Yes, salinity correction factors can be calculated by using the USGS DOTABLES program at http://water.usgs.gov/software/DOTABLES/
Refer to part C.
If the Optical DO Probe or Dissolved Oxygen Probe has been calibrated for fresh water then any measurements in saline waters should be multiplied by the salinity correction factor to calculate the actual DO concentration. Salinity correction factors can be obtained from the DOTABLES program as a function of (a) salinity or conductance, and (b) water temperature.
The Excel file below can be used the calculate DO values in saline waters using the equation and tables listed in the Dissolved Oxygen and Optical DO Probe sensor booklets.