The Influence of crude oil and oil dispersant in the physiology of adult Gulf Killifish

The fish gill epithelium is a sensitive site of interaction between a fish and its environment partially due to its role in ion regulation. Addition of dispersant to crude oil can result in increased bioavailability of aromatic and aliphatic hydrocarbons. Treatment waters were generated at nominal salinities of 4, 12, and 18 g/L. Control water was left undisturbed. Dispersant water was mixed at 22 mL of Corexit-9500 to 80 L of treatment water. Oiled water was initially mixed at an approximate 1:4 oil:water ratio by volume and the dispersant was used at a 10:1 oil:dispersant ratio to generate oil/dispersant water. Treatment waters at the previously mentioned nominal salinities were weathered for 1, 4, and 16 weeks in treatment mesocosms. Gulf killifish were sampled for plasma after 48 and 96 hours of exposure to treatment waters. Impacts of treatment water on adult Gulf killifish physiology were determined through measurements of hematocrit and plasma ion concentrations of sodium, potassium, and chloride.

鱼类鳃上皮 (fish gill epithelium) 是鱼类与环境相互作用的敏感位点，这在一定程度上源于其在离子调节中的功能。将分散剂 (dispersant) 添加至原油 (crude oil) 中，可提升芳香族烃 (aromatic hydrocarbons) 与脂肪族烃 (aliphatic hydrocarbons) 的生物可利用性 (bioavailability)。本实验的处理水体设定盐度分别为4、12、18 g/L；对照组水体 (control water) 保持静置，未施加任何处理。分散剂组水体的配制方式为：取22 mL Corexit-9500与80 L处理水体混合均匀。油处理组水体 (oiled water) 初始按油:水体积比约1:4混合配制，且油与分散剂的配比为10:1，以此制备油/分散剂复合处理水体。前述设定盐度的处理水体被置于中型实验生态系统 (mesocosms) 中，分别进行1周、4周和16周的风化老化处理。将海湾底鳉 (Gulf killifish) 暴露于处理水体中48小时与96小时后，采集其血浆 (plasma) 样本。通过测定血细胞比容 (hematocrit) 以及血浆中钠离子、钾离子与氯离子的浓度，分析处理水体对成年海湾底鳉生理状态的影响。