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

知识价值。最近在墨西哥湾北部中上层（200-1000米）深处发现的地下石油羽流将石油暴露的威胁带到开阔海洋营养金字塔的关键环节：中上层深海群落。在墨西哥湾北部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深水地平线井场中上层生物与石油碳氢化合物之间大量相互作用的可能性。到目前为止，深海生态系统基本上没有石油污染，其居民可能对石油污染非常敏感。墨西哥湾中上层浮游微生物/大型浮游动物的组合具有高度的多样性和垂直流动性。绝大多数鱼类和甲壳类动物白天生活在600米以下的深度，晚上迁徙到250米以上的深度。因此，中水物种遇到地下石油羽流的可能性非常高。简而言之，如果羽流存在，大部分的中水群落将通过它们迁移。本研究项目将：(1)利用机遇船获取当今1000米水柱上层微藻种类组成、分布和丰度的数据，并将这些数据与过去几十年获得的数据进行比较；(2)利用气相色谱法（GCMS）对生物组织中的烃类组分进行分析，评估该群落已经暴露于地下油羽的程度，并将这些结果与之前收集的保持在- 800度的标本进行比较；(3)利用肌肉组织的d13C和d15N来评估支持中浮游生物生物量的碳和氮来源的变异性，并确定现在和以前收集的标本的营养地位。该项目收集的数据将提供一个稳定的同位素基线，以便评估当前和未来的地下石油影响。更广泛的影响。更广泛的影响包括培训船上采样的博士后，中远洋动物的生物学，以及基本的地球化学方法和数据解释。ppi已经与电视和报纸记者建立了定期的互动，他们一直站在船上采样和地球化学分析的最前沿，首次描述了石油泄漏产生的地下羽流。随着石油泄漏报道的继续，与印刷和视觉媒体的互动将在整个研究过程中继续进行。

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.