. UNSTAD ◽  
KURT S. TANDE
Keyword(s):  
Environmental Conditions ◽  
Depth Distribution ◽  
Barents Sea ◽  
Calanus Finmarchicus ◽  
The Barents Sea

scholarly journals Contribution of Calanus species to the mesozooplankton biomass in the Barents Sea

2017 ◽  
Vol 75 (7) ◽  
pp. 2342-2354 ◽  
Author(s):  
Johanna Myrseth Aarflot ◽  
Hein Rune Skjoldal ◽  
Padmini Dalpadado ◽  
Mette Skern-Mauritzen
Keyword(s):  
Barents Sea ◽  
Zooplankton Community ◽  
Zooplankton Biomass ◽  
Calanus Finmarchicus ◽  
The Arctic ◽  
Arctic Water ◽  
Mesozooplankton Biomass ◽  
The Barents Sea ◽  
Main Driver ◽  
Calanus Species

Abstract Copepods from the genus Calanus are crucial prey for fish, seabirds and mammals in the Nordic and Barents Sea ecosystems. The objective of this study is to determine the contribution of Calanus species to the mesozooplankton biomass in the Barents Sea. We analyse an extensive dataset of Calanus finmarchicus, Calanus glacialis, and Calanus hyperboreus, collected at various research surveys over a 30-year period. Our results show that the Calanus species are a main driver of variation in the mesozooplankton biomass in the Barents Sea, and constitutes around 80% of the total. The proportion of Calanus decreases at low zooplankton biomass, possibly due to a combination of advective processes (low C. finmarchicus in winter) and size selective foraging. Though the Calanus species co-occur in most regions, C. glacialis dominates in the Arctic water masses, while C. finmarchicus dominates in Atlantic waters. The larger C. hyperboreus has considerably lower biomass in the Barents Sea than the other Calanus species. Stages CIV and CV have the largest contribution to Calanus species biomass, whereas stages CI-CIII have an overall low impact on the biomass. In the western area of the Barents Sea, we observe indications of an ongoing borealization of the zooplankton community, with a decreasing proportion of the Arctic C. glacialis over the past 20 years. Atlantic C. finmarchicus have increased during the same period.

Impacts of Cold Climate Environmental Conditions on a Riser System Design and Installation

2015 ◽  
Author(s):  
Adekunle Peter Orimolade ◽  
Ove Tobias Gudmestad
Keyword(s):  
Environmental Conditions ◽  
Oil And Gas ◽  
Barents Sea ◽  
Research Work ◽  
Cold Climate ◽  
Field Development ◽  
Climate Region ◽  
Probability Of Occurrence ◽  
The Barents Sea ◽  
Development Concept

Interests in exploration and production of oil and gas in cold climate areas has increased in recent times. This can be attributed to the continual depletion of reserves in mature fields, and recent discoveries of large quantities of oil and gas in the cold climate region, including the more recent discovery of the Alta Reservoir, in the Barents Sea. However, marine operations in this region are faced with challenges resulting from its arctic conditions. Knowledge of the physical environment is important in designing offshore structures, and in planning, and executing marine operations. Selection of a suitable field development concept may be influenced by the probability of occurrence of rare events, such as drifting icebergs. Furthermore, occurrence of mesoscale phenomenon such as polar low pressures may adversely affect planned marine operations. In addition, uncertainties in weather forecasting will reflect on the available weather window to perform installation and interventions works. This paper presents some of the challenges in designing and planning for marine operations in the cold climate region. A possible field development concept for the open water areas of the Norwegian sector of the Barents Sea is discussed. The current research work considers the need for further assessment of the probability of occurrence of drifting icebergs as of importance when selecting field development concept. The Floating Production Storage and Offloading (FPSO) is proposed, and this should be designed with an internal turret system that can be disconnected and reconnected. Some of the challenges associated with riser systems design when considering a turret system with the capability to disconnect and reconnect are discussed. This paper also propose the use of ensemble forecasts as an alternative to the use of alpha factors to estimate operational weather window when planning for marine operations in the Barents Sea. The unpredictability nature of the environmental conditions, especially in the early winter is considered a challenge to marine operations.

Calanus finmarchicus abundance, production and population dynamics in the Barents Sea in a future climate

2014 ◽  
Vol 125 ◽  
pp. 26-39 ◽  
Author(s):  
G. Skaret ◽  
P. Dalpadado ◽  
S.S. Hjøllo ◽  
M.D. Skogen ◽  
E. Strand
Keyword(s):  
Population Dynamics ◽  
Barents Sea ◽  
Future Climate ◽  
Calanus Finmarchicus ◽  
The Barents Sea

scholarly journals Interannual dynamics of zooplankton in the Kola Section of the Barents Sea during the recent warming period

2019 ◽  
Vol 76 (Supplement_1) ◽  
pp. i10-i23
Author(s):  
Irina P Prokopchuk ◽  
Alexander G Trofimov
Keyword(s):  
Barents Sea ◽  
Zooplankton Community ◽  
Zooplankton Biomass ◽  
Calanus Finmarchicus ◽  
The Arctic ◽  
Zooplankton Abundance ◽  
Total Zooplankton ◽  
The Barents Sea ◽  
Warming Period ◽  
Total Zooplankton Biomass

Abstract Our research focused on the analysis of interannual variability of zooplankton in the Kola Section (the Barents Sea) in the period of current warming in the Arctic basing on previously unpublished data. The zooplankton community was investigated based on the analysis of 240 plankton samples, collected in late May–early June 2009–2017. A total of 74 zooplankton taxa of nine phyla were identified in the plankton samples, but copepods were the most diverse and numerous taxonomic group. The biodiversity index varied considerably from year to year, but a stable tendency for the index to increase since the beginning of the period studied was observed. Copepods dominated in terms of abundance and biomass, comprising on average 73–96% of the total zooplankton abundance and 81–96% of the total zooplankton biomass. Calanus finmarchicus was the main zooplankton species utterly dominated by abundance and biomass (on average 92 and 97% respectively). Considerable differences in zooplankton abundance and biomass at different stations of the section were observed. Although the investigations were carried out during a warming period, interannual differences in zooplankton abundance and biomass were observed. Zooplankton biomasses were higher in the years with higher temperatures and stronger water inflow.

scholarly journals Elemental and Mineral Composition of the Barents Sea Recent and Late Pleistocene−Holocene Sediments: A Correlation with Environmental Conditions

Minerals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 593
Author(s):  
Liudmila L. Demina ◽  
Olga Dara ◽  
Ramiz Aliev ◽  
Tatiana Alekseeva ◽  
Dmitry Budko ◽  
...  
Keyword(s):  
Grain Size ◽  
Mineral Composition ◽  
Late Pleistocene ◽  
Environmental Conditions ◽  
Barents Sea ◽  
Size Composition ◽  
Novaya Zemlya Archipelago ◽  
Grain Size Composition ◽  
X Ray ◽  
The Barents Sea

A comprehensive examination of the elemental (including radionuclides and heavy metals), mineral, and grain-size composition of sediments from different areas of the Barents Sea was performed. Sediment cores were sampled in the Central Deep, Cambridge Strait (Franz Josef Land Archipelago), Russkaya Gavan’ Bay (Novaya Zemlya Archipelago), and Bear Island Trough. We aim to evaluate how the modern and more ancient environmental conditions are reflected in the elemental and mineral composition, as well as to test indicative elemental ratios. The applied methods include elemental analysis using gamma-ray spectroscopy, X-ray fluorescence (XRF), Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), and X-Ray Difractometry XRD analysis of minerals. Difference in sedimentation rates, grain-size composition, and sources of material, are reflected in downcore variation of Si/Al, Mn/Fe, P/Al, Ti/K, and quartz-feldspar ratios. At boundary Early Holocene/Late Deglaciation, intensive bottom currents from the West-Southern shelf areas contributed to increase of Si/Al and Zr/Ca ratios. Distinct growth of the Si/Fe ratio within the sediments deposited over Late Pleistocene to Mid Holocene may be caused by increased contents of the coarse sand material, as well as by abundant fluxes of clay-mineral-loaded glacial meltwater during the main deglaciation phase. The Mn/Fe ratio used as redox proxy, displayed peaks at different depths related to oxygen concentration growth in bottom water.

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