in what environment do coral reefs form
Corals Corals usually develop into one of three characteristic structures: fringing reefs, barrier reefs or atolls. Click the image to see an animation. 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 âfringing, barrier or atoll.