Research has been ongoing on for some time to help prevent the erosion of the island from choking off and killing the coral. Easter Island coral reef is one of the world’s most productive ecosystems, providing complex and varied marine habitats that support a wide range of other organisms. Fringing reefs just below low tide level have a mutually beneficial relationship with mangrove forests at high tide level and sea grass meadows in between: the reefs protect the mangroves and seagrass from strong currents and waves that would damage them or erode the sediments in which they are rooted, while the mangroves and sea grass protect the coral from large influxes of silt, fresh water and pollutants. This level of variety in the environment benefits many coral reef animals, which, for example, may feed in the sea grass and use the reefs for protection or breeding.
The Easter Island coral reefs are home to a large variety of animals, including fish, seabirds, sponges, cnidarians, which includes some types of corals and jellyfish, worms, crustaceans including shrimp, cleaner shrimp, lobsters and crabs, mollusks including cephalopods, echinoderms including starfish, sea urchins and sea cucumbers, sea squirts, sea turtles and sea snakes. Aside from humans, mammals are rare on coral reefs, with visiting cetaceans such as dolphins being the main exception. A few of these varied species feed directly on corals, while others graze on algae on the reef. Reef biomass is positively related to species diversity.
The same hideouts in a reef may be regularly inhabited by different species at different times of day. Nighttime predators such as cardinal fish and squirrelfish hide during the day, while damselfish, krill, surgeonfish, triggerfish, wrasses and parrotfish hide from eels and sharks.