Article Title: Toxicity of Oil Spill Dispersant on freshwater fish Poeciliopsis occidentalis and Bacterial Nitrobacter sp
Ecotoxicology of Oil Spill Dispersants – OSD/LT and OSD/Seacare employed in the upstream sector of the Nigeria petroleum industry were investigated in freshwater systems. Methodology for ecotoxicological assessment of the oil spill dispersants were carried out using the static with renewal option for acute toxicity at concentrations 0, 10, 100, 1000, 10000, 100000 ppm for 96h lethal dose (LD50) higher organism fresh water fish Topminnow Poeciliopsis occidentalis and 24h median lethal concentration (LC50) for Nitrobacter. The ecotoxicological assessment of the 96hour Median Lethal Dose (LD50 ppm) of the Oil Spill Dispersants at concentrations 0, 10, 100, 1000, 10000, 100000ppm to higher organism; fresh water fish Poeciliopsis occidentalis OSD/LT (55999ppm), OSD/Seacare (1774ppm) The 24h median lethal concentration (LC50 ppm) of Oil Spill Dispersants to microorganism Nitrobacter sp. in freshwater were; OSD/LT (47184.7ppm), OSD/Seacare (29251.7ppm). Conclusively, the study revealed that Oil Spill Dispersants OSD/Seacare is more toxic than OSD/LT, both with test fish Poeciliopsis occidentalis and microorganism Nitrobacter in freshwater environment with a significant gap. Based on these findings; the use of Oil spill Dispersant OSD/Seacare should be with high caution or discontinued in the upstream sector of the Nigeria Petroleum Industry.