Blue whales, also known as the whale is a whale belongs Mysticeti division (baleen whales). [9] Length 30 meters (98 ft) [10] and weighs 180 tons (200 short ton) [ 11] or even more, it is the largest animal remains and heaviest ever existed. [12] The body long and slender blue whale, may have bluish-gray on the back and light than on the abdomen. [13] There are at least three blue whale subspecies: B. m. musculus live in waters north Atlantic and north Pacific, B. m. intermedia live in the Southern Ocean and B. m. brevicauda (pygmy blue whale) live in the Indian Ocean and the South Pacific. Like other whales, their food mostly plankton and small crustaceans. [14] Before the 20th century, blue whales exist with large number of individuals in most oceans world. But more than 100 years, we hunted to near extinction until protected by the international law in 1966. According to a report in 2002, there were approximately 5000-12000 individuals living around world, [15] including at least 5 groups. Before being hunted, the blue whale population the largest in Antarctica waters around 239,000 individuals (from 202,000 to 311,000). [16] The smaller population (approximately 2,000 individuals) are concentrated in the east coast north Pacific, Antarctica. There are two different populations in the North Atlantic and at least two more populations in the Southern Hemisphere. In 2014, the number of blue whales in California have recovered to near pre hunting period. [17]
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