Habitat assessment of Kura barbell (Barbus cyri) in Klarood River, Mazandaran Province, Southern Caspian Sea Basin

Abstract

Introduction: Due to the importance and necessity of the inland fish fauna in Iran, this research focused on assessing the habitats of indicator fish species in the Klarood River, one of the main tributaries of the Babolrood River in Mazandaran, during the autumn of 2021. The highly variable physicochemical, hydrological, and geomorphological conditions, along with the dynamic nature of the river, created diverse habitats for fish and other aquatic organisms. Furthermore, this research emphasizes the importance of habitat studies for understanding and managing water resources. An accurate understanding of the environment and habitat conditions can aid in the restoration and preservation of river ecosystems. The studies in this text focus on the significance of habitat suitability models for predicting the distribution and abundance of species in habitats.
Materials and Methods: In this study, first, after literature review and the field survey of Babolrood river basin, a representative site in a tributary of Babolrood river which is named Klarood with the lowest human pressures and the highest habitat diversity was determined. Then, at the defined site, based on the REFORM protocol, some transects were selected at specific intervals based on expert judgment, and then in each transect, environmental parameters such as flow velocity, depth, biotic and abiotic substrates were measured. After this stage, sampling of fish was done by electro-shocker device in about 150 points randomly and zigzagging. Moreover, at each fishing point, the above-mentioned environmental parameters were measured again and then habitat suitability curves and index were calculated.
Results: The results showed that the species prefers flow velocity of 0-30 (cm) and 30-90 (cm) depth. Also, among the available biotic and abiotic substrates, species prefer "Xylal", "FPOM" and "Mesolithal" substrates respectively. Also, the habitat suitability index of this species was estimated e 0.71.
Conclusion: The results of this study can be used as a guide for management and restoration of species as well as river ecosystems for this catchment.