THEY are reputed to be some of the smartest animals in the oceans, and now scientists have found proof that porpoises are mostly managing to avoid turbines generating renewable electricity off the coast of Scotland.

The Sea Mammal Research Unit at the Scottish Oceans Institute at St Andrews University with backing from the Scottish Government observed harbour porpoises around a turbine in the Pentland Firth.

Large animals such as marine mammals are considered to be vulnerable to the risks of collisions with turbines and their support structures.

The most important finding was that porpoises were “clearly able to detect the presence of the turbine and its support structure and, although there is evidence of some attraction to the turbine support structure, they generally avoided the high-risk rotor region”.

Using the porpoises’ own echolocation system – audible ‘clicks’ – scientists were able to log each movement close to the turbine. Only one of 340 near approaches by porpoises put the mammal close to the turbine’s rotors.

The research report stated: “From the perspective of potential impacts of the tidal energy industry on marine mammals, these results are extremely important.

“Tidal turbines have the potential to cause injury or mortality to marine mammals through direct contact with moving turbine parts. However, such impacts would be effectively reduced if animals exhibited appropriate avoidance responses to the turbines.

“Responses to the tidal turbine occur at two different scales: a separate study showed that there is a significant reduction in porpoise presence within 140 m of the turbine when it is operating.

“The current study shows that those individuals that do still come close respond to the turbine and directly evade the turbine rotors. This means that the risk of collisions between porpoises and the rotors of the tidal turbine in the current study is likely to be extremely low compared to if the animals were not responding to the turbine.”

The scientists sounded a warning, however: “Porpoises were clearly able to detect the presence of the turbine and its support structure and, although there is evidence of some attraction to the turbine support structure, they generally avoided the high-risk rotor region. This information is critical in understanding the environmental effects of these novel, and potentially dangerous, anthropogenic structures.

“As the tidal energy industry looks to expand, it will also become increasingly important to consider the potential effects of arrays of tens or hundreds of turbines on a range of different wildlife species.”