Environmental DNA (eDNA) for Monitoring Fish at Marine Energy Project Sites

Environmental DNA (eDNA) is the collection of genetic material shed by organisms in their environment, which enables species detection without direct observation or physical capture. eDNA provides a versatile and cost-effective method for identifying target species across different environments and conducting broad biodiversity assessments. This approach is particularly relevant for monitoring some environmental effects of marine energy devices, such as tidal turbines and wave energy converters, which may pose a risk to marine animals and habitats already under stress from global changes and human activities at sea. Key risks to fish species include collision with turbine blades, habitat alteration, and displacement of individuals or populations from natural habitats. 

Uncertainties around these effects on fish species have caused marine energy project delays and costly monitoring campaigns to collect sufficient data to assess potential risks during regulatory processes and permitting. Licenses granted to tidal and riverine energy sites in the United States have often required extensive data collection on fish diversity and habitat use, especially for species listed in the Endangered Species Act, which may be challenging depending on site conditions and species abundance, behavior, and life histories. eDNA is an efficient monitoring method that is complementary to the commonly used approaches (e.g., optical and acoustic imagery, trawl surveys). eDNA offers a timely solution to overcome challenges and provide reliable field data to assess risks, reduce permitting delays, and facilitate the sustainable development of marine energy projects.