FULL ARTICLES
Schematic distribution of the single-species TAC (total allowable catch) and RAС (recommended annual catch) in the complex quotas was developed for 2019 based on the long-term average annual data on the structure of the catches in major types of fishing within the Petropavlovsk-Commander subzone. Comparison of this distribution and real catches for this period was provided.
Based on the longterm observations for 1963–2019, the article provides an assessment of the yellowfin sole generation mortality dynamics depending initial abundance and population dynamics in view of abundance and biomass. Individual growth and matiration rates were evaluated in generations with different initial abundance and in different states of population dynamics. Results indicated about intraspecific competition in yellowfin sole in the eastern part of the Sea of Okhotsk, expressed in specifics of the dynamics of stock abundance, growth and maturation. Forming generation stock abundance in early and later ages has different character. The more exceeding number of parental eggs spawned, the more generation abundance of yearlings getting exactly compensated by mortality (complete compensation). Older generations demonstrate the phenomen of “overcompensation”, when mortality of generations appeared in the years of higher egg production exceeds fertility. In the period of population growth and stabilization at a high level the period of the Yellowfin sole abundance fluctuation cycle gets shorter and the amplitude – smaller. Effects of intraspecific competition on the growth of individuals are revealed. Negative effects of the competition authentically revealed in elder age groups were not observed in younger age groups. An increase of the Yellowfin sole abundance brings negative effects on maturation rate of males with almost no such effects on females. To the greatest extent such effects can be seen in young age groups, at the beginning and middle stage of maturation.
Analysis of the distribution of size-functional groups of brown king crab on the continental spole in the eastern part of the Sea of Okhotsk was provided based on the data collected in 1998–2003. Aggergation rates were evaluated for males and females. Size structure of the population depended on the depth and site. Recommendations for maximum efficient fishery are provided.
Data about the taxonomic composition and spatial distribution of bottom invertebrates of Kronotsky Gulf were obtained on results of bottom grab survey carried in September 2002. Analysis of the samples revealed 72 species of Polychaeta, 21 species of molluscs (Bivalvia), 17 species of crustaceans (mostly Amphipoda), 2 species of echinodermata (Echinoidea and Ophiuroidea). The average biomass in the depth range 25–200 m was 242±116 g/m2 where average density was 306±51 organisms/m2. The most high values of biomass were observed in the outlet parts of the rivers Zhupanova, Semyachik, Kronotskaya, where contribution of sea dollar Echinarachnius parma communities was principal. Despite fluctuations of the biomass of particular taxons during 50 years, the total biomass keeps stable (206–242 g/m2). Like in 1949 E. parma plays the main role in most bottom communities.
The state of the aggregation of Pacific oyster Crassostrea gigas (Thunberg, 1793) in the Losos Bight (Aniva Bay) in 2013–2020 was assessed. For now, this aggregation has been in depression as a result of intense fishing. The abundance of the aggregation of commercial individuals (shell height >120 mm) was poor two recent years. The total stock estimated is 31.5 t; the commercial stock – 4.7 t.
ISSN 2782-6236 (Online)