Merritt Walker and Julie Lively

Bycatch, or nontargeted catch, is common for both recreational and commercial fishermen. It can be as simple as catching a red snapper while targeting grouper or as tedious as sorting through saltwater catfish or jellyfish to pick out shrimp. Shrimpers regularly tow trawl nets — large nets dragged behind boats — that collect everything in their path. The amount and type of bycatch vary depending on the season and location. Because shrimp trawl gear is nonselective, regulations are in place to minimize bycatch.

In Louisiana, commercial shrimp is valued at over $60 million in 2023 (dockside), with landings over 73 million pounds from state and federal waters. Shrimpers operating in federal waters must use a turtle excluder device (TED) and a bycatch reduction device (BRD) in every net, and often four nets are pulled per boat. A TED is an angled metal frame, square or oval, with vertical bars sewn into the net. It guides large animals, like sea turtles or adult red drum, to an escape opening. BRDs are installed further down the net in the posterior section known as the codend or tailbag. These devices act as engineered escape routes for finfish and other bycatch. Currently, Gulf shrimpers can choose from five certified BRD types, but no new BRD has been certified in 15 years. Different shrimp species and fishing practices use different net configurations, but most shrimpers use the fisheye — a BRD with a round escape opening — and report shrimp loss with all existing devices.

LSU AgCenter and Louisiana Sea Grant researchers worked with Texas Sea Grant, the National Oceanic and Atmospheric Administration (NOAA) Restoration Center and NOAA Fisheries on the Better BRD Project, which aims to improve bycatch reduction and offer more efficient BRD options for the Gulf shrimp fishery. The project is part of a broader initiative to restore finfish populations affected by the 2010 Deepwater Horizon oil spill.

The project began with dockside visits across the Gulf from Brownsville, Texas, to Key West, Florida, to identify promising gear modifications already in use by shrimpers, who are known for their ingenuity and willingness to troubleshoot gear issues. Over 2021 and 2022, the team inspected 390 nets across 228 vessels.

Several promising gear designs emerged: Tom’s fisheye, the Chauvin TED, the Drury TED, the large mesh section (LMS) and the triangular cut TED. Tom’s fisheye, used in the Australian prawn fishery, closely resembles the fisheye design already familiar to Gulf shrimpers. The Chauvin, Drury and triangular-cut TEDs are flapless designs, meaning no netting covers the TED opening, which allows finfish to escape more easily. One of these TEDs may eventually allow shrimpers to meet both federal requirements with one device. The LMS, used primarily in eastern Texas and western Louisiana’s white shrimp fleet, features a section of 3- to 4-inch mesh in the codend, enabling larger finfish to swim out.

With several candidates identified, proof-of-concept tests were conducted aboard a NOAA research vessel, deploying experimental gear on one side of the vessel and standard gear on the other. Scientists compared catches to assess performance.

Louisiana Sea Grant and the LSU AgCenter, with Texas Sea Grant, oversaw the next two phases of research involving Gulf shrimpers directly. During pilot testing, six vessels were outfitted with experimental BRDs, and shrimpers were encouraged to modify the gear and provide feedback. This effort helped the team understand what worked and what changes might improve efficiency and usability.

The team is now conducting scientific testing with a university researcher aboard each vessel. These researchers collect data after each trawl, enabling the project team to measure the effectiveness of experimental BRDs in reducing finfish bycatch while retaining shrimp.

Once testing concludes, devices that meet performance benchmarks will be recommended to NOAA for full regulatory review. All BRDs used in federal waters must reduce bycatch by 30% compared to a net without a device, and potential new BRDs will undergo the same process. If certified, these devices will be promoted through dockside outreach, workshops, training and incentives to encourage adoption.

In addition to testing new gear, the team has worked with the industry to make sure current BRDs are installed correctly and used efficiently. Small changes can increase the number of shrimp that escape a BRD, directly impacting the shrimpers’ income. Through videos, industry meetings and dockside visits across the Gulf, the team has worked to help shrimpers get the most from their gear.

Through the Better BRD Project, shrimpers, scientists and fisheries managers are working together to improve sustainability while maintaining profitability for the industry.

Merritt Walker is the Better Bycatch program manager for Louisiana Sea Grant, and Julie Lively is the executive director of Louisiana Sea Grant and a professor in the LSU School of Renewable Natural Resources.

This article appears in the fall issue of Louisiana Agriculture.

A side view of a net shows a top-shooting turtle excluder device and a fisheye bycatch reduction device. Graphic by Robert Ray

AgCenter and Sea Grant agents Thu Bui, left, and Mark Shirley test bycatch reduction devices. Photo by Louisiana Sea Grant