AP BIOLOGY

Detailed explanation-1: -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-2: -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: -The mixture of seawater and fresh water in estuaries is called brackish water and its salinity can range from 0.5 to 35 ppt.

Detailed explanation-4: -In slightly stratified or partially mixed estuaries, saltwater and freshwater mix at all depths; however, the lower layers of water typically remain saltier than the upper layers. Salinity is greatest at the mouth of the estuary and decreases as one moves upstream.