Yes, it does!
The solubility of oxygen in water depends on the total concentration of dissolved solids in the water. This can be expressed as salinity in g/kg. For example, sea water has a salinity of approx. 35 g/kg.
In pure water, at 25°C and 1 bar, the oxygen saturation (max. amount of oxygen that can be dissolved in water) is 8.95 mg/l. For water with a salinity of 5 g/kg, the saturation is only 7.80 mg/l. For sea water that would be 6.60 mg/l.
You can conclude that, if you are not measuring in pure water, salinity compensation for your dissolved oxygen measurement is important.23/01