Laboratory experiments to determine effects of previous exposure to oil on Fundulus grandis avoidance behavior

Fish were exposed to four different concentrations of oil utilizing the Louisiana Universities Marine Consortium (LUMCON) saltmarsh mesocosm facility in Cocodrie, Louisiana (twelve hydrologically-isolated mesocosm tanks planted with Spartina alterniflora and exposed to experimental oiling: control/no oil (0.0 L oil m-2), low (0.1 L oil m-2), medium (0.5 L oil m-2), and high (3.0 L oil m-2)). Fish were then removed and used in trials to determine how previous exposure impacted oil avoidance behavior. Using 38-L tanks with oil sediments on one side and unoiled on the other, fish occupancy patterns were observed. Oiled sediments were randomized and included oil at a range of concentrations (low: 10 mL oil/L, medium: 20 mL oil/L, or high: 40 mL oil/L). Observations of fish location in the tank were made for a period of 10 minutes and the proportion of time spent in oil and no oil sections of the tank were recorded.