Acoustic Detection of Marine Fish and Mammals in the Vinicity of Tidal Turbines

The evolving science of acoustic ecology is clarifying the importance of sound in the life function of aquatic animals in general and fish and marine mammals in particular.  Almost all permitted construction and industrial activities in aquatic environments must comply with noise exposure criteria.  The physics of underwater sound propagation combined with the frequently dynamic behavior of aquatic animals in a noise impacted region complicate noise exposure modeling and estimation.  Animal response data is limited and sensitivity differences between species prevent generalization across all exposed species. Strategies for achieving operational compliance in multi-species situations are considered.

Assessment of the risk of injury or mortality requires evaluation of exposure and application of stimulus-response models.  In aquatic environments, for most species of interest from marine mammals to juvenile fish, exposure evaluation is very difficult and stimulus-response models are not available.  A “virtual take” approach for endangered salmon that was used to achieve operational compliance for a channel deepening project that involved removal of a large amount of basalt by blasting is presented.