Connecting historical tortoiseshell trade to modern IUU fishing networks

What began as research into historical data on rare hawksbill sea turtles could help illuminate the shadowy modern world of illegal, unreported, and unregulated fishing, according to a new paper published in the journal Science Advances. The study also revealed that a dramatically larger number of the critically endangered turtles were killed for the tortoiseshell trade, six times higher than earlier estimates.

The project started nearly a decade ago when Dr. Kyle Van Houtan — then with the National Oceanic and Atmospheric Administration, now Monterey Bay Aquarium’s director of science and senior author of the paper — was leading a sea turtle research program in Hawaii.

“Our goal was to give hawksbills the attention they deserve,” Kyle says. “Hawksbill sea turtles are critically endangered throughout their range, mostly due to threats from illegal harvesting.” The turtles can grow to more than three feet long and 150 pounds and are distinct for their beautiful, mottled shells. 

“They also have a long slender neck that allows them to search for food in the cavities between branches of coral in a reef. There they find sponges, algae and other invertebrates,” Kyle explains.

“They can really shape a coral reef, allowing coral colonies and the reef ecosystem to thrive,” says Dr. Emily Miller, assistant research scientist at the Aquarium and the paper’s first author.