This drop has placed greater pressure on places where the animals are still plentiful, including many parts of the United States.
Florida-based biologist Matthew Aresco, a member of the IUCN's Tortoise and Freshwater Turtle Specialist Group, has spent more than a decade studying the state's turtles.
Dramatic and quick declines in Florida turtles prompted the recent law, Aresco said.
In the past several years, people working in the state had noticed a large number of turtles being harvested, he said.
"For a time no one really understood what was going on—that Asian buyers had come into Florida and now there was a big increase in demand."
Background statistics cited in Florida's draft turtle rule state that declared exports of U.S. wild-caught softshell turtles grew by 400 percent between 2000 and 2004.
Patricia Behnke, of the Florida Fish and Wildlife Conservation Commission in Tallahassee, said that monitoring turtle populations is difficult.
But continuing to harvest turtles without some form of monitoring could put a major dent in the reptiles' populations, she said.
"We thought the most conservative measure—and the best thing for freshwater turtles—is to ban commercial harvests from the wild and move this into the aquaculture industry," she said.
American turtle farming is already a big business: Nearly 32 million live turtles were exported from the U.S. between 2003 to 2005, according to a study by World Chelonian Trust, a turtle conservation group.
And of those, more than 31 million—a large amount of which were red-eared sliders—were farmed hatchlings shipped to Asian aquaculture facilities that then raised the turtles to adulthood.
But the number of wild-caught turtles legally shipped during the period is still staggering, the study said—some 700,000.
That's a particularly tough blow, because turtles are long-lived animals: Most Florida species, for example, take between 3 to 13 years to reach reproductive age.
At least one fisher who has long relied on income from turtle harvesting was disappointed with the new law.
William Shockley, a second-generation commercial turtle fisher in Okeechobee, Florida, said that tough new laws like this one are a political overreaction.
"For them to say the things they've been saying is ludicrous. They don't have the science to back it up," he said.
"They've based a lot of their studies on other states that don't have a climate like Florida's, especially South Florida. When the turtles can flourish here, they will flourish."
Shockley said fishers know that turtle catches fluctuate annually with the amount of rainfall, which determines the area of wet habitat available for turtles.
They've also long known how to manage turtle harvests sustainably, he stressed.
Peter Paul van Dijk, director of Conservation International's freshwater turtle and tortoise conservation program, agreed that some turtle species probably could be harvested sustainably under traditional fishing systems.
These programs employ limited "take" quotas and provide ample time for populations to grow.
"But the problem is that demand is potentially insatiable," van Dijk explained.
"It's basically an open-ended fishery, and unless you have real controls in place, there is every financial incentive to just overharvest, take the profit now, and then move on to another species."
Van Dijk hopes that farming will be able to keep the heat off wild turtle populations.
"My personal opinion is that of the various possible trends, I would think that farming turtles would be a lesser evil than [wild] collection."
But turtle farming isn't without its problems.
Most farmers rely on collecting wild animals to supplement breeding stocks on the farms.
Some farms have also been unmasked as "laundering" operations for the illegal sale of wild turtles—such as a New York State racket that state investigators dubbed "Operation Shell Shock."
The March 2009 undercover investigation of trade in protected New York State reptile and amphibian species led to charges against 18 people.
But Florida biologist Matt Aresco—who also directs a conservation reserve that houses tortoises—said that farms may well be the turtle's best bet.
"It will be a positive if the farms become self-sustaining and operate with their original breeding stock rather than continuing to go to the well," i.e., collecting more wild turtles for breeding, he said.
"That's an important part of it, and it has the potential to be a big loophole if it's not regulated and enforced."
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