Pub Date : 2024-06-25DOI: 10.1134/s0032945224700127
K. M. Gorbatenko, I. V. Melnikov, A. Yu. Sheibak
Abstract
From 1982–1990 to 2006–2010 in the western part of the Bering Sea biomass of the walleye pollock Gadus chalcogrammus decreased by almost an order of magnitude, from 7.2 to 0.7 million tons. However, in the last decade (2011–2020) its biomass increased to the long-term average value (4.0 million tons). In the eastern part of the sea, the pollock biomass dynamics was of the wave-like nature with the highest value in 1982–1990 and the lowest, in 2006–2010. The food spectrum of the walleye pollock is wide and includes 16 taxonomic groups of aquatic organisms. The main part of average annual food mass consumed by pollock in the Bering Sea in 1982–2020 consisted of zooplankton (74.1%). During different study periods, annual feed consumption varied from 91.1 to 373.0 (average 239.3) million tons per year. Significant fluctuations in the volume of food consumed are mainly associated with the dynamics of the species’ biomass.
{"title":"Feeding of Walleye Pollock Gadus chalcogrammus (Gadidae) in the Epipelagic Zone of the Bering Sea","authors":"K. M. Gorbatenko, I. V. Melnikov, A. Yu. Sheibak","doi":"10.1134/s0032945224700127","DOIUrl":"https://doi.org/10.1134/s0032945224700127","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>From 1982–1990 to 2006–2010 in the western part of the Bering Sea biomass of the walleye pollock <i>Gadus chalcogrammus</i> decreased by almost an order of magnitude, from 7.2 to 0.7 million tons. However, in the last decade (2011–2020) its biomass increased to the long-term average value (4.0 million tons). In the eastern part of the sea, the pollock biomass dynamics was of the wave-like nature with the highest value in 1982–1990 and the lowest, in 2006–2010. The food spectrum of the walleye pollock is wide and includes 16 taxonomic groups of aquatic organisms. The main part of average annual food mass consumed by pollock in the Bering Sea in 1982–2020 consisted of zooplankton (74.1%). During different study periods, annual feed consumption varied from 91.1 to 373.0 (average 239.3) million tons per year. Significant fluctuations in the volume of food consumed are mainly associated with the dynamics of the species’ biomass.</p>","PeriodicalId":48537,"journal":{"name":"Journal of Ichthyology","volume":"92 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141509012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-25DOI: 10.1134/s0032945224700176
Yu. K. Kurbanov, D. A. Terentiev
Abstract
Based on the materials collected during the monitoring of bottom trawl fishery, the data on the distribution, thermal habitat conditions and size composition of the rock greenling Hexagrammos lagocephalus in the southwestern Bering Sea in the winter-spring period are presented for the first time. The main sites of catches of this species are located in areas with a complex bottom relief, mainly at protruding capes at depths of 134–498 m at a near-bottom layer of water temperature of 0.5–3.8°C. High frequency of occurrence and catches in February–March were recorded in the range from 201–400 m, while in April–May, a gradual migration of some fish to the shelf was observed. It was found that rock greenling is not characterized by spatial changes in the size composition, and the catches are mainly formed by medium-sized individuals with a total length of 39–47 cm. The results of the analysis of the length–weight relationship of fish in the southwestern Bering Sea in comparison with that in the Pacific waters off Kamchatka and the northern Kuril Islands may indicate a similar growth pattern of rock greenling in adjacent waters.
{"title":"First Data on the Distribution, Some Features of Ecology and Size Composition of Rock Greenling Hexagrammos lagocephalus (Hexagrammidae) in the Southwestern Bering Sea during the Winter-Spring Period","authors":"Yu. K. Kurbanov, D. A. Terentiev","doi":"10.1134/s0032945224700176","DOIUrl":"https://doi.org/10.1134/s0032945224700176","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Based on the materials collected during the monitoring of bottom trawl fishery, the data on the distribution, thermal habitat conditions and size composition of the rock greenling <i>Hexagrammos lagocephalus</i> in the southwestern Bering Sea in the winter-spring period are presented for the first time. The main sites of catches of this species are located in areas with a complex bottom relief, mainly at protruding capes at depths of 134–498 m at a near-bottom layer of water temperature of 0.5–3.8°C. High frequency of occurrence and catches in February–March were recorded in the range from 201–400 m, while in April–May, a gradual migration of some fish to the shelf was observed. It was found that rock greenling is not characterized by spatial changes in the size composition, and the catches are mainly formed by medium-sized individuals with a total length of 39–47 cm. The results of the analysis of the length–weight relationship of fish in the southwestern Bering Sea in comparison with that in the Pacific waters off Kamchatka and the northern Kuril Islands may indicate a similar growth pattern of rock greenling in adjacent waters.</p>","PeriodicalId":48537,"journal":{"name":"Journal of Ichthyology","volume":"39 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141513818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}