This lesson plan from the Smithsonian Institution introduces students to the effects of oil on the oceans, whether introduced by a disastrous spill, oil-bearing rock layers on the ocean floor, industrial waste or run-off. Students then simulate an oil spill and calculate the costs of various clean-up methods. A student fact sheet is also provided. The lesson plan is most appropriate for middle and high school students and can be adapted to meet state or national standards in biology, chemistry and social studies.