The aim of the work is to determine the criteria of the marine shallow-water ecosystem stability using the Northern region of the Caspian Sea as a case study. For each 260 reference points, we received data on 76 parameters, including physical-geographical, hydrochemical, and hydrobiological characteristics that have been analyzed by the method of principle components. The analyzes of these data allowed us to reveal and evaluate principal geoecological factors that influence the distribution of

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... Acipenseridae in the Caspian Sea as a top level of the ecosystem's trophic chain. The main geoecological factors and the factor of anthropogenic load of the Caspian Sea ecosystems' stability have been determined. KEY WORDS: The North Caspian Sea, criteria of the aquatic ecosystem stability, subaquatic natural complex, anthropogenic load, landscape forming factors, factor analyses, sturgeon population.