Maui’s surrounding waters are a premier destination for observing marine life, attracting thousands of visitors annually. This area of the Pacific Ocean serves as a significant biological center, drawing a diverse population of large marine mammals. The islands offer a uniquely sheltered aquatic environment that supports various life cycles for these ocean travelers.
The Primary Visitor: North Pacific Humpbacks
The most celebrated species to frequent the area is the North Pacific Humpback Whale. These baleen whales travel thousands of miles from their summer feeding grounds near Alaska to the warm, shallow Hawaiian waters. An adult can reach lengths of 45 to 50 feet and weigh between 25 and 40 tons, with females typically being the larger sex. The unique pattern of white markings on their long pectoral fins and tail flukes acts like a fingerprint, allowing researchers to identify individual animals.
While in Hawaiian waters, the humpbacks do not feed, relying on the thick layer of blubber accumulated during the summer months. Their focus shifts to mating, giving birth, and nursing their young. Male whales are known for their complex, ethereal songs, which can travel for miles underwater and are thought to be part of their mating display. Competitive groups of males frequently engage in surface behaviors, vying for access to a female.
Breaching involves the whale launching its entire body out of the water, crashing back down with a thunderous splash. Other common activities include pectoral fin slapping and tail lobs, which are believed to be forms of communication or play. Newborn calves, which are about 13 to 16 feet long at birth, remain closely bonded with their mothers, growing rapidly on highly nutritious milk.
The Whale Season and Migration Patterns
The annual arrival of the humpbacks defines Maui’s “whale season,” which runs from early November or December through April or May. The peak period for sightings and surface activity is centered between mid-January and March. This timing reflects one of the longest migrations undertaken by any mammal, a journey of approximately 3,000 miles that takes the whales about four to six weeks to complete.
The purpose of this migration is reproductive, as the warm, clear waters provide a safe environment for new mothers and their vulnerable calves. The whales seek out the sheltered, shallow environment of the Maui Nui Basin, the channel between Maui, Molokaʻi, Lānaʻi, and Kahoʻolawe. This area is designated as the Hawaiian Islands Humpback Whale National Marine Sanctuary.
The Sanctuary protects the humpbacks’ breeding and calving habitat and covers a large portion of the surrounding state and federal waters. The warm tropical temperatures are ideal for newborn calves, which lack the blubber reserves needed to survive in the colder feeding grounds of the North Pacific. The sanctuary status enforces regulations, such as a 100-yard no-approach zone for boats, to minimize disturbance.
Less Common Species and Year-Round Marine Mammals
Maui’s waters are also home to other marine mammals, many of which are year-round residents or sighted less frequently. These species are often toothed whales (odontocetes), which inhabit deeper, offshore waters compared to the shallow channels favored by humpbacks. Short-finned Pilot Whales are among the most commonly sighted non-humpback whales, often traveling in large, cohesive social groups.
False Killer Whales are characterized by their dark coloration and sleek bodies. This species is actually a large member of the oceanic dolphin family, and a small, genetically distinct population resides permanently in Hawaiian waters. Other rare visitors include Sperm Whales and various Beaked Whales, which are deep-diving species that occasionally surface further from the coast.
Smaller marine mammals are a constant presence in the area. Hawaiian Spinner Dolphins are frequently seen, known for the acrobatic spinning leaps that give them their name. These playful dolphins tend to rest in nearshore bays during the day and hunt offshore at night. Bottlenose Dolphins are also year-round residents, often observed in pods, and are significantly larger than their spinner dolphin counterparts.