Effect of an energy turbine on fish eDNA as indicator for species composition

The effect of energy turbines on the species composition of the fish community in the nearby environment of the turbine was tested using environmental (eDNA). Both turbines in the Marsdiep (Wadden Sea) and Lake IJssel were included. The turbines are expected to influence the behaviour of fish by either disturbance due to sounds or physical damage due to contact with the turbine.Water samples for eDNA were taken close to the installations and analysed for fish community composition. For the Marsdiep turbine, samples were taken during turbine operations in summer 2015 and winter 2016 and in the same period in the consecutive year. Lake IJssel samples were taken during autumn 2017. DNA was extracted from the water samples and 12S fish eDNA was amplified. Community composition was inferred from sequences generated by Illumina sequencing.For the Wadden Sea samples, species composition during the operation and the year after significantly differed, however, normal year-to-year variation could not be excluded. Although year-to-year variations could not be excluded, the turbine effect seems to be more strong on pelagic species, for which prey species avoid the turbine and predator species are more attracted by the turbine. The water samples taken at Lake IJssel showed no significant differences at samples taken nearby the discharge turbine and reference samples