Mucus Production by Corals Exposed during an Extreme Low Tide

Abstract

An extreme low tide resulted in the severe exposure of corals on the reef flat surrounding Coconut Island in Kaneohe Bay, Oahu, Hawaii. The exposed corals produced vast quantities of mucus that aggregated as mucous ropes near the shoreline. These mucous ropes were heavily laden with carbonate sediments, amorphous materials, microflora, and microfauna. Compared to the purified liquid mucus of the coral Fungia scutaria, the consolidated mucous ropes were rich in organic material and phosphorus. Pure mucus was relatively low in trophic quality. While the pure mucus may provide corals with some protection against dessication, it is not a particularly rich food source for reef heterotrophs. Perhaps the most important role of coral mucus is the consolidation of microscopic organic particulates into macroscopic aggregates of considerably higher trophic quality than the pure mucus itself.