AP BIOLOGY

Detailed explanation-1: -Marine ecosystems are aquatic environments with high levels of dissolved salt. These include the open ocean, the deep-sea ocean, and coastal marine ecosystems, each of which has different physical and biological characteristics.

Detailed explanation-2: -Estuarine ecosystems are those with oceanic water which is diluted with freshwater run-off from the land. Marine ecosystems are those with oceanic water.

Detailed explanation-3: -An estuary is a partially enclosed, coastal water body where freshwater from rivers and streams mixes with salt water from the ocean. Estuaries, and their surrounding lands, are places of transition from land to sea.

Detailed explanation-4: -The most important marine ecosystems for marine life are estuaries and coral reefs. These two marine ecosystems are important because the estuaries are breeding territories for many marine animals, because it is easy for young-lings to survive there, since there are no known predators that live in that region.