What is water from a sea or ocean with an average salinity of 35 ppt called?

• A. Seawater
• B. Freshwater
• C. Brackish water
• D. Saltwater

Answer: (A)

Salinity tells us how salty water is, measured in parts per thousand. The ocean has an average salinity of about 35 ppt, so water from a sea or ocean with that salinity is seawater. Freshwater has very low salinity, brackish water sits between freshwater and seawater in salinity, and while saltwater is a common everyday term for salty water, the precise term for ocean water is seawater. Therefore, water from the sea with about 35 ppt salinity is seawater.