An estuary is an area where a freshwater river or stream meets the ocean. In estuaries, the salty ocean mixed with a freshwater river, resulting in brackish water. Brackish water is somewhat salty, but not as salty as the ocean. Water continually circulat

An estuary is an area where a freshwater river or stream meets the ocean. In estuaries, the salty ocean mixed with a freshwater river, resulting in brackish water. Brackish water is somewhat salty, but not as salty as the ocean. Water continually circulates into and out of an estuary. Tides create the largest flow of saltwater, while river mouths create the largest flow of freshwater. When dense, salty seawater flows into an estuary, it has an estuarine current. High tides can create estuarine currents. Saltwater is heavier than freshwater, so estuarine currents sink and move near the bottom of the estuary.When less-dense freshwater from a river flows into the estuary, it has an anti-estuarine current. Anti-estuarine currents are strongest near the surface of the water. Heated by the sun, anti-estuarine currents are much warmer than estuarine currents.