In October 2011, the government declared that an area covering nearly 2,000,000 square kilometres (772,000 sq mi) of ocean shall be reserved as a shark sanctuary. This is the world's largest shark sanctuary, extending the worldwide ocean area in which sharks are protected from 2,700,000 to 4,600,000 square kilometres (1,042,000 to 1,776,000 sq mi). In protected waters, all shark fishing is banned and all by-catch must be released. However, some have questioned the ability of the Marshall Islands to enforce this zone.