Influence of Anthropogenic Factor on Freshwater Fish Population and Human Health in Yakutia

Abstract

This article discusses the problems of three environmental disasters as a result of mass overfishing of valuable commercial fish, mass influx of people, aerotechnogenic emissions, negative discharge of industrial and agricultural effluents to the main spawning and feeding areas of large freshwater sections of river systems: Lena, Yana, Indigirka and Kolyma. There has been a sharp decline in the number and biological diversity of fish including valuable commercial fish such as Siberian sturgeon as taimen, nelma, muksun, chir, peled, Siberian vendace, etc. Their inhibitory effect on the functional systems of the body is accompanied by a change in the basic biological parameters of fish, a decrease in numbers, a decrease in the proportion of older age groups and the replacement of valuable long-cycle stenobiont species with low-value short-cycle eurybionts. The reasons for the annual spawning of fish may be delays in oogenesis or atresia of eggs depending on the nature of the disturbance of the normal reproductive cycle, fish population density, availability of males, contamination of spawning grounds, impairment of vitellogenesis and reconstruction of all oocytes of vitellogenesis onset under unfavorable temperature conditions and insufficient nutrition. Morphopathological analysis of whitefish has revealed the following anomalies in the structure and condition of organs: weak pigmentation of the body, shortening of the jaws, weak turgor of the muscles, curvature and an uneven number of rays in the fins, curvature of the spine, curvature and bifurcation of gill stamens, mucus galling, pale liver discoloration, not gonads, swelling of the kidneys, the presence of parasites in more than two organs, obesity of the heart. The Index of Dysfunctional State (ANN) varied from 0 to 8, an average of 2.02. Despite the rather high occurrence of anomalies in fish, the results of morphopathological analysis make it possible to attribute the studied watercourses to the zone of relative ecological well-being. Thus, taking into account the leading role of whitefish in the creation of ichthyomass in northern ecosystems and taking into account two main forms of their economic use (fishing and commercial cultivation), we can give a general assessment of the potential opportunities for whitefish and outline promising ways of maintaining whitefish.