Particle counts in different size fractions taken during mesocosms GOMOO, GOM open ocean, and GOMCOAST, GOM coastal waters

Aggregation is a phenomenon that has been observed following oil spills. The size and number of aggregates can change with specific microbial communities, or the presence of chemical dispersants such as Corexit. In order to assess the impact of oil exposure on the formation of small aggregates (&lt;100um), two mesocosm experiments were conducted during July 2016; GOMOO (Gulf of Mexico Open Ocean) and GOMCOAST (Gulf of Mexico Coastal waters). Oil and dispersant exposure were facilitated using the water accommodated fraction (WAF) of oil, a chemically enhanced WAF (CEWAF, mixture of oil and Corexit) and a dilute CEWAF (DCEWAF). 15mL aliquots were taken every 24h from each mesocosm for immediate analysis on a Z2 dual-threshold Coulter counter (Beckman Coulter). The Coulter counter was outfitted with a 100µm aperture, and particles were counted in three ranges; 10-20µm, 20-50µm and &gt;50µm. The data presented will be particle counts (particles/mL) over time within each size fraction. Estimated oil equivalents are reported in GRIIDC datasets R4.x263.000:0038 and R4.x263.000:0039.油溢事件后常会出现聚集现象。聚集体的尺寸与数量会随特定微生物群落的组成，或是包括柯蒂斯（Corexit）在内的化学分散剂的存在而发生改变。为评估石油暴露对小型聚集体（<100μm）形成的影响，研究团队于2016年7月开展了两项中型实验生态系（mesocosm）试验：GOMOO（墨西哥湾开阔海域，Gulf of Mexico Open Ocean）与GOMCOAST（墨西哥湾近岸海域，Gulf of Mexico Coastal waters）。实验通过石油水可溶组分（WAF）、化学强化型水可溶组分（CEWAF，即石油与柯蒂斯的混合物）以及稀释型化学强化水可溶组分（DCEWAF）来施加石油与分散剂暴露处理。每24小时从每个中型实验生态系中采集15mL等分试样，即刻使用Z2双阈值库尔特计数器（Beckman Coulter，贝克曼库尔特）进行分析。该库尔特计数器配备100μm孔径管，将颗粒按三个粒径范围计数：10~20μm、20~50μm及>50μm。本数据集呈现的是各粒径分级中随时间变化的颗粒浓度（颗粒数/mL）。估算油当量数据已在GRIIDC数据集R4.x263.000:0038与R4.x263.000:0039中公布。