The features of seasonal distribution and fishing of chub mackerel in the Central-Eastern Atlantic area were studied. The analysis were completed by data of chub mackerels biology collected during field work in 2004-2017, and data of fishing and statistical information taken from the Center of the Fisheries Monitoring and Communication System of the Federal Agency of Fishery in 2004-2019. Seasonal distribution of chub mackerel were determined by calculations of the main fishing aggregations, which were found as trawls with a mass fraction of chub mackerel more than 50% of the caught number of all species. The task were decided after processing of 96433 rows of fishing data. Authors wrote the program in SQL with the features of the Postgres DBMS. Distribution of chub mackerel by season revealed the process of shifting the fishing fleet due to the redistribution of aggregations of large-sized and small-sized fish during migrations. During spawning activity calculation of distances and migration rates is the maximum for small-sized chub mackerel 221,4 km / month and 4 km / day, accordingly, for large-sized chub mackerel - presumably 2 times more. Therefore, the period of feeding activity of large-sized chub mackerel from April to July in the EEZ of Mauritania is characterized by a decrease in the distance and speed of migration. That is optimal and cost-effective for the operation of the fishing fleet.

The biological substantiation of possibility of long-term forecasting abundance of juvenile of the Japanese scallop Patinopecten (=Mizuhopecten) yessoensis, (Jay, 1856) - the basic object of cultivation in Primorsky Territory, on easy-to-see duration of the ice period in shallow bays is presented. Predictability become cornerstone created in the past century of the method of through cultivation of the sea scallop and mechanism for its actualization.

Hematological indices have been provided for different-aged Coregonus muksun groups of three rehabilitation broodstock generations at a fish plant on sig fish species reproduction. The quantity blood indices fluctuated depending on water temperature, fish age and their physiological state. The fluctuations of hematological indices, revealed inside a generation and one-aged ones between generations, testify to heterogeneity of a fish stock formed. The highest indices have been noted in muksun of the second and the third generations reared between 14 and 16°C water temperature.

Two-year-old coregonines (broad whitefish Coregonus nasus) were grown in cages on experimental feeds. After 55 days (the feeds expiry date was two months) the feeds began to spray with a solution of vitamin C, which increased the vitamin content in liver and muscles and retained a high level of Omega-3 acids in those tissues. The fish was growing at the same growth rate in all fish cages with normal blood values. The fish which did not receive additional C Vitamin had reduced content of polyunsaturated fatty acids in muscles, especially docosahexanoic acid - 15,9% versus 21,8%, while the content of monounsaturated oleic acid was increased - 34,5 against 26,7%. All fishes had similar fatty acid profile in their liver. Apparently, it is the muscles that are a reserve of essential fatty acids for the liver and other organs having an enhanced need in Оmega-3 acids.

The study presents the results of quantitative analysis of the deep-water morpho-ecological group state of Baikal omul, considered as a separate stock. The available information support allowed to apply the cohort model implemented in TISVPA and Synthesis software complexes. The Synthesis software was applied for assessment of the near-deep morpho-ecological group of the Baikal omul first time. Stock biomass estimates obtained in two software complexes confirmed the conclusion about a continuous stock abundance decrease obtained by other researchers earlier. In international fisheries practice the stock recovery implies a stock size increase to a certain biological reference point. In this research it is proposed to use as a target reference point a biomass at which the stock produces the maximum surplus production. Based on the results of Combi software calculations, the estimate of such biomass was 1281 tons. The analysis showed recruitment will not be able to ensure the fishery stock recovery to the target reference point in the next 5 years due to the spawning stock biomass decrease in the years before the moratorium on the fishery.

Based on the results of ichthyological surveys carried out in May-November 2012 and in February 2013 using fixed net and beach seine the seasonal distribution of herring in Ptichye Lake (lagoon) on south-eastern Sakhalin was first described. Herring spawning was show to occur in May-June. The main spawning substrate is sea grasses of the genus Zostera, brown and red algae. After spawning, fish migrate to the sea for feeding and in September-November they migrate back to the lake for wintering. Maximum herring numbers and frequency are observed in May and November. During the observation period, herring up to 31 cm long and weighing up to 330 g at the age of 8 years was noted. The basis of herring aggregations was fish 12-22 cm long, weighing 20-80 g at the age of 2 to 5 years. It is suggested that the herring of Lake Ptichye belongs to the type lake herring.

Fluctuation of number of larvae of fishes in coastal zone is considered and pelagial the Meshinsky gulf of the Kuibyshev reservoir in 2012-2017 with different hydrological conditions, and also change of indicators of their specific variety in both biotopes. It is established that average sizes of total number of larvae of fishes fluctuated these years in a in coastal zone in terms of one effort from 53,7 to 401,8 copies (respectively on m³ water 1 volume from 812,7 to 5659,0 copies) and in pelagial - on 1 m³ from 0,36 do 2,21 piece. Fluctuation of level and water temperature in the spring these years significantly did not influence efficiency of reproduction of fishes. The number of species of larvae of fishes to littorals and pelagial in 2012-2017 equaled 13-17. In coastal zone only small fry larvae, and in pelagial of a larva the perches of fishes dominated (Volga zander and a perch). The index of a specific variety of Shannon at larvae of fishes in pelagial was higher, than in coastal zone. It is connected with that in pelagial value of an indicator of abundant is lower and smaller distinctions in the number of separate types were observed.