AP BIOLOGY

Detailed explanation-1: -An estuary is an area where a freshwater river or stream meets the ocean. In estuaries, the salty ocean mixes with a freshwater river, resulting in brackish water. Brackish water is somewhat salty, but not as salty as the ocean. An estuary may also be called a bay, lagoon, sound, or slough.

Detailed explanation-2: -Estuaries and their surrounding wetlands are bodies of water usually found where rivers meet the sea. Estuaries are home to unique plant and animal communities that have adapted to brackish water-a mixture of fresh water draining from the land and salty seawater.

Detailed explanation-3: -When fresh water and saltwater meet in an estuary, they do not always mix very readily. Because fresh water flowing into the estuary is less salty and less dense than water from the ocean, it often floats on top of the heavier seawater.

Detailed explanation-4: -The first zone is where the river begins to meet the saltwater. It has more fresh water than saltwater. Next is a middle zone where there is an almost equal mix of fresh and saltwater. The last zone is where the water begins to flow into the ocean, and is mostly saltwater.

Detailed explanation-5: -Estuaries: Nurseries of the Sea Estuaries are often called the “nurseries of the sea, ” because so many animals reproduce and spend the early part of their lives there. Salty seawater mixes with fresh water draining from the land to create habitats with unique conditions that are not found elsewhere.