Winter variability in the diets of groundfish inhabiting a subarctic sound with a focus on Pacific herring and walleye pollock piscivory

The article discusses the impact of competition in the market of aquatic biological resources on the end-user price of fish products and the introduction of an auction quota mechanism for the catch of aquatic biological resources proposed by the Federal Antimonopoly Service of Russia to increase competition in the industry and cut prices in retail fish markets. The study aims to test the hypothesis that the fishing industry has a high level of monopolisation and low competition based on the data on the allocation of quotas for the aquatic biological resources of the largest fishery region—the Far East fishery basin. Technical issues of conducting research in the Far East fish products market are considered using concentration coefficients and taking into account its specificity, geographical location, and trade flows of fish products. Based on the distribution of quotas for the total allowable catch of the magister armhook squid (Berryteuthis magister), walleye pollock, Pacific herring, cod, Kamchatka crab, and smear dab in the subzones of the Far East fishing area, (1) market shares of fishing enterprises are analysed, leading producers are identified in each of the analysed segments with an estimate of their specific share in the total volume of quotas for aquatic biological resources, (2) the CR3 concentration ratio and the Herfindahl-Hirschman index are calculated, with the variance of the quotas, the mode and the median of the distribution of the quotas additionally calculated. Assessment of the CR3 concentration index and the Herfindahl–Hirschman index for the producers of Pacific herring, walleye pollock, cod, Kamchatka crab,and smear dab allowed classifying these markets as non-concentrated, while a significantly higher concentration was found for the magister armhook squid producers. The study did not confirm the assumption of monopolisation and high concentration of the fishing industry. The formation of the retail market price of fish products is influenced by various factors, including logistics, the number of resellers, and some others. Alternative distribution channels for fishing companies, reduction of the number of intermediaries between producers and retail consumers, and the creation of fish markets may prove an effective way to develop the industry.

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Features of feeding for pacific herring Clupea pallasii, walleye pollock Theragra chalcogramma, and arabesque greenling Pleurogrammus azonus in Peter the Great Bay (Japan Sea) in summer season

Izvestiya TINRO ◽

10.26428/1606-9919-2014-176-189-200 ◽

2014 ◽

Vol 176 (1) ◽

pp. 189-200

Author(s):

Olga I. Pushchina ◽

Sergey F. Solomatov ◽

Boris M. Borisov

Keyword(s):

Peter The Great Bay ◽

Food Competition ◽

Walleye Pollock ◽

Theragra Chalcogramma ◽

Pacific Herring ◽

Clupea Pallasii ◽

Peter The Great ◽

Great Bay ◽

Pleurogrammus Azonus ◽

Arabesque Greenling

Qualitative and quantitative indices of feeding and competitive relationships are investigated for pacific herring Clupea pallasii , walleye pollock Theragra chalcogramma , and arabesque greenling Pleurogrammus azonus on the data of bottom trawl surveys conducted over the shelf and upper continental slope of Peter the Great Bay in June-September of 2002-2009. Daily rations of these species in summer are estimated as 4.5, 3.0 and 4.3 % of body weight on average, respectively. The diet depends on their bathymetric distribution and structure of prey: generally, the portion of plankton and nektobenthos reflects the species ability to dwell beyond the bottom and changes from 66.9 and 32.1 % for herring and 45.2 and 46.9 % for pollock to 30.2 and 31.8 % for greenling. The rest of the greenling diet is presented by benthic invertebrates (24.8 %) and nekton (13.2 %). Mysids are the main common diet component for all three species, their portion in the herring and pollock diets is extremely high in Peter the Great Bay comparing with other habitats of these species, obviously because of high abundance of mysid shrimps and low concentrations of large-sized zooplankton (particularly euphausiids) in the Bay. Role of the considered species in demersal ichthyocenosis of Peter the Great Bay is not high enough for food competition between them, taking into account their active seasonal migrations and low stocks of herring and pollock in recent times.

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Predator foraging mode shifts affecting mortality of juvenile fishes during the subarctic spring bloom

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f98-185 ◽

1999 ◽

Vol 56 (3) ◽

pp. 364-376 ◽

Cited By ~ 41

Author(s):

T M Willette ◽

R T Cooney ◽

K Hyer

Keyword(s):

Surface Layer ◽

Spring Bloom ◽

Life Stage ◽

Walleye Pollock ◽

Analysis Of Covariance ◽

Oncorhynchus Gorbuscha ◽

Pacific Herring ◽

Juvenile Growth ◽

Calanoid Copepods ◽

Foraging Mode

We examined some processes affecting foraging mode shifts among Pacific herring (Clupea pallasi) and walleye pollock (Theragra chalcogramma) during the spring bloom in Prince William Sound, Alaska. The duration of the bloom of the copepod Neocalanus was reduced when the surface layer became strongly stratified in May. Stronger surface layer stratification observed in 1995 and 1996 was associated with higher salinities below 50 m depth compared with 1994. Functional response models for Pacific herring and adult walleye pollock feeding on large calanoid copepods indicated that these predators began to switch to alternative prey as the mean biomass of large calanoid copepods declined below about 0.2 and 1.0 g/m3, respectively. Analysis of covariance indicated that Pacific herring and walleye pollock tended to switch from large calanoid copepods to nekton prey after the copepod bloom declined (p = 0.028). Mortality of pink salmon (Oncorhynchus gorbuscha) was negatively correlated with the duration of the copepod bloom during the juvenile life stage (p = 0.013), as well as with juvenile growth rate (p < 0.001), juvenile body weight at release (p < 0.001), and the number of juveniles released (p < 0.001). Our results indicate that bottom-up processes affecting the duration of the spring bloom and juvenile growth also modify top-down processes involving foraging mode shifts toward piscivory and mortality of juvenile fishes.

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First-Year Energy Storage Patterns of Pacific Herring and Walleye Pollock: Insight into Competitor Strategies

Ecosystem Approaches for Fisheries Management ◽

10.4027/eafm.1999.12 ◽

1999 ◽

Author(s):

A.J. Paul ◽

J.M. Paul

Keyword(s):

Energy Storage ◽

Walleye Pollock ◽

First Year ◽

Pacific Herring ◽

Insight Into ◽

Storage Patterns

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Modern specialized fishery of sea fish in the western Bering Sea

Izvestiya TINRO ◽

10.26428/1606-9919-2021-201-76-101 ◽

2021 ◽

Vol 201 (1) ◽

pp. 76-101

Author(s):

A. O. Zolotov

Keyword(s):

Bering Sea ◽

Walleye Pollock ◽

Pacific Herring ◽

Pacific Cod ◽

The West ◽

Trawl Fishery ◽

Western Bering Sea ◽

By Catch ◽

Far Eastern ◽

Sea Fish

The shelf and continental slope of the western Bering Sea, being among the most productive areas of the Far-Eastern Seas of Russia, became exploited by commercial fishery half a century ago, after introduction of 200-mile exclusive economic zones in 1977 and relocation of the Russian fishing fleet from the eastern Bering Sea to its western part. In 2010-2019, about 20 % of the total catch of sea fish in the Far-Eastern basin (excluding pacific salmons) were caught in the West Bering Sea fishery zone. Among the fishery districts of the Russian Far East, this area is currently the 1st one by annual catch of pacific cod, grenadiers, sculpins and sablefish, 2nd — by catch of walleye pollock, halibuts and skates, 3rd — by catch of rockfishes, and 4th — by catch of pacific herring and flounders. Features of specialized fishery in the West Bering Sea fishery zone in 2010-2019 are clarified. Now 48 types of the specialized fishery can be distinguished here, while 96.3 % of the average annual landing is provided by the following 8 most important types: walleye pollock midwater trawl fishery (77.8 % of mean annual catch); pacific herring midwater trawl fishery (6.1 %); pacific cod bottom longline fishery (4.7 %); walleye pollock Danish seine fishery (2.7 %); grenadiers bottom longline fishery (2.4 %), pacific cod Danish seine fishery (0.9 %); squids bottom trawl fishery (0.9 %); and pacific cod bottom trawl fishery (0.8 %). All these types of fishery are highly specialized and portion of the target objects in the catches ranges from 76 to 96 % (according to official statistics), while the by-catch accounted as 4-24 %. The is no specialized fishery on such objects as rockfishes, arrowtooth and kamchatka flounders, and sablefish in the West Bering Sea fishery zone, but they are landed as by-catch. The fishery statistics with the data sorting to specialized fishery and by-catch can be used quite effectively for the stocks assessment and determining acceptable level of their exploitation, with recommendations for fishery regulation, including evaluation the possible level of non-specialized by-catch.

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