More than 90 percent of longline fishing conducted in international waters originates from international fleets, primarily from Japan, Taiwan, Korea, and China. Saving the leatherbacks will require the cooperation of these countries, said Steiner.
Compounding the population toll caused by longline fishing, leatherback sea turtle eggs are considered a delicacy in many parts of the world. Eggs are actively harvested in parts of Latin America and Asia.
Most nations, however, have taken steps to protect leatherback sea turtle nesting beaches over the past few decades. Costa Rica has turned a major nesting beach into a national park, and the turtles have had legal protection in Mexico for over a decade. "One of the key things to understand is harvesting an adult has a much bigger effect on population than an egg," said Crowder. Many of the eggs may not make it to reproductive age, whereas an adult can actively reproduce.
To save leatherback turtles from extinction, scientists say the most important step is to place an immediate ban on longline and gillnet fishing until alternate, turtle-safe methods can be developed.
This is not an easy task, said Steiner. Turtle excluder devices developed for trawl net fishing fleets allowed the Kemp's Ridley sea turtle to recover from the brink of extinction in the 1980s. But no such technology presently exists for longline fishing.
The world's appetite for swordfish has a significant impact on leatherback turtle populations. According the Pew Charitable Trusts study, longlines set out to catch swordfish are ten times more likely to entangle a leatherback than a longline set for tuna.
Steiner's Save the Leatherback Campaign is actively targeting supermarkets in California to post warnings about the high level of mercury found in swordfish, which he says is much higher than the levels advised as safe by the U.S. Food and Drug Administration.
Additionally, the scientists are asking that all beaches where leatherback sea turtles are known to nest and lay eggs be protected and all egg harvesting be banned.
"Things are dire for the leatherbacks in the Pacific right now," said Steiner. "We need to do everything at once."
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