Reef

Definition of Reef: Reefs are defined structures in the marine environment that arise from the seabed and cover an extensive area. Or as hard mineral substrates such as rocks, till, or stones, primarily moraine ridges with block and stone cover in gravel/sandy surroundings, which rise mildly to prominently above the seafloor;. biogenic hard substrates such as honeycomb (Sabellaria) reefs and mussel banks are present; they are permanently submerged; often they are overgrown with mussels and a characteristic macrofauna. Reefs can be both natural and artificial in origin. Reefs have a number of ecological functions: feeding grounds for birds and marine mammals; habitat and retreat; habitat and nursery area with high species diversity; spawning grounds and feeding ground for fish; stepping-stone and regeneration reservoir for the expansion of benthic organisms. This is the common definition for Reef, other definitions can be discussed in the article