Glad Emma's been diagnosed. This makes perfect sense; particularly when the water levels are so low and anything aquatic is going to be more concentrated.
When I take these two to the beach, I make sure that we go in the saltwater first. They will bite at it - taste it - hate it and then the rest of the day, they're not drinking a ton of creek water too (because this beach has both fresh and salt water). I know my kooky method is working because, when we get back to the truck after hours of being at the beach "swimming" LOL, they drink a ton of water in their dish that I keep cool in the truck.
Bea's face when tasting salt water is pretty funny...but so hard to catch on film! (I've tried)