History of Turtle Excluder Devices

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One of the major threats to sea turtles is getting caught in fishing gear and drowned. The term for this accidental catch is bycatch. Bycatch is a leading threat to sea turtles worldwide. One of the first places where sea turtle bycatch received significant attention was in the Gulf of America (formerly Gulf of Mexico) and South Atlantic shrimp trawl fisheries. Since the 1970s, scientists, resource managers, and fishermen have worked together to reduce the frequency of sea turtle bycatch in trawl nets. They succeeded with the development of the turtle excluder device, commonly called a TED. The use of TEDs has been a tremendous conservation success story for sea turtles while still allowing the fishing industry to operate successfully.

A TED is a grid, made of metal bars, that is fit into a trawl net. Small animals, such as shrimp, pass through the grid into the mesh bag at the end of the trawl and are caught. When larger animals, such as sea turtles, sharks, and stingrays, enter the trawl net, they are stopped by the TED and are able to exit through an opening either at the top or bottom of the net.

Early TED Design (1970s)

By 1978, all sea turtles found in the northern Gulf had been placed on the endangered species list as either threatened or endangered. Shrimp trawling operations were shown to have the greatest impact on sea turtle populations in the Gulf. In an effort to reduce or eliminate sea turtle captures incidental to shrimping, NOAA Fisheries initiated a gear development project in cooperation with several environmental groups, as well as the Southeastern and Texas Shrimp Association. 

The initial turtle excluders attempted to entirely prevent turtles from entering a trawl by placing large mesh webbing panels across the net opening. Two panel designs were developed and fitted to several different trawl types. The first of these designs reduced turtle captures by only 30 percent while showing shrimp losses between 38 and 53 percent. The second design was significantly more successful, reducing turtle captures by 79 percent. 

This design, however, still exhibited ineffective shrimp retention, showing catch losses between 15 and 30 percent. In addition to excessive shrimp losses, both webbing panel designs were prone to clogging with everything from large debris to small marine organisms. Following more than two years of extensive testing and modification, webbing panel excluders were deemed impractical.

Design Improvements (1980s)

By the early 1980s, NOAA Fisheries had begun developing a new style of turtle excluder. This new TED was of rigid construction located well inside the net. Rather than prevent entry into the trawl as the webbing panel designs sought to do, the TED was designed to separate turtles already inside the net from the catch of the target species. This design was essentially a modification of a device already used by commercial shrimp fishermen to exclude jellyfish from their trawls. The box-like frame of the TED, at a weight of approximately 100 pounds, was significantly larger than the jellyfish excluder.

Initial tests of the TED were encouraging. Turtle separation rates of 89 percent were obtained with minimal shrimp loss. Observing the promising performance of prototype TEDs, NOAA Fisheries discontinued research on all webbing panel separators. With their gear expertise and full resources invested in TED research and design, NOAA Fisheries began to realize the potential of these devices to eject large finfish as well as other unwanted bycatch.

During the subsequent testing and evaluation of the TED, it was noted that turtles have a tendency to swim upward when captured and/or released. Acting on this observation, top-opening TED designs were tested with impressive results. A turtle capture reduction rate of 97 percent was achieved with minimal shrimp loss.

In 1981, NOAA Fisheries initiated a program to encourage the voluntary use of the TED by the shrimping industry. The agency partnered with state Sea Grant marine advisory programs to conduct workshops and demonstrations. TEDs were manufactured by commercial companies under contract with NOAA Fisheries and distributed to individual fishermen interested in the device.

In 1982, in response to feedback from shrimp fishermen, the overall size of the TED was reduced. This reduction in size was supported by information collected by onboard fishery observers regarding the size of turtles caught in shrimp trawls. It was determined that the size of the excluder could be reduced without adversely affecting the TED’s ability to reduce turtle captures.

NOAA Fisheries then began to explore additional modifications and incentives to encourage TED use in the industry. 

In 1983, NOAA Fisheries initiated studies to improve the bycatch reduction abilities and general design of the TED. Alternative lightweight TED construction materials such as plastic and fiberglass were evaluated during this time. Bycatch reduction studies specifically targeting the capture of unwanted finfish led to the introduction of innovative finfish separators. A side-opening finfish separator combined with a finfish deflector resulted in reduction rates of finfish up to 70 percent during daytime trawling and 50 percent during nighttime fishing. Some sacrifice in shrimp catches were required to achieve these rates.

The advantages of bycatch exclusion made the TED more attractive to fishermen, especially those in the northern Gulf. This benefit of finfish reduction seemed to outweigh some of the more unfavorable aspects of the device. Limited numbers of fishermen in North Carolina, Georgia, Alabama, Mississippi, Louisiana, and Texas voluntarily adopted TEDs. However, it appeared that most of the interest was due to the potential of the device to reduce finfish bycatch.

Regulations Requiring Mandatory Use of TEDs

In response to stakeholder concerns, NOAA Fisheries called for a mediated meeting between representatives of the shrimp industry and environmental protection groups. These negotiations eventually influenced the proposed regulations requiring the mandatory use of TEDs by specific vessels in the commercial shrimp industry. These proposals effectively ended the voluntary usage of TEDs by commercial fishermen.

Additionally, the proposed regulations prompted the University of Georgia Marine Extension Service to design and test several alternative single grid turtle exclusion devices. These devices were lighter, smaller, and more affordable than the TED designed by NOAA Fisheries. Several designs were found to be effective in reducing turtle captures, offering the shrimp industry more options to comply with the proposed regulations.

On June 29, 1987, NOAA Fisheries published final regulations (50 FR 24244) implementing mandatory TED usage requirements in the U.S. shrimping industry. Initially, only four TED designs were approved. These were the NOAA Fisheries’ TED, the Cameron TED, the Matagorda TED, and the Georgia TED. On October 5, 1987, NOAA Fisheries issued a final rule/technical amendment to authorize an additional type of TED. The Morrison soft-TED differed from previous TED designs in being constructed from an upward-sloping panel of flexible webbing instead of the rigid grid used in hard TEDs.

A series of legal actions followed the initial 1987 regulations, resulting in inconsistent TED requirements and usage.

Finally, in 1989 federal regulations went into effect requiring widespread use of TEDs. This resulted in the extensive use of commercial TEDs as well as the development of new TED designs. With widespread use of commercial TEDs came more information on the efficiency of various designs. Combined results of state Sea Grant tests and data from fisheries observers indicated that the single grid TEDs varied in efficiency with regard to shrimp retention. This variation appeared, in part, dependent upon the bycatch associated with different shrimping grounds. Additionally, fishermen were still reporting shrimp losses and some original designs were not strong enough to withstand rigorous fishing conditions.

In response to these problems, our gear technologists worked with both fishermen and commercial gear manufacturers to modify single grid TEDs, improving their strength and efficiency.

Shrimp Import Legislation for Sea Turtle Conservation (1989)

In 1989, as TED development and evaluation continued, President George H. W. Bush signed Public Law 101-162. Section 609 of this law required the Department of State, in consultation with the Department of Commerce, to negotiate with foreign nations to develop sea turtle conservation agreements. 

Section 609 also established an annual certification program for countries exporting wild-caught shrimp and products from that shrimp. To export to the United States, countries must be certified by the Department of State for harvesting shrimp under conditions that do not threaten sea turtles (such as deepwater and cold-water shrimp fishing) or minimize the impact on them. For many nations, this includes having a regulatory program comparable to that of the United States, requiring the use of TEDs to reduce sea turtle bycatch. Section 609 certifications are published annually in the U.S. Federal Register.

By requiring foreign producers to meet U.S. standards, the law ensures U.S. shrimp harvesters compete on a level playing field, safeguarding U.S. jobs, promoting fair trade, and supporting responsible global fishing practices.

Learn more about shrimp import legislation for sea turtle conservation 

International TED Implementation

Since the early 1990s, the Department of State, NOAA Fisheries, and many partners have helped other countries develop their own TED regulations and TED enforcement programs. NOAA Fisheries also helps fishermen around the world to adopt and use TEDs through workshops and regular verification visits. As of 2026, 36 nations and Hong Kong are certified to export wild-caught shrimp to the United States based upon their use of TEDs in their commercial trawl fisheries.

Learn more about Section 609 Certification

Further TED Developments and Regulations

Throughout the 1990s, existing TED designs and regulations continued to improve and a variety of new TEDs, both rigid and soft, were introduced. TED use in all shrimp otter trawls—the primary gear used in offshore shrimping—became mandatory in 1992, with some minor exceptions. The first major change was the 1994 approval of a TED modification designed for leatherback sea turtles, which are much larger than other species of sea turtles in the U.S., to escape from small grid TEDs. Also significant was the 1998 introduction of a new soft-TED, the Parker TED. Additionally, 2003 saw the introduction of larger TED escape openings to improve the exclusion of leatherback turtles and adult loggerheads and green turtles. The double-cover escape opening was introduced, consisting of two mesh flaps covering the escape hole, providing enhanced turtle exclusion as well as improved shrimp retention.

Following 30 years of mandatory use of TEDs throughout the shrimp fishing industry, gear improvements are introduced almost yearly. Our gear experts continue to work with the industry evaluating new designs aimed at solving fishery- and region-specific issues. As new designs are proven to be effective, NOAA Fisheries authorizes the use of new designs in regulation. In 2012, the approved TED requirements were updated to allow the use of new materials and to modify existing approved TED designs.

While TED use in all otter trawls has been mandatory since 1992, TED use in skimmer trawls (specifically, skimmer trawls over 40 ft) remained voluntary until 2021. Skimmer trawls are used mainly in inshore waters because they are highly maneuverable. The boats and nets are smaller and can be managed by a single fisherman. Originally, TEDs were not required in skimmer trawls because the nets can be pulled at will and were required to be retrieved every 55 minutes to remove any trapped sea turtles. However, trained observers found that the 55 minute tow limit was not being followed, resulting in prolonged submergence and drowning of sea turtles. This led to the development of TEDs for skimmer trawls and new regulations. NOAA gear experts began testing skimmer trawl TEDs in 2008. In 2021, NOAA Fisheries published regulations requiring TEDs on all skimmer trawl vessels greater than 40 feet in length.

Ongoing Improvements in TED Technology

TED designs continue to evolve to better reduce sea turtle bycatch. By late 2024, commercial testing was completed on a TED with narrower bar spacing. Traditional TEDs, designed to exclude adult sea turtles, have bars 4 inches apart. This spacing increases the chance that smaller juvenile turtles might slip between the bars and become trapped in the trawl net. TEDs with bars spaced 2.5 inches apart can exclude up to 100% of juvenile sea turtles with minimal shrimp loss. 

Another TED modification, the Chauvin flapless TED, is growing in popularity. TEDs have escape openings in the trawl net that are usually covered by a single or double cover flap to reduce shrimp loss. However, the Chauvin flapless TED is widely used because of a different benefit: finfish bycatch reduction. The Chauvin TED is so successful at reducing finfish bycatch that in 2022 the already approved device began separate testing as a bycatch reduction device.