While in previous centuries has not hunted whales sapphire because of their speed and weight, by the mid 19th century, they began to hunt regularly. During the 20th century was fished about 350,000 blue whales. In the southern hemisphere were created for the settlement of hunters and processors that are whales during the whaling season spills of a busy life and work. Out of season, the village would be deserted. The consequence of such intense fishing was a big drop in catches after the 1930th year because of Azure whales are almost no longer existed. However, only the 1966th entered into force on the international protection provisions.
Before the period of the great whaling, the world's seas floating about 200,000 specimens of blue whale, of which almost 90% in the South Seas. Today, despite the protection that now has lasted for almost 40 years, the total population of these species has only a few thousand individuals. The exact scope of the population is very difficult to determine. How far is observed strength of the recovery of these whales, some experts believe that the total population is too small to be able to re-grow. It was noted that blue whales in the North Atlantic, due to lack of partners of its kind, more often mate with other species of whales. This creates new species of whales, and blue whales are disappear as a species.
Since commercial whaling was banned, has not been established whether the world population of blue whales is stable or increasing. In Antarctica, it is estimated that 7.3% of the population number increases every year. It is assumed that the Icelandic population in California and also on the rise. The size of the entire world population of blue whales is estimated at between 5,000 and 12,000 individuals (2002.), But there is great uncertainty in the estimates in many areas. According to the IUCN Red List, the blue whale is an endangered species, and it was this list since it was first made.
Blue whales are particularly vulnerable in Japan. Given that they have bacon and steak just like pigs because they are mammals, especially the price of their meat. Fishermen are allowed an annual quota of how many whales can be caught, but they largely do not respect and love more and more whales. Given that fewer whales, they are forced to go farther from shore and to hunt in the prohibited zones, which brings them into conflict with authorities, but this does not prevent them to continue business as usual.
The largest known population is located in the northeastern Pacific (from Alaska to Costa Rica) and has about 2,000 blue whales. Most often seen flying over California. Sometimes this population extends over the northwestern Pacific Ocean, recorded meetings are rare in the area between Kamchatka and extreme northern parts of Japan.
The total population of North Atlantic blue whales is between 600 and 1500th.