Mission Plan Education Spawning Grounds Reef Fishes ... Islands in the Stream 2001 This large sea fan Plumarella pourtalessi expands a basketstar in the current to capture plankton. Photo: John Reed . Click image for larger view. John K. Reed Harbor Branch Oceanographic Institution, Division of Biomedical Marine Research Senior Research Scientist Deep-water coral reefs, also referred to as bioherms, coral banks, or lithoherms, typically consist of thickets of live coral, capping mounds of unconsolidated sediment and coral rubble, and are often built upon an underlying rock base structure. Deep reefs usually are found in regions of fairly strong currents or zones of upwelling. The coral structures capture suspended sediment and build up mounds to heights of a few meters to 150 m (492 ft). Corals are found at average depths of 70 m to 1,000 m (230 to 3,280 ft). At these depths, the corals lack zooxanthellae, the algal symbiont found in shallow, reef-building corals. However, the deep-water reefs still provide habitat for thriving and diverse reef communities. Oculina varicosa coral forms massive colonies over 1 m in diameter at depths of 200 to 300 feet. Photo: John Reed | |
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