Coral reef islands and atolls. The reef face is the zone above the reef floor or the reef drop-off. This zone is often the reef's most diverse area. Coral and calcareous algae provide complex habitats and areas that offer protection, such as cracks and crevices. Invertebrates and epiphytic algae provide much of the food for other organisms. A common feature on this forereef zone is spur and groove formations that serve to transport sediment downslope. The reef flat is the sandy-bottomed flat, which can be behind the main reef, containing chunks of coral. This zone may border a lagoon and serve as
Coral reef of Varadero Coral reef of Varadero Coral reef of Varadero is a coral reef located in the Bay of Cartagena, Colombia. Its paradoxical existence, harboring high coral cover and diversity despite the poor water quality and sediments discharged during the last 500 years by the Canal del Dique into the Bay, has drawn special interest by the scientific community and local and international media. The persistence of the Varadero reef is currently threatened by a project to modernize Cartagena’s port, not only by the direct damage produced by the dredging of a new shipping lane through the reef, but also by the