If you are worried about metal corrosion, then assuming the light ring is properly connected to the bonding wire (as it should be), then all you need to do is to add a zinc sacrificial anode buried in moist soil and everything on the bond wire should have increased protection from metal corrosion. Most likely it will more than make up for any issues caused by the higher salt level. It's probably not needed, but would add peace of mind of it's of concern.