Spatial and temporal distribution of pelagic microorganisms and their proteolytic activity over a partly destroyed coral reef

Abstract

Bacterial number, biomass and exoproteolytic activity were determined in the surface water of a coral reef near Bohol (Philippines). Bacteriological results from this partly destroyed reef (seaweed farming) were compared with literature values from healthy reef systems. While total bacterial numbers were more or less evenly distributed over the reef transects, saprophytes and proteolytic activities showed distinct increases at the reef crest and also at the reef lagoon boundary. These were the only undisturbed parts of the reef. It is suggested that coral mucus with its high content of proteinaceous organic matter is a major source of nutrients for bacteria in the water column over the reef. Specific exoproteolytic activity per bacterial cell was considerably higher in the water over the healthy parts of the reef than over the disturbed parts and also higher than in waters from temperate zones.