...we don't know what technology Noah might have used to give each of the animals the best environment as possible. As for freshwater fish, Noah didn't need to have an aquarium. You are assuming that all the water around the earth had to be either SALTY or FRESH! And what basis do you have for this assumption? None. I personally would not know for sure whether the flood was all salty, partly salty in only certain regions of the globe, or all fresh, but I see no reason to not believe that some areas were salty and others fresh.