Environmental Conservation Division, Northwest Fisheries Science Center, National Oceanic and Atmospheric Administration, 2725 Montlake Boulevard East, Seattle, WA 98112, United States.
Aquat Toxicol. 2013 Oct 15;142-143:303-16. doi: 10.1016/j.aquatox.2013.08.011. Epub 2013 Aug 31.
The 2010 Deepwater Horizon disaster in the Gulf of Mexico was the largest oil spill in United States history. Crude oils are highly toxic to developing fish embryos, and many pelagic fish species were spawning in the northern Gulf in the months before containment of the damaged Mississippi Canyon 252 (MC252) wellhead (April-July). The largest prior U.S. spill was the 1989 grounding of the Exxon Valdez that released 11 million gallons of Alaska North Slope crude oil (ANSCO) into Prince William Sound. Numerous studies in the aftermath of the Exxon Valdez spill defined a conventional crude oil injury phenotype in fish early life stages, mediated primarily by toxicity to the developing heart. To determine whether this type of injury extends to fishes exposed to crude oil from the Deepwater Horizon - MC252 incident, we used zebrafish to compare the embryotoxicity of ANSCO alongside unweathered and weathered MC252 oil. We also developed a standardized protocol for generating dispersed oil water-accommodated fractions containing microdroplets of crude oil in the size range of those detected in subsurface plumes in the Gulf. We show here that MC252 oil and ANSCO cause similar cardiotoxicity and photo-induced toxicity in zebrafish embryos. Morphological defects and patterns of cytochrome P450 induction were largely indistinguishable and generally correlated with polycyclic aromatic compound (PAC) composition of each oil type. Analyses of embryos exposed during different developmental windows provided additional insight into mechanisms of crude oil cardiotoxicity. These findings indicate that the impacts of MC252 crude oil on fish embryos and larvae are consistent with the canonical ANSCO cardiac injury phenotype. For those marine fish species that spawned in the northern Gulf of Mexico during and after the Deepwater Horizon incident, the established literature can therefore inform the assessment of natural resource injury in the form of potential year-class losses.
墨西哥湾的 2010 年深海地平线灾难是美国历史上最大的石油泄漏事件。原油对发育中的鱼类胚胎具有高度毒性，在受损的密西西比峡谷 252 号（MC252）井口（4 月至 7 月）被封堵的前几个月，许多洄游鱼类在墨西哥湾北部产卵。美国此前最大的溢油事件是 1989 年埃克森·瓦尔迪兹号搁浅事件，当时有 1100 万加仑的阿拉斯加北坡原油（ANSCO）泄漏到威廉王子湾。埃克森·瓦尔迪兹号溢油事件发生后，许多研究都确定了鱼类早期生命阶段中常规原油损伤表型，主要是由发育中的心脏毒性引起的。为了确定这种损伤是否会扩展到暴露于深海地平线-MC252 事件原油的鱼类，我们使用斑马鱼来比较 ANSCO 与未经风化和风化的 MC252 油的胚胎毒性。我们还开发了一种标准化方案，用于生成分散的油-水容纳馏分，其中包含在墨西哥湾海底羽流中检测到的微滴大小范围内的原油微滴。我们在这里表明，MC252 油和 ANSCO 会导致斑马鱼胚胎产生类似的心脏毒性和光诱导毒性。形态缺陷和细胞色素 P450 诱导模式在很大程度上是不可区分的，并且通常与每种油类型的多环芳烃（PAC）组成相关。对在不同发育窗口中暴露的胚胎进行的分析提供了对原油心脏毒性机制的更多了解。这些发现表明，MC252 原油对鱼类胚胎和幼鱼的影响与典型的 ANSCO 心脏损伤表型一致。对于那些在深海地平线事件期间和之后在墨西哥湾北部产卵的海洋鱼类物种，因此，已建立的文献可以为自然资源损伤评估提供信息，形式为潜在的年产损失。
