Oil spills have been a recurring theme of our industrial society for over a hundred years. As our society has become reliant on the use of fossil fuels, such as oil, for energy, these fuels must be transported great distances. Sometimes, these journeys end in accidents, such as the infamous Exxon-Valdez incident, in which oil is spilled directly into the ocean. While these accidents achieve notoriety and are typically widely reported, they are not the only kind of oil spill that affects the marine environment. Oil spilled on land can reach lakes, rivers, and wetlands where it can damage the environment. When spilled oil reaches an aquatic environment, it causes damage to the entire ecosystem within that environment. It can cause direct harm to the organisms that live on or around the water surface as well as those that live underwater. This harm can damage the food chain, including resources that are used by humans for food. However, there is no direct relationship between the size of an oil spill and the damage it will cause to the environment due to the reasons outlined below.
The severity of the ecological damage caused by an oil spill depends on a wide variety of factors. The characteristics of the oil that has been spilled is one of the main factors. The term oil refers to a wide range of hydrocarbon based substances. These hydrocarbon based substances include crude oil and other petroleum products, but also include animal fats, vegetable oils, and other non-petroleum based oils. The different types of oil have different physical and chemical properties, and these properties directly affect the way that the oil will spread and break down and the overall hazard it can pose for the ecosystem. Factors which affect the ability of an oil spill to spread include surface tension, specific gravity, and viscosity.
The characteristics of the particular marine environment in which the oil has been spilled can also affect...