DOZENS of underwater listening devices are set to be installed in the Moray Firth to monitor the effect that offshore wind-farm developments may have on dolphins.
A two-turbine demonstration wind development already operates in the firth and other projects are planned in the area as the growing renewables sector takes off.
The waters are home to Scotland's only resident population of bottlenose dolphins, as well as seals, porpoises and whales.
A team of Aberdeen University biologists, based at Cromarty lighthouse, has applied to the Scottish Government for a licence to launch the monitoring project from July.
The team wants to put 76 acoustic monitoring devices into the water – some as far as 70 miles out to sea – to find out if wind-farm construction and boat traffic disturb the dolphins, as well as other cetaceans.
The work builds on research carried out last year on a smaller scale and closer to the shore.
The 18in-long acoustic devices can detect porpoises, dolphins and whales from the echo- location clicks they make to determine the location and shape of nearby items.
The listening devices record for up to six months at a time, making it possible to investigate whether the cetaceans avoided areas where boat traffic was particularly busy or wind farms were being built.
Dr Paul Thompson, the base's director, said: "This is the most extensive deployment we have done and it will be further offshore. It will help us get a better understanding of the distribution of particular species.
"We will be looking at the impact primarily of oil and gas exploration, but also the development of wind farms. During construction phase of these developments, it can be quite noisy and affect marine mammals.
"It will allow us to get a better understanding of how they use different parts of the Moray Firth and to understand what parts are most important to porpoises, as opposed to dolphins."
The Aberdeen University team is involved in long-term studies to assess the response of marine wildlife to environmental change and to understand how natural and man-made changes can affect the creatures. Their research is used to help support policies, conservation action and sustainable management of the area.
The 130-strong resident population of endangered bottlenose dolphins is one of only two in the UK, and their presence attracts thousands of wildlife tourists each year.
Ten years ago, it was estimated that the population could die out within 50 years if nothing was done to protect them.
Numerous other human influences, including dolphin-watching trips, fishing, sewage outfalls, agriculture and the use of power boats and jet-skis on the firth, have been cited in the past as possible threats.
A code of conduct has been introduced in recent years to ease pressure on the animals from firth users.