Department of Biological Sciences, Florida Atlantic University, Building 01, Sanson Science, 777 Glades Road, Boca Raton, FL 33431, USA.
Sci Total Environ. 2013 Oct 1;463-464:61-71. doi: 10.1016/j.scitotenv.2013.05.067. Epub 2013 Jun 19.
Leatherback sea turtles (Dermochelys coriacea) are long-distance migrants that travel thousands of km from foraging grounds to breeding and nesting grounds. These extensive journeys are fueled by ingestion of an estimated 300-400 kg of prey/d and likely result in exposure to high concentrations of environmental toxicants (e.g., mercury compounds). Increased bodily concentrations of mercury and its compounds in nesting female turtles may have detrimental effects on reproductive success. Leatherbacks have relatively low reproductive success compared with other sea turtles (global average hatching success ~50-60%). To assess toxicants and necessary nutrients as factors affecting leatherback turtle reproductive success at Sandy Point National Wildlife Refuge (SPNWR), St. Croix, U.S. Virgin Islands, we collected blood from nesting female leatherbacks and tissues from their hatchlings (blood from live turtles, liver and yolk sac from dead turtles). We compared the concentrations in those tissues to hatching and emergence success. We found that on SPNWR, hatching and emergence success were more closely related to seasonal factors than to total mercury and selenium concentrations in both nesting females and hatchlings. Selenium concentrations of nesting females were positively correlated with those of their hatchlings. Mercury and selenium in the liver of hatchlings were positively correlated with one another. Turtles with greater remigration intervals tended to have higher blood selenium concentrations, suggesting that selenium accumulates in leatherbacks through time. Through hazard quotients, we found evidence that selenium may be at or above concentrations that may cause physiologic harm to hatchlings. We also found evidence that population level differences exist for these trace elements. The concentrations of mercury and selenium established in this manuscript form a baseline for future toxicant studies.
棱皮龟（Dermochelys coriacea）是一种长途迁徙动物，它们从觅食地迁徙数千公里到繁殖和筑巢地。这些长途旅行是通过摄入估计 300-400 公斤的猎物/天来提供燃料的，并且可能导致暴露于高浓度的环境毒物（例如，汞化合物）中。筑巢雌性海龟体内汞及其化合物浓度的增加可能对繁殖成功产生不利影响。与其他海龟（全球平均孵化成功率为 50-60%）相比，棱皮龟的繁殖成功率相对较低。为了评估毒物和必要的营养物质作为影响美国维尔京群岛圣克罗伊岛 Sandy Point 国家野生动物保护区（SPNWR）棱皮龟繁殖成功的因素，我们从筑巢的雌性棱皮龟身上采集血液，并从它们的幼龟身上采集组织（活体海龟的血液、死海龟的肝脏和卵黄囊）。我们比较了这些组织中的浓度与孵化和出壳成功率。我们发现，在 SPNWR，孵化和出壳成功率与季节性因素的关系比筑巢雌性和幼龟体内的总汞和硒浓度更为密切。筑巢雌性的硒浓度与它们的幼龟呈正相关。幼龟肝脏中的汞和硒呈正相关。具有较大再迁移间隔的海龟往往具有较高的血液硒浓度，这表明硒随着时间的推移在棱皮龟体内积累。通过危害商数，我们发现有证据表明，硒的浓度可能达到或超过可能对幼龟造成生理伤害的浓度。我们还发现，这些微量元素在种群水平上存在差异。本手稿中确定的汞和硒浓度为未来的毒物研究奠定了基础。
