Routine shipping, run-offs and dumping of oils on the ocean surfaces happen every day. Oil spills cause major problems, and can be extremely harmful to local marine wildlife such as fish, birds and sea otters and other aquatic life. Because oil does not dissolve, it stays on the water surface and suffocates fish. Oil also gets caught in the feathers of seabirds, making it difficult for them to fly. Some animals die as a result.