SHARK THREAT !
SHARK THREAT !
2006-02-24 at 11:16:00 am #14619
Study warns of threat to sharks
Sharks could be more vulnerable to the fishing industry than was previously thought, research has revealed.
Marine scientists led by Aberdeen University have discovered that the deepest oceans of the world appear to be shark free.
One possible reason, they tell a Royal Society journal, may be lack of food.
The researchers warn that the findings mean all shark populations are
within reach of human fisheries and could be at greater risk than was
In their paper
published on Wednesday – The absence of sharks from abyssal regions of
the world’s oceans – the international team of researchers reports that
sharks have failed to colonise at depths greater than 3,000m.
Sharks are found throughout the world’s oceans and it
had been hoped new species would be discovered as exploration went
There is no hidden reserve of sharks in the deep sea – it’s highly unlikely we are going to find anymore
Prof Monty Priede
However, 20 years of exploration combined with analysis of records over
the past 150 years, has convinced the scientists that the world’s
oceans are 70% shark-free.
The average depth of the oceans is 4,000m and bony fish – relatives of cod – thrive down to around 9,000m depth.
The scientists do not know why sharks are absent there but suggest one possible reason could be a lack of food resources.
Professor Monty Priede, director of Oceanlab at Aberdeen University,
said: “Sharks are apparently confined to around 30% of the world’s
“All populations are therefore within reach of human fisheries, near the surface and at the edges of deep water.
“Sharks are already threatened worldwide by the intensity of fishing activity.
“But our finding suggests they may be more vulnerable to over-exploitation than was previously thought.
“As far as we can see, there is no hidden reserve of sharks in the deep
sea. All we see is all there is – it’s highly unlikely we are going to
find any more.”
The scientists based their conclusions on a wide range
of data, which includes information gathered during a major expedition
along the Mid-Atlantic Ridge between Iceland and the Azores in 2004.
The team also used findings built up over the last two
decades when the university’s Oceanlab started developing landers -
remotely operated vehicles – which have been used in deep waters all
over the world.
Expeditions using landers visited deep areas including the South Atlantic off the Falkland Islands.