Sea Mammal Research Unit of the University of St Andrews, in collaboration with SMRU Consulting, has published the results of a Scottish Government-funded study that developed and tested new technology for the detection and measurement of marine mammal behaviour around tidal turbines.
The technology has been developed and tested for the fine scale underwater movements of marine mammals in the vicinity of marine tidal energy devices.
The Scottish Government has set targets for renewable energy, a portion of which is expected to come from tidal energy. However, current uncertainty about the potential effects that tidal turbines have on seals, dolphins and porpoises remains a key issue, SMRU explained.
The project has developed monitoring systems which are capable of the detection and tracking of seals, porpoises and dolphins underwater in three dimensions. This will help to understand the behaviour of animals in close proximity to tidal turbines and their potential to avoid collisions with these structures.
Underwater microphone systems, which pick up the natural sounds that animals make, have been developed which will allow the clicks and whistles of harbour porpoises and dolphins to be detected and tracked in 3D from a seabed mounted platform.
However, these listening systems will not detect species that are silent or make sounds only infrequently (e.g. seals, whales, basking sharks). Underwater sonar systems can image marine mammals and provide a basis for detection and tracking of seals, whales and basking sharks. In this project, a novel sonar technique that allows tracking of marine mammals in 3D was developed and tested, and software was developed to automatically identify marine mammals in sonar images to distinguish them from other things such as fish or marine debris.
The project was funded as part of the Scottish Government’s demonstration strategy which is a strategic research programme addressing the various issues and challenges of developing offshore and marine renewables. The demonstration strategy is a component of the Marine Scotland Survey, Deploy and Monitor approach to reducing the environmental uncertainty in the consenting of renewable energy developments in Scottish waters.
Information on priority environmental interactions, such as those with marine mammals, will be obtained and used to inform the consenting of future developments.
The next phase of this project will see the technology as part of this project deployed at Phase 1a of MeyGen’s Inner Sound project in the Pentland Firth later this year. This will provide a tailored monitoring system for understanding the behaviour of marine mammals around operating tidal turbines and will enable data to be collected that will refine estimates of collision risk, according to SMRU.