Little information is available describing the biodiversity of Tongan reefs. Some 192 species of scleractinian corals have been recorded at 11 reefs around Tongatapu. Other studies have revealed 229 reef fish from 39 families, 55 bivalves, 83 gastropods and 13 holothurians. In all cases these are likely to be considerable underestimates. Coral cover on the reefs is likely to be highly variable, with records of only 2 percent in Monuafe but up to 50 percent at Hakaumama‘o Reef.