DeLorenzo M E, Eckmann C A, Chung K W, Key P B, Fulton M H
NOAA/National Ocean Service/National Centers for Coastal Ocean Science, 219 Fort Johnson Rd., 29412 Charleston, SC, USA.
University of South Carolina, Columbia, SC, USA.
Ecotoxicol Environ Saf. 2016 Dec;134P1:256-263. doi: 10.1016/j.ecoenv.2016.09.008. Epub 2016 Sep 16.
Chemical dispersants can be a useful tool to mitigate oil spills, but the potential risks to sensitive estuarine species should be carefully considered. To improve the decision making process, more information is needed regarding the effects of oil spill dispersants on the health of coastal ecosystems under variable environmental conditions such as salinity. The effects of salinity on the toxicity of two oil dispersants, Corexit 9500 and Finasol OSR 52, were examined in this study. Corexit 9500 was the primary dispersant used during the 2010 Deepwater Horizon oil spill event, while Finasol OSR 52 is another dispersant approved for oil spill response in the U.S., yet considerably less is known regarding its toxicity to estuarine species. The grass shrimp, Palaemonetes pugio, was used as a model estuarine species. It is a euryhaline species that tolerates salinities from brackish to full strength seawater. Adult and larval life stages were tested with each dispersant at three salinities, 5, 20, and 30 ppt. Median acute lethal toxicity thresholds and oxidative stress responses were determined. The toxicity of both dispersants was significantly influenced by salinity, with greatest toxicity observed at the lowest salinity tested. Larval shrimp were significantly more sensitive than adult shrimp to both dispersants, and both life stages were significantly more sensitive to Finasol than to Corexit. Oxidative stress in adult shrimp, as measured by increased lipid peroxidation activity, occurred with exposure to both dispersants. These data will assist environmental managers in making informed decisions regarding dispersant use in future oil spills.
化学分散剂可以作为减轻石油泄漏危害的一种有用工具，但对于敏感河口物种的潜在风险应予以仔细考虑。为了改进决策过程，需要更多关于在诸如盐度等可变环境条件下石油泄漏分散剂对沿海生态系统健康影响的信息。本研究考察了盐度对两种石油分散剂（科里xit 9500和菲纳索尔OSR 52）毒性的影响。科里xit 9500是2010年深水地平线石油泄漏事件中使用的主要分散剂，而菲纳索尔OSR 52是美国另一种被批准用于应对石油泄漏的分散剂，但关于其对河口物种的毒性所知甚少。草虾（Palaemonetes pugio）被用作典型的河口物种。它是一种广盐性物种，能耐受从微咸水到全强度海水的盐度。分别在5、20和30 ppt这三种盐度下，用每种分散剂对草虾的成体和幼体阶段进行了测试。测定了半数急性致死毒性阈值和氧化应激反应。两种分散剂的毒性都受到盐度的显著影响，在测试的最低盐度下观察到最大毒性。幼体虾对两种分散剂都比成体虾敏感得多，而且两个生命阶段对菲纳索尔的敏感性都显著高于科里xit。通过脂质过氧化活性增加来衡量，成体虾在接触两种分散剂时都会出现氧化应激。这些数据将有助于环境管理者在未来石油泄漏事件中就分散剂的使用做出明智决策。
