Examinations of Sea Turtle Carcasses Found Stranded within Shrimp Statistical Subarea 18 Located on the Upper Texas Coast
Clark T. Fontaine; Dickie B. Revera
Mexico were not maintained by the Federal Government prior to 1956. To expedite geographical assignment of commercial trawling effort, and hence classification of shrimp landings as to origin, the continental shelf of the United States Atlantic Dependable statistics of trawling operations and shrimp production in the Gulf of Coast and the northern Gulf of Mexico were subdivided coast-wide into statistical subareas. One of the more active shrimp subareas is subarea 18 located on the upper Texas coast and coincidental with the location of the National Marine Fisheries Service (NMFS) Laboratory in Galveston, Texas. Along with the opportunity to monitor strandings of sea turtles within shrimp subarea 18, there was also the opportunity to closely examine the carcasses themselves (necropsy) to perhaps determine cause of death, how caught, what the animal had been eating, size, abnormalities, and other pertinent biological data and information. In most cases the carcasses were in such poor condition, due to rapid postmortem changes, examinations were limited to external observations or very perfunctory necropsy. However, in some few cases the carcasses were found very fresh in which instance they examined closely by either a veterinarian, a NMFS staff member, or both.
This paper is a report of the examinations and necropsy performed upon sea turtles stranded dead within shrimp statistical subarea 18 during a seven year period, from January 1, 1995 through December 31, 2001. Statistical subarea 18 provides 101 miles of beach accessible to four wheel drive vehicle of which 92 miles were covered in the surveys reported here. Every effort was made to complete beach surveys once a week; even so some surveys were missed due to high tides, extremely foul weather, or equipment breakdown. Further, every effort was made to necropsy each and every carcass found during survey, however, in most cases the autolytic postmortem changes made it impossible to complete anything but external observations on most carcasses. Unless the carcass was very fresh the gross necropsy was performed on the beach and the carcass buried at the site. At the minimum, an external examination noting any and all wounds and injuries was performed. However, due to the post-mortem condition of most carcasses, complete necropsies, including histopathology, were rare. In general, most necropsies included external exam, gross examinations of gastrointestinal contents, trachea, esophagus, determination of sex, and general health. There were 710 sea turtle carcasses found dead stranded on the beach within shrimp statistical subarea 18 on the upper Texas coast of which 710 were examined externally (100%), 272 received complete gross examination (38.3%), 39 had only the trachea and esophagus examined (5.5%) and 15 received complete and full necropsy (2.1%).