Preliminary Study of the Relationship Between Caddisfly Larvae and Environmental Variables in Şimşir Stream (Karabük, TURKEY)

Şimşir Stream is located in Yenice Forest, which has been selected as one of the 100 forest hotspots with high biodiversity and needs urgent protection, and the study area includes two protection zones. Determining the current situation in an area that has not yet been exposed to human influence helps to monitor the response of the rivers in cases that may arise later, such as climate change, pollution, land use, and morphological degradation. Trichoptera are one of the most important groups of macroinvertebrates used to assess such disturbances in streams. Trichoptera larvae were collected from 8 stations along the Şimşir Stream during 2019 and 2020 seasonally by kick-sampling. During this investigation, 17 genera belonging to 15 families were identified. Environmental variables were recorded to determine the relationship with larvae. Most of the stations, except the station located on the tributary, showed positive correlations with water velocity, dissolved oxygen, pH, electrical conductivity, and stream width. It was found that the rate of the boulder in the substrate was one of the most important variables affecting the distribution of larvae. The only station that was sampled in the tributary of the stream had different taxa from other stations, and this showed the contribution of the tributary to the fauna.