Marine fishes rely on their sensory systems to survive. A study is the first to quantify the physiological effects of whole crude oil on the olfactory function of a marine vertebrate — the Atlantic stingray. Results of the study, confirm that exposure to crude oil, at concentrations mimicking those measured in coastal areas following the Deepwater Horizon oil spill in 2010, significantly impaired olfactory function in the Atlantic stingray after just 48 hours of exposure.