Final answer:
Abandoned oil is the residual crude oil from a spill that forms thick lumps, posing harm to wildlife. Cleanup methods include skimmer ships, controlled burning, dispersants, and bioremediation, and are chosen based on the circumstances of the spill and its environmental impact.
Step-by-step explanation:
Abandoned oil refers to crude oil that, following an oil spill, remains in the environment after the lighter fractions have evaporated and natural degradation processes have occurred. This oil can form thick asphalt lumps that are harmful to wildlife, including birds, fish, and shellfish. Proper procedures for dealing with abandoned oil depend on various factors including the spill size, environmental conditions, and potential impacts on the ecosystem. Common cleanup methods include:
- Using skimmer ships to vacuum oil from the water's surface, effective mainly for small spills.
- Controlled burning, which is used in the early stages before the light, ignitable part of the oil evaporates but can pollute the air.
- Applying dispersants (detergents) that help break up the oil and accelerate decomposition, though potential toxicity is a concern.
- Bioremediation, which involves adding microorganisms that specialize in decomposing oil. This can be effective, but the input of foreign organisms must be managed carefully to avoid disturbing the natural balance of the ecosystem.
Each technique has its own set of trade-offs and potential impacts on the environment. For instance, the Deepwater Horizon oil spill in the Gulf of Mexico was a significant event that required an array of these methods to mitigate the damage to the affected areas.