Hawaiian Monk Seal - Oceana

Marine Mammals

Hawaiian Monk Seal

Monachus schauinslandi


Restricted to the Hawaiian Islands


Nest on beaches; feed on coral reefs and associated sand flats

Feeding Habits

Foraging predator


Order Pinnipedia (seals, sea lions, and relatives), Family Phocidae (true seals)


Hawaiian monk seals are generalist predators known to eat fishes, squids/octopuses, and crustaceans, like crabs and lobsters. They are also one of the few species known to successfully hunt and eat garden eels – elongate, shy eels that live in deep burrows in sand flats near coral reefs – and they have been documented diving to depths of more than 1000 feet (300 m) while foraging. Though adult Hawaiian monk seals are quite large (over 7 feet long [over 2 meters] and over 400 pounds [200 kilos]), they are still taken as prey by some large coastal sharks, especially tiger sharks, and scientists who study Hawaiian monk seals witness tiger sharks taking small to medium individuals, near their preferred beaches, almost daily.

Historically, there were three species of monk seals (Hawaiian, Mediterranean, and Caribbean), but all have been significantly affected by human activity, including direct hunting, accidental capture in fishing gear, and habitat destruction. Unfortunately, the Caribbean monk seal could not endure several centuries of hunting and accidental capture and has gone extinct. Both the Mediterranean monk seal and the Hawaiian monk seal are critically endangered and are very highly vulnerable to extinction. Conservation measures for these species by several non-government and government agencies are underway, and most countries that overlap with their geographic ranges (only the U.S. in the case of the Hawaiian monk seal) have offered them some or extensive legal protection.

Fun Facts About Hawaiian Monk Seals

1. Hawaiian monk seals grow up to 7 feet (2.1 m) long and 600 pounds (272 kg).

2. Hawaiian monk seals can live for at least 30 years.

3. Hawaiian monk seals are endemic to the Hawaiian Islands and Johnston Atoll, which lies nearly 1,000 miles southwest of Hawaii.

4. Hawaiian monk seals shed their top layer of fur every year in a fast process known as a “catastrophic molt.”

5. Hawaiian monk seals can remain under water for up to 20 minutes.

6. Hawaiian monk seals can dive more than 1,804 feet (550 m) deep but prefer to swim in shallow waters 200 feet (61 m) or less.

7. Hawaiian monk seals can be found sleeping on beaches for days at a time, as well as underwater in caves.1

Engage Youth with Sailors for the Sea

Oceana joined forces with Sailors for the Sea, an ocean conservation organization dedicated to educating and engaging the world’s boating community. Sailors for the Sea developed the KELP (Kids Environmental Lesson Plans) program to create the next generation of ocean stewards. Click here or below to download hands-on marine science activities for kids.

Kids Environmental Lesson Plans


NOAA Fisheries

IUCN Red List