WHENEVER OIL SPILLS into our environment, damage occurs. But the amount of damage done depends on many factors. Salt- or freshwater, water temperature, shoreline contour, nature of the oil spilled, air temperature, wind and wave action, season of the year, amount of sunlight, all of these variables affect the severity of the spill. The list of factors affecting damage is endless, which is why oil spills pose so many challenges. No hard-and-fast set of rules exist for what happens during an oil spill; no two oil spills are alike.

Type of oil

The most important factor in any oil spill is what type of oil has been spilled. Crude oil acts differently than jet fuel, kerosene, or gasoline, for example.

In the 1970s two oil spills occurred in Maine within one year of each other. Each one involved a different type of oil. In...