HYDROECOLOGICAL CONDITION OF THE AGRAKHAN BAY AND POSSIBILITIES FOR ITS IMPROVEMENT
UDC 556.545, 574.5, 639.2/3
Magritsky D.V., Goncharov A.V., Moreido V.M., Samokhin M.A., Abdusamadov A.S., Kuptsov S.V., Dzhamirzoev G.S., Erina O.N., Sokolov D.I., Arkhipkin V.S., Tereshina M.A., Surkov V.V., Semenova A.A. Hydroecological Condition of the Agrakhan Bay and Possibilities for Its Improvement // Arid Ecosystems. 2022. Vol. 28. № 4 (93). P. 163-178. | PDF
In the XX century, as a result of a combination of natural and anthropogenic factors, there was a significant transformation of the Agrakhan Bay on the eastern coast of the Terek Delta. The comprehensive studies carried out in 2018-2020 made it possible to identify the main causes of this degradation, characterize the current state of the reservoir and scientifically substantiate recommendations for its improvement. It is shown that as a result of shallowing and reduction of the area of the water mirror, the bay has lost its former significance as a spawning and growing reservoir that provides the Western Caspian region with young valuable commercial fish species. Catches by 2018 fell by 10 times compared to the beginning of the XX century; sturgeon, which used to be famous for the Agrakhan Bay, practically disappeared. Especially unfavorable is the state of the northern part of the bay, which has turned into a group of shallow reservoirs, little connected with each other and with the sea. And the situation continues to deteriorate every year.
The study of hydrological-morphological, hydrobiological, fishery, hydrochemical parameters showed that there is hope for improving the condition of wetlands on the site of the former bay. A detailed analysis of the water balance using multivariate limnological calculations showed that there is sufficient water for flooding and partial restoration of water bodies of the hydrographic system of the Agrakhan Bay. Clearing silted and overgrown channels, deepening and collapsing of preserved reservoirs, directing the necessary volumes of river water to the Northern and Southern Agrakhan (in accordance with the calculated supply schedule), will reduce overgrowth and siltation of water bodies, restore water exchange between them, improve water quality, revive the fisheries of the region, improve the habitat conditions of many rare and protected animal species, increase the recreational attractiveness of the region.
Keywords: Agrakhan Bay, Caspian Sea, fisheries, degradation of the bay, water quality, ecological condition, ecological rehabilitation, spawning-growing reservoirs, rare species, hydrological modeling.
Financing. The collection and analysis of materials was carried out under a state contract with the West Caspian STB No. NIR-18-01. The preparation of the article was carried out within the framework of the research of the Department of Land Hydrology of the Geographical Faculty of Lomonosov Moscow State University, carried out within the framework of the state task (CITIS number: 121051400038-1).