Department of Natural Resources and Environmental Management, University of Hawai'i at Mānoa, Honolulu, HI 96822, United States.
Department of Natural Resources and Environmental Management, University of Hawai'i at Mānoa, Honolulu, HI 96822, United States; Auburn University, School of Forestry and Wildlife Science, Auburn, AL, United States.
Sci Total Environ. 2018 Jan 1;610-611:402-411. doi: 10.1016/j.scitotenv.2017.07.242. Epub 2017 Aug 12.
In addition to eating contaminated prey, sea turtles may be exposed to persistent organic pollutants (POPs) from ingesting plastic debris that has absorbed these chemicals. Given the limited knowledge about POPs in pelagic sea turtles and how plastic ingestion influences POP exposure, our objectives were to: 1) provide baseline contaminant levels of three species of pelagic Pacific sea turtles; and 2) assess trends of contaminant levels in relation to species, sex, length, body condition and capture location. In addition, we hypothesized that if ingesting plastic is a significant source of POP exposure, then the amount of ingested plastic may be correlated to POP concentrations accumulated in fat. To address our objectives we compared POP concentrations in fat samples to previously described amounts of ingested plastic from the same turtles. Fat samples from 25 Pacific pelagic sea turtles [2 loggerhead (Caretta caretta), 6 green (Chelonia mydas) and 17 olive ridley (Lepidochelys olivacea) turtles] were analyzed for 81 polychlorinated biphenyls (PCBs), 20 organochlorine pesticides, and 35 brominated flame-retardants. The olive ridley and loggerhead turtles had higher ΣDDTs (dichlorodiphenyltrichloroethane and metabolites) than ΣPCBs, at a ratio similar to biota measured in the South China Sea and southern California. Green turtles had a ratio close to 1:1. These pelagic turtles had lower POP levels than previously reported in nearshore turtles. POP concentrations were unrelated to the amounts of ingested plastic in olive ridleys, suggesting that their exposure to POPs is mainly through prey. In green turtles, concentrations of ΣPCBs were positively correlated with the number of plastic pieces ingested, but these findings were confounded by covariance with body condition index (BCI). Green turtles with a higher BCI had eaten more plastic and also had higher POPs. Taken together, our findings suggest that sea turtles accumulate most POPs through their prey rather than marine debris.
除了食用受污染的猎物外，海龟还可能通过摄入吸收了这些化学物质的塑料碎片而接触到持久性有机污染物 (POPs)。鉴于人们对远洋海生龟类中的持久性有机污染物的了解有限，以及摄入塑料对持久性有机污染物暴露的影响，我们的目标是：1）提供三种太平洋远洋海生龟类的基线污染物水平；2）评估与物种、性别、长度、身体状况和捕捞地点有关的污染物水平趋势。此外，我们假设，如果摄入塑料是持久性有机污染物暴露的重要来源，那么摄入的塑料量可能与积累在脂肪中的持久性有机污染物浓度相关。为了实现我们的目标，我们将脂肪样本中的持久性有机污染物浓度与来自同一海龟的先前描述的摄入塑料量进行了比较。从 25 只太平洋远洋海生龟（2 只红海龟、6 只绿海龟和 17 只榄蠵龟）的脂肪样本中分析了 81 种多氯联苯（PCBs）、20 种有机氯农药和 35 种溴化阻燃剂。榄蠵龟和红海龟的ΣDDTs（滴滴涕和代谢物）高于ΣPCBs，其比值与南海和南加州的生物群相似。绿海龟的比值接近 1:1。这些远洋龟的持久性有机污染物水平低于以前在近岸龟中报告的水平。持久性有机污染物浓度与榄蠵龟摄入的塑料量无关，这表明它们主要通过猎物接触持久性有机污染物。在绿海龟中，ΣPCBs 浓度与摄入的塑料片数量呈正相关，但这些发现与身体状况指数（BCI）的协方差相混淆。BCI 较高的绿海龟摄入的塑料更多，且持久性有机污染物也更多。总的来说，我们的研究结果表明，海生龟类主要通过其猎物而不是海洋碎片积累大多数持久性有机污染物。
