Adult blue whale. Credit: NOAA

The blue whale population of California appears to have recovered to near historic levels, this according to a recent study done by the Marine Mammal Science.

Whaling once brought the California blue whale population to near extinction. This was a sad fact for all known blue whale populations around the world.

Being so big, their territory is naturally equivalent to immense size, and defining the California population is therefore somewhat of a misnomer. Although being most visible at about 30 to 60 kilometers off the coast of California – these whales swim along a very large area indeed, from the eastern side of the Pacific Ocean and the Equator to the north and the Gulf of Alaska.

Lead author Cole Monnahan of the University of Washington, wrote in a press release, “The recovery of California blue whales from whaling demonstrates the ability of blue whale populations to rebuild under careful management and conservation measures,”.

The researchers estimate the blue whale population of California to about 2,200 animals today. This it very close to its estimated historical level of about 2,500 animals.

The researchers were able to count the whales using several different methods, such as acoustic data, which proved determinate in avoiding mixing different population together. Since another population lives in the waters off Japan and Russia for which the whales had a considerably different call.

The team also presents some bad news, however. The researchers believe the number of California blue whales struck by ships is above-allowed limits. With 11 naturally “potential biological removal” rate a year, instead of the 3,1 whales per year allowed by the U.S. Marine Mammal Protection Act.

However, co-author Trevor Branch wrote, “We think the California population has reached the capacity of what the system can take as far as blue whales.”.

Monnahan adds, “Our findings aren’t meant to deprive California blue whales of protections that they need going forward. California blue whales are recovering because we took actions to stop catches and start monitoring. If we hadn’t, the population might have been pushed to near extinction–an unfortunate fate suffered by other blue whale populations.”

The protection of the biggest animal on the planet (ever to exist) is indeed “a conservation success story.”

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