Department of Oceanography and Coastal Sciences, School of the Coast and Environment, Louisiana State University, #1241 Energy, Coast & Environment Building, Baton Rouge, LA, 70803, USA,
Environ Monit Assess. 2014 Jun;186(6):3941-56. doi: 10.1007/s10661-014-3670-4. Epub 2014 Feb 12.
We conducted controlled laboratory exposure experiments to assess the toxic effects of water-accommodated fractions (WAFs) of South Louisiana sweet crude oil on five phytoplankton species isolated from the Gulf of Mexico. Experiments were conducted with individual and combinations of the five phytoplankton species to determine growth inhibitions to eight total petroleum hydrocarbon (TPH) equivalent concentrations ranging from 461 to 7,205 ppb. The composition and concentration of crude oil were altered by physical and chemical processes and used to help evaluate crude oil toxicity. The impact of crude oil exposure on phytoplankton growth varied with the concentration of crude oil, species of microalgae, and their community composition. At a concentration of TPH < 1,200 ppb, dinoflagellate species showed significantly better tolerance, while diatom species showed a higher tolerance to crude oil at higher concentrations of TPH. For both groups, the larger species were more tolerant to crude oil than smaller ones. The toxicity potential of crude oil seems to be strongly influenced by the concentration of polycyclic aromatic hydrocarbons (PAHs). The addition of the dispersant, Corexit® EC9500A, increased the amount of crude oil up to 50-fold in the water column, while the physical enhancement (vigorous mixing of water column) did not significantly increase the amount of TPH concentration in the water column. The species response to crude oil was also examined in the five-species community. Each phytoplankton species showed considerably less tolerance to crude oil in the five-species community compared to their individual responses. This study provides baseline information about individual phytoplankton responses to crude oil and dispersed crude oil for subsequent research efforts seeking to understand the impacts of oil on the phytoplankton in the bigger picture.
我们进行了对照实验室暴露实验，以评估南路易斯安那州甜原油的水容纳馏分 (WAF) 对从墨西哥湾分离的五种浮游植物的毒性影响。实验采用五种浮游植物的单独和组合进行，以确定八种总石油烃 (TPH) 当量浓度范围为 461 至 7,205 ppb 的生长抑制作用。通过物理和化学过程改变原油的组成和浓度，并用于帮助评估原油毒性。原油暴露对浮游植物生长的影响因原油浓度、微藻种类及其群落组成而异。在 TPH < 1,200 ppb 的浓度下，腰鞭毛藻类表现出明显更好的耐受性，而在较高 TPH 浓度下，硅藻种类对原油表现出更高的耐受性。对于这两组，较大的物种比较小的物种对原油更耐受。原油的毒性潜力似乎受到多环芳烃 (PAH) 浓度的强烈影响。分散剂 Corexit® EC9500A 的添加将水柱中原油的浓度增加了 50 倍，而物理增强（水柱的剧烈混合）并没有显著增加水柱中 TPH 的浓度。还在五物种群落中检查了物种对原油的反应。与它们的个体反应相比，每种浮游植物在五物种群落中对原油的耐受性要低得多。本研究为后续研究提供了关于浮游植物个体对原油和分散原油反应的基线信息，这些研究旨在更全面地了解石油对浮游植物的影响。
