Epperly and Teas: Escape openings in turtle excluder devices 



473 



turtles (TEWG, 1998: 2000) and indicates that, for logger- 

 head sea turtles, TEDs have not achieved a 9T'/r reduction 

 in captures by shrimp trawlers. Loggerhead turtles are ex- 

 ceeding in size the required minimum height of openings 

 in TED before reaching maturity, especially in the Gulf of 

 Mexico where the allowed opening is smaller than that in 

 the Atlantic. This anomaly had not been noted previously 

 because, since 1990, turtles used for TED trials have been 

 small (<21 cm in body depth, n=1415; NMFS-'). Based on 

 stage elasticities, a proportional reduction in mortality in 

 the smallest size classes not fitting through the TED open- 

 ings (large immature turtles) would result in the greatest 

 increased annual population multiplication rate (Grouse 

 et al., 1987; Heppell. 1998a: Epperly et al., 2001). A reduc- 

 tion in subadult and adult mortality from drowning in 

 trawls would benefit all species and subpopulations of sea 

 turtles (Heppell, 1998b). 



To decrease the mortality on large turtles caused by 

 trawling, the opening dimensions of TEDs need to be 

 larger than the current minimum requirements and need 

 to be the same in the Gulf of Mexico and the Atlantic. 

 Possible management options include the following: 1) in- 

 crease the dimensions to accommodate some desired pro- 

 portion of adults or the total population and 2) adopt the 

 "leatherback" modification (Federal Register, 1993, 1994, 

 1995) for all areas and all times, which would allow the 

 exclusion of turtles of all sizes, including leatherbacks 

 which are the largest of the sea turtles. In response to our 

 findings, an advance notice of a proposed rulemaking, to 

 effect a change in TED requirements, was issued by NMFS 

 (Federal Register, 2000). After consideration of public com- 

 ments, NMFS advertised a proposed rule to change the 

 TED requirements (Federal Register, 2001). NMFS should 

 also consider extending the TED regulations to other bot- 

 tom trawl fisheries of the Gulf of Mexico and along the 

 Atlantic seaboard, including in the Northeast United 

 States, whenever turtles and bottom trawling activity 

 may co-occur. 



Acknowledgments 



We thank the following people for providing morphometric 

 measurements: Allen Foley, Tim Fontaine, Jerris Foote, 

 Jonathan Gorham, Ben Higgins, John Hammond, Joanne 

 Braun McNeill, Joe Parsons, Mike Salmon, Jeffrey Schmid, 

 and Jeanette Wyneken. We thank the state coordinators 

 of the Sea Turtle Stranding and Salvage Network and its 

 innumerable volunteers, past and present, for providing 

 the numbers and size distributions of stranded sea turtles. 

 We also thank Joseph Powers for his constructive review of 

 the manuscript and Jamie Serino for allowing us to use his 

 copyrighted drawing of a turtle. 



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