This article provides new information about the current status of populations of commercial marine mammals and their use in the Russian Federation in 2014–2019. Large-scale commercial harvesting in the seas of Russian North-West and Far East stopped in the mid 1990s, and for now harvesting persists as element of traditional indigenous economy and nature management, or according trapping quotas for cultural, educational or scientific purposes. At the same time, the volume of harvesting has significantly decreased (from 250 000 to 5000–6000 in a year), and for whales – the size of the animals caught. It is demonstrated, that harvesting seals, according to renewed data on the abundance of far-eastern subpopulations of seals and in view of in-fact poor scales of local coastal harvesting (<25% of the allocated quotas realized), can be of a commercial scale without any harm for populations in terms of sustainable use approuch to canch up to 3500 ringed seals, 3000 harbor seals, 7000 ribbon seals and 1500 bearded seals in the Sea of Okhotsk, 2400 ringed seals, 4000 harbor seals, 2500 ribbon seals and 1600 bearded seals in the Russian part of the Bering Sea, 5000 ringed seals, 1500 harbor seals, 1300 ribbon seals, and 3600 bearded seals in the Russian part of the Chukchi Sea. With the total abundance of Caspian seals amounting to 280 000 animals the total allowable catch can be 8400 heads, including 4200 heads in the Russian Federation area of responsibility, or 1.5% of the total number. However, on the reason to the fact that in 2020 the species was listed in the Red Book of the Russian Federation, commercial fishing ceased from that time. Given the current status of the northern fur seal grouping on Tyuleniy Island, it is sufficient to adhere to a quota of 3621 bachelor fur seals (aged 2–5 years). On the Commander Islands, 370 bachelor seals 2–5 years old, 1535 one-year-old seals can be harvested. According to the assessment, the total abundance of Baikal seal in 2018 was 137 400 heads. Therefore, it is proposed to harvest 3000 seals (<2.5% of the stock). The abundance of Greenland seals estimated for 2014–2019 is 1 251 680–1 564 320 heads (including the recruitment 128 786). According to data of the ICES/NAFO WGHAR–2019 working group the reccommended catch of Greenland seals in 2020 should be 21 172 animals regardless of their age. Of this total, 14 159 animals should be harvested in the White Sea (the Russian Federation). To preserve the stable population of the Pacific walruses, taking into account their harvesting by North America’s natives as well as non-commercial losses and the size of the unrecorded harvesting, the harvesting quotas should not exceed 3200 animals. On the reason of poor utilization of the quotas, it was proposed to leave the TAC in the previous volumes – 1496 heads per year.

Results of the research of downstream migration of sockeye salmon smolts in the Ozernaya River in 2004–2018 are represented, including characterization of the age and body length-weight composition and of the dynamics of distribution of capturing smolts in the river section. The downstrem migration is analyzed in the interannual aspect, evaluated quantitavely, and coefficients in the equation of the linear regression “juvenile escapement – adule return” are provided.

Analysis of the catches, spawning runs and density of the fish in spawning grounds has revealed maximum run and catch for 2011–2019 averaged, despite a decrease in the average number of chum salmon on spawning grounds and an increase in the commercial catches for mentioned period. Comparing to earlier decades, the age composition of the individuals from the spawning runs and the age composition of generations for recent years demonstrate growing contribution of the older ages 4+ or 5+. The body length and weight of chum salmon in the spawning runs demonstrate an opposite trend – to a decrease, when minimum values getting typical in the modern period. Trend to a decrease of the average body weight of the fish is also observed for generations.

The Listvennichnaya River follows through the lake of the same name before emergence into the Bay Listvennichnaya on the southeastern coast of Kamchatka peninsula. The total length of the river is 15 kms (Verkhnaya Listvennichnaya River + Listvennichnoye Lake + Nizhnaya Listvennichnaya River). Coho salmon spawn in both rivers. There are no any research data about partly (or totally) feeding juvenile coho salmon from the upper river in Listvennichnoye Lake before migration to the sea. Presence of false annual rings in the freshwater zone of scale of mature coho salmon of the Listvennichnaya River can be seen in 50–70% individuals, what makes reading the freshwater age more complicated. Averaged for 2015–2017 the group 2.1 dominated (79.9%) in the age composition of mature coho salmon collected in 130 m from the mouth of the Listvennichnaya River (1.1 – 2.05, 3.1 – 18.1%). High frequency of coho salmon underyearlings (228 individuals in the catches for 2 years) in 130 m from the river mouth in July–September makes us to suggest emerging the fish into the sea, but there were no individuals aged 0.1 in spawning runs.

The article provides analysis of versions of Yellowfin sole Limanda aspera (Pallas [1814]) stock abundance in early ontogenesis under different combinations of two factors – duration of the pelagic period and water temperature, based on using simulating models. An assessment of mortality of the fish during the pelagic period and on the bottom is made. Changes of the simulated stock abundance of yellowfin sole are demonstrated as Paulik diagrams step by step in the early ontogenesis in different simulations hypothesized. Characterization of the correlation between the “parents – progeny” and stock of yearlings or the stock settled on the bottom in the years with different temperature conditions during the pelagic period of the juvenile fish is made. The water temperature effects are maximum on the duration of the pelagic period of the fish. The main period in forming the yellowfin sole stock abundance is the period after settling on the bottom.