About half of it is moved by ocean-going tanker ships. Most of the rest moves in pipelines. Accidents happen, especially in bad weather, and sometimes oil is spilled. This amounts to about 3 million tonnes of oil a year. Most of the oil spilled comes from small spills, not from large accidents that make the news.
Accidents occur on all the oceans of the world.
So much oil is transported from the Middle East that there are more spills in that part of the world than anywhere else. Oil spills foul the fur and feathers of larger animals. Spills can kill fish eggs and tiny ocean creatures that other animals feed on. Oil spills foul beaches and shallow water plants that many animals eat. Companies reduce accidents by carefully planning their oil operations and training their employees.