(Morris Animal Foundation) Oysters likely suffered toxic effects from the oil dispersant Corexit® 9500 when it was used to clean up the 2010 Deepwater Horizon oil spill, said Morris Animal Foundation-funded researchers at the University of Connecticut. The team determined this by comparing the low levels of toxicity of oil, the dispersant and a mixture of the two on Eastern oysters. The team published their findings in the journal Aquatic Toxicology.