ECOLOGY OF ORGANIC AGGREGATES IN THE VICINITY OF A CORAL REEF1

A marked increase in the concentration of suspended particulate organic aggregates occurs in oceanic water as it crosses the windward coral reef at Eniwetok Atoll and enters the lagoon. Evidence is presented indicating that these aggregates consist of mucus released by corals. Export of mucus into the lagoon by the reef community was estimated at 20 mg m-’ hr-l. This accounts for about 2.0% of total reef community production and is equivalent to about 40% of coral respiration. Field observations and experimental evidence suggest that aggregates of mucus may be an important food source for zooplankton in the vicinity of coral reefs.