Meeting Abstract

P3.8  Thursday, Jan. 6  Salps to sea turtles: Hg and Se in leatherback sea turtles (Dermochelys coriacea). Lessons learned from two populations. PERRAULT, J.*; MILLER, D.L.; WYNEKEN, J.; Florida Atlantic Univ.; Veterinary Diagnostic and Investigational Lab., Univ. of Georgia-Tifton; Florida Atlantic Univ. jperrau2@fau.edu

Leatherback turtles are pelagic migrants that specialize on gelatinous zooplankton prey. They experience higher reproductive failure than other sea turtle species. Within the turtles that hatched, we documented muscular anomalies that were similar to those found in selenium (Se) deficient bovine calves. Se acts in the liver to detoxify mercury compounds (Hg). As Hg levels rise, in vivo Se may become exhausted, resulting in Se deficiency. Both Hg and Se accumulate through food and water intake. The muscle anomalies led us to hypothesize that Hg and Se levels in leatherbacks affect nest success. We documented Hg and Se concentrations in nesting female leatherback turtles and their hatchlings from Florida and St. Croix and measured nest success. We found that hatchling liver Hg and Se concentrations significantly correlated with leatherback turtle nest success. Additionally, we found that Hg tended to decrease as the season progressed and that nesting female blood Se significantly correlated with Se in the blood of their hatchlings. To our knowledge, no studies have documented Hg and/or Se concentrations in leatherback prey items. Jellyfish that consume zooplankton likely sequester Hg and Se from these planktonic sources, which could be passed on to the next level in the food chain. We measured Hg and Se levels in their prey and found that they have measurable levels of these elements, oftentimes at higher concentrations than those found in the blood of nesting females. Our study is the first to document Hg and Se concentrations in hatchling sea turtles and to show that contaminants play a role in reproductive success in sea turtles. Additionally, we found that mercury biomagnifies within this food chain.