MODELING THE DYNAMICS OF THE ECOLOGICAL NICHE OF STARRED STURGEON (<i>ACIPENSER STELLATUS</i> PALLAS, 1771) IN THE NORTHERN PART OF THE CASPIAN SEA BASED ON SUMMER LONG-TERM MONITORING DATA (1992-2006)

Abstract

Models of ecological niches of stellate sturgeon ( Acipenser stellatus Pallas, 1771) in the northern part of the Caspian Sea based on long-term monitoring data (1992-2006) are presented. The analysis of the results of the study of the long-term patterns of the spatial distribution of alien species of polychaete Hediste diversicolor , mollusc Abra ovata and crustaceans are reported. Estimates of the effect of abiotic and biotic factors on the formation of ecological niches of the stellate sturgeon in the eastern and western regions of the northern part of the Caspian Sea are presented. Graphical schemes of the spatial distribution of stellate sturgeon in different years of monitoring in the plane of two main components (PCA) are given. It is shown that the salinity of water and the density of crustaceans are the leading factors for constructing models of ecological niches.