Coral Reef Recovery Subsequent to the Freshwater Kill of 1965

Abstract

The reef coral community on the landward side of a patch reef near Kahaluu in Kaneohe Bay, Oahu, Hawaii was resurveyed 18 yr after all live coral was killed by a thick lens of freshwater runoff from a flashflood in 1965. The initial phase of recovery of the reef was documented from 1968 to 1973. A resurvey of the reef was conducted in 1983, using the same methods as the 1973 study. Species, abundance, and distribution of corals on the patch reef were measured and recorded along a series of 10 transects. Results show large increases in size and numbers of colonies, area, and depth range covered by corals. Greatest coral abundance was reported in the upper 5 m, but community diversity did not increase because the fast-growing finger coral, Porites compressa, became more dominant. The pattern of coral community succession at this sheltered location was similar to that observed at other environments in the Hawaiian Archipelago. Recovery appears to be rapid in protected, low-wave-energy environments such as Kaneohe Bay, which are infrequently affected by major disturbances. Almost 20 yr after major disturbance, the Kahaluu patch reef slope coral community is approaching the climax conditions of other reef slope communities in Kaneohe Bay not disturbed by the 1965 flashflood.