Macondo source oils and artificially weathered oil residues from 150 °C+ to 300 °C+, including artificially photo oxidized oils, were prepared and used for generating low energy water accommodated fractions (LE-WAFs) in order to assess the impact of oil weathering on WAF chemistry composition and toxicity to marine organisms. Two pelagic species representing primary producers (the marine algae Skeletonema pseudocostatum) and invertebrates (the marine copepod Acartia tonsa) were tested. Obtained acute toxicity levels, expressed as EC/LC50 values, were in the same range or above the obtained maximum WAF concentrations for WAFs from most weathering degrees. Based on % WAF dilutions, reduced toxicity was determined as a function of weathering. The chemical compositions of all WAFs were compared to compositions obtained from water samples reported in the GRIIDC database using multivariate analysis, indicating that WAFs of photo oxidized and two field weathered oils resembled the field data the most.

制备了Macondo原料油和150°C +至300°C +的人工风化油残渣（包括人工光氧化油），并用于生成低能水份（LE-WAF），以评估油风化对WAF的影响化学成分和对海洋生物的毒性。代表主要生产者（海藻Skeletonema pseudocostatum）和无脊椎动物（海洋co足类A螨Acartiatonsa）的两种浮游物种）进行了测试。获得的急性毒性水平（以EC / LC50值表示）在相同的范围内或高于从大多数风化度获得的WAF的最大WAF浓度。基于WAF稀释百分比，确定降低的毒性与风化有关。使用多变量分析将所有WAF的化学成分与从GRIIDC数据库中报告的水样中获得的成分进行比较，表明光氧化油和两种田间风化油的WAF最类似于现场数据。