Meeting Abstract

P3.11  Tuesday, Jan. 6  Why is nest success low? Hg, Se, and blood parameters in nesting leatherback sea turtles (Dermochelys coriacea) and their young. PERRAULT, J.*; WYNEKEN, J.; JOHNSON, C.; THOMPSON, L.J.; MILLER, D.L.; Florida Atlantic University; FAU; Loggerhead Marinelife Center; Nestle Purina PetCare; VDIL, University of Georgia jperrau2@fau.edu

Leatherback sea turtles have low hatch success compared to other sea turtle species. We investigated potential causes of low hatch success and hatchling vigor. We hypothesized these and other anomalies found in dead-in-nest leatherbacks are correlated with Hg and Se levels (Se detoxifies Hg). We surveyed dead hatchlings for evidence of Hg exposure and other indicators of compromised vigor. Blood collected from 40 nesting leatherbacks was analyzed for Hg, Se, and blood parameters. Their nests were inventoried after emergence and we examined those results for relationship to maternal health. Maternal blood Hg and Se concentrations ranged from 1-77 ppb and 0.4-20 ppm, respectively. Neither significantly correlated with hatchling emergence success. Hg levels decreased over time in turtles that were sampled in sequential nesting events, suggesting maternal transfer to the offspring. Maternal Se tended to increase as the season progressed, indicating that these turtles may be feeding on Se-rich food sources between nesting events. Next, blood samples from live hatchlings, and livers collected from dead-in-nest hatchlings were analyzed. For hatchlings, liver Hg ranged from 0.1-0.3 ppb and liver Se ranged from 1-2 ppm. Hatchling blood Se ranged from 1-7 ppm. Two metabolic measures from blood surveys correlated with emergence success (anion gap, BUN); their functional relationship is unclear. We also analyzed liver Hg and Se in 6 hatchlings (<5 days old) brought into the lab for a separate study. Hg concentrations in these turtles increased with age, consistent with Hg mobilization from the yolk sac. Our study is the first to establish Hg and Se levels in hatchling leatherbacks, and to identify the roles of their mothers in transferring their Hg and Se loads to their offspring.