Shipping problems: Oil spills
Local people lose their livelihoods as fisheries and tourism areas are temporarily closed; the clean up costs are enormous; and tens of thousands of marine animals and plants are killed or harmed.
And the damage goes on. The chemicals used to break up the oil can be toxic, and it's impossible to remove all the spilled oil. Even after an area has been cleaned up, it can take a decade or more to fully recover.
There's also the problem of the oil that goes down with the ship, which can contaminate the seabed and marine organisms.
This oil can also resurface. In 2001, a cyclone off the island of Yap in Micronesia disturbed the oil tanker USS Mississinewa, which was sunk during World War II. For two months, thousands of litres of oil and gasoline leaked out of the rusted ship wreck onto the beaches of the atoll, stopping the 700 islanders from fishing. There are hundreds of other shipwrecked tankers around the world.