Shrimp retention characteristics of the Morrison Soft TED: a selective webbing exclusion panel inserted in a shrimp trawl net

Abstract Regulations mandating the use of TEDs (Turtle Excluder Device or Trawling Efficiency Device) in the southeastern United States shrimp fishery are now a reality. One of these devices showing promise as an excluder and shrimp catcher is the Morrison Soft TED. This is a deflector panel of 203-mm stretched mesh webbing installed on the inside of a shrimp trawl. In theory, shrimp should be forced through the mesh of the panel and into the bag, while larger organisms such as jellyball jellyfish ( Stomolophus melagris ), horseshoe crabs ( Limulus polyphemus ), rays, sharks, and sea turtles are deflected up and out of the net. This study was conducted in two phases. In Phase 1, the Morrison TED was certified as an effective device for excluding sea turtles. Phase 2, which is the focus of this paper, considers the shrimp retention characteristics of this TED. Forty-eight tows were made during July 1987 through January 1988, aboard a modified shrimp trawler. A total shrimp catch rate of approximately 4.5 kg h −1 in the control net was the desired criterion for accepting a sample in the results. This occurred 27 (56.3%) times and all statistical analysis was performed on these data. A paired t -test indicated no significant difference in shrimp catch between the two nets. The TED net reduced the total biomass caught by an average of 24%, or approximately 56 kg per tow, and did not catch any animals larger than 4.5 kg.