More protection needed in feeding areas
Although key loggerhead sea turtle nesting areas around Cyprus, Greece and Turkey are relatively well-protected, the species is still vulnerable to small-scale fishing operations around Syria, Libya and Egypt and Tunisia. Thousand of the sea turtles, on the IUCN Red List, are killed each year when they travel to to those regions in search of food, according to a new study led by researchers at the University of Exeter.
“The mortality rate and level of bycatch in these countries is very concerning,” said Robin Snape, a postgraduate research student with the Marine Turtle Research Group at the Centre for Ecology and Conservation at Penryn Campus. “There is poor understanding of the need for conservation and of the impacts that fishing practices can cause. This is particularly difficult to manage when local people are dependent on fish for their food and livelihood,” said Snape, who, along with a team of researchers, tracked the movement of loggerheads in the Mediterranean.
The European research supports the results of similar studies in the U.S. that pointed to the need for protection not just of nesting areas, but at sea and in feeding grounds. Sea turtles are long-lived, late maturing species that occur throughout the global oceans.
Snape said there’s a need to study fishing practices and new ways of minimizing the impacts of bycatch — when turtles are inadvertently caught up in nets used by fishermen.
“Although this is difficult at the moment when countries are at war or politically unstable, Cyprus as an EU member state is well situated to address its significant sea turtle bycatch,” Snape said.
The researchers used satellites to track turtles from Cyprus, showing that the loggerheads don’t always return to their place of birth to lay eggs. After breeding females visit feeding grounds over an area covering the continental shelf of Cyprus, the Levant and North Africa sometimes up to 2,100 kilometers from their nesting sites.
Three of the 27 adult female loggerhead turtles that were tracked by using satellite devices over a ten year period from north Cyprus nesting beaches died within a year of being followed. The study, published in the journal Diversity and Distributions, shows researchers believe the turtles died as bycatch, a result of being caught accidentally in fishing nets.
The figures suggest an 11 percent mortality rate per year, which is a higher rate than expected in a species that is thought to be very long lived. Turtles need to live longer so that they can produce enough offspring to keep the species going.
“Whilst the Mediterranean loggerhead turtle population is dependent on the continuation of decades of intense conservation work at core nesting sites in Greece, Cyprus and in Turkey, we now need to move into the water to secure the future of the species mitigating threats from fisheries and oil and gas related seismic activity,” said project leader, Professor Brendan Godley.
“Encouragingly, we have been involved in some recent work elsewhere that has shown that the simple and inexpensive measure of putting LED lights on nets can reduce turtle bycatch significantly.Our knowledge of the impacts of seismic activity is embryonic,” Godley said.