Vol. 19 No. 2 2002 Endangered Species UPDATE 35 The Science and Policy Behind Proposed Sea Turtle Conservation Measures Lekelia D. Jenkins Nicholas School of the Environment and Earth Sciences, Duke University Marine Laboratory, 135 Duke Marine Lab Road, Beaufort, NC 28516, USA ldj@duke.edu Abstract In recent months, two major actions have been initiated that may change the landscape of sea turtle conservation and potentially ignite controversy. The first action involves an October 2001 proposal by the National Marine Fisheries Service's to substantially amend Turtle Excluder Device regula- tions. The extended public comment period for this proposal concluded on February 15, 2002. In the other action, two environmental groups jointly filed a petition on January 10, 2002, to list certain subpopulations of loggerhead sea turtles (Caretta caretta) as endangered. Both the petition and the proposal result from public concern and scientific evidence that current conservation mea- sures are not sufficient to allow recovery of some sea turtle populations, mostly likely loggerhead and perhaps leatherback and green turtles as well. Background All sea turtles that traverse U.S. wa- ters are listed under the Endangered Species Act of 1973 (ESA). The Kemp's ridley (Lepidochelys kempii), leatherback (Dermochelys coriacea), and hawksbill ( Eretmochelys imbricata) turtles are listed as endan- gered. The loggerhead ( Caretta caretta), olive ridley (Lepidochelys oliveacea), and green ( Chelonia mydas) turtles are listed as threatened, with the exception of two breeding populations of green turtles and one breeding population of olive ridley turtles, which are listed as endangered. The National Research Council (1990) reported that in U.S. waters shrimp trawling is the primary source of anthropogenic mortality for sea turtles. The Council estimated that during the 1980s shrimp trawling drowned 44,000 loggerhead and Kemp's ridley turtles each year. In order to reduce this mortality, Na- tional Marine Fisheries Service (NMFS) mandated the voluntary use of Turtle Excluder Devices (TEDs) in 1987; these regulations became compulsory in 1990. This regulation and subsequent amendments require most shrimp and summer flounder trawlers, operating in the Southeastern U.S., to have a NMFS-approved TED installed in each net. A TED consists of an angled barrier, known as a grid, which has vertical slots wide enough to allow shrimp to pass into the net bag but narrow enough to deflect turtles out of an escape opening in the net (Fig- ure 1). NMFS has certified a num- ber of TED designs, which must ex- clude 97% of the sea turtles that en- ter the net. In addition, the escape opening, when stretched to form a tri- angle, must meet or exceed certain parameters. Along the Atlantic Coast the required width is 35 inches and the height is 12 inches; in the Gulf of Mexico the required width is 32 inches and the height is 10 inches (Federal Register 1992). The use of TEDs, in combination with other conservation measures, appear to be partially successful in helping to recover sea turtle popula- tions. The Turtle Expert Working Group (2000) found that the popula- tion size of Kemp's ridley turtles is increasing exponentially. However, this same report found that of the four genetically distinct subpopulations of loggerhead turtles, only one is stable or increasing, the status of two are unknown, and the northern subpopu- lation has been declining since the 1970s. This downward population trend in the northern subpopulation, which ranges from North Carolina to northeast Florida, factors significantly into the activities of recent months. Science: population trends and fisheries bycatch In 1980, the South Carolina Depart- ment of Natural Resources (SCDNR) began monitoring loggerhead nesting activity because the state has an ex- tensive population of these threatened turtles (Figure 2). The quality long- term data generated from studies in South Carolina comprises a signifi- cant portion of the available knowl- edge about loggerhead populations, which is one of the better-studied sea turtle species. Thus this data is widely used in making policy decisions that often have ramifications for other sea turtle species, as is the case with the proposed TED regulations. SCDNR conducted ground and aerial beach surveys on a five-year