Surging demand for turtle meat in Asia could jeopardize the future of native Iowa shellbacks, according to reptile experts and the Department of Natural Resources.
Turtle prices have spiked in response to increased demand from Asia, where the highly prized reptiles have been nearly wiped out. The lucrative market in turn has increased trapping pressure in Iowa and other states where the practice is permitted.
Few states offer less protection for turtles than Iowa, according to the Tucson, Ariz.-based Center for Biological Diversity, which in 2009 asked officials in Iowa and seven other states to ban the commercial harvest of turtles.
“Freshwater turtles do not have a reproductive rate high enough to sustain themselves under commercial harvest pressures,” said Collette Adkins Giese, an attorney with the Center for Biological Diversity.
Citing a lack of “solid evidence to show deleterious impacts of humans (if any) on Iowa turtle populations,” the Natural Resources Commission unanimously denied the petition for a ban on commercial turtle harvest.
“We want to ensure that turtles are not overharvested, but we lack sufficient data to make the case that their numbers are declining,” said DNR fisheries biologist Scott Gritters, who coordinates the state’s commercial turtle licensing program.
Gritters said the DNR is drafting a white paper, now 37 pages long, that summarizes what state biologists know about the status of three turtle species legally harvested in Iowa: the common snapping turtle, softshell turtles (both smooth and spiny) and painted turtles.
Though the DNR plans to propose no turtle harvest rule changes during the upcoming year, Gritters said size limits and a closed season during turtles’ reproductive cycle are under consideration.
While the commercial harvest of turtles is prohibited in three states adjacent to Iowa — Illinois, Nebraska and South Dakota — commercial harvesters in Iowa can trap an unlimited number of turtles the year around. They must pay a $100 annual license fee and report their harvest monthly to the DNR.
Neither the DNR nor the Center for Biological Diversity is worried about the non-commercial taking of turtles by Iowans, who are allowed to harvest a maximum of 100 pounds live weight per year by virtue of their purchase of a fishing license.
Mount Mercy University biology professor Neil Bernstein, a turtle expert, describes Iowa commercial turtle harvest regulations as lax but agrees with the DNR that more information is needed to formulate effective rules.
Bernstein said he worries that commercial trappers sometimes take protected species, such as the Blanding’s and wood turtles, and that trappers are free to take turtles during their reproductive season.
“We’ve got to give them some refuge for breeding,” he said.
At a minimum, the state ought to close the season during the late spring and early summer when female turtles leave the water to lay their eggs, said Iowa State University ecology professor Fred Janzen.
“Turtles are just different,” said Janzen, a herpetologist who founded the ISU research program known as “Turtle Camp” in 1988. Because turtle eggs and babies are so vulnerable to predation, adults have to live a long time just to maintain a stable population, he said.
In Iowa, commercial harvests have increased from 29,000 pounds in 1987 to 235,000 pounds in 2007, according to the DNR’s Gritters. During that same 20 years, the number of licensed harvesters increased from 35 to 176, he said.
The number of licensed Iowa commercial turtle harvesters has since declined to 133 this year — a decrease attributable at least in part to poor trapping conditions caused by widespread flooding in 2008 and 2010.
But Janzen said he thinks any reduction in trapping pressure is more likely due to turtle populations already in decline because of overharvesting.
Janzen said turtle populations, unlike deer or pheasant numbers, are difficult to accurately estimate.“If we are not sure what’s out there, we ought to err on the side of caution rather than exploitation. Once they are gone, they won’t come back,” he said.