АНАЛИЗ СТРУКТУРЫ ПРОМЫСЛА И ДИНАМИКИ РОСТА СТАДА СЕВЕРНОГО МОРСКОГО КОТИКА (CALLORHINUS URSINUS) ОСТРОВА ТЮЛЕНИЙ В ПЕРИОД ЭКСПЛУАТАЦИИ И ПОСЛЕ ЕЁ ЗАВЕРШЕНИЯ

Abstract

Based on a long time series providing biological monitoring data of the Northern fur seal population on Tyuleny Island and detailed information on the harvesting characteristics of this population, we have analyzed trends in its growth. The research results of changes in the average reproductive success of bulls and the age structure of Northern fur seal males on Tyuleny Island are presented as indicators of harvesting impact on the reproductive potential of the population. Evidence has shown that selective harvesting was practiced, where most productive bulls were removed from the population. This led to a significant change in the age structure of the population and a significant reduction in the population growth. Despite a slight increase in the natural survival of almost all age groups, the population growth slowed down sharply. The proximity of the growth potential indicator to the critical unitary value revealed in recent years leads to a bleak forecast. Further growth in the Northern fur seal population, if any, will not be rapid. To accelerate it, it is necessary to provide a new natural restructuring of the population structure, improving its qualitative composition and increasing the proportion of males with high reproductive success.