The Open Ocean Trustee Implementation Group recently completed a project addressing juvenile sea turtle bycatch in the Gulf of America otter trawl shrimp fishery. In partnership with the fishery, the project team developed and tested modified turtle excluder devices (TEDs). They found that a reduction in bar spacing on the TED grid successfully excludes small turtles and maintains shrimp catch.
Complete test results can be found in the following reports, available online:
- 2022 and 2023 Small Bar Turtle Testing Report (PDF, 36 pages)
- 2022 and 2023 Independent Proof of Concept Testing (PDF, 15 pages)
- 2023 Dependent Commercial Testing (PDF, 18 pages)
Photo: NOAA Fisheries (ESA Permit 20339)
TEDs are devices used in shrimp trawl nets to reduce sea turtle bycatch (species caught unintentionally). The current industry standard TED has a bar spacing of 4-inches. While TEDs are highly successful at reducing bycatch, small juvenile sea turtles with body depths of less than 2 inches are not always excluded by current designs. This happens both because of the turtle's small size and limited strength to use the escape flap on the TED.
The goal of the Reducing Juvenile Sea Turtle Bycatch Through the Development of Reduced Bar Spacing in Turtle Excluder Device project was to test whether a TED with 2.5-inch bar spacing allowed juvenile sea turtles to more easily escape, as compared to current 4-inch bar spaced TED designs, while maintaining shrimp retention rates.
As we restore sea turtle species injured by the 2010 Deepwater Horizon oil spill, we work closely with both recreational and commercial fisheries. In support of this project, a stakeholder working group—made up of otter trawl shrimp fishery members from across the Gulf—was established. They provided feedback on proposed TED designs, testing protocols, and overall project direction.
In the end, the project successfully evaluated TEDs with a reduced bar spacing for their impact on juvenile sea turtle exclusion and shrimp catch rates in the otter trawl shrimp fishery. The outcomes all show that not only does this modified design reduce juvenile sea turtle bycatch, but it also causes no significant decrease in shrimp catch.
After testing, the project team engaged with shrimp industry anglers across the Gulf to discuss the results of the project and potential future opportunities for engagement. Through this outreach, they identified shrimp vessel owners interested in testing these smaller bar spaced TEDs during commercial operations.
One shrimper, Gary Graham, who served on the Stakeholder Working Group, is hopeful. He shared, “if that smaller grid size can help reduce the bycatch, I'm all in favor of it."
The Open Ocean TIG recently approved further work to reduce sea turtle bycatch in the Gulf of America in Open Ocean Restoration Plan 4. This additional funding will be used to make the three TED configurations tested in this project available for shrimpers who would like to voluntarily use small bar TEDs on their vessels.
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