http://www.waterencyclopedia.com/Ce-Cr/Corals-and-Coral-Reefs.html A coral reef is a structure in the sea constructed by coral skeletons and limestone debris that remains in place after the plant or animal dies. The structure is geological, the…
http://en.wikipedia.org/wiki/Aquatic_ecosystem From Wikipedia, the free encyclopedia An estuary mouth and coastal waters, part of an aquatic ecosystem An aquatic ecosystem is an ecosystem in a body of water. Communities of organisms that are dependent on each other and on their environment…
ttp://en.wikipedia.org/wiki/River_ecosystem From Wikipedia, the free encyclopedia This stream in the redwoods together with its environment can be thought of as forming a river or lotic ecosystem The ecosystem of a river is the river viewed as…