Grey Reef Shark

Photo: Luis P. B. · CC BY-NC

Grey reef sharks congregate along the outer wall adjacent to Kosrae's Blue Hole, drawn by the upwelling nutrients that concentrate prey in the thermocline zone. Kosrae's low fishing pressure means these sharks retain their natural, unhurried behaviour — they cruise at recreational depth well within camera range rather than retreating as is common at more visited sites. Divers ascending the outer wall at the end of the dive frequently count five or more individuals simultaneously.