Leatherback turtles may disappear from the Pacific Ocean within ten years, according to scientists meeting at the 24 th Annual Symposium on Sea Turtle Conservation and Biology in San Jose, Costa Rica, February 23-28, 2004. Earthwatch-supported scientists Drs. Jim Spotila (Drexel University) and Frank Paladino (Indiana-Purdue University) presented data from the Pacific Coast of Costa Rica supporting the perilous population trend.

"The Pacific leatherbacks currently face an annual mortality rate of up to 30 percent," said Spotila, principal investigator of Earthwatch's Costa Rican Sea Turtles along with Paladino. "That rate is clearly unsustainable, and without dramatic intervention we can expect to see them disappear in as soon as a decade."

Named for its smooth, leathery carapace, the leatherback has graced ocean waters from the tropics to the Arctic for more than 100 million years. Although leatherbacks are the widest ranging marine vertebrate, their population in the Pacific has dwindled down to fewer than 3,000 reproductive females today. Females nesting on the Pacific Coast of Mexico and Central America have dropped from 91,000 in 1980 to fewer than 1,500 in 2004.

Leatherbacks around the world face threats ranging from destructive fishing practices such as longline fisheries to the poaching of turtle eggs, which some cultures regard as a delicacy. Although Caribbean and Atlantic populations appear stable, Spotila and his colleagues suggest that fishing pressures and more global effects could threaten them in the long term as well.

"Climatic fluctuations can have serious impacts on oceanographic conditions which determine food quality and availability for leatherbacks," said Bryan Wallace, doctoral candidate at Drexel University and co-principal investigator on Costa Rican Sea Turtles . "This could lead to longer periods of time out at sea for leatherbacks trying to tank up before going back to their nesting beaches, thus keeping them exposed to fishing risks for longer."

In addition to the plight of leatherbacks, five of the other six marine turtle species are also at risk of extinction. Kemp's ridley and hawksbill turtles are classified by the IUCN (World Conservation Union) Red List as Critically Endangered, as is the leatherback.

"Red Listing is very important for flagging species experiencing dramatic declines and is used throughout the world to develop conservation priorities," said Dr. Jeffrey Seminoff (NOAA-National Marine Fisheries Service), principal investigator of Earthwatch's Sea Turtles of Baja project. "Kind of like a global Endangered Species Act."

Seminoff, who has been working for the IUCN Red List program since 2000, and his colleague Alberto Abreu (Unidad Académica de Mazatlán, Mexico), presented an assessment of the program at the San Jose meeting, highlighting the need for more careful demographic data.

Scientists at the conference, which was attended by more than 1,000 experts from 70 countries, called for a two-pronged approach to reverse the rapid population decline of sea turtles. The first is to require stronger protections and more careful management of nesting beaches. The second is to encourage safer fishing techniques that will reduce unintentional "by-catch" of sea turtles.

"The best hope for the leatherback's future must be multi-dimensional," said Wallace. "It must include education and empowerment of local communities as well as visitors, such as Earthwatch volunteers, and continued sound scientific monitoring to inform conservation decisions."

Long-term efforts of beach protection and nest relocation by volunteers on Earthwatch's Saving the Leatherback Turtle project on St.Croix, for example, have allowed that leatherback population to rebound significantly in the last seven years. So there is room for optimism, but it will take an international effort, and more comprehensive ocean protection, to stop the Pacific leatherback's slide to extinction.

Earthwatch Institute is an international nonprofit organization which supports scientific field research worldwide by offering members of the public unique opportunities to work alongside leading field scientists and researchers. The Institute's mission is to engage people worldwide in scientific field research and education to promote the understanding and action necessary for a sustainable environment.