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
A fourth subspecies, "B. m. indica", was identified by Blyth in 1859 in the northern Indian Ocean, but is now thought to be the same subspecies as "B. m. brevicauda", the pygmy blue whale. Records for Soviet catches seem to indicate that the female adult size is closer to that of the pygmy blue than "B. m. musculus"; the populations of "B. m. indica" and "B. m. brevicauda" appear to be discrete, and the breeding seasons differ by almost six months. Along mainland Indian coasts, appearances of whales had been scarce excluding unconfirmed record(s), the first blue whale since after the last stranding record in Maharashtra in 1914, was sighted off Kunkeshwar along with several Bryde's whales in May 2015.