What’s Being Done to Save the Hawaiian Monk Seal (and What You Can Do to Help)

The Hawaiian monk seal is one of the world’s most endangered marine mammals. For more than six decades, the population has declined. And while recent numbers show a slight growth, they are not enough to regain historic population levels.

About the Hawaiian Monk Seal

Hawaiian monk seals grow to be 6-7 feet long, weigh 400-600 pounds, and can live more than 30 years. Males and females are generally the same size — the only way to tell them apart is to look at their genitals. While they are born black, they eventually turn dark gray or brown on their backs and yellowish brown or light gray on their bellies. About once a year, they undergo a “catastrophic molt,” when they shed the top layer of fur and skin. Natural bleach marks or scars make it easy to identify the Hawaiian monk seal, and many have identification tags on their rear flippers to allow conservation organizations to track them as well.

Hawaiian monk seals are called “generalist feeders,” which means they eat common fish, octopuses, squids, crustaceans and eels. Because they can dive more than 1,800 feet and hold their breath for 20 minutes, they look for prey close to the seafloor. And unlike other seals that live in colonies, Hawaiian monk seals prefer a more solitary lifestyle.

Seals mate in the water and give birth between March and August on sandy beaches. The gestation period is usually between 10-11 months, and seals only have one single pup per pregnancy. Mothers care for their young for several weeks before the pups venture out to forage on their own.

Threats to the Hawaiian Monk Seal

It’s estimated that there are 1,600 seals left in the wild — roughly 400 in the main Hawaiian islands and 1,200 in the northwestern Hawaiian islands. Sadly, though, there has been a significant decline in this population over the last 25 years.

Humans pose a major threat to the Hawaiian monk seal in several ways. Intentional killing, sleep disturbance, intentional feeding and boat strikes — all human-imposed — are detrimental to this population. The seals frequently visit popular tourist beaches, often giving birth there, which creates a hazard for both the seal and the human, as mothers are aggressive and protective of their young. 

Food limitations create another threat to the Hawaiian monk seal population. In certain places, they must compete with sharks and other large sea predators for food. Climate change also affects food availability, as water temperature dictates what sea animals can live in certain places.

These seals are also at risk for shark attacks. Though uncommon, Galapagos sharks can occasionally hunt pups in shallow water.

Conservation Efforts for the Hawaiian Monk Seal

While these seals are protected under the Marine Mammal Protection Act and the Endangered Species Act, the National Oceanic and Atmospheric Administration (NOAA) is a key player in their conservation and management efforts. They provide education and outreach and respond to seal sightings and strandings. The organization also works to decrease human-seal interactions, and it provides veterinary care and rehabilitation to injured seals and vaccinations to protect seals against common diseases.

How You Can Help the Hawaiian Monk Seal

The Hawaiian islands are a popular tourist spot, and monk seals often show up on populated beaches. If a Hawaiian monk seal appears on a beach near you, stay at least 50 feet away. And if it’s a mother and her pup, keep an even further distance as mothers are protective and can be aggressive if they feel their baby is in danger. If the seal is in a roped-off area, abide by the rules and stay behind the rope. Finally, call the NOAA Fisheries Marine Wildlife Hotline at (866) 755-6622 to report the sighting.

Also, consider donating to organizations that focus on the conservation of the Hawaiian monk seal, including the Marine Mammal Center.

Learn more about the Hawaiian monk seal here.