PNNL

Abstract

Many fish species are threatened worldwide by overfishing, contamination, coastal development and other anthropogenic activities as well as the impacts of climate change. Marine renewable energy (MRE) is under development as a sustainable alternative to carbon-based energy sources. However, regulators and stakeholders often worry that MRE devices will add another threat to fish populations under pressure. This paper presents a review of the current knowledge of potential effects on fishes from MRE development. These may include: collision with devices that may lead to injury or death; underwater noise generated by MRE devices that may affect fish behavior and health; electromagnetic fields from power cables and other electrical infrastructure that may lead to attraction or avoidance of certain sensitive species of fish; changes to critical fish habitat, including nursery, feeding and spawning grounds; and displacement of fish populations or communities around arrays of multiple MRE devices. Field- and laboratory-based studies that have examined fish presence, avoidance, and evasion around MRE devices suggest that collisions are rare. Progress is being made on modeling tools to estimate fish encounter rates with MRE devices, the consequences of collisions, and population-level ecological risks. Similarly, studies exposing fishes to turbine-generated noise and electromagnetic fields demonstrate little effect on fish behavior, with MRE device noise falling below reported hearing thresholds. Inquiries into effects of MRE devices on fish is in its infancy and future research is needed to ensure the health of fish populations while also facilitating the continued development of sustainable energy sources.