Некоторые особенности биологии и формирования скоплений минтая южных Курильских островов в осенне-зимний период

• Main Authors: Багинский, Д., Частиков, В.
• Format: Text
• Language: unknown
• Published: Федеральное государственное унитарное предприятие «Тихоокеанский научно-исследовательский рыбохозяйственный центр» 2004
• Subjects: Okhotsk; Pacific; okhotsk sea
• Online Access: http://cyberleninka.ru/article/n/nekotorye-osobennosti-biologii-i-formirovaniya-skopleniy-mintaya-yuzhnyh-kurilskih-ostrovov-v-osenne-zimniy-period; http://cyberleninka.ru/article_covers/6237642.png

Район южных Курильских островов является одним из немногих, где до настоящего времени осуществляется относительно масштабный промысел минтая. Вместе с тем запасы этого вида повсеместно снижаются, что обусловлено в первую очередь естественными причинами. В рассматриваемом районе запас минтая является трансграничным между Россией и Японией, и применительно к нему актуальны вопросы общности или дифференцированности запасов, их популяционного статуса и состояния. В данной работе сделана попытка проследить изменение численности южнокурильской популяции минтая и взаимосвязь этого процесса с некоторыми климатоокеанологическими факторами, промыслом и биологией данного вида. Использованы данные, собранные в ходе контрольного лова в 1998-2001 гг. Показано влияние промысла на нерестовые скопления минтая. Changes of the abundance and biological condition of the walleye pollock belonged to the South-Kuril population are investigated and interpreted by some climatic and oceanographic factors and fishery activity, as well. The South Kuril region is one of the few ones where rather large catch of walleye pollock is carried out till nowadays, meanwhile the stocks of this species reduced in other regions. The general decreasing of the pollock stock in the North Pacific is supposed to be reasoned by natural factors, not by a fishery. In the South Kuril region, rather dense congestions of prespawning pollock were observed in the Kunashir Strait and adjacent area, and congestions of immatures concentrated on the Pacific shelf of Iturup Island, as a rule. At the Okhotsk Sea side of Iturup Island, rarefied congestions were observed of the pollock of both large and small size. General features of the spatial distribution of the pollock were almost the same in any year of investigation, from 1998 to 2001. However, the square of congestions, their density and total biomass have decreased within each winter. Moreover, gradual reduction of body length of the pollock in the congestions of the Kunashir Strait was observed during a prespawning period, because of earlier spawning of large-size individuals. The share of spawning fish usually grew until late December early January. The share of males ready to spawning was higher annually than the share of females, and both shares were not high, comparing to the whole population. The ratio of sexes in the prespawning congestions in the Kunashir Strait was annually close to 1: 1. So, the period before the peak of spawning in early January isn't significant for the reproduction of the walley pollock in the Kunashir Strait. Trawl fishery on prespawning congestions of walleye pollock has negative effect for the process of spawning. The acting restriction of allowable volume of catch in December is not effective measure for protection of the pollock population because of this month is not a time of mass spawning. Moreover, the restriction of the number of trawling vessels will be more effective than the restriction of the catch value. There is recommended to limit the fishing fleet operating on the prespawning congestions of the pollock in the Kunashir Strait by 4 large-tonnage vessels.