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Simple Summary: Todarodes pacificus is an important cephalopod. This study analyzed the migration path and feeding ecology of T. pacificus by the stable isotope values of the proostracum of the gladius. This result showed that T. pacificus in the East China Sea migrated to low latitudes and nearshore areas during their life history, and the trophic level of their food exhibited no large changes during migration. T. pacificus in the Sea of Japan migrated to high latitudes and offshore areas during their life history, and the trophic level of their food decreased during migration. When the proostracum grew to 120 mm from the distal end, T. pacificus in both areas began to migrate. This study provides a scientific basis for further study on the fishery ecology and life history of T. pacificus. The Japanese flying squid (Todarodes pacificus) is an important cephalopod in the northwest Pacific Ocean. In this study, the proostracum of the gladius of T. pacificus samples collected by Chinese squid fishing vessels in the East China Sea and the Sea of Japan in August and December 2018 were continuously cut, and stable isotope values of the cut fragments were used to analyze the migration path and feeding ecology of T. pacificus. The results showed that when the proostracum grew to 120 mm from the distal end, T. pacificus began to migrate. In the East China Sea, T. pacificus migrated to low latitudes and nearshore areas, and the trophic level of their food showed no large changes during migration. In the Sea of Japan, T. pacificus migrated to high latitudes and offshore areas, and the trophic level of their food showed a decreasing trend during migration. There was no significant difference in migration or feeding ecology between females and males, but the competitive capacity of the females may be stronger than that of the males. The results provided a scientific basis for the scientific management and development of T. pacificus resources. [ABSTRACT FROM AUTHOR]

Simple Summary: The bioindication of oil and gas fields is an important task in geomicrobiology. Our study expands the field of geomicrobiological methods and allows us not only to suggest the possibility of the presence of an oil and gas deposit but also its type. We used cultural and molecular genetic methods to study microorganisms, in particular their ability to oxidize hydrocarbons under aerobic and anaerobic conditions. We carried out a comparative analysis of cultured and molecular methods for the bioindication of oil and gas deposits to detect deposits and describe the relevant types(traditional and gas-hydrate). The most promising method in this area was the one used for assessing the anaerobic degradation of hydrocarbons. Studying the mcrA, pmoA, dsrB, alkBB, bssA and masD biomarker genes made it possible to identify areas with different types of deposits based on the distribution of the alkBB, bssA and masD genes. The bssA and masD genes predominated in the gas-hydrate region. With the help of cultured methods, it was possible to describe the type of deposits based on taxonomic diversity (Rhodococcus spp.). In addition, the ability of aerobic and facultative anaerobic hydrocarbon-oxidizing microorganisms to anaerobically utilize hydrocarbons was described using cultured methods. The bioindication of oil and gas fields is a field of geomicrobiology that is mainly devoted to the detection of hydrocarbon-oxidizing microbial indicator species or functional genes in total DNA. However, it appears promising to use the physiological properties of microorganisms detection deposit type of hydrocarbons, in particular their ability to oxidize hydrocarbons under aerobic and anaerobic conditions. In this study, the most promising approach in this area was the method used for assessing the anaerobic degradation of hydrocarbons. When comparing molecular genetics and cultured methods of bioindication, it can be concluded that molecular biomarkers of functional genes for the anaerobic destruction of hydrocarbons (masD) make it possible to separate areas with traditional and gas-hydrate types of deposits. Using cultured methods, we found that representatives of the Nocardiaceae family of the phylum Actinomycetota were tied to the areas where gas hydrates were found. The ability of aerobic and facultative anaerobic hydrocarbon-oxidizing microorganisms to anaerobically utilize hydrocarbons was determined with cultured methods. For the first time, this ability was revealed for the genera Stenotrophomonas, Psychrobacter, Micrococcus and Peribacillus. The wide distribution of this ability that we found in strains isolated from both study regions suggests its prominent role in the destruction of hydrocarbons in marine sediments. [ABSTRACT FROM AUTHOR]

Scallops are bivalve filter-feeding mollusks that can attain a large size and have great importance in terms of their ecological roles and commercial value. Overfishing has led to a decrease in scallop stocks worldwide, leading to intense development of the aquaculture industry. The latter is well-established in Asian countries in the East Sea and Sea of Japan. In this paper, we summarized information regarding the biology, stock dynamics, and fishery of yesso scallops inhabiting Russian waters of the Sea of Japan. This species has relatively rapid growth rates and reaches a marketable size of 100 mm in shell height at age 3–5 years. In Russian waters, the total commercial stock of yesso scallops in 2021 was estimated at 2784 t. Commercial fisheries have been banned since 2020 due to the depletion of natural stocks as a result of illegal fishing and overexploitation. The total allowable catch for yesso scallops has been set at 3 t for monitoring and recreational purposes. The cultivation of the scallops includes spat collection, spat intermediate culture, and final grow-out on the seafloor or in suspended cages. In the past decade, this industry has demonstrated rapid growth and currently accounts for >16,000 t per year. Environmental fluctuations and epizootics seem to be the most important challenges for the scallop aquaculture sector in the Sea of Japan. [ABSTRACT FROM AUTHOR]

The understanding of the spatio-temporal distributions of the species habitat in the marine environment is central to effectual resource management and conservation. Here, we examined the potential habitat distributions of Japanese common squid (Todarodes pacificus) in the Sea of Japan during a four-year period. The seasonal patterns of preferential habitat were inferred from species distribution models, built using squid occurrences detected from night-time visible images and remotely-sensed environmental factors. The predicted squid habitat (i.e., areas with high habitat suitability) revealed strong seasonal variability, characterized by a reduction of potential habitat, confined off of the southern part of the basin during the winter-spring period (December-May). Apparent expansion of preferential habitat occurred during summer-autumn months (June-November), concurrent with the formation of highly suitable habitat patches in certain regions of the Sea of Japan. These habitat distribution patterns were in response to changes in oceanographic conditions and synchronous with seasonal migration of squid. Moreover, the most important variables regulating the spatio-temporal patterns of suitable habitat were sea surface temperature, depth, sea surface height anomaly, and eddy kinetic energy. These variables could affect the habitat distributions through their impacts on growth and survival of squid, local nutrient transport, and the availability of favorable spawning and feeding grounds. [ABSTRACT FROM AUTHOR]

The East/Japan Sea (hereafter, the East Sea) is highly dynamic in its physical phenomena and biological characteristics, but it has changed substantially over the last several decades. In this study, a recent decadal trend of primary productivity in the East Sea was analyzed based on Moderate-Resolution Imaging Spectroradiometer (MODIS)-derived monthly values to detect any long-term change. The daily primary productivities averaged using monthly values from 2003 to 2012 were 719.7 mg⋅C⋅m-2⋅d-1 (S.D. ± 197.5 mg⋅C⋅m-2⋅d-1, n = 120) and 632.3 mg⋅C⋅m-2⋅d-1 (S.D. ± 235.1 mg⋅C⋅m-2⋅d-1, n = 120) for the southern and northern regions of the East Sea, respectively. Based on the daily productivities, the average annual primary production in the East Sea was 246.8 g⋅C⋅m-2⋅y-1, which was substantially higher than that previously reported in deep oceans. However, a decreasing trend (13% per 10 years) in the annual primary production was observed in the East Sea within the study period from 2003 to 2012. The shallower mixed layers caused by increased temperature could be a potential cause for the decline in annual production. However, this decline could also be part of an oscillation pattern that is strongly governed by the Pacific Decadal Oscillation (PDO). A better understanding of primary productivity patterns and their subsequent effects on the marine ecosystem is required for further interdisciplinary studies in the East Sea. [ABSTRACT FROM AUTHOR]

For the first time the presence of dinophysistoxin-1 (DTX-1) in a culture of Prorocentrum foraminosum was revealed in cells and in the culture medium. The clone was isolated from coastal waters of the Sea of Japan and identified by molecular analyses of SSU and D1/D2 regions of LSU rDNA. The concentration of DTX-1 in cells was 8.4 ± 2.5 pg/cell and, in cell-free media, 27.9 ± 14.7 μg/L. The toxin presence was confirmed by HPLC with high-resolution tandem mass-spectrometry. [ABSTRACT FROM AUTHOR]

The fully coupled WRF/Chem (Weather Research and Forecasting/Chemistry) model is used to simulate air quality over coastal areas of the Sea of Japan. The anthropogenic surface emissions database used as input for this model was based primarily on global hourly emissions data (dust, sea salt, and biomass burning), RETRO (REanalysis of the TROpospheric chemical composition), GEIA (Global Emissions Inventory Activity), and POET (Precursors of Ozone and their Effects in the Troposphere). Climatologic concentrations of particulate matter derived from the Regional Acid Deposition Model (RADM2), chemical mechanism, and the Secondary Organic Aerosol Model (MADE/ SORGAM) with aqueous reactions were used to deduce the corresponding aerosol fluxes for input to the WRF/Chem model. The model was first integrated continuously over 48 hours, starting from 00:00 UTC on 14 March 2008, to evaluate ozone concentrations and other precursor pollutants. WPS meteorological data were used for the WRF/Chem model simulation in this study. Despite the low resolution of global emissions and the weak density of the local point emissions, it was found that the WRF/Chem model simulates the diurnal variation of the chemical species concentrations over the coastal areas of the Sea of Japan quite well. The Air Quality Management Division of the Ministry of the Environment in Japan selected the maximum level of the air quality standard for ozone, which is 60 ppb. In this study, the atmospheric concentrations of ozone over the coastal area of the Sea of Japan were calculated to be 30-55 ppb during the simulation period, which was lower than the Japanese air quality standard for ozone. [ABSTRACT FROM AUTHOR]