Разнообразие рыб в техногенных водных объектах горных территорий бассейна Амура

Abstract

Human impact on the population and diversity of fish in the mountainous regions of the Amur River basin has been increasing due to mining, deforestation, construction, and the development of hydroelectric power stations and reservoirs. Hundreds of man-made water bodies are located here, with hardly any research conducted on fish diversity in them. Meanwhile, the ichthyofauna of mountainous areas, in comparison with the flatland fauna, is less resistant to adverse influences. The taxonomic and coenotic diversity of fish was studied at 15 locations in 37 technogenic water bodies (18 settling ponds, three ponds, eight flooded quarries, five diverted or otherwise severely altered major watercourses, as well as in a drainage ditch of a minor tributary, a reservoir, and tailings) in the valleys of mountain and foothill tributaries of the Amur. In addition, natural streams and one lake were examined at each location; over 270 fish specimens of 21 species were collected. The taxonomic diversity of fish in technogenic water bodies includes 21 species from 17 genera, nine families and six orders. The order of Cypriniformes is represented by 12 species, Salmoniformes – by 5; the rest are represented by one species each. All species have been found in quarries and ponds; Lagovskiy minnow Rhynchocypris lagowskii (found at 11 sites) and lake minnow Phoxinus (Eupallasella) percnurus (9), siberian stone loach Barbatula toni (11) and Amur spleeper Perccottus glenii (6) are most common. Loach mainly lives here temporarily, other species inhabit these water bodies permanently; they have been breeding here, their populations increasing in numbers. Some reservoirs with a high level of water exchange provide a temporary habitat for typical river species, i.e. grayling, lenok, taimen, and Amur sculpin. The coenotic diversity of man-made reservoirs in terms of its species composition is close to the ichthyocenoses of the lakes in the lower parts of the valleys. As for artificial watercourses, 11 species were found there; most are present there temporarily. The composition of fish communities in watercourses is represented by depleted patterns of river ichthyocenoses. The number of species and their composition in technogenic water bodies depends on the geographic location of the site, the diversity of natural water bodies at the location–primarily, the presence or absence of lakes, the extent and pattern of watercourse alterations, and specific characteristics of the man-made water ponds and watercourses. Most species spread to the technogenic water bodies from local rivers, some–from lakes located nearby, while others were likely to be carried over by human hand and birds.