Although once hunted to near-extinction, a new study suggests that populations of humpback whales in the North Pacific have made a dramatic comeback in the last few decades.

Although once hunted to near-extinction, a new study suggests that populations of humpback whales in the North Pacific have made a dramatic comeback in the last few decades.

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. While the number is unimpressive compared to 7 billion and counting humans on the planet, it’s a big step up from the estimated 1500 of the migratory marine mammals estimated to have inhabited the region when hunting ceased in 1966.

Researchers took pictures of the whale’s flukes (part of the tail) at 6 feeding/breeding spots around the Pacific, and then compared them with photos from locations where the whales are known to winter.

“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.”

The whales are protected under federal laws that include the Marine Mammal Protection Act and the Endangered Species Act.

Their resurgence has created debate over whether they should still be considered endangered, according to Naomi McIntosh, superintendent for the humpback sanctuary.

“Those discussions are bound to happen, and we knew that going into the study, we anticipated it,” she said. “I think it’s too early to make that call.”

The number of collisions between whales and boats has been increasing, probably because the population is larger, Walters said. Whale entanglements in marine debris, fishing gear and aquaculture structures also are a growing concern.