Scientists survey 500 million corals in Pacific Ocean, more than expected 1 minute read Sydney, Australia, Mar 2 (efe-epa).- A scientific study published Tuesday counted the number of corals in the Pacific Ocean at 500 million, a higher number than previously estimated, giving hope for the survival of several threatened species. Research shows that each of the eight of the most common species in the Pacific Ocean has a population of more than 7.8 billion – roughly Earth’s population – according to a statement from Australian James Cook University. It also said that of the 80 species considered by the International Union for Conservation of Nature at high risk of extinction, the population of 12 of them is more than 1 billion colonies, according to co-author Sean Connolly, from the university’s Center of Excellence for Coral Reef Studies.