February 27, 2013
Refuges For Endangered Leatherback Turtles Quickly Disappearing
Alan McStravick for redOrbit.com - Your Universe Online
The leatherback sea turtle is the largest species of marine turtle and also the largest living reptile. Known to weigh as much as 2000 pounds and reach up to six feet in length, this gentle giant of the oceans is the subject of a multi-decade study, the results of which were published yesterday in the journal Ecosphere.
Leatherback sea turtles were listed as critically endangered by the International Union for Conservation of Nature last year. Researchers from the State University of Papua Indonesia, the National Oceanic and Atmospheric Administration (NOAA) Fisheries Service, University of Alabama at Birmingham and the World Wildlife Fund (WWF) Indonesia contend these magnificent creatures may be in serious danger of losing their battle for survival on the beaches of Indonesia. The study documents the continued decline of the leatherback sea turtle nesting grounds located in the western Pacific Ocean.
"At least 75 percent of all Leatherback turtles in the western Pacific Ocean hatch from eggs laid on a few beaches in an area known as Bird's Head Peninsula in Papua Barat-Indonesia," said Peter Dutton, co-author of the paper and a researcher at NOAA's Southwest Fisheries Science Center. "Our analysis indicates the number of leatherback turtle nests on this beach has declined 78 percent over the last 27 years."
The female of the species typically lay clutches of approximately 100 eggs. During the nesting season this act can be repeated several times. After only about two months the leatherback hatchlings leave the nest and travel across the beach and into the ocean where they reach maturity. They are also known for their improbable migration pattern, with journeys that take them as far as California, some 6000 miles away. The California coastline provides a bounty of jellyfish and other delicacies for the turtles to feed upon.
The rapid decline of the leatherback turtle over the previous three decades can be attributed to a number of factors, say the researchers. From excessive harvesting of eggs, to predation of the nest by local feral pigs and other predators, to entanglement in commercial fishery nets, the danger for the leatherback turtle´s survival is present on many fronts.
The research team, comprised of lead author Ricardo Tapilatu and co-authors Manjula Tiwari and Dutton, conceived and developed a nesting beach census and management plan. Developed over a decade ago, their plan was part of an international partnership intended to slow the decline of the species.
"The turtles nesting at Papua Barat, Papua New Guinea, and other islands in our region depend on food resources in waters managed by many other nations for their survival," said Tapilatu. "It is important to protect leatherbacks in these foraging areas so that our nesting beach conservation efforts can be effective".
"The international effort has attempted to develop a science-based nesting beach management plan by evaluating and addressing the factors that affect hatching success such as high sand temperatures, erosion, feral pig predation, and relocating nests to maximize hatchling output," explained Manjula Tiwari, a researcher at NOAA's Southwest Fisheries Science Center in La Jolla, California.
Perhaps most heartening is the recognition by outside groups of the value of conservation efforts on behalf of the leatherback turtle. One such group, the International Seafood Sustainability Foundation (ISSF), has worked to raise funds from industry-affiliated members in support of UNIPAs nest-protection program with the local communities on Bird´s Head Peninsula.
"NOAA Fisheries Service is committed to doing our part in the international effort to recover the leatherback turtle through advancing science, implementing our recovery plans and management efforts such as the establishment of critical habitat off California," said Cisco Werner, Director of the Southwest Fisheries Science Center. "Reducing threats on the nesting beaches and at leatherback foraging areas will require continued international cooperation and action if we hope to save Pacific leatherbacks from extinction."
Success in this endeavor is not assured, but with cooperation between private corporations and the research community, the long-term prospects for the survival of the leatherback turtle look more positive than they have in decades.