THE CORAL COMMUNITIES OF LORD-HOWE ISLAND

Lord Howe Island (31 degrees 33'S,159 degrees 05'E) is surrounded by t he southern-most coral reefs in the Pacific Ocean, The status of the b enthic communities at Lord Howe Island was quantified in 1992-93 using replicated video-transects at 20 sites in the shallow reefal area (<2 0 m depth). The cover of hard coral was comparable with coral cover on some tropical reefs, ranging from less than 10% at some reef flat sit es to greater than 40% cover at two seaward beach sites. The process o f reef formation is apparently slow, and accretion of limestone is loc alized. A total of 59 scleractinian coral species were recorded during this study (including 19 new records), bringing the total number reco rded at Lord Howe Island to 83. The coral communities contain a unique association of tropical species at their southern limits of distribut ion, and subtropical species which are rare or absent from the Great B arrier Reef. Many of the species that have been recorded from Lord How e Island are rare, and may have resulted from chance recruitment of on ly a few larvae. There have been few major changes in the coral commun ities at Lord Howe Island in the past 16 years. At two inshore sites t here was an apparent reduction in hard coral cover in the 1980s.