scholarly journals Integrating spatial and temporal mortality from herring on capelin larvae: a study in the Barents Sea

2009 ◽  
Vol 66 (10) ◽  
pp. 2183-2194 ◽  
Author(s):  
O. P. Pedersen ◽  
T. Pedersen ◽  
K. S. Tande ◽  
D. Slagstad
Keyword(s):  
Experimental Data ◽  
Mortality Rate ◽  
Barents Sea ◽  
Field Surveys ◽  
Fish Stocks ◽  
The Barents Sea ◽  
Spatio Temporal ◽  
The Impact ◽  
Important Fish ◽  
Temporal Overlap

Abstract Pedersen, O. P., Pedersen, T., Tande, K. S., and Slagstad, D. 2009. Integrating spatial and temporal mortality from herring on capelin larvae: a study in the Barents Sea. – ICES Journal of Marine Science, 66: 2183–2194. Barents Sea herring and capelin are commercially very important fish stocks. We investigate the spatial and temporal mortality rate of capelin larvae in 2001 as a function of herring predation. Our methods are based on Lagrangian modelling, field surveys, and experimental data. The impact of juvenile herring predation on capelin recruitment is corroborated, in particular the importance of the integrated spatio-temporal overlap between the two stocks. Capelin larvae were reduced to 20–50% in two weeks in accordance with different simulation scenarios. Hamre advanced a hypothesis in 1994 that juvenile herring are important predators of capelin larvae and a main cause of poor capelin recruitment in years when herring are very abundant in the Barents Sea. This hypothesis is supported through the results of this work.

scholarly journals Boulder pits of the White Sea Region

2021 ◽  
Vol 12 (4-2021) ◽  
pp. 104-125
Author(s):  
M. M. Shakhnovitch ◽  
Keyword(s):  
Coastal Zone ◽  
Russian Federation ◽  
Barents Sea ◽  
White Sea ◽  
The White Sea ◽  
Field Surveys ◽  
Finnish Lapland ◽  
The Barents Sea ◽  
The Russian Federation

The purpose of the article is to introduce into scientific circulation little-known and controversial objects made of stones discovered during our field surveys in 2019 on the Tersk Coast of the White Sea near the Khlebnaya River. The monument consists of 27 boulder structures of four types: ring-shaped layouts with a recess in the center –– boulder pits (24), “seid”, “pile”, a flat boulder with stones laid on it. Boulder pits within the borders of the Russian Federation are found in the coastal zone of the Western and Northern White Sea regions and the Barents Sea. The distribution of such objects is noted in Finnmark and Finnish Lapland and correlates with the area of historical settlement of local Sami groups. We tend to interpret the “boulder pits” as objects associated with non-Christian cult practices, possibly of a funerary nature.

scholarly journals Comparison of the biophysical and trophic characteristics of the Bering and Barents Seas

2005 ◽  
Vol 62 (7) ◽  
pp. 1245-1255 ◽  
Author(s):  
George L. Hunt ◽  
Bernard A. Megrey
Keyword(s):  
Bering Sea ◽  
Barents Sea ◽  
Single Species ◽  
Atlantic Water ◽  
Walleye Pollock ◽  
Fish Stocks ◽  
Eastern Bering Sea ◽  
The Barents Sea ◽  
Shelf Seas ◽  
Bottom Waters

Abstract The eastern Bering Sea and the Barents Sea share a number of common biophysical characteristics. For example, both are seasonally ice-covered, high-latitude, shelf seas, dependent on advection for heat and for replenishment of nutrients on their shelves, and with ecosystems dominated by a single species of gadoid fish. At the same time, they differ in important respects. In the Barents Sea, advection of Atlantic Water is important for zooplankton vital to the Barents Sea productivity. Advection of zooplankton is not as important for the ecosystems of the southeastern Bering Sea, where high levels of diatom production can support production of small, neritic zooplankton. In the Barents Sea, cod are the dominant gadoid, and juvenile and older fish depend on capelin and other forage fish to repackage the energy available in copepods. In contrast, the dominant fish in the eastern Bering Sea is the walleye pollock, juveniles and adults of which consume zooplankton directly. The southeastern Bering Sea supports considerably larger fish stocks than the Barents. In part, this may reflect the greater depth of much of the Barents Sea compared with the shallow shelf of the southeastern Bering. However, walleye pollock is estimated to occupy a trophic level of 3.3 as compared to 4.3 for Barents Sea cod. This difference alone could have a major impact on the abilities of these seas to support a large biomass of gadoids. In both seas, climate-forced variability in advection and sea-ice cover can potentially have major effects on the productivity of these Subarctic seas. In the Bering Sea, the size and location of pools of cold bottom waters on the shelf may influence the likelihood of predation of juvenile pollock.

scholarly journals Quantifying relative fishing impact on fish populations based on spatio-temporal overlap of fishing effort and stock density

2013 ◽  
Vol 70 (3) ◽  
pp. 618-627 ◽  
Author(s):  
Morten Vinther ◽  
Margit Eero
Keyword(s):  
Fishing Effort ◽  
Fish Populations ◽  
Fishing Mortality ◽  
Fishing Impact ◽  
Management Measures ◽  
Stock Assessments ◽  
Spatio Temporal ◽  
Substantial Decline ◽  
The Impact ◽  
Temporal Overlap

Abstract Vinther, M., and Eero, M. 2013. Quantifying relative fishing impact on fish populations based on spatio-temporal overlap of fishing effort and stock density. – ICES Journal of Marine Science, 70: 618–627. Evaluations of the effects of management measures on fish populations are usually based on the analyses of population dynamics and estimates of fishing mortality from stock assessments. However, this approach may not be applicable in all cases, in particular for data-limited stocks, which may suffer from uncertain catch information and consequently lack reliable estimates of fishing mortality. In this study we develop an approach to obtain proxies for changes in fishing mortality based on effort information and predicted stock distribution. Cod in the Kattegat is used as an example. We use GAM analyses to predict local cod densities and combine this with spatio-temporal data of fishing effort based on VMS (Vessel Monitoring System). To quantify local fishing impact on the stock, retention probability of the gears is taken into account. The results indicate a substantial decline in the impact of the Danish demersal trawl fleet on cod in the Kattegat in recent years, due to a combination of closed areas, introduction of selective gears and changes in overall effort.

NUMERICAL MODELING OF POLAR LOWS OVER THE BARENTS SEA: IMPACT OF WRF PARAMETRIZATIONS ON THE QUALITY OF FORECAST.

2017 ◽  
Author(s):  
Antonina Polezhayeva ◽  
Antonina Polezhayeva
Keyword(s):  
Boundary Layer ◽  
Numerical Experiments ◽  
Barents Sea ◽  
Wrf Model ◽  
Polar Lows ◽  
The Barents Sea ◽  
Polar Low ◽  
Planetary Boundary Layer Parameterization ◽  
The Impact

Polar lows are generally characterized by severe weather in the form of strong winds, showers and occasionally heavy snow, which have sometimes resulted in the loss of life, especially at sea. Numerical simulations with mesoscale atmospheric models is a good alternative to investigate polar low phenomenon, because they produce temporally and spatially regular-spaced fields of atmospheric variables with high resolution. To describe the evolution of atmospheric processes the Advanced Weather Research and Forecasting (WRF-ARW) model was used. The principal objectives of this study were 1) the understanding of mesoscale WRF model and adapting the model for the Barents Sea region; 2) to conduct numerical experiments using WRF model with different Planetary Boundary Layer parameterization (PBLs) schemes and investigate the impact of each scheme on the quality of forecast; and 3) the investigation of the capability of WRF model to successfully simulate evolution of polar lows. The impact on the quality of forecast was investigated. The results of the study, obtained by numerical modeling of polar mesoscale low over the Barents Sea. One polar low, near Spitsbergen, from 24 of March to 26 of March 2014 were targeted. The results of numerical experiments showed that each of Planetary Boundary Layer parameterization scheme isn't successful for simulation of polar low.

The impact of CSEM on exploration decisions and seismic: two case studies from the Barents Sea

First Break ◽  
2014 ◽  
Vol 32 (11) ◽  
Author(s):  
S. Fanavoll ◽  
P.T. Gabrielsen ◽  
S. Ellingsrud
Keyword(s):  
Case Studies ◽  
Barents Sea ◽  
The Barents Sea ◽  
The Impact

Impact of Atlantic water inflow on winter cyclone activity in the Barents Sea: Insights from coupled regional climate model simulations

2020 ◽  
Author(s):  
Mirseid Akperov ◽  
Vladimir A. Semenov ◽  
Igor I. Mokhov ◽  
Wolfgang Dorn ◽  
Annette Rinke
Keyword(s):  
Climate Model ◽  
Barents Sea ◽  
Regional Climate ◽  
Lower Troposphere ◽  
Static Stability ◽  
Atlantic Water ◽  
Water Inflow ◽  
Cyclone Activity ◽  
The Barents Sea ◽  
The Impact

<p>The impact of the Atlantic water inflow (AW inflow) into the Barents Sea on the regional cyclone activity in winter is analyzed in 10 ensemble simulations with the coupled Arctic atmosphere-ocean-sea ice model HIRHAM-NAOSIM for the 1979–2016 period. The model shows a statistically robust connection between AW inflow and climate variability in the Barents Sea. The analysis reveals that anomalously high AW inflow leads to changed baroclinicity in the lower troposphere via changed static stability and wind shear, and thus favorable conditions for cyclogenesis in the Barents/Kara Seas. The frequency of occurrence of cyclones, but particularly of intense cyclones, is increased over the Barents Sea. Furthermore, the cyclones in the Barents Sea become larger (increased radius) and stronger (increased intensity) in response to an increased AW inflow into the Barents Sea, compared to years of anomalously low AW inflow.</p><p>The authors acknowledge the support by the Russian-German project funded by the Federal Ministry of Education and Research of Germany and Ministry of Science and Higher Education of the Russian Federation (grant 05.616.21.0109 (RFMEFI61619X0109)).</p>

The combined effect of transport and temperature on distribution and growth of larvae and pelagic juveniles of Arcto-Norwegian cod

2005 ◽  
Vol 62 (7) ◽  
pp. 1375-1386 ◽  
Author(s):  
Frode Vikebø ◽  
Svein Sundby ◽  
Bjørn Ådlandsvik ◽  
Øyvind Fiksen
Keyword(s):  
Barents Sea ◽  
Field Studies ◽  
Trophic Levels ◽  
Direct Effects ◽  
Climatic Parameters ◽  
Fish Stocks ◽  
The Barents Sea ◽  
Effects Of Temperature ◽  
Pelagic Juveniles ◽  
Pelagic Juvenile

Abstract Temperature has been identified in field studies as the physical parameter most influential on growth and recruitment of Arcto-Norwegian cod. However, it has been pointed out by many authors that temperature in this context has not only direct effects on the cod, but also indirect effects through lower trophic levels. Moreover, it has been said that temperature might also be a proxy for other climatic parameters. The present paper analyses the direct quantitative effects of temperature on larval and pelagic juvenile growth from spawning in Lofoten until the 0-group fish settle in the Barents Sea. The approach taken is that of a modelling study, supported by analysis of existing data on fish stocks and climate. It is shown that transport and temperature alone can reproduce key features of the 0-group weight distribution and concentration in the Barents Sea for two consecutive years. The extent of the dispersion of the larvae and pelagic juveniles, as well as the ambient temperature they experience on their route, are shown to depend upon their depth in the water column and, to a lesser degree, the time of spawning.

Effects of predation from pelagic 0-group cod (Gadus morhua) on mortality rates of capelin (Mallotus villosus) larvae in the Barents Sea

2007 ◽  
Vol 64 (12) ◽  
pp. 1710-1722 ◽  
Author(s):  
Elvar H Hallfredsson ◽  
Torstein Pedersen
Keyword(s):  
Mortality Rate ◽  
Stomach Content ◽  
Gadus Morhua ◽  
Barents Sea ◽  
Stomach Contents ◽  
Mortality Rates ◽  
Mallotus Villosus ◽  
The Barents Sea ◽  
Predation Mortality ◽  
Capelin Mallotus Villosus

Surveys were carried out in 2002 and 2003 to test whether predation from pelagic 0-group cod (Gadus morhua) juveniles affects mortality rates of Barents Sea capelin (Mallotus villosus) larvae. In 2002, capelin larvae were observed in 17% of the cod stomachs and predation was observed at 19 of 50 stations. In 2003, capelin larvae were observed in 8% of the cod stomachs and predation was observed at 19 of 37 stations. The stomach contents and zooplankton samples were dominated by copepods and krill. The number of capelin larvae in cod stomachs increased with increasing capelin larvae abundance and cod length and decreased with increasing stomach content of copepods and prey abundance of krill. The time when capelin larvae could be recognised after ingestion in the cod stomachs was estimated experimentally and depended on predator and prey lengths. The estimated overall predation mortality rate from juvenile cod on capelin larvae was about 1.5% per day for both years and can potentially have a significant effect on the survival of capelin larvae, depending on the overlap in the different years.

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.

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