Comparison of blood values in foraging, nesting, and stranded loggerhead turtles (Caretta caretta) along the coast of Georgia, USA

The health status of 83 loggerhead sea turtles (Caretta caretta; 39 foraging, 31 nesting, and 13 stranded turtles) was analyzed using physical examinations, hematology, plasma biochemistry, plasma protein electrophoresis, and toxicologic parameters. Significant differences were noted in a number of health parameters between turtles exhibiting each of these behaviors. On physical examinations, stranded turtles had the highest prevalence of heavy carapace epibiont loads, miscellaneous abnormalities, emaciation, and weakness. Differences in hematologic values included a lower packed cell volume, higher number of lymphocytes, and lower number of monocytes in stranded turtles; lower white blood cell counts in foraging turtles; and significant differences in total solid values among turtles exhibiting all behaviors with the lowest values in stranded turtles and the highest values in nesting turtles. Differences in plasma biochemistry values included the highest uric acid, creatine kinase, and CO2 values in stranded turtles; the highest glucose and potassium values in foraging turtles; and the highest cholesterol and triglyceride values, and lowest alanine aminotransferase, in nesting turtles. Differences in total protein, albumin, and globulin were found using plasma biochemistry values, with lowest values in stranded turtles and highest values in nesting females, whereas differences in blood urea nitrogen between turtles included the lowest values in nesting turtles and the highest in foraging turtles. Plasma organochlorine and polychlorinated biphenyl levels were below their limits of quantification in the 39 foraging, 11 nesting, and three stranded turtles tested. A statistically significant difference was noted in the level of whole blood mercury between the 23 foraging and 12 nesting turtles tested. There was no difference in arsenic or lead levels between turtles exhibiting any of the three behaviors. Although a few limitations exist with the present study and include unknown ambient temperatures, turtle handling times that varied from 15 min to 53 min per turtle, and the use of a different laboratory for processing complete blood counts and plasma biochemistries in stranded versus foraging and nesting turtles, we provide baseline blood values for two cohorts (foraging and nesting) of loggerhead sea turtles on the coast of Georgia. Additionally, we demonstrate significant differences in clinical findings and blood parameters between foraging, nesting, and stranded loggerhead turtles in the region.