Hawaiian monk seals are endangered marine mammals that are endemic to the Hawaiian Islands. They are the only marine mammal found solely in U.S. waters. They are born at about 35 pounds and 3 feet long, with black fur. As they age, they shed their dark fur for a silvery-gray coat, with lighter creamy coloration on their underside. The Hawaiian Monk Seal haul out on land to rest and give birth. Monk seals can dive as deep as 1500ft but generally average about 200 feet. Male monk seals sometimes kill pups or females of their own species in group attacks called “mobbing.
Signs are often posted on the beaches of Midway, warning people to keep their distance from resting seals.