population dynamics, rational fishing, intensity and selectivity of fishing, emissions, regulation of the level of fishing impact, stock-market-fishing system

The article proposed to discuss a concept of new strategy for the sustainable use of populations of aquatic organisms using as an example a fishery for Walleye Pollock in the Far Eastern seas of the Russian Federation. It is shown that the current regulations governing the impact of fishing contained in the Fishing Regulations do not quite consider changes related to the dynamics of pollock populations parameters. As a result, there is an uncontrolled and often negative impact of fishing, which leads to changes in the phenotypic and size-age structure of W. Pollock populations being fished, which ultimately affects the profitability of fishing. It is proposed to develop a separate strategy for each W. Pollock stock unit, which annually regulates the level of fishing impact, depending on the state of the stocks and market conditions. The proposed strategy concept makes it possible to regulate not only the allowable volume of catch, but also the size structure of catches, by changing the fishing parameters every year. It will keep the harvested stocks stable and will help to obtain the maximum possible fishing profitability.

Transformation of baroclinic tidal waves in the conditions of the shelf of the Far Eastern seas

This work is devoted to the study of the regimes of transformation of baroclinic tidal waves under the conditions of the Far Eastern seas within the framework of a fully nonlinear numerical model. Two sections were selected to study the features of wave dynamics – in the Sea of Okhotsk (Sakhalin Island shelf) and in the Bering Sea (near Cape Navarin). On the basis of the performed calculations, regional and seasonal features of the transformation of baroclinic waves and the structure of the flow induced by them were revealed. It is shown that the dynamics in the winter season is less intensive. The rotation effect on the formation of solibore in the studied conditions is analyzed. The obtained estimates of wave amplitudes and velocities are consistent with the published data of field observations in the Sea of Okhotsk. For the Bering Sea, the conditions are shown to be favorable for the generation of intensive internal waves, which indirectly confirms the hypothesis of influence of such waves on the formation of underwater sand dunes.

Comparative analyses of changes in the ice cover of the Tatar Strait in relation to 1961-1990 and 1991-2020 climate normals

Current warming in the Northern Hemisphere has encompassed not only the surface atmosphere, but also manifested itself in a change in the state of the sea ice cover, as an integral part of the climate system. One of the indicators of the warming was a reduction in ice cover observed in the water area of the Far Eastern seas since the late 1980s. The prospective areas of hydrocarbon deposits discovered in the Tatar Strait, as well as the existing needs for the transportation of hydrocarbons along the shipping routes in the strait, led to the emerging interest in researching the ice regime of the Sea of Japan in the modern climatic era. The proposed paper analyses the changes in ice cover of the Tatar Strait in relation to 1961–1990 and 1991–2020 climate normals. The regularities of the long-term variability of ice cover within non-overlapping 30-year periods were revealed. The analysis of the dynamics of ice cover anomalies, calculated for each normal separately, was carried out. An assessment of the distribution of winter types in the periods under study was carried out. The characteristic features of variations in the intra-seasonal course of ice cover and the dates of the onset of ice phases in different types of winters were identified.

Features of the geological structure and oil and gas content of the shelves of the Far Eastern Seas

Russian shelf is one of the most important areas for hydrocarbon forecast and mineral resources development. The main features of the geological structure of the shelves of the Far Eastern seas are discussed in the paper. The most promising basins on the Okhotsk shelf are located around Sakhalin island where the majority of the hydrocarbon fields have been discovered. The Bering and the Japan shelf has not been sufficiently studied by now but nevertheless has high oil and gas potential. The main focus is made on the geological and geophysical data, licensing, lithological and stratigraphic structure, seismic interpretation, oil and gas fields distribution. The structural-tectonic zoning of the entire Far Eastern region has been done in order to identify zones of deep troughs with thick sedimentary cover to predict the sources of hydrocarbon generation.

Postmagmatic tectonics of basement granites of the Far Eastern seas of Russia

The article contains the results of tectonogeodynamic paleoreconstructions and numerical spatio-temporal basin modelling, which allowed to reveal the structural features and formation conditions of the base of the Far Eastern seas of the Russian Federation, as well as the occurrence of crystalline protrusions in the pre-Cenozoic bases at the stage of prototectonics and posthumous tectonics, which are primarily due to heterogeneity of the viscous properties of various layers of the earth’s crust, i.e. its tectonic and material stratification. A large-scale lateral redistribution of the substance, its outflow out of the areas of increased compression and injection into areas of geodynamic shelters has taken place at this stage. Mechanisms of the formation of a void space within protrusions have been considered. A conceptual model of the formation of petroleum deposits within the granite massifs of the base has been proposed.