New species of deep water fish discovered by Scottish scientists

SCOTTISH marine scientists have discovered an entirely new species of fish living more than four miles below the surface in a deep ocean trench previously thought to be devoid of life.

The experts at Aberdeen University's Oceanlab said yesterday that their remarkable discovery has prompted the need for a complete rethink into the survival of marine populations at extreme depths.

They have discovered a species of snailfish living at a depth of 7,000 metres, or 4.3 miles, in the Peru-Chile trench where scientists had previously been convinced marine life did not exist.

And during their expedition to the trench in the South East Pacific Ocean they were also able to film "mass" groupings of cusk-eels and large crimson red crustacean scavengers living at the same depths.

Dr Alan Jamieson, the Oceanlab scientist who led the expedition, said: "Our findings, which revealed diverse and abundant species at depths previously thought to be void of fish, will prompt a rethink into marine populations at extreme depths.

"The thinking was that after 2,600 metres there would be much fewer fish and fewer species and that deep water fish would be eking out an existence in the darkness. But we are finding that the populations are actually very, very high.

"One of our most significant discoveries was the filming of a feeding frenzy of a species of cusk-eel - known as Ophidiids which grow to between 30 and 60 centimetres long - which went on for 22 hours.

"That was a big surprise. There were so many fish it was difficult to count them."

Scientists from Oceanlab were the first to discover signs of life "beyond the abyss" when two years ago they filmed a different previously unknown species of snailfish 7,700 metres - almost five miles - below the surface of the Pacific Ocean in the Japan Trench, 6,000 miles away from their latest discovery.

But Dr Jamieson said the new discovery of the completely new species of snailfish in the deep waters off the Chilean coast was also highly significant.

He said: "These findings prompt a re-evaluation of the diversity and abundance of life at extreme depths. Each of the deep trenches across the globe hosts a unique assembly of animals which can differ greatly from trench to trench.

"The Peru-Chile trench was explored in the 1970s and scientists at that time concluded that beyond 5000 metres there was no fish. But we have completely destroyed that theory. There are plenty of fish beyond that depth.We have identified at least ten different species."

Dr Toyonobu Fujii, another member of the Aberdeen University research team, said: "How deep fish can live has long been an intriguing question and the results from this expedition have provided deeper insight into our understanding of the global distribution of fish in the oceans."

The expedition off Chile was the seventh of the "Hadeep" project - a research programme with Tokyo University and New Zealand's National Institute of Water and Atmospheric research institute to investigate life in the "hadal" regions of the world's oceans which is anything below 6,000 metres.