text: In general, lighter refined petroleum products such as diesel and gasoline are more likely to mix in the water column and are more toxic to marine life, but tend to evaporate relatively quickly and do not persist long in the environment. Heavier crude or fuel oil, while of less immediate toxicity, can remain on the water surface or stranded on the shoreline for much longer. Oil from the Exxon Valdez and Gulf War oil spills, while weathering over time, has persisted along the shoreline for years after the spill.