The structure of fish communities in Bistrita River, upstream the confluence with Siret River (Romania)

Abstract

The researches were carried out in 2020 on the main course of Bistrița River, upstream the confluence with Siret River. The biological material was sampled in 10 sampling sites placed on the main course of Bistrița River. Seventeen fish species were identified, one of them being a non-native one: Pseudorasbora parva. We found that the chub and the Prussian carp are characteristic species. Species diversity is quite high, being identified even 12 fish species in some of the sampling sites. There is an unequal distribution of individuals by species. The main threats in the research area are the organic inputs and the increase of turbidity. However, there are no great imbalances, and there is a good capacity for self-support of aquatic communities.