Effects of water quality on the species richness and population distribution of waterbirds in Ahlat marshes, Turkey

This study aims to evaluate the effect of water quality on species richness and population distribution of waterbirds in the Ahlat Marshes. Water quality values of temperature, pH level, dissolved oxygen total dissolved solids, salinity, and conductivity were measured. The waterbird species richness was assessed using the Shannon-Wiener and Simpson indices. The results of the prediction model in the Generalized Linear Model showed water temperature to be an important environmental variable to explain the richness of waterbird species. However, a meaningful relationship was not identified to support the relationship between the richness of the waterbird species and other water quality variables. In addition, the Multiple Linear Regression model determined that pH level together with water temperature has a positive effect on the waterbird species in the Ahlat Marshes. The marshes exhibit “low variety” according to the Shannon-Wiener Diversity Index, with the highest value at observation point A6 surrounded by protected dense marshland. At the same observation point, we also found “highest dominance” based on the Simpson Index. During the study, it was recorded 1128 individuals belonging to 15 resident species were identified. The Rallidae waterbird family represented the highest species composition (41.5%). Water temperature, pH level, and DO parameters between the independent variables affected the waterbird abundance by 20%.