Hawaiian Monk Seal warning sign, Poipu Beach, Kaua'i, Hawaii. The Hawaiian Monk Seal (Monachus schauinslandi) is Hawaii's only pinniped. Monk Seals are sometimes refered to as "living fossils" because they are the oldest living members of the pinniped order and have remained virtually unchanged for 15 million years. Many believe these monk seals got their name from their monk-like preference for solitude. Ancient Hawaiians named the seal Ilio-holo-i-ka-uaua, which means 'dog that runs in rough waters'. Hawaiian Monk Seals have been known to dive as deep as 600 ft. to feed and can stay underwater for up to 20 minutes. An important way in which they differ from other phocids is the fact that they evolved entirely free of terrestrial enemies due to their living on remote oceanic islands. Hawaiian Monk Seals are genetically tame and easily approached by humans. Their population is currently estimated to be between 1,200 and 1,500 individuals. They are considered an endangered species.