scholarly journals Dimensional age characteristics of juveniles cod Gadus morhuaLinnaeus, 1958 and Pollachius virenssites (Linnaeus, 1958) in the coastal zone of the Barents Sea in July 2018.

2020 ◽  
Vol 11 (5-2020) ◽  
pp. 12-17
Author(s):  
O.V. Bondarev ◽  
Keyword(s):  
Growth Rate ◽  
Coastal Zone ◽  
Barents Sea ◽  
Atlantic Cod ◽  
Age Groups ◽  
Older Age ◽  
Allometric Growth ◽  
Previous Period ◽  
The Barents Sea

Data on the length of juveniles Atlantic cod and pollock in the coast of the Barents Sea in July 2018 are presented. It was established that, compared with the previous period, the growth rate of fishincreased. In July 2018, juveniles Atlantic cod and pollock from the Kola Bay and East Murman lips are characterized by positive allometric growth. Older age groups of fish from the Kola Bay also have positive alometric growth, and negative in Zelenetskaya Bay.

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 Production characteristics of settlements bivalve Mya arenaria Linne, 1758 of the Barents Sea

2021 ◽  
Vol 12 (3-2021) ◽  
pp. 141-150
Author(s):  
O.V. Smolkova ◽  
Keyword(s):  
Growth Rate ◽  
Intertidal Zone ◽  
Linear Growth ◽  
Barents Sea ◽  
Mya Arenaria ◽  
The Barents Sea ◽  
Growth Equations ◽  
Production Characteristics

The linear growth equations and production for bivalve Mya arenaria (Linne, 1758) in the intertidal zone Yarnyshnaya and Zelenetskaya bays of Barents Sea are represented. Our studies have shown that length of the shell Mya reached 26.3–62.5 mm, the highest age was 11 years. Indicators of the growth rate of mollusks from Zelenetskaya Bay are significantly higher than those of mollusks from Yarnyshnaya Bay. Linear growth is described by the Bertalanfi equations: Lt = 84.27 [1–e–0.0721 (t–0.1244)] – for mollusks from Yarnyshnaya Bay, Lt = 118.49 [1–e–0.0566 (t–0.2744)] – for mollusks from Zelenetskaya Bay. Production in the intertidal zone of the Yarnyshnaya Bay was lower (44.8 g/m2 with a biomass of 330 g/m2) than in the intertidal zone of the Zelenetskaya Bay (90.5 g/m2, with a biomass of 258 g/m2). The P/V-value is the coefficient of 0.14 and 0.35, respectively.

Pseudobranchial tumours in Atlantic cod, Gadus morhua L., from the Barents Sea

1981 ◽  
Vol 4 (6) ◽  
pp. 527-532 ◽  
Author(s):  
E. C. EGIDIUS ◽  
J. V. JOHANNESSEN ◽  
E. LANGE
Keyword(s):  
Gadus Morhua ◽  
Barents Sea ◽  
Atlantic Cod ◽  
The Barents Sea

scholarly journals Consumption of juvenile herring (Clupea harengus) by cod (Gadus morhua) in the Barents Sea: a new approach to estimating consumption in piscivorous fish

2004 ◽  
Vol 61 (3) ◽  
pp. 343-359 ◽  
Author(s):  
Geir Odd Johansen ◽  
Bjarte Bogstad ◽  
Sigbjørn Mehl ◽  
Øyvind Ulltang
Keyword(s):  
Gadus Morhua ◽  
Barents Sea ◽  
Age Groups ◽  
Predation Rate ◽  
Clupea Harengus ◽  
Time Range ◽  
Digestion Time ◽  
New Approach ◽  
Piscivorous Fish ◽  
The Barents Sea

Consumption of different age groups of juvenile, Norwegian, spring-spawning herring (Clupea harengus) by northeast Arctic cod (Gadus morhua) in the Barents Sea in 1992–1997 is estimated using cod stomach content data. We present a new approach to the problem of estimating consumption by fish. The new method is based on the estimation of digestion time for single prey items based on the difference between fresh weight at ingestion and weight in the stomach at time of sampling. Estimation is based on a gastric evacuation model for cod and area-specific sea temperatures. This is used to estimate the time (tmax) it takes for a prey to become digested to a stage where length is no longer measurable. Predation rate is then estimated for all prey with digestion time ≤tmax as number of prey eaten in the time range defined by tmax. This rate is combined with estimates of the proportion of the cod stock consuming the prey and area-specific abundance of cod, giving consumption of herring on a seasonal and yearly basis. The consumption estimates differ from those obtained using current methods. Predation mortality of herring is estimated directly from the consumption estimates by combining them with acoustic herring abundance data.

scholarly journals Methods and results of in situ target-strength measurements of Atlantic cod (Gadus morhua) during combined trawl-acoustic surveys

2009 ◽  
Vol 66 (6) ◽  
pp. 1225-1232 ◽  
Author(s):  
Viacheslav A. Ermolchev
Keyword(s):  
Gadus Morhua ◽  
Barents Sea ◽  
Atlantic Cod ◽  
Biological Data ◽  
Target Strength ◽  
Fish Length ◽  
The Barents Sea ◽  
Total Fish ◽  
Acoustic Surveys

Abstract Ermolchev, V. A., 2009. Methods and results of in situ target-strength measurements of Atlantic cod (Gadus morhua) during combined trawl-acoustic surveys. – ICES Journal of Marine Science, 66: 1225–1232. This paper presents methods for collecting acoustic and biological data, including in situ target-strength (TS) estimates of fish, with results presented for Atlantic cod (Gadus morhua) obtained from combined trawl-acoustic surveys. These include fish in the small, average, and maximum length classes, within the range 5–136 cm (total fish length, LT). The investigations were done using Simrad EK500/EK60 echosounders with split-beam transducers and special post-processing software. Based on an analysis of data collected in the Barents Sea during 1998–2007, a relationship TS = 25.2 log10(LT) − 74.8 was obtained for Atlantic cod at 38 kHz, with TS in dB and LT in centimetres. Seasonally, and for depths between 50 and 500 m, the variability in cod TS was 3.1 dB, decreasing with depth. The largest day–night difference in mean TS was in August–September, with changes as large as 1.0–1.7 dB. In the other seasons, the day–night difference was <1.0 dB.

scholarly journals Diets of the Barents Sea cod (<i>Gadus morhua</i>) from the 1930s to 2018

2021 ◽  
Vol 13 (3) ◽  
pp. 1361-1370
Author(s):  
Bryony L. Townhill ◽  
Rebecca E. Holt ◽  
Bjarte Bogstad ◽  
Joël M. Durant ◽  
John K. Pinnegar ◽  
...  
Keyword(s):  
Gadus Morhua ◽  
Visual Analysis ◽  
Barents Sea ◽  
Atlantic Cod ◽  
Fish Diet ◽  
The North ◽  
The United Kingdom ◽  
Federal Research ◽  
The Barents Sea ◽  
The Uk

Abstract. A new dataset on the diet of Atlantic cod in the Barents Sea from the 1930s to the present day has been compiled to produce one of the largest fish diet datasets available globally. Atlantic cod is one of the most ecologically and commercially important fish species in the North Atlantic. The stock in the Barents Sea is by far the largest, as a result of both successful management and favourable environmental conditions since the early 2000s. As a top predator, cod plays a key role in the Barents Sea ecosystem. The species has a broad diet consisting mainly of crustaceans and teleost fish, and both the amount and type of prey vary in space and time. The data – from Russia, Norway and the United Kingdom – represent quantitative stomach content records from more than 400 000 fish and qualitative data from 2.5 million fish. Many of the data are from joint collaborative surveys between Norway and Russia. The sampling was conducted throughout each year, allowing for seasonal, annual and decadal comparisons to be made. Visual analysis shows cod diets have changed considerably from the start of the dataset in the 1930s to the present day. There was a large proportion of herring in the diets in the 1930s, whereas in more recent decades capelin, invertebrates and other fish dominate. There are also significant interannual asynchronous fluctuations in prey, particularly capelin and euphausiids. Combining these datasets can help us understand how the environment and ecosystems are responding to climatic changes, and what influences the diet and prey switching of cod. Trends in temperature and variability indices can be tested against the occurrence of different prey items, and the effects of fishing pressure on cod and prey stocks on diet composition could be investigated. The dataset will also enable us to improve parametrization of food web models and to forecast how Barents Sea fisheries may respond in the future to management and to climate change. The Russian data are available through joint projects with the Polar Branch of the Russian Federal Research Institute of Fisheries and Oceanography (VNIRO). The UK and Norwegian data (Townhill et al., 2020) are being released with this paper at https://doi.org/10.21335/NMDC-2139169383.

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