PLANS to build Scotland's largest offshore wind farm near the island of Tiree may be thwarted by fears it could jeopardise the survival of the area's basking sharks.

The £7 billion scheme is proposed for an area west of Tiree in waters that are a vital mating ground for the creatures.

Now campaign group No Tiree Array wants the seas around the 30 square mile island to be designated a marine nature reserve for the species to prevent Scottish Power Renewables building between 180 to 300 offshore turbines of up to 656ft high on the site.

The so-called Argyll Array is on hold for 18 months so more information can be gained on its probable impact on wildlife.

The islanders' case has the backing of Scottish Natural Heritage.

Dr Suzanne Henderson, who is leading SNH's basking shark tagging project, said: "Not only do these areas have the highest populations but also courtship-like behaviour such as breaching the water, parallel swimming or nose-to-tail swimming takes place. This is the first time we have seen the sharks jump out of the water. It seems to only occur in these areas and we don't know why they're doing it. We think this area is very important."

A ScottishPower spokesman said it was carrying out comprehensive surveys into a variety of species in the area.