Flora of the Reserve is represented by 310 species of vascular plants, including 10 species of trees, 11 of shrubs, 5 of lianas, and 284 species of grass plants. Among vulnerable and endangered plants listed in the Red Book of the Republic of Moldova there are 5 species: White water-lily, Floating fern, Water caltrop, Marsh fern, Wild grape.

According to research done by zoologists, the fauna of terrestrial vertebrate animals consists of 248 species, including 40 species of mammals or 54.8% of the number of species of mammals from the Republic, 192 species of birds (67%), 7 species of reptiles (50%) and 9 species of amphibians (69.2% of the total number of amphibians from the Republic). The birds included in the Red Book of the Republic of Moldova: Pygmy Cormorant, Great Egret, Squacco Heron, Common Spoonbill, Great White Pelican, Mute Swan, Glossy Ibis, etc. In the Reserve area are met rare species of mammals like Otter, Wild cat, Weasel, European mink, Wild boar etc.

It is important to mention the remarkable significance of the Reserve for stop-over, feeding, reproduction and overwintering of a large number of aquatic and semi-aquatic birds and for the refuge of rare and protected national and international species.

The aquatic fauna is characterized with over 30 species of fish. There are rare species as Common bream, Pond perch, Sterlet, Pumpkinseed sunfish, Burbot, European mudminnow. Lake Beleu, besides the fact that offers favourable conditions for many species of terrestrial vertebrate animals, serves as a breeding place for various species of fish arriving from the rivers Danube and Prut.

On 20 June 2000, Natural Reserve "Lower Prut" was included as a component part of the Ramsar site 1029 (WI Site 3MD001).