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

智力上的优点。最近在墨西哥湾北部中层(200-1000米)深度发现的地下石油羽流使石油暴露在公海营养金字塔的一个关键环节--中上层深海群落。在GOM北部400米和1000米深处已经发现了石油碳氢化合物。分散剂的广泛使用和非常深的井口增加了中上层群落与源自深水地平线井场的石油碳氢化合物之间发生实质性相互作用的可能性。到目前为止，深海生态系统在很大程度上没有石油造成的污染，其居民可能对此非常敏感。GOM的中层微型浮游动物/大型浮游动物组合具有高度的多样性和垂直移动性。绝大多数鱼类和甲壳类物种白天生活在600米以下的深度，晚上迁徙到250米以下的深度。因此，水中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，很大一部分中水群落将通过它们迁徙。这项研究项目将：(1)利用机会号船获取关于当今水柱上部1000米处微粒子物种组成、分布和丰度的数据，并将这些数据与以前几十年获得的数据进行比较；(2)利用气相色谱-质谱仪对生物组织中的碳氢化合物组分进行分析，评估该群落已暴露于地下油羽的程度，并将这些结果与以前收集的标本进行比较；(3)利用肌肉组织的d13C和d15N，评估支撑中上层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位置。该项目收集的数据将提供稳定的同位素基线，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采样、中层海洋动物生物学以及基本的地球化学方法和数据解释方面培训一名博士后研究员。私人投资机构与电视和报纸记者建立了定期互动，一直站在船上采样和地球化学分析的最前线，这些分析首先描述了漏油产生的地下羽流。随着漏油报道的继续，与印刷和视觉媒体的互动将在整个研究期间继续进行。

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.