Scientists call for urgent action to prevent loggerhead turtle disaster

June 2008. Scientists from Earthwatch, the international environmental charity, fear that the longline fishing season will have a devastating impact on endangered loggerhead turtles in the Mediterranean Sea.

Earthwatch scientist Ricardo Sagarminaga van Buiten, who is studying common dolphin and marine turtles in the Alboran Sea, says, "The longlining season has just begun and we have another period ahead of us that could be disastrous for the endangered loggerhead turtle populations that travel and feed in the south-west Mediterranean. We can expect that around 20,000 will end up getting caught on Spanish fleet longlining hooks alone."

Alboran Sea
The Alboran Sea lies at the western end of the Mediterranean, between Spain and Morocco to the east of the Gibraltar Straights. The Alboran Sea has the highest biodiversity within the Mediterranean, but this region also supports large fishing operations which result in thousands of loggerhead deaths each year when the turtles are caught up in fishing lines (known as bycatch).

Mitigation measures
Van Buiten is calling for tried and tested mitigation measures to be urgently adopted, such as using alternative bait, fishing deeper, using small circular hooks and avoiding turtle hotspots. These measures were tested with the support of NOAA's National Marine Fisheries Service. Van Buiten believes these measures could reduce bycatch rate by more than 85 per cent, and if turtles that are accidentally caught by Spanish fishermen are better handled, their chances of survival should also increase.

But Van Buiten fears changes could come too late to save affected turtle populations. "The data coming out of monitoring programmes throughout the Atlantic range - where these turtles nest - is not very promising, with major nesting populations dropping at a fast rate."

Satellite tracking loggerhead turtles
Urgent action is all the more crucial in the light of his latest research findings.Van Buiten and colleagues from WIDECAST (the Wider Caribbean Sea Turtle Conservation Network) have become the first to document real-time migrations of loggerhead turtle from the Mediterranean across the Atlantic Ocean. Using satellite transmitters, they tagged three loggerhead turtles. Click here to see the satellite tracking map.

"At least one, and possibly two of the three turtles that left the Mediterranean went to the Caribbean, indicating the possible importance of the Mediterranean Sea to western Atlantic nesting stocks south of the US," said Van Buiten.

Since 1999, Earthwatch volunteer teams led by Van Buiten and Dr. Ana Canadas have been working on board a 20-metre wooden vessel in the Alboran Sea to monitor marine species.