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Hawaiian Monk Seals

Endemic to Hawai`i, Hawaiian monk seals are the most endangered seal species in the U.S., with only an estimated 1,100 seals remaining. Major breeding populations are at six locations in the Northwestern Hawaiian Islands; a relatively small, but apparently increasing number of seals live in the main Hawaiian Islands.

Prey includes bottom-dwelling and reef fish, eels, octopus, squid, and crustaceans. Most feeding occurs at depths less than 325 feet (although they sometimes dive over 1,640 feet).

The maximum age of the Hawaiian monk seal is believed to be 25-30 years. Females reach sexual maturity at 5-10 years of age. Pups are weaned at 5-6 weeks of age. Pups measure about 3 feet at birth and weigh about 30 pounds; their weight may increase to as much as 150 to 200 pounds before weaning.

The Hawaiian monk seal may be named for its solitary nature, bald appearance and for the rolls of skin around its neck, similar to a monk’s hood.

Scientific Name: Monachus schauinslandi
Hawaiian monk seal photo by Flip Nicklin
Flip Nicklin/Minden Pictureses
LENGTH About 3’4” (1 m)
WEIGHT 35-40 lb (16-18 kg)
LENGTH MALE 6'11" (2.1 m)
FEMALE 7’10" (2.4 m)
WEIGHT MALE 510 lb (230 kg)
FEMALE 600 lb (270 kg)
LIFE SPAN 20 - 30 years

The Hawaiian monk seal is protected under the Endangered Species Act, the Marine Mammal Protection Act and wildlife laws of the State of Hawai‘i. These laws prohibit harassing, harming, or killing a monk seal. It is important to remember that all monk seals, both alive and dead, are protected. In 1988, critical habitat was designated on all beach areas and ocean waters to a depth of 120 feet around the Northwestern Hawaiian Islands. If you are lucky enough to see a monk seal in the wild, please keep a minimum distance of 150 feet (50 yards) to ensure you do not disturb it. A disease transferred from dogs to seals could threaten the entire monk seal population so please keep your pets leashed and away from seals. Federal permits are required to conduct research on monk seals both in the wild and in captivity.


~ Report violations to the NOAA Fisheries Enforcement Hotline at 1-800-853-1964.

~ Report monk seal sightings and marine mammal emergencies (including injuries and entanglements) to NOAA Fisheries at 1-888-256-9840.


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