Hawaiian monk seal

Photo: Djibo Zanzot · CC BY-SA

The Hawaiian monk seal is one of the world's most endangered marine mammals, with a total population estimated below 1,500 individuals and endemic to the Hawaiian archipelago. Niihau's undisturbed reef and low human presence make it a critical foraging ground, where seals hunt reef fish, octopus, and eels along the shallow basalt shelves. Encounters during dives are rare and deeply significant — monk seals are federally protected and approaching within 50 feet is prohibited, but individuals are known to approach curious divers of their own accord.