The great cormorant (Phalacrocorax carbo) in the middle course of the Nistru River. This species was first observed in this part of the river between Naslavcea and Holoşniţa villages in 1998 by members of the Zoological Institute’s Ornithological and Herpetological Society. Since then, the number of birds steadily increased to reach 500 in the year of 2005. As the previous investigators consider, this phenomenon was caused by considerable ecological changes which started in 1986 when the Novodnestrovsk Hydropower Station was build and the part of the river course between two dams– at Novodnestrovsk and at Dubăsari - became a reservoir. As a result, the species composition of fish is changing and a lot of small young fish appeared. This assured good feeding conditions for fish-eating birds, including the great cormorant.