The OES-Environmental 2020 State of the Science Report: Environmental Effects of Marine Renewable Energy Development Around the World builds on and serves as an update and a complement to the 2013 Final Report for Phase 1 of OES-Environmental and the 2016 State of the Science Report. Its content reflects the most current and pertinent published information about interactions of marine renewable energy (MRE) devices and associated infrastructure with the animals and habitats that make up the marine environment. It has been developed and reviewed by over 60 international experts and scientists from around the world as part of an ongoing effort supported by the OES collaboration that operates within the International Technology Cooperation Framework of the International Energy Agency (IEA).
The 2020 State of the Science Report consists of 14 chapters which can be downloaded as a whole or individually. Download Chapter 4: Risk to Marine Animals from Underwater Noise Generated by Marine Renewable Energy Devices here. Download the Chapter 4 Supplementary Material here.
Marine animals use sound in the ocean like terrestrial animals and humans use sight on land—to communicate, navigate, find food, socialize, and evade predators. Anthropogenic noise in the marine environment has the potential to interfere with these activities. At high levels, underwater sound can cause physical harm. The amplitude, frequency, directionality, and propagation losses of the noise source, as well as prevailing ambient noise, must be taken into account when considering the risks to marine animals. Also of importance are the animals’ hearing thresholds and their behavioral responses to the noise source.
Progress on quantifying the direct and indirect effects of underwater noise on marine animals has been complicated by the relatively small number of MRE devices that have been deployed. Confounding factors include difficulties associated with accurately measuring noise from MRE devices and the challenge of understanding how underwater noise affects the behavior of marine animals. However, international technical specifications have been developed that present a standardized approach for measuring noise from MRE devices. More significantly, the underwater noise emitted by several MRE devices has been characterized in the field and found to fall below regulatory action levels and guidance developed in the United States for protecting marine mammals and fish from harm due to underwater noise. A few studies have made progress toward establishing links between MRE device noise and animals’ behavioral responses. A significant challenge remains in differentiating between MRE device noise and ambient noise.
Evidence suggests that underwater noise emitted from operational MRE devices is unlikely to significantly alter behavior or cause physical harm to marine animals. Therefore, the risk to marine animals from underwater noise generated by MRE devices can potentially be considered to not be significant for small numbers of devices.
The Short Science Summary for the chapter is available here.