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The Blue Whale (Balaenoptera musculus) is a mammal which belongs to the baleen whales suborder. It is the largest animal known to have ever lived. It was described by Linnaeus in 1758.

It is a filter-feeder, using its baleen to strain plankton out of the seawater and may reach 30 meters long and up to 150 tons.

Its lung capacity is 5,000 litres.

The blue whale has a tiny dorsal fin, visible only briefly during the dive sequence. It has a spectacular 9m vertical single column blow.

Size

The Blue Whale is believed to be the largest animal ever to have lived on Earth. The largest creature known from the dinosaur era is the Brachiosaurus of the Mesozoic Age, which is estimated to have weighed upto 80 tonnes. There is some uncertainty as to the biggest Blue Whale ever found. Most data comes from Blue Whales killed in Antarctic waters during the first half of the twentieth century and was collected by whalers not well-versed in standard zoological measurement techniques. The longest whales ever recorded were two females measuring 33.6m and 33.3m respectively. There are some disputes over the reliability of these measurements however and the longest whale measured by scientists ( at the American National Marine Mammal Laboratory (NMML)) was 29.9m long - about the same length as a Boeing 737 aeroplane. Blue Whales are also very difficult to weigh on account of their massive size. Most Blue Whales killed by whalers were not weighed as a whole but cut up into manageable pieces before being weighing. This caused an under-estimate of the total weight of the whale due to loss of blood and other fluids. Even still measurements between 160 and 190 tons were recorded of animals upto 27m in length. The weight of a 30m individual is believed by the NMML to be in excess of 200 tons.

Population and Whaling

Blue Whales are not easy whales to catch,kill and retain. Their speed and power through the water meant that they were not often the target of early whalers who instead targeted Sperm and Right Whales. However as the number of these species declined whalers eyed the meaty prize of the largest baleen whales. In 1864 Norwegian Svend Foyn equipped a steam-powered boat with harpoons specifically designed for catching large whales. Although initially plagued by teething troubles the method saw caught on and by the end of the nineteenth century stocks of Blue Whale in the North Atlantic had dimished. Killing of Blue Whales rapidly spread across the oceans and by 1925, the United States, Britain and Japan had joined Norway in chasing whales on huge 'factory ships' that processed whales and 'catcher boats' that caught the whales and handed them onto the factory ships. In 1930 41 ships killed 28,325 Blue Whales. By then end of the World War Two populations had rapidly depleted and in 1946 the first quotas restricting international trade in whales were introduced. These were ineffective because of the lack of differentiation between species. Rare species could be hunted equally with those found relative abundantly. By the time Blue Whale hunting was finally banned in 196x by the International Whaling Commission 350,000 individuals had been killed. The total world population is now 3-4,000 with the largest concentration of 2,000 individuals located off the coast of California. This group represents the best hope for a long-term recovery in Blue Whale population.

References

• Blue Whales, John Calambokidis and Gretchen Steiger. ISBN 1900455218