Investigation of the effects of some environmental variables on the zoobenthic community structure: The case of Porsuk Stream (Sakarya River, Türkiye)

In order to examine the effects of some physicochemical parameters on the zoobenthic community structure in Porsuk Stream, seasonal zoobenthic samples were collected from 6 stations between 2020-2021, and some physicochemical parameters were also measured. Within the scope of the study, a total of 30 families, 4 from the Gastropoda, 1 from the Bivalvia, 3 from the Clitellata, and 22 from the Insecta, were identified. Families Tubificidae, Erpobdellidae, and Chironomidae were identified at each station. Dominant groups in Porsuk Stream zoobenthos; Tubificidae (41.90 %), Chironomidae (16.68 %), Gammaridae (7.84), Valvatidae (6.16 %), Naididae (5.30 %), Asellidae (3.73 %), Physidae (% 3.48 %), Dreissenidae (3.16 %), Baetidae (3.07 %), Simuliidae (1.70 %), Erpobdellidae (1.69%) and Lymnaeidae (1.32 %), respectively. The highest dissolved oxygen value was measured in the Sobran Stream with an average of 11.3 mg/L. Detection of Caenidae from Ephemeroptera and Hydropsychidae from Trichoptera with low tolerance to pollution and results of the Canonical Correspondence Analysis in this station shows that dissolved oxygen concentration is effective on the distribution of taxa determined in the basin. At the same time, this station has the highest BMWP (64) and Shannon (2.22) values.