Blood analytes of immature Kemp's ridley sea turtles (Lepidochelys kempii) from Georgia, USA: reference intervals and body size correlations.

Health assessments of wildlife species are becoming increasingly important in an ever-changing environment. Kemp's ridley sea turtles (Lepidochelys kempii; hereafter, Kemp's ridleys) are critically endangered and incur several on-going threats to their population recovery; therefore, it is imperative to advance the understanding of baseline blood analyte data as a diagnostic and monitoring tool. For in-water, trawl-captured, immature Kemp's ridleys (minimum N = 31) from Georgia, USA, the objectives of this study were to (1) establish reference intervals (RIs) for packed cell volume (PCV) and 27 plasma biochemistry analytes and (2) determine length-specific relationships in blood analytes. We observed significant positive correlations between minimum straight carapace length and PCV, amylase, calcium:phosphorus ratio, cholesterol, magnesium, triglycerides, total solids, total protein and all protein fractions (e.g. alpha-, beta- and gamma-globulins); aspartate aminotransferase and chloride showed significant negative relationships. These results suggest that certain blood analytes in Kemp's ridleys change as these animals grow, presumptively due to somatic growth and dietary shifts. The information presented herein, in due consideration of capture technique that may have impacted glucose and potassium concentrations, represents the first report of blood analyte RIs for Kemp's ridley sea turtles established by guidelines of the American Society for Veterinary Clinical Pathology and will have direct applications for stranded individuals in rehabilitative care and for future investigations into the health status of wild individuals from this population.

Perfluoroalkyl contaminants in plasma of five sea turtle species: comparisons in concentration and potential health risks.

The authors compared blood plasma concentrations of 13 perfluoroalkyl contaminants (PFCs) in five sea turtle species with differing trophic levels. Wild sea turtles were blood sampled from the southeastern region of the United States, and plasma was analyzed using liquid chromatography tandem mass spectrometry. Mean concentrations of perfluorooctane sulfonate (PFOS), the predominant PFC, increased with trophic level from herbivorous greens (2.41 ng/g), jellyfish-eating leatherbacks (3.95 ng/g), omnivorous loggerheads (6.47 ng/g), to crab-eating Kemp's ridleys (15.7 ng/g). However, spongivorous hawksbills had surprisingly high concentrations of PFOS (11.9 ng/g) and other PFCs based on their trophic level. These baseline concentrations of biomagnifying PFCs demonstrate interesting species and geographical differences. The measured PFOS concentrations were compared with concentrations known to cause toxic effects in laboratory animals, and estimated margins of safety (EMOS) were calculated. Small EMOS (<100), suggestive of potential risk of adverse health effects, were observed for all five sea turtle species for immunosuppression. Estimated margins of safety less than 100 were also observed for liver, thyroid, and neurobehavorial effects for the more highly exposed species. These baseline concentrations and the preliminary EMOS exercise provide a better understanding of the potential health risks of PFCs for conservation managers to protect these threatened and endangered species.

Predaceous ants, beach replenishment, and nest placement by sea turtles.

Ants known for attacking and killing hatchling birds and reptiles include the red imported fire ant (Solenopsis invicta Buren), tropical fire ant [Solenopsis geminata (Fabr.)], and little fire ant [Wasmannia auropunctata (Roger)]. We tested whether sea turtle nest placement influenced exposure to predaceous ants. In 2000 and 2001, we surveyed ants along a Florida beach where green turtles (Chelonia mydas L.), leatherbacks (Dermochelys coriacea Vandelli), and loggerheads (Caretta caretta L.) nest. Part of the beach was artificially replenished between our two surveys. As a result, mean beach width experienced by nesting turtles differed greatly between the two nesting seasons. We surveyed 1,548 sea turtle nests (2000: 909 nests; 2001: 639 nests) and found 22 ant species. S. invicta was by far the most common species (on 431 nests); S. geminata and W. auropunctata were uncommon (on 3 and 16 nests, respectively). In 2000, 62.5% of nests had ants present (35.9% with S. invicta), but in 2001, only 30.5% of the nests had ants present (16.4% with S. invicta). Turtle nests closer to dune vegetation had significantly greater exposure to ants. Differences in ant presence on turtle nests between years and among turtle species were closely related to differences in nest placement relative to dune vegetation. Beach replenishment significantly lowered exposure of nests to ants because on the wider beaches turtles nested farther from the dune vegetation. Selective pressures on nesting sea turtles are altered both by the presence of predaceous ants and the practice of beach replenishment.