its called an estuary :]
Estuary
An estuary is usually where the fresh water of a river meets the salty sea. The mixing of fresh and salt water forms brine.
Land and water intermingle at coastlines, where the land meets the sea or ocean. Saltwater and freshwater intermingle in estuaries, where rivers meet the sea, creating a unique ecosystem with a mix of salt and fresh water.
A clue is in their name - sea turtle - sea is salt water.
Fresh water - sea water kills.
The mouth of a river where it meets the sea, with a mixing of fresh and salt tidal water
A gallon of fresh water is heavier than a gallon of sea water because fresh water is denser than sea water.
Sea water is salt water.
Put it in the sea.
Fresh water...
grilse
At an estuary, where a river meets the sea.