Once hunted to the brink of extinction, humpback whales have made a dramatic comeback in the North Pacific Ocean over the past four decades, a new study says.
The study released Thursday by SPLASH, an international organization of more than 400 whale watchers, estimates there were between 18,000 and 20,000 of the majestic mammals in the North Pacific in 2004-2006.
Their population had dwindled to less than 1,500 before hunting of humpbacks was banned worldwide in 1966.
"It's not a complete success, but it's definitely very encouraging in terms of the recovery of the species," said Jeff Walters, co-manager of the Hawaiian Islands Humpback Whale National Marine Sanctuary.
The study, sponsored by the National Oceanic and Atmospheric Administration, is the most comprehensive analysis ever of any large whale population, said David Mattila, science coordinator for the sanctuary.
At least half of the humpback whales migrate between Alaska and Hawaii, and that population is the healthiest, Mattila said.
But isolated populations that migrate from Japan and the Philippines to Russia are taking a longer to recover after whaling operations ceased, he said.
"Whales are long-lived and give birth one at a time .... so if the population gets pushed too low, it may take quite awhile to come back. Maybe that's what's happening in the west," Mattila said.
The whales are protected under federal laws that include the Marine Mammal Protection Act and the Endangered Species Act.