The University of New Orleans has been awarded a $232,559 grant to design a device that effectively protects sea turtles from being captured in small shrimping nets.
Though federal law has long required shrimpers to use such instruments—called turtle excluder devices or TEDS— in their nets, the technology has been limited to use by shrimpers using vessels longer than 25-feet with nets designed for fishing deeper waters.
Shrimpers using smaller nets in shallower waters inshore have no effective options that enable them to keep the shrimp in and the turtles out, said Martin O’Connell, associate professor of earth and environmental sciences and director of the Nekton Research Laboratory at UNO’s Pontchartrain Institute for Environmental Sciences.
It’s easier to design an escape for the largest turtles when your net spans more than 16-feet. But when the net measures 12-feet or smaller, shrimpers risk sacrificing their catch through the turtle escape hole.
“It’s just basic physics,” O’Connell said. “Larger animals need to get out, so you need to have a large enough hole, but you’re working with a smaller net.”
Most sea turtle species that occur in U.S. waters have been classified as threatened or endangered since 1978. Data from the National Research Council suggests the primary cause of sea turtle death is incidental capture in the U.S. shrimp trawls.
This grant from the National Oceanic Atmospheric Administration is the latest in O’Connell’s ongoing work to improve turtle excluder devices.
O’Connell works closely with the grant’s co-principal investigator Meg Uzee-O’Connell, research associate with the Pontchartrain Institute of Environmental Sciences, and Jeff Gearhart, a Mississippi-based fisheries biologist with NOAA’s National Marine Fisheries Service.
Meghan Gahm, a Ph.D. candidate in UNO’s engineering and applied science degree program, will be collecting data for the project over the next two years, measuring the effectiveness of various turtle excluder device designs in the field. To collect the data, researchers involve divers to travel alongside the moving trawls, filming the action and comparing shrimp catch sizes and numbers of turtles trapped when the turtle excluder device is being employed and when it is not.
“We are going to try to study and get the best tool for everybody, where you don’t lose as much shrimp but also the turtles survive,” O’Connell said.