The leatherback turtle is disappearing from its most important nesting sites in the western Pacific, according to a new study.
Female leatherback turtle on nesting beach
The study found that the number of leatherback turtle nests in the Bird’s Head Peninsula of New Guinea has dropped by a staggering 78% in the last 30 years. These beaches account for three-quarters of the western Pacific’s nesting leatherback turtles, meaning this decline could have serious consequences for the future of the species in the Pacific Ocean.
“Sea turtles have been around about 100 million years and survived the extinction of the dinosaurs but are struggling to survive the impact of humans,” said Thane Wibbels, one of the researchers.
Fishermen holding a dead, captured leatherback turtle
The leatherback turtle is the largest of the world’s turtles, and is listed as Critically Endangered on the IUCN Red List. Like all sea turtles, this species faces a range of threats, including entanglement in fishing gear, boat strikes, harvesting of its eggs by humans, and predation of its eggs by feral dogs and pigs. In addition, the leatherback turtle also accidentally consumes plastic bags, mistaking them for its jellyfish prey.
Climate change is also a serious threat to the leatherback turtle. Rising sea levels and increasingly frequent and violent storms may erode nesting beaches and destroy nests, while changing ocean currents are likely to affect the turtle’s prey.
Feral dogs are a threat to leatherback turtles, digging up and eating their eggs
The gender of leatherback turtle hatchlings is determined by the temperature at which the eggs are incubated, so warmer sand is likely to produce more females, skewing the species’ sex ratio. In addition, warmer temperatures have been known to cause abnormalities in hatchlings, and to affect the health and development of the young turtles.
In comparison to the Atlantic Ocean, where several nesting populations of leatherback turtles have increased in recent years, the status of the species in other oceans is of greater concern.
“The leatherback is one of the most intriguing animals in nature, and we are watching it head towards extinction in front of our eyes,” said Wibbels.
Conservationists have begun programmes to move leatherback turtle nests to more sheltered and shaded areas, where the eggs will be cooler, in the hope of increasing the success rate of hatchlings.
Leatherback turtle hatchlings face many perils, and very few survive to adulthood
The leatherback turtle is legally protected throughout most of its range, and a variety of other conservation measures are underway to help save this impressive marine reptile. For example, the attachment of Turtle Excluder Devices (TEDs) to fishing nets to reduce bycatch of turtles has been recommended.
However, much still needs to be done to save this marine giant. According to the researchers, a range of conservation measures need to be implemented at nesting beaches and in national and international waters if the decline of the Pacific’s last remaining leatherback stronghold is to be reversed.
Read more on this story at Mongabay – Leatherback sea turtles suffer 78 percent decline at critical nesting sites in Pacific.
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Liz Shaw, ARKive text author