Data on forecasted catch, actual catch and their ratio are presented for the main species of pacific salmon; the salmon fishery in 2022 is analyzed. The forecast of the salmon annual catch in the Far-Eastern fishery basin for 2022 should be recognized as generally satisfactory (reliability of 84.6 %).
Pacific salmon fishery in the Far East of Russia in 2022 is analyzed. The reasons for discrepancy between forecasted and actual landing of pacific salmon are discussed. Measures to improve the management and scientific support of the pacific salmon fishery are proposed.
Spatial distribution, abundance and biomass of fish species, cephalopods and jellyfishes are determined in the epipelagic layer on the data of trawl surveys conducted with RV TINRO and RV Professor Kaganovsky in the Pacific waters at Kuril and Commander Islands, western Bering Sea, and Okhotsk Sea in 2022. Modern state of the nekton communities is considered, in particular the state of pink and other species of pacific salmon in summer and autumn seasons. New data on the size-weight composition of pacific salmon are presented; materials for spatial differentiation between their regional groups of pink salmon are available.
Pacific salmon fishery in the Sakhalin-Kuril region in 2022 is analyzed. The data on predicted and actual catch are presented.
Results of the 2022 salmon fishing season in the North Pacific are presented, including the data on landing of pacific salmon in the Far East of Russia, on the Pacific and Arctic coasts of North America and in Japan.
The results of the salmon fishing in Khabarovsk Region in 2022 are presented and the reasons for deviations between the actual and predicted catch are analyzed. Influence of the fishing conditions on the catches is considered. Approaches for forecasting the salmon stocks under changing environments of reproduction are discussed, possible ways to improve the forecasting methods are proposed, and prospects for the salmon fishing in 2023 are shown.
Modern technique of counting pink salmon juveniles in trawl surveys by two research vessels simultaneously makes it possible to cover the surveyed area in a short time that excludes repeated counts of actively migrating fish at adjacent transects. Such survey in the fall of 2022 was conducted jointly by RV TINRO and RV Professor Kaganovsky. The main aggregations of pink salmon in the offshore areas of the Bering and Okhotsk Seas were accounted that guaranteed reliability of the primary materials for prediction of the pink salmon return and catches in 2023. Two regional groups of pink salmon were separated in the mixed aggregation of juveniles in the Okhotsk Sea using the method of EM-clustering; the ratio of «northern» and «southern» complexes of their local stocks was determined as 55 : 45 %. The total number of pink salmon was assessed as 0.94 ∙ 109 ind. in the Bering Sea and 2.70 ∙ 109 ind. in the Okhotsk Sea. Expected return of pink salmon in 2023 was preliminary estimated as 200 ∙ 106 ind. for the Bering Sea and at least 270 ∙ 106 ind. for the Okhotsk Sea.
Results of marine trawl surveys for accounting of pink salmon in 2021 and 2022 and the main results of the salmon fishery in 2022 are presented. The main stages of forecasting of the pink salmon fishery in the Far Eastern basin are described. Differentiation of mixed aggregations of pink salmon is discussed. In 2022, specialists of Kamchatka Branch used for the first time a new method based on variability of SNP loci, along with the traditional methods (morphological express-method and genetic method based on mtDNA analysis). This method provided additional dividing the mixed aggregations of autumn pink salmon in the Sakhalin-Kuril area to the herds from southern Kuril Islands and from eastern Sakhalin. The fishery forecasts for pink salmon were adjusted several times during the fishing season. These adjustments had no a significant effect for the catch increasing in the Okhotsk Sea basin, but allowed to land 10,500 t additionally in the Bering Sea.
Comparative data on changes in structure and length of the spawning run for chum salmon, cherry salmon and pink salmon in the rivers of the northern part of Primorsky Territory are presented for 1998–2022. Appearance of new seasonal groups is noted for all these species. Length of the periods of spawning has become longer.
Monitoring of pink salmon (Oncorhynchus gorbuscha) migration to the estuaries and spawning grounds in the rivers of southeastern and southwestern Sakhalin, including the Aniva Bay, was conducted in summer 2022 using a no-tipping technique with unmanned aerial vehicles (UAV). Abilities, advantages and disadvantages of UAV use for such surveys are discussed to provide a scientific basis for improved management of salmon fishery in the Far East of Russia.
Commercial capability of the certain rivers in Shelikhov Bay (Okhotsk Sea) is analyzed for modern conditions. The fishery load on stocks of pacific salmon and char in these rivers is estimated.
Biological and morphophysiological parameters of juvenile coho salmon of artificial origin grown at the Yansky salmon hatchery in the Magadan region are analyzed. The breeding conditions and the larvae and juveniles development in 2017–2021 are compared.
Chum salmon spawners returned for spawning in the rivers of Prostor and Kurilsky Bays on Iturup Island (Kuril Islands, Sakhalin Region) were examined in the period from September 19 to November 4, 2022. Both females and males had mostly the age 3+ (68.8 % in the Prostor Bay and 62.2 % in the Kurilsky Bay). The portion of males in the age 2+ was in 3.8 times higher than the portion of females, with the average value of 19.2 %; the summary portion of older age groups (4+ and 5+) was 15.4 %. Chum salmon spawners were distinguished by relatively small body weight, similar for the fish of the same age in both bays, on average 2.27 and 2.57 kg for females and males of age 3+, respectively, that was lower than the weight of chum salmon spawners in the previous 8 years.
The reasons of «failed» forecasts for catch of pink salmon at the mainland coast of the Tatar Strait are analyzed. The classical «stock–recruitment» models produce regular errors in the forecasts of runs of pacific salmon under changing conditions of reproduction. To reduce the prediction errors, these models should include parameters of meteorological conditions in the freshwater period of salmon life. In particular case of pink salmon in the Tatar Strait, a relationship is revealed between the year-class strength and precipitation in winter during the period of egg incubation. Including this factor to the model based on Ricker equation increases the proportion of certainty in the variance of recruitment by more than 30 %.
The route survey in the lower part of the Utesny creek (Paramushir Island) was conducted to explore the state of spawning grounds for pink salmon Oncorhynchus gorbuscha and to examine their filling by spawners. The spawners were subjected to biological analysis with measuring their morphometric and physiological parameters. Besides, the data on granulometric composition of soils on the spawning grounds were updated.
ISSN 2658-5510 (Online)