Fewer than 1,500 humpbacks were left in the North Pacific in 1966, the year international whaling was banned. Since then, their numbers have steadily climbed to an estimated 18,000.
The increase in the humpback whale population in the North Pacific has been credited to the whaling ban and to federal laws added to protect whales, including the Marine Mammal Protection Act and the Endangered Species Act in the 1970s, according to NOAA.
The Hawaiian Islands Humpback Whale National Marine Sanctuary, managed jointly by NOAA and the state, was established in 1992 by Congress to protect the whales and their habitat in the Main Hawaiian Islands. The sanctuary achieved full designation after its first management plan was completed in June 1997.
Although the number of humpbacks has been increasing, the whales remain endangered. Some isolated populations of humpbacks, mainly in the Western Pacific Ocean, still exist in low numbers, according to NOAA’s SPLASH (Structure of Population, Levels of Abundance, and Status of Humpbacks) project.
Over 400 researchers, 50 organizations and 10 countries joined efforts to come up with a 2006 SPLASH report that found out the humpback population that migrates to Hawai‘i in the winter to be approximately 10,000 and have an annual growth of about 6 percent.
The humpback whales are believed to have an average life span of 40 to 45 years, said Jean Souza, Kaua‘i program coordinator for the National Oceanic Atmospheric Agency.
“One of the reasons why Congress established the sanctuary, to begin with, was because Hawaii is the only state where the whales come to breed and calve,” said Souza, adding NOAA believes approximately 12,000 came to Hawai‘i this past whale season.
The remaining humpbacks of the North Pacific, approximately 8,000, spend the winters in the Western Pacific or down the coast of Mexico and Central America.
Local marine biologist Carl Berg said Japan has announced it will stop whaling temporarily, and there’s no cultural-resource hunting of humpbacks in Alaska.
The main threats humpbacks face in the sanctuary are entanglement, vessel collisions, acoustic disturbance, water quality and marine debris.
Taken from an article by Léo Azambuja, staff writer, The Garden Island