The National Oceanic and Atmospheric Administration has launched a review of whether it should take North Pacific humpback whales off the endangered species list.
NOAA Fisheries is responding to a petition filed by a group of Hawaii fishermen saying the whale should no longer be classified as endangered because its population has steadily grown since the international community banned commercial whaling nearly 50 years ago.
There are more than 21,000 humpback whales in the North Pacific, compared with about 1,400 in the mid-1960s.
The Hawaii Fishermen's Alliance for Conservation and Tradition Inc. filed the petition in April. It seeks to have NOAA Fisheries first classify humpback whales in the northern Pacific Ocean as a distinct population. Then, it asks the agency to declare that population is no longer endangered.
The agency, in a notice published in the Federal Register on Thursday, said the petition presents substantial scientific and commercial information indicating the population is distinct and that a delisting may be warranted. It will study the issue for the next year.
NOAA last removed a species from the endangered list in 2008, when it determined the Caribbean monk seal had gone extinct. The last time a species' recovery prompted delisting was in 1994, when the agency removed the eastern North Pacific population of gray whales from the list.
The Hawaii fishermen's petition is the first seeking to delist humpback whales since the animals were classified as endangered in 1970.
The group doesn't want whaling to resume and is not seeking permission to hunt the whales.
Instead, they want NOAA Fisheries to remove species from the endangered list when their populations have recovered to maintain a balance with other species that keep getting added.
Humpbacks are found around the world—globally they number about 60,000—but the petition is seeking delisting for whales only in the North Pacific.
More than half of those in the North Pacific spend the winter breeding and calving in Hawaii's warm waters, where they've become a major draw for tourists. North Pacific humpbacks also winter off Mexico, Central America, Japan and the Philippines.
In the summer, they migrate to feed on krill and fish in waters off Alaska, Canada and Russia.
Explore further: Fishermen want humpback whales off endangered list