four coral reefs successively farther from point source of frequently occurring westward-moving terrigenous sediment plumes; generated by resuspension of fine-grained sediments; examined for effects of terrigenous influx into reef environment. used linear photographic transects parallel to each 5 m depth; total coral cover and cover by species; number of species, and number of colonies used. total cover was reduced near source of sediment influx; cover and diversity increased with distance from source, and amounts of sediment trapped on the reefs decreased suggesting that the plume was an important factor contributing to the deterioration of these reefs. both coral cover and number of species decreased with high sediment inputs. Sediment resistant coral species (as described in literature) also found in this study, tolerated adverse environment, and their percent of cover was relatively constant from site to site. - Sediment stress has drastically reduced the total cover and number of species in the reefs with high sediment inputs. effects include partial or total burial of coral colonies, bleaching, and colonization of the coral surface by filamentous blue-green algae and sponges. The reduced light levels resulted in domination of the community by deeper fore-reef coral species.