The Structure and Diversity of Fish Communities from Predeltaic Danube Area

The paper is presenting some aspects regarding the structure of fish communities from 22 Km of predeltaic sector of Danube River, between themouth of Siret River (km 155) and Prut River (Mm 72.5). The aim of the study isto assess the ecological status of the area, using some analytical and synthetic ecological indices, but also diversity and equitability indices. From March to December 2010, in four fishing areas (km 150-151, Mm 77-78, Mm 76-77,Mm 74-74.5), 14692 fish of 29 species, from 6 families and 6 orders, were collected. The best represented family is Cyprinidae with 16 species. Thenumerical abundance ranged between 1 fish/species (zingel, Danube streber and schraetzer - rare species) and 7019 fish/species (pontic shad - abundant specie). The Ponticshad (47.77%) and Azov shad (11.20%) are eudominant species, having the biggestpotential in fish productivity; common bream (9.15%) and common carp (7.36%) are dominant species.