Hawaiian Monk Seal

The Hawaiian monk seal (Neomonachus schauinslandi) is an earless seal endemic to the Hawaiian Islands and one of the most endangered marine mammals in the United States. Roughly 1,600 individuals remain in the wild as of 2024 (NOAA Fisheries) — still listed as Endangered under the U.S. Endangered Species Act, though the IUCN downlisted the species from Endangered to Vulnerable in 2024 after a decade of steady population growth. Here’s what you need to know about this iconic Hawaiian species and the conservation effort bringing it back from the brink.

Adult Hawaiian monk seals typically weigh 375–600 pounds (170–270 kg) and measure roughly 6–7.5 feet (1.8–2.3 m) long, with females slightly larger than males — they’re actually earless seals (family Phocidae), not eared seals, distinguished by their lack of external ear flaps. They spend their days lounging on beaches or resting in shallow water nearshore with just their heads exposed, foraging mainly on reef fish, eels, octopus, and squid.

• Status: Endangered (U.S. ESA); Vulnerable (IUCN Red List) 
• Known as: Hawaiian Monk Seal
• Estimated numbers left in the wild: ~1,600 (NOAA, 2024).

Description

The Hawaiian monk seal is one of just three species – one probably extinct – that lives in tropical waters. This animal is named for its cowl-like skin folds on the head, as well as its solitary habits.

Monk seals are about 2.3 meters long and weigh 225 to 275 kilograms. They are earless seals with no external ears and are covered in dark grey fur molted yearly.

Hawaiian monk seals spend a lot of time in the water, partly thanks to the mild temperatures of the local seas. They forage through the nearby coral reefs, eating spiny lobsters as one of their major dietary items and preying on octopuses, eels, and fish.

When in need of rest, or when a storm is approaching, they return to the beach and haul out onto dry land. In the case of a threatening storm, they may take shelter in the foliage growing directly behind the beach, highly unusual behavior for a seal.

Breeding is problematic for Hawaiian monk seals because there are too many males, which translates into sexual aggression and possible killing of females by gangs of amorous males. Furthermore, the female monk seal does not leave her pup to feed during the six weeks until the pup is weaned.

This causes massive weight loss and weakens the female, leaving her vulnerable to sharks or illness once she returns to the sea to feed. The maximum life expectancy is probably 30 years.

Location

The Hawaiian monk seal is found throughout the Hawaiian Archipelago — from its historical stronghold in the remote Northwestern Hawaiian Islands (protected within Papahānaumokuākea Marine National Monument) to a small but growing population in the Main Hawaiian Islands, where dozens of pups are now born each year.

About the Hawaiian Monk Seal

The Hawaiian monk seal is found only in the Hawaiian Islands, and adults can weigh up to roughly 600 pounds and grow to about 7.5 feet long. It spends much of its time resting on beaches or foraging in shallow reef waters near shore.

These species forage mainly along the ocean floor, preying on reef fish, eels, octopus, squid, and crustaceans such as spiny lobster.

It has a gestation period of about eleven months and typically gives birth to a single pup. It spends much of the day resting on beaches or in dense vegetation. It is a solitary animal, except for mothers and their pups.

Hawaiian monk seals were historically hunted for their meat, oil and sealskin. Today they remain endangered because of human activities like fishing net entanglement, marine debris, and disease. There are approximately 1,600 Hawaiian monk seals left in the world (NOAA Fisheries, 2024), and they are protected under U.S. federal law.

Hawaiian Monk Seal is one of the Hawaiian islands’ most iconic animals

The Hawaiian Monk Seal is one of the Hawaiian Islands’ most iconic animals. Hawaiian monk seals are known for their furry belly and round face, which they use to bob in the water.

Hawaiian monk seals are endemic to Hawaiian Islands, meaning that they can only be found in Hawaii. They are one of the rarest seal species in Hawaiian oceans and came close to extinction.

This species remains endangered, but its population has been slowly recovering since 2013 thanks to conservation efforts such as captive breeding programs and safe havens for Hawaiian Monk Seals.

Approximately 1,600 Hawaiian monk seals live throughout Hawaiian waters. Its habitats range from Hawaiian waters, sand bars, coral reefs, and shallow lagoons.

These species preys on fish like eels, squid, mackerels, jacks, groupers , octopuses and small sharks. They are solitary animals that only come together to mate or when females have pups.

Hawaiian Monk Seals live in shallow water

Hawaiian monk seals spend the majority of their time on beaches or in shallow water. They can occasionally be seen in Hawaiian waters. It is one of the three distinct species of monk seals, and they have little DNA in common with other types.

Hawaiian Monk Seals are very territorial, they will often haul out on the same beach if that is their own territory. They eat fish, octopus and eels which is why they tend to live in shallow water or near reefs so that they can find food easily.

Hawaiian monk seal conservation is a top priority

Hawaiian monk seal conservation is a top priority. The species remains endangered due to habitat loss from human development and coastal dredging, along with a rising number of incidents involving seals entangled in fishing nets and marine debris.

These species are also affected by tourism. Hawaiian monk seals and humans can meet on beaches where seals congregate. Mothers often leave their pups unattended to rest. Frequently, Hawaiian monk seal resting spots are nearby human activities such as surfing or fishing. Since they associate so closely with people, they may be at risk of attacks from humans because Hawaii is the only place they inhabit.

NOAA Fisheries leads Hawaiian monk seal conservation through its Hawaiian Monk Seal Research Program, which conducts population monitoring, trains seal-response teams, and coordinates recovery efforts. The Marine Mammal Center operates Ke Kai Ola, the world’s only hospital dedicated to Hawaiian monk seals, rehabilitating malnourished and injured seals for their habitat and release back into the wild.

The Hawaiian Monk Seal Recovery Team — a group of scientists appointed under the U.S. Endangered Species Act — guides the species’ long-term recovery plan and works toward eventual down-listing from Endangered.

Conservation

Threats

Humans are one of the Hawaiian monk seal’s biggest threats, with intensive hunting in the 19th century by sealers and whalers driving the species to near-extinction, followed by disturbance to key pupping beaches as U.S. military presence expanded across the Northwestern Hawaiian Islands during and after World War II.

Hunting is no longer a major hazard, but human disturbance can drive seals out of valuable habitats even if the disturbance is limited.

Many secondary threats are also taking a toll on Hawaiian monk seals, entanglement in fishing nets, or marine debris heading the list.

Toxoplasmosis from cat-dropping run-off is a new danger that has killed several seals. A shortage of females means that many males often try to mate with a female at one time, possibly killing her in the process. Finally, many of the natural prey items of these seals have been overfished, leading to starvation, especially among youngsters.

Conservation efforts

The Hawaiian monk seal is the subject of a concentrated conservation effort by the United States government and various environmental groups. The seals and the coral reefs they depend on for food are protected within Papahānaumokuākea Marine National Monument, one of the largest marine protected areas on Earth.

Further efforts include raising the number of females by isolating and raising female pups in special areas where they are given adequate food and kept safe from disturbance or “mobbing,” as well as protective care for undernourished female pups.

Additional methods of conserving the species are planned, including vaccination, feeding, relocation to other Hawaiian islands, and even drugging of males to lower their aggression and prevent them from killing females.

Organizations

Monk Seal Foundation

The Monk Seal Foundation focuses on scientific education, protection, and recovery programs to help the Hawaiian Monk Seal to survive in the wild and provide a sanctuary for injured seals.

Conclusion

Hawaiian monk seals are an endangered species. Despite their Hawaiian name, these rare tropical seals only survive in the northern Hawaiian Islands and the surrounding coral reefs. This creature is a popular attraction for tourists since they may be seen sunbathing on beaches or napping underwater in caves (however, this behavior has decreased owing to pollution).

Although Hawaiian monk seals have few natural predators beyond sharks, humans represent a variety of hazards, including historical hunting, fishing nets, and marine litter containing toxins that commonly kill them when accidentally ingested.

Females are also frequently attacked by other males. Furthermore, due to an abundance of males relative to females, there is a danger of sexual aggression and possible female deaths at the hands of gangs of amorous males during the breeding season. Nursing mothers stay with their pup on the beach for the entire five-to-seven-week nursing period without leaving to feed themselves — a fast that leaves them dangerously depleted by the time the pup is weaned.

Papahānaumokuākea Marine National Monument protects the core of the Hawaiian monk seal’s remaining habitat, and NOAA Fisheries, The Marine Mammal Center, and dedicated researchers continue working to help this uniquely Hawaiian species recover.

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