Thousands of loggerhead turtles are killed annually in areas of Syria, Libya and Egypt and Tunisia where they travel to find food, a new study led by researchers at the University of Exeter has highlighted.
Robin Snape, a postgraduate research student with the Marine Turtle Research Group at the Centre for Ecology and Conservation at Penryn Campus and a team of fellow conservation biologists found that many adult loggerhead turtles are migrate to areas of the Mediterranean where they are dying, trapped in fishing nets used by small scale fishing operations in Cyprus, the Middle East and North Africa.
The researchers tracked female turtles by satellite from Cyprus and provided new evidence that the turtles, rather than returning to the place of their birth to lay their eggs, will sometimes nest in a number of countries. Following breeding, females travel to foraging sites over an area covering the continental shelf of Cyprus, the Levant and North Africa sometimes up to 2,100km 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.
This suggests an 11 per cent 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.
Robin Snape, who is based in northern Cyprus, said: "The mortality rate and level of bycatch in these countries is very concerning. 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. Wider studies are needed into fishing practices, the exact methods being used and into how we can mitigate bycatch. 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."
Project leader, Professor Brendan Godley added: "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. 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."
Shelf life: Neritic habitat use of a turtle population highly threatened by fisheries by Robin T. E. Snape, Annette C. Broderick, Burak. A. Çiçek, Wayne J. Fuller, Fiona Glen, Kimberley Stokes and Brendan J. Godley is published in Diversity and Distributions.
Diversity and Distributions