Assessment of the sanitary and microbiological state of the habitating environment of water biological resources in the northern part of the Caspian sea

Abstract

Both the habitat of aquatic biological resources and almost all ecological and trophic groups of biocenoses are subject to the negative impact of anthropogenic activities in the coastal zone and in the Caspian Sea. Anthropogenic eutrophication caused by domestic and industrial wastewater, fertilizers, disrupts the balance in the structure of biocenoses. Toxic technogenic emissions lead to changes in the state of natural aquatic ecosystems. In order to maintain balance in the face of anthropogenic changes, it is necessary to assess the state of these ecosystems. Оne of the indicators in assessing the quality of the habitat of aquatic biological resources is the sanitary condition of the reservoirs of the Volga-Caspian region. The sanitary and bacteriological state of the northern part of the Caspian Sea was studied as a fishery reservoir and habitat for aquatic biological resources. Based on the results obtained, the degree of pollution of the reservoir and the anthropogenic impact on the studied reservoir. In 2021 seasonal changes in the number of saprotrophic and oligotrophic bacteria in sea water and soil were noted in the waters of the Northern Caspian. In summer, water quality was classified as “clean” water (category 1), while in autumn it deteriorated and was assessed as “polluted” water (category 2). High values of the coli index and the presence of lactose-positive E. coli testified to the presence of household, including fecal, pollution in the coastal zone of the Northern Caspian Sea. At the same time, conditionally pathogenic bacteria (aeromonads, pseudomonads) were not isolated in the studied water samples. The obtained microbiological data indicate a slight anthropogenic impact on the study area.