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In the past 20 years, researchers in Hawaii and Florida have documented the occurrence and prevalence of FP in local green turtle populations (Balazs 1991; Bresette et al. 2002; Ehrhart et al. 1996; Fick et al. 2000; Herbst et al. 1999; Murakawa et al. 2000; Provancha et al. 1998; Schroeder et al. 1998). The only difference that had been detected in the way this disease is expressed in these two widely separated populations was that tumors were common in the oral cavities of afflicted green turtles from Hawaii but seemed to be absent in the oral cavities of afflicted green turtles from Florida (Balazs et al. 1997). We present here the first two known cases of oral tumors associated with FP in green turtles from Florida.

On 28 March 1998, a live green turtle stranded on the beach at Patrick Air Force Base (Brevard County, 28º 22.5’N and 80º 36.1’W). The straight line carapace length (SCL, from the nuchal notch to the posterior marginal tip) of this turtle was 33.3 cm. It had numerous large (> 4 cm) tumors (unless otherwise specified these were always masses that were consistent in gross appearance with marine turtle fibropapilloma) on many areas of the body (but not on the eyes) and an approximately 6-cm-diameter tumor along the right side of the mouth. The attachment point of the tumor was on the dorsal surface of the oral cavity, on the soft tissue immediately posterior to the alveolar surface on the right side of the rhamphotheca. The base of the tumor was flattened and elongated so that the bulk of it rested outside the mouth and the mouth could close. This turtle was not emaciated when it was found, so we do not believe it had chronic difficulty in feeding. Because the bulk of the tumor was outside the mouth, it did not appear to interfere with breathing. The external appearance of this tumor was typical of a fibropapilloma, but it was not examined histologically.

On 5 March 2002, a live green turtle was captured at the St. Lucie Power Plant’s intake canal located on Hutchinson Island in St. Lucie County (27° 22.3’N and 80° 14.9’W). The SCL of this turtle was 63.2 cm. It had numerous small (< 4 cm) tumors on many areas of the body (including the eyes) and an approximately 7-mm-diameter tumor completely inside the oral cavity. The attachment point of this tumor was on the right side of the oral cavity where the maxilla meets the mandible. The tumor did not appear to interfere with feeding or breathing. The turtle was in good condition and of normal body weight (33.0 kg). Dr. Nancy Mettee of the MarineLife Center of Juno Beach removed the entire tumor, and a sample was sent to Dr. Elliott Jacobson of the College of Veterinary Medicine at the University of Florida for histological evaluation. Dr. Jacobson reported that the histology of the tumor was compatible with FP.

The rarity of the two oral tumors reported here is significant given the large number of green turtles with FP that have been examined in Florida. The Florida Sea Turtle Stranding and Salvage Network (FLSTSSN) documented the oral tumor found in 1998. From January 1980 through July 2002, participants in the FLSTSSN examined 989 dead or debilitated (i.e., stranded) green turtles with FP in Florida. Of those turtles examined, only one (0.1%) was reported to have a tumor-like mass in the oral cavity. Because the oral cavities of stranded green turtles may not have always been carefully and consistently examined, it may be more appropriate to consider only those green turtles that were necropsied and thus exposed to much greater scrutiny. Of the 280 green turtles with FP that were necropsied, only the one reported here (0.4%) had any findings suggestive of oral tumors.

Biologists from the sea turtle research program at the St. Lucie Power Plant documented the oral tumor found in 2002. This research program has been ongoing for more than 25 years, and more than 3000 green turtles have been captured (Bresette et al. 1998). Beginning in 1994, green turtles captured at the power plant were specifically examined for the presence of tumors associated with FP. When tumors were found externally on a turtle, the measurements and location of each tumor were noted and the oral cavity was examined. From January 1994 through July 2002, 127 green turtles were found with FP and only one of those (0.8%) was found to have an oral tumor.

Because oral tumors can interfere with breathing and feeding (Balazs et al. 1997), these two recent cases in Florida are cause for concern. Nevertheless, the occurrence of oral tumors among green turtles with FP in Florida is still far less than the occurrence of oral tumors documented for green turtles in Hawaii. (0.4%-0.8% vs. 40%-74%, respectively; Balazs 1997, Murakawa et al. 2000).

To better assess the frequency of oral tumors and to detect any future increase in their prevalence, it is vital that a standardized protocol for examining the oral cavities of green turtles be adopted by researchers throughout Florida. As is already practiced by some researchers, we recommend using an avian speculum to hold the jaws open and a narrow-beam light to illuminate the surfaces of the oral cavity. We also recommend using a standard search pattern to examine all the surfaces of the oral cavity.

Acknowledgments: We are grateful for the dedicated efforts of the participants in the FLSTSSN. We thank Dr. Nancy Mettee of the MarineLife Center of Juno Beach and Dr. Elliott Jacobson of the College of Veterinary Medicine at the University of Florida for their efforts in removing and analyzing the tumor taken from the turtle at the power plant. We also thank George Balazs, who encouraged us to take a better look into the oral cavities of green turtles in Florida. This report was improved by reviews from Anne Meylan, Andrea Mosier, Judy Leiby, and Jim Quinn. The work was authorized by the National Marine Fisheries Service and the Florida Fish and Wildlife Conservation Commission. The work was funded by the Florida Game and Freshwater Fish Commission (grant NG92-100), Florida’s Sea Turtle License Plate, the National Marine Fisheries Service, and Florida Power and Light Company.

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