Coral reef a protective area, or it may lie between the reef and the shore, and in this case is a flat, rocky area. Fish tend to prefer it when it is present. The reef lagoon is an entirely enclosed region, which creates an area less affected by wave action and often contains small reef patches. However, the "topography of coral reefs is constantly changing. Each reef is made up of irregular patches of algae, sessile invertebrates, and bare rock and sand. The size, shape and relative abundance of these patches changes from year to year in response to the various factors
Deep-water coral off Africa’s west coast. In addition to ocean bottoms, scientists find "Lophelia" colonies on North Sea oil installations, although oil and gas production may introduce noxious substances into the local environment. The world's largest known deep-water "Lophelia" coral complex is the Røst Reef. It lies between deep, west of Røst island in the Lofoten archipelago, in Norway, inside the Arctic Circle. Discovered during a routine survey in May 2002, the reef is still largely intact. It is approximately long by wide. Some further south is the Sula Reef, located on the Sula Ridge, west of Trondheim on the mid-Norwegian Shelf,