Abstract：
Oceanic oil spills present significant ecological risks that have the potential to contaminate extensive areas, including coastal regions. The occurrence of the 2019 oil spill event in Brazil resulted in over 3000 km of contaminated beaches and shorelines. While assessing the impact on benthic and beach ecosystems is relatively straightforward due to direct accessibility, evaluating the ecotoxicological effects of open ocean oil spills on the pelagic community is a complex task. Difficulties are associated with the logistical challenges of responding promptly and, in case of the Brazilian mysterious oil spill, to the subsurface propagation of the oil that impeded remote visual detection. An oceanographic expedition was conducted in order to detect and evaluate the impact of this oil spill event along the north-eastern Brazilian continental shelf. The pursuit of dissolved and dispersed oil compounds was accomplished by standard oceanographic methods including seawater polycyclic aromatic hydrocarbons (PAHs) analysis, biomass stable carbon isotope (δ13C), particulate organic carbon to particulate organic nitrogen (POC:PON) ratios, nutrient analysis and ecotoxicological bioassays using the naupliar phase of the copepod Tisbe biminiensis. Significant ecotoxicological effects, reducing naupliar development by 20-40 %, were indicated to be caused by the presence of dispersed oil in the open ocean. The heterogeneous distribution of oil droplets aggravated the direct detection and biochemical indicators for oil are presented and discussed. Our findings serve as a case study for identifying and tracing subsurface propagation of oil, demonstrating the feasibility of utilizing standard oceanographic and ecotoxicological methods to assess the impacts of oil spill events in the open ocean. Ultimately, it encourages the establishment of appropriate measures and responses regarding the liability and regulation of entities to be held accountable for oil spills in the marine environment.
摘要：
海洋石油泄漏带来了重大的生态风险，有可能污染广大地区，包括沿海地区。2019年巴西漏油事件的发生导致超过3,000公里的海滩和海岸线受到污染。虽然评估对底栖和海滩生态系统的影响相对简单，但由于直接可访问性，评估公海溢油对中上层群落的生态毒理学影响是一项复杂的任务。困难与迅速作出反应的后勤挑战有关,在巴西神秘的石油泄漏事件中,石油的地下传播阻碍了远程视觉检测。进行了海洋学考察，以检测和评估巴西东北部大陆架漏油事件的影响。通过标准的海洋学方法，包括海水多环芳烃（PAHs）分析，实现了对溶解和分散油化合物的追求。生物量稳定碳同位素(δ13C)，颗粒有机碳与颗粒有机氮（POC：PON）的比率，使用co足类Tisbebiminiensis的幼体相进行养分分析和生态毒理学生物测定。显著的生态毒理学影响，将无节幼体发育减少20%至40%，被证明是由公海中分散的石油的存在引起的。提出并讨论了油滴的均匀分布加剧了油品的直接检测和生化指标。我们的发现可作为识别和追踪石油地下传播的案例研究，证明利用标准海洋学和生态毒理学方法评估公海溢油事件影响的可行性。最终,它鼓励就对海洋环境中的石油泄漏负责的实体的责任和监管制定适当的措施和对策。
