Probe into death of rare leatherback turtle near Dunbar
A 6ft leatherback turtle drowned off the east coast of Scotland after being caught in fishermen's creel ropes, experts have found.
Pathologists said a necropsy of the female reptile found bruising consistent with creel ropes.
She was found on Thursday, a mile off the Dunbar coast.
The 350kg turtle is the fourth to have been found dead around Scotland in the last two weeks.
Pathologists carried out a post-mortem examination in Edinburgh on Monday.
The endangered species, which dates back more than 100 million years, is a rare sight in Scottish waters.
They have been known to die from eating plastic carrier bags which they mistake for jellyfish, their primary food source.
Due to large one-way spines in their throats, the leatherbacks cannot regurgitate plastic bags. They either cause a blockage in the reptile's gut or it make feel full, causing it to stop eating and starve to death.
Matt Barnes, from the Marine Conservation Society, told the BBC Scotland news website before the necropsy that leatherback turtles could hold their breath for up to six hours.
But he added: "If it was tangled in a fishing line then it would panic and drown within minutes.
"It is uncommon to have four dead leatherbacks in two weeks."
The other turtles were found dead at Drumbeg in Sutherland; off the Isle of Coll; and on the Isle of Skye, north of Elgol.
A necropsy on the turtle found in Sutherland found it too had died from drowning. No examinations were carried out on the other two turtles because one was too decomposed and the other was too difficult to access.
The last sighting of a leatherback turtle in the Forth estuary took place in 2009.
The necropsy was performed at the National Museum of Scotland in Edinburgh.
Dr Andrew Brownlow, a pathologist for the Scottish Marine Animal Stranding Scheme, said it was "very unusual" to have four deaths in Scottish waters.
He said: "We found evidence of entanglement most likely from creel ropes due to bruising and impressions left in the tissue.
"There was also congestion in the lungs which is a consistent finding in animals that have run out of oxygen underwater."
"We also found a small amount, about 30cm, of fishing twine, which although it had nothing to do with its death, shows these animals are vulnerable to ingesting marine debris."
He urged people to report any sightings of leatherback turtle deaths.
Leatherbacks, the largest turtles in the world, nest in the Caribbean and are classed as an endangered species. They can reach up to three metres in length and weigh a ton.