Coral reefs are situated in humid oceans close to the equator. The major coral reef is the Great Barrier Reef in Australia. The subsequent main coral reef is situated off the shore of Belize, in Central America. Further reefs are situated in Hawaii, the Red Sea, and other areas in humid oceans. Coral ecosystems are a basis of nutrition for millions; shield the shorelines from hurricanes and erosion; offer home, to reproducing and nursery grounds for economically important fish species; provide jobs and income to local economies from fishing, recreation, and tourism; are a source of new medicines etc. Coral reefs begin to form when free-swimming coral larvae attach to submerged rocks or other hard surfaces along the edges of islands or continents. As the corals grow and expand, reefs take on one of three major characteristic structures —fringing, barrier or atoll.
