Oceans & salinity: What is the average salinity of sea water? Express the typical open-ocean salinity value used in oceanography. Choose the correct value.

What is being asked?
The typical mean salinity value for ocean water.

Given data

• Standard oceanographic average

Concept/Approach
Open-ocean salinity averages around 35 parts per thousand (‰), equivalent to approximately 35 grams of salts per kilogram of seawater (~3.5%).

Verification
35‰ = 35/1000 = 0.035 = 3.5%

Final Answer
35‰ (about 3.5%)