The Timor Sea (Indonesian: Laut Timor; Portuguese: Mar de Timor) is a relatively shallow sea bounded to the north by the island of Timor, to the east by the Arafura Sea, to the south by Australia and to the west by the Indian Ocean. The sea contains a number of reefs, uninhabited islands and significant hydrocarbon reserves. International disputes emerged after the reserves were discovered resulting in the signing of the Timor Sea Treaty. The Timor Sea was hit by the worst oil spill for 25 years in 2009.