National Oceanic and Atmospheric Administration/National Ocean Service/National Centers for Coastal Ocean Science, 219 Fort Johnson Rd, Charleston, SC, 29412, USA.
Eckerd College, St. Petersburg, FL, USA.
Environ Sci Pollut Res Int. 2017 Sep;24(26):21476-21483. doi: 10.1007/s11356-017-9784-9. Epub 2017 Jul 26.
Chemical dispersants can be a beneficial method for breaking up oil slicks; however, their use in mitigation could pose potential toxic effects on the marine ecosystem. Dispersants may be transported to lower salinity habitats, where toxicity data for aquatic species have not been established. This study examined the effect of salinity on oil dispersant toxicity in the eastern mud snail, Ilyanassa obsoleta, using two dispersants authorized for oil spill response, Corexit® 9500A and Finasol® OSR 52. Median lethal toxicity values (LC50) and sublethal effects were examined at 10, 20, and 30 ppt salinity in adult and larval mud snails. Two biomarkers (lipid peroxidation and acetylcholinesterase) were used to measure sublethal effects. The 96-h static renewal LC50 values indicated significant differences in toxicity between dispersants and salinities. Larval snails were significantly more sensitive than adult snails to both dispersants, and both life stages were significantly more sensitive to Finasol than to Corexit. Larval snails were more sensitive to dispersants at lower salinity, but adult snails were more sensitive at higher salinities. Dispersants increased lipid peroxidation and decreased acetylcholinesterase activity. These results demonstrate that dispersant toxicity varies among compounds and organism life stages, and that physicochemical properties of the environment, such as salinity, can affect the potential toxicity to estuarine species.
化学分散剂可以是一种有效的方法来分解浮油；然而，它们在缓解方面的使用可能对海洋生态系统造成潜在的毒性影响。分散剂可能会被运送到盐度较低的栖息地，而在这些栖息地中，水生物种的毒性数据尚未建立。本研究使用两种已获授权用于应对溢油事件的分散剂，即 Corexit® 9500A 和 Finasol® OSR 52，研究了盐度对东方泥螺（Ilyanassa obsoleta）中油分散剂毒性的影响。在成年和幼虫泥螺中，研究了 10、20 和 30 ppt 盐度下的中位致死毒性值（LC50）和亚致死效应。使用两种生物标志物（脂质过氧化和乙酰胆碱酯酶）来测量亚致死效应。96 小时静态更新 LC50 值表明分散剂和盐度之间的毒性存在显著差异。幼虫泥螺对两种分散剂的敏感性均显著高于成年泥螺，且两种生命阶段对 Finasol 的敏感性均显著高于 Corexit。幼虫泥螺在低盐度下对分散剂更敏感，但成年泥螺在高盐度下对分散剂更敏感。分散剂会增加脂质过氧化和降低乙酰胆碱酯酶活性。这些结果表明，分散剂的毒性因化合物和生物个体生命阶段而异，环境的物理化学性质，如盐度，会影响到河口物种的潜在毒性。
