What can we do to conserve coral reefs? Coral reefs are critically important ecosystems, providing a wide range of benefits to both humans and marine life. They support extraordinary biodiversity and marine species, including fish, sea mammals, and invertebrates.While they only cover less than one percent of the ocean, coral reefs support an estimated 25% of sea life. They provide nursery, spawning, refuge, and feeding areas for various sea organisms. These include mollusks, crustaceans, and sea urchins.