The Hawaiian Islands provide shelter and foraging grounds for a diverse group of cetaceans in the central Pacific Ocean. While many people associate Hawaii exclusively with the annual migration of the Humpback whale, the archipelago’s Exclusive Economic Zone (EEZ) hosts a variety of species. These populations include seasonal visitors, year-round residents, and large, deep-water transients that only occasionally pass through the area.
The Primary Migrants: Humpback Whales
The North Pacific Humpback whale is the most celebrated and commonly sighted whale species in Hawaiian waters. These massive baleen whales undertake one of the longest migrations of any mammal, traveling up to 3,000 miles from their cold summer feeding grounds in the North Pacific, primarily off Alaska and the Bering Sea. Their arrival typically begins in November and December, with peak season occurring between January and March, before their departure in April and May.
The purpose of this long journey is not to feed, but to utilize the warm, shallow, and predator-free Hawaiian waters for mating, birthing, and nursing their young. Calves are born in this protected environment and gain strength before making the journey north with their mothers. The shallow channels between Maui, Moloka‘i, and Lāna‘i, collectively known as the ‘Au‘au Channel, are particularly favored breeding and calving areas.
Male Humpbacks are known for their complex, repetitive songs, which can travel great distances underwater and are thought to play a role in mating rituals. Visitors often witness the whales’ dramatic acrobatic displays, such as breaching, where they launch a large portion of their body out of the water, and pec or tail slapping. Approximately two-thirds of the entire North Pacific Humpback population returns to Hawaii annually.
Year-Round Resident Whales
Several species of toothed whales, or odontocetes, maintain permanent, year-round populations within the Hawaiian EEZ. The Short-Finned Pilot Whales are the most frequently encountered odontocetes around the main islands. These highly social animals live in stable family pods, often numbering 20 to 30 individuals, and use echolocation to hunt for squid and fish in deep, offshore waters.
The False Killer Whale is another significant resident. These sleek, dark-bodied predators are genetically divided into three stocks in Hawaii, including a pelagic group and a distinct Main Hawaiian Islands (MHI) insular population. The MHI insular population is small, estimated at fewer than 170 individuals, and is genetically isolated, making it unique to the islands’ nearshore waters.
False Killer Whales are known for their cooperative hunting methods, sharing large prey like tuna, and their tendency to forage at depth. Acoustic studies have shown that both resident species exhibit deep-diving behavior, with pilot whales often clustering dives between 200 and 300 meters, utilizing the deep trenches that surround the islands.
Rarely Seen Deep-Water Transients
The vast expanse of the Hawaiian EEZ is also a transit zone for species that rarely approach the main islands’ shallow shelves. The Sperm Whale, the largest of the toothed whales, occasionally passes through these deep waters. These giants are champion divers, capable of plunging thousands of feet to hunt for their primary prey, the giant squid.
Other baleen whales, like the Blue Whale and the Fin Whale, are also documented, though sightings are extremely rare. Blue Whales, the largest animals on Earth, are confirmed more often by their powerful, low-frequency vocalizations picked up by hydrophones than by visual observation. The Fin Whale, the second-largest species, is detected acoustically throughout much of the year, typically using Hawaiian waters as a transit point. These deep-water travelers are only briefly present, traversing areas where the seafloor drops rapidly to depths of several thousand feet.
Responsible Whale Watching and Viewing
Viewing these marine mammals requires adherence to federal regulations designed to ensure their safety and minimize disturbance. The Marine Mammal Protection Act (MMPA) and the Hawaiian Islands Humpback Whale National Marine Sanctuary regulations prohibit the close approach of Humpback whales. For all watercraft, including vessels, kayaks, and paddleboards, the law mandates maintaining a distance of at least 100 yards from any Humpback whale.
This 100-yard rule applies year-round to all Hawaiian waters out to 200 nautical miles, protecting the whales in their breeding and transit areas. Furthermore, aircraft, including drones, must not operate lower than 1,000 feet above a Humpback whale. These regulations are enforced by the National Oceanic and Atmospheric Administration (NOAA) and local agencies. Visitors are encouraged to observe wildlife passively, appreciate them from a distance, and report any violations or entangled animals to the appropriate authorities.