Great white sharks in Mediterranean
Published 17/11/2010 | 11:31
Australian great white sharks have ended up in the Mediterranean after going "walkabout", a study has shown.
Four of the deadly predators found off the coasts of Turkey, Tunisia and Sicily had DNA that showed they belonged to a family from Down Under.
Scientists believe their ancestors turned up near the popular holiday destinations after making a navigational error. They may then have found themselves trapped in the enclosed sea.
Later generations stayed in the Med - thankfully in low numbers - because, like salmon, great whites like to return to their birth place.
Dr Les Noble, a member of the research team from the University of Aberdeen, said: "We were absolutely astonished - it was a moment of scientific serendipity.
"We looked at the DNA signature of the sharks and found they were all from the same extended family. The founding mothers had the same DNA as great white sharks found off the coast of Australia."
Two of the sharks were caught in the Bay of Edremit, Turkey, two years ago. The third was found off Tunisia in 2006 and the fourth off Sicily 20 years ago.
The original journey to Europe was probably made by a few pregnant females as long as 450,000 years ago, according to the scientists.
They may have taken a "wrong turn" due to a number of factors including climate change, high sea levels and unusual ocean eddy-currents called Agulhas rings.
Scientists already knew that sharks frequently swim between Australia and Africa, and navigate by following currents.