The Biological Effects of 2-butoxyethanol on Pagurus sp. of Intertidal Hermit Crabs: A Dispersant Ingredient Used in Oil Spill Disasters

British Petroleum used 1.8 million gallons of the oil dispersant Corexit to clean-up the Deepwater Horizon spill. A component that comprises 30% to 60% of the dispersant Corexit 9527, namely 2-butoxyethanol (LD₅₀ 2.5 g/kg in rats), has been reported to be four times more toxic than oil. Studies conducted by the Swedish Environmental Protection Agency suggest that a combination of oil and Corexit is far more toxic than either the petroleum or dispersant alone. In this study we investigate the effect of 2-butoxyethanol on an intertidal hermit crab, Pagurus sp. Our work aims to determine the effect of 2-butoxyethanol, alone and combined with oil, has on Pagurus sp. by measuring the LC₅₀ and investigating the relationship between exposure to the compound and the crabs’ behavior. Using LC₅₀ data reported in the literature, 1,490 mg/L (96 hour) and 1,650-1700 mg/L (24 hour), for bluegill and goldfish respectively, we will compare our LC₅₀ data on the marine organism Pagurus crab. Our studies will employ live hermit crabs in an environment that will resemble their natural habitat. Toxicity will be measured through behavior and mortality rate as a function of varying the crabs’ exposure times to petroleum and/or 2-butoxyethanol. Additionally, our investigation will verify that the literature value half-life of 2-butoxyethanol in water is one to four weeks. This research has implications for future usage of oil dispersants, as well as gaining a better understanding of the current state of Gulf coast marine life affected by the oil spill.