Whale
The IWC has designated two whale sanctuaries: the Southern Ocean Whale Sanctuary, and the Indian Ocean Whale Sanctuary. The Southern Ocean whale sanctuary spans and envelopes Antarctica. The Indian Ocean whale sanctuary takes up all of the Indian Ocean south of 55°S. The IWC is a voluntary organization, with no treaty. Any nation may leave as they wish; the IWC cannot enforce any law it makes.
Blue whale
Migratory patterns of these subspecies are not well known. For example, pygmy blue whales have been recorded in the northern Indian Ocean (Oman, Maldives and Sri Lanka), where they may form a distinct resident population. Furthermore, sightings have been recorded from elsewhere in and adjacent to Arabian Sea, including from Gulf of Aden, Persian Gulf, coasts of Bay of Bengal including Bangladesh to Myanmar, and within the Strait of Malacca. The first official confirmation within Thailand's EEZ occurred at Trang in 2013.