This is the VOA SpecialEnglish Environment Report.

Scientists have appealed for international cooperation to protectleatherback sea turtles. The scientists say the world's leatherbackpopulation has dropped more than ninety percent over the past twentyyears. They warn that leatherback turtles around the world willdisappear if current fishing methods continue.

Leatherbacks are the world's largest turtles. They can grow morethan two meters long and weigh more than four-hundred kilograms. Butthey do not have hard, protective shells like most turtles. Theirbacks are covered with oily, ribbed skin.

Leatherbacks are able to dive almost a kilometer below the oceansurface in search for food. They have survived for millions of years-- since the time of the dinosaurs.

The scientists presented their findings at the yearly meeting ofthe American Association for the Advancement of Science. Delegatesmet earlier this month in Denver, Colorado.

Larry Crowder of Duke University told the meeting thatleatherbacks are quickly disappearing. He warned that the creaturescould disappear within the next ten to thirty years.

Leatherback turtles usually mate every other year. The femalesswim thousands of kilometers to warm breeding areas. They leavetheir eggs on the beach at night, then return to the ocean. Manypeople gather on beaches to watch this event.

For years, experts thought leatherback turtles were safe becausethey are found in a number of countries. However, recent studies areforcing experts to re-examine this idea.

In nineteen-eighty-eight, scientists found that more thanone-thousand-three-hundred turtles left their eggs on the Pacificbeaches of Costa Rica. Ten years later, that number fell to justone-hundred-seventeen turtles.

Scientists blame fishing for the sharp drop in the number ofturtles. Leatherbacks and other sea creatures get caught in fishinglines. They drown. Or they can be pulled into fishing boats andkilled.

In the United States, the federal government and some states haverestricted or banned long fishing lines. Scientists say fixing theproblem will require efforts by governments and by the fishingindustry. They are calling for new fishing agreements to save theleatherback turtles.

This VOA Special English Environment Report was written by GeorgeGrow.