Sharks' future in doubt as they shun ocean depths

Fears for the future of the world's sharks have been raised by research which suggests their territory is smaller than previously thought.

Experts at Aberdeen University have discovered the highly-adapted predator does not go below about 9,000ft.

This means there is unlikely to be any unknown species in the deep ocean abysses and that fishing fleets are already exploiting the last populations left on the planet.

The average sea depth is more than 12,000ft, so the research suggests about 70 per cent of the ocean depths are free of sharks.

Professor Monty Priede, of Aberdeen University, wrote a paper for the Royal Society, along with colleagues from England, Norway, the United States and Germany, which is published today.

He told The Scotsman: "The deepest recorded shark was a humble thing called a Portuguese dogfish. The deepest specimen was caught off the south-west coast of Ireland.

"This species is now considered to be severely reduced and endangered - we have almost exterminated the world's deepest shark before we knew it was the world's deepest shark."

One theory for the sharks' preference for staying within 9,000ft of the surface is that there is too much competition for food from other fish, such as grenadiers.

Source: news.scotsman.com