RAPID Deepwater Horizon Oil Spill: Impact of sub-surface oil plumes on mesopelagic micronekton

智力上的优点。最近在墨西哥湾北方中层（200- 1 000米）深处发现了地下石油羽流，使石油暴露威胁到公海营养金字塔的一个关键环节：深海水层群落。在墨西哥湾北方400米和1000米深处发现了石油烃。分散剂的广泛使用和非常深的井口增加了中层生物群与源自深水地平线井场的石油碳氢化合物之间发生重大相互作用的可能性。到目前为止，深海生态系统基本上没有受到石油污染，其居民可能对石油污染非常敏感，墨西哥湾的中层微型浮游生物/大型浮游动物组合多样性很高，而且在垂直方向上是移动的。绝大多数鱼类和甲壳类物种白天生活在600米以下的深度，晚上则迁移到250米以上的深度。因此，中层水物种遇到地下石油羽流的机会非常高。简而言之，如果羽状物存在，那么很大一部分中层水社区将通过它们迁移。该研究项目将：（1）利用“机遇号”获得关于当今微浮游生物种类组成、分布和在1 000米以上水柱中丰度的数据，并将这些数据与前几十年获得的数据进行比较;（2）利用生物组织中碳氢化合物组分的GCMS分析，评估群落已经暴露于地下油羽的程度，（3）评价支持中层生物量的碳源和氮源的变异性，并利用肌肉组织的d13 C和d15 N确定现今和以前采集的标本的营养位置。本项目收集的数据将提供一个稳定的同位素基线，以便评估目前和未来的地下石油影响。更广泛的影响。更广泛的影响包括在船上取样、中层动物生物学、基本地球化学方法和数据解释方面培训一名博士后研究员。PI已经与电视台和报纸记者建立了定期互动，他们一直站在船上取样和地球化学分析的最前沿，这些分析首次描述了石油泄漏产生的地下羽流。在整个研究过程中，将继续与印刷和视觉媒体进行互动，因为漏油事件的报道仍在继续。

Intellectual merit. The recent discovery of subsurface oil plumes in the northern Gulf of Mexico (GOM) at mesopelagic (200-1000 m) depths brings the threat of oil exposure to a critical link in the open ocean trophic pyramid: the pelagic deep-sea community. Petroleum hydrocarbons have been identified at depths of 400 and 1000 m in the northern GOM. Extensive use of dispersants and a very deep well-head raise the likelihood of a substantial interaction between the mesopelagic community and petroleum hydrocarbons originating at the Deepwater Horizon well site. Until now, the deep pelagic ecosystem has remained largely free of oil-derived pollution and its inhabitants are likely to be very sensitive to it. The mesopelagic micronekton/macrozooplankton assemblage of the GOM is both highly diverse and vertically mobile. The great majority of the fish and crustacean species reside at depths below 600 m during the day, performing a migration into the upper 250 m at night. Thus, chances of mid-water species encountering subsurface oil plumes are extraordinarily high. Briefly put, if the plumes are present, a large fraction of the mid-water community will be migrating through them. This research project will: (1) obtain data on present-day micronekton species composition, distribution, and abundance in the upper 1000 m of the water column using ships of opportunity, and compare those data with those acquired in previous decades; (2) evaluate the degree to which the community has already been exposed to subsurface oil plumes using GCMS analysis of hydrocarbon fractions in organismal tissues, and comparing those results with previously collected specimens maintained at -80o; (3) evaluate the variability in sources of carbon and nitrogen supporting mesopelagic biomass and determine the trophic position of present day and previously collected specimens using d13C and d15N of muscle tissue. The data collected in this project will provide a stable isotope baseline allowing for evaluation of present and future subsurface oil impact. Broader impacts. Broader impacts include training a postdoctoral fellow in shipboard sampling, the biology of mesopelagic fauna, and basic geochemical methodologies and data interpretation. The PIs have established regular interactions with TV and newspaper reporters have been on the forefront of the shipboard sampling and geochemical analyses that first described the subsurface plumes emanating from the oil spill. Interaction with print and visual media will continue throughout the study as the oil spill coverage continues.