Identification of bentic organisms in the Kizilirmak river using enviromental DNA analysis

In recent years, it is considered that the studies conducted with the eDNA method in biodiversity researches are increasing. It is found that environmental DNA (eDNA) based metabarcoding approaches are appropriate for benthic macrobenthic communities. Benthic macroinvertebrate are preferred biological elements in biological monitoring studies in rivers and lakes due to their responses to environmental variables and bioindicator properties. In this study, both the morphological method and eDNA from water method were used to determine biodiversity for this reason, 4 stations and eDNA analysis was performed from a total of 8 samples, were selected from the part of the Kızılırmak river within the borders of Nevşehir province. For morphological method, samples were taken by hand net (10-minute kick) collection has taken place water samples were taken as bottom water for eDNA. DNA samples from the water were obtained by centrifugation and subsequent isolation. V3 – V4 regions were used as 18S rRNA gene region for metabarcoding. In addition, the eDNA method was applied to the sample water from the containers stored in ethyl alcohol of the benthic samples taken for the morphological method Number of taxa; It was found to be higher in eDNA analysis (16) than in morphological sampling (11). In addition, there are differences between the sample groundwater and the water sample in terms of the determined groups. As a result of the analysis carried out for the sample groundwater, a total of 13 taxa were found. When the eDNA results from the water are compared, the order of the stations is 3=2>1>4. There are individuals who could not be assigned from Arthropoda, Insecta and Annelida groups based on the individual numbers of macrobenthic organisms in the river. Among the samples taken from the stations, Odonata, Hemiptera and Spongilla groups were not observed in the morphological and bottom water analysis, but were detected in the sample groundwater analysis. In physicochemical analyzes, low oxygen level (2.99 mg/l) was measured at Gülşehir station. As a result of the study, it is seen that the pollution level in the river is considerably higher. The study showed that the eDNA analysis method can be used in the monitoring of benthic organisms, which are an important biodiversity element.