Core bars are stainless. CE/S2/SE are not. You can try to polish it if the corrosion isn’t too bad. Ocean air shouldn’t be enough on its own - your pickup poles would corrode first.
Did you buy it new? If so, contact PRS customer support. They’ll replace it. If you bought used, it might have been replaced with an aftermarket bar. Buy a replacement bar, they are cheap (Core $20, CE/S2/SE $10).