Puako, Hawai'i 

Drop Off

Following the reef flat is a vertical drop-off of 3-6 meters which leads to the main Puako reef. This is area of caves and crevices filled with encrusting corals and sponges. Tube corals (Tubastraea coccinea), best observed at night, cover many of the walls creating orange carpets. Other corals, such as species of the genus Leptoseris and Pavona, are also common. Black sea urchins, mainly Echinothrix diadema and E. calamaris, are common in holes on the walls. Green sea turtles (Chelonia midas) are commonly found sleeping in caves. This threatened species feeds on seaweeds growing on the vertical cliffs and reef flat, especially members of the red seaweed genus Pterocladia. Turtles are also commonly seen sleeping in depressions on the main reef and gracefully swimming over the bottom. Schools of small fish may occasionally be seen feeding off the seaweeds and encrusting invertebrates on the backs of green sea turtles.