Marine energy risk to salmon studied

The salmon pass through the firth between the Scottish mainland and Orkney when they leave rivers for open sea and later return to breed. Sites in the firth have been earmarked for renewable energy projects.

The Crown Estate, which owns 50% of Scotland's foreshore and almost all the seabed out to 12 nautical miles, has leased a number of locations in the Pentland Firth to companies for the development of wave and tidal energy devices.

It is funding the research by the University of the Highlands and Islands (UHI), which are investigating the potential risks the machines pose to young salmon, known as smolts, and adult fish.

The possible threats include fish colliding with the equipment and the devices disrupting migratory routes.

James Fraser, principal and vice-chancellor, told the BBC News that the salmon study aimed to fill a gap in scientists' understanding of the fishes' migratory behaviour.