The impact of herbivorous fish introduction on the formation of fish communities in water bodies (based on the Khauzkhan Reservoir, Turkmenistan)

Abstract

The dynamics of the structure of fish species complex in the community of the Khauzkhan Reservoir (Turkmenistan) has been analyzed from the time when it was filled in 1966 to 1990. In order to quantify the observed changes in the fish population, the indices of diversity and dominance and the dynamic phase portrait method have been used and the structural changes have been visualized. Changes in the dominant complex of species and the dynamics of the relative abundance in the catches of fish groups belonging to different faunal complexes and ecological groups have been also considered. A relation between the changes in the structure of fish species complex in the community under study and the changes in the ecosystem of the reservoir has been found. It has been shown that the introduction of herbivorous fish from the first years of the reservoir filling has resulted in a new stage in the formation of its ichthyofauna, which is known as the stage of acclimatization, and in the extension of the formation process. Currently, the fish population of the Khauzkhan Reservoir is at the 4th stage of formation – the stage of an increase in the anthropogenic impact.

Keywords

• fish population
• introduced species
• herbivorous fish
• stages of ichthyofauna formation
• khauzkhan reservoir