Department of Chemistry, Haverford College, Haverford, PA 19041, USA.
Proc Natl Acad Sci U S A. 2012 Dec 11;109(50):20303-8. doi: 10.1073/pnas.1118029109. Epub 2012 Mar 27.
To assess the potential impact of the Deepwater Horizon oil spill on offshore ecosystems, 11 sites hosting deep-water coral communities were examined 3 to 4 mo after the well was capped. Healthy coral communities were observed at all sites >20 km from the Macondo well, including seven sites previously visited in September 2009, where the corals and communities appeared unchanged. However, at one site 11 km southwest of the Macondo well, coral colonies presented widespread signs of stress, including varying degrees of tissue loss, sclerite enlargement, excess mucous production, bleached commensal ophiuroids, and covering by brown flocculent material (floc). On the basis of these criteria the level of impact to individual colonies was ranked from 0 (least impact) to 4 (greatest impact). Of the 43 corals imaged at that site, 46% exhibited evidence of impact on more than half of the colony, whereas nearly a quarter of all of the corals showed impact to >90% of the colony. Additionally, 53% of these corals' ophiuroid associates displayed abnormal color and/or attachment posture. Analysis of hopanoid petroleum biomarkers isolated from the floc provides strong evidence that this material contained oil from the Macondo well. The presence of recently damaged and deceased corals beneath the path of a previously documented plume emanating from the Macondo well provides compelling evidence that the oil impacted deep-water ecosystems. Our findings underscore the unprecedented nature of the spill in terms of its magnitude, release at depth, and impact to deep-water ecosystems.
为评估深水地平线（Deepwater Horizon）石油泄漏对近海生态系统的潜在影响，在油井被封堵 3 至 4 个月后，研究人员检查了 11 个栖息深水珊瑚群落的地点。在距离马孔多油井（Macondo well）超过 20 公里的所有地点都观察到了健康的珊瑚群落，其中包括 2009 年 9 月曾访问过的七个地点，那里的珊瑚和群落似乎没有变化。然而，在马孔多油井西南 11 公里的一个地点，珊瑚群出现了广泛的应激迹象，包括不同程度的组织损失、骨板增大、过度黏液分泌、共生蛇尾类动物白化，以及被棕色絮状物质（floc）覆盖。根据这些标准，对单个珊瑚丛的影响程度从 0（最小影响）到 4（最大影响）进行了排名。在该地点拍摄的 43 株珊瑚中，46%的珊瑚有超过一半的珊瑚丛受到影响的证据，而近四分之一的珊瑚受到影响的面积超过 90%。此外，这些珊瑚的 53%的蛇尾类动物伙伴表现出异常的颜色和/或附着姿势。从絮状物中分离出的藿烷类石油生物标志物的分析提供了强有力的证据，表明这些物质含有来自马孔多油井的石油。在马孔多油井先前记录的羽流路径下方存在最近受损和死亡的珊瑚，这有力地证明了石油对深海生态系统造成了影响。我们的发现强调了这次泄漏的空前性质，无论是在规模、在深处释放，还是对深海生态系统的影响方面。
