After being hunted down to near extinction 110 years ago, researchers from the University of Washington noticed California Blue Whales reproducing at sustainable numbers.
There are about 2,200 California Blue Whales the Pacific Ocean’s eastern side, that constitutes 97 percent of historic levels, whereas in 1931 there were only 951.
“For us, this is a great conservation success story,” said Cole Monnahan, a doctoral student in ecology and resource management based at the University of Washington. “We caught way too many whales from this population, but when we left them alone, they recovered.”
“And that is really good news,” he added. “That it is possible.”
Blue whales are the largest animals in the world. They can weigh up to 190 tons and can be as long as 33 meters.
Blue whales (Balaenoptera musculus) are now placed on the International Union for Conservation of Nature (IUCN) endangered species list after being hunted down heavily from 1905 to 1971, in the North Pacific. According to new data published earlier this summer in the journal PLOS ONE, about 3,400 California blue whales were caught between 1905 and 1971.
Around 11 blue whales are struck by ships passing through the West Coast of the United States, each year. However this doesn’t contribute to such massive decline in their number.
Whaling was declared illegal and was banned in 1966 by the International Whaling Commission.
“We think the California population has reached the capacity of what the system can take as far as blue whales,” stated assistant professor of aquatic and fishery sciences, University of Washington and the senior author of the paper Trevor Branch.
“They are increasing as fast as they can — about 10% a year,” Branch said, “but at that rate their numbers will double every 10 or 11 years or so, so you can see how it will take many more decades before they get back to where they were.”
The lead author of the study, Monnahan, credits the successful recovery to “… careful management and conservation efforts.”
The new findings were published online Friday in the journal Marine Mammal Science, entitled Do ship strikes threaten the recovery of endangered eastern North Pacific blue whales?