Abstract
This study aimed to investigate the fish fauna in the downstream sector of the Zarineh River, Urmia Lake basin. Seven stations were sampled along the Zarineh River before and after Shahin-Dezh City to help gain a better understanding of human activities on its fish fauna. The results revealed 11 fish species, which belong to three families, including Cyprinidae, Nemacheilidae and Gobiidae. Nine of them were Cyprinidae. Out of 11 species, five species, Carassius gibelio, Rhodeus amarus, Pseudorasbora parva, Hemiculter leucisculus and Rhinogobius lindbergii were exotic that were unintentionally introduced to the Zarineh River along with Asian carps. The threats to fish fauna are categorized into two categories: natural and anthropogenic. According to the observations, anthropogenic activities such as overfishing, pollutions, sand and gravel extraction, dam construction and introduction of exotic fish species were among the main threats for the ichthyofauna of the Zarineh River.