If the great flood flooded the entire surface of the earth, then how did all of the salt water animals whose?

evolution led them to be able to exist ONLY in water that was a certain salinty continue to exist? The rain would have diluted the salt water and killed all of the organisms (sea weed, fish, whales … everything)? In addition, the salt water would have mixed with the fresh water in the lakes and rivers and killed all of the fresh water organisms. TODAY, if you take one organisms from fresh to saltwater, or reverse, it dies. Why didn’t all of the aquatic organisms on earth die?
If the great flood flooded the entire surface of the earth, then how did all of the salt water animals whose evolution led them to be able to exist ONLY in water that was a certain salinty continue to exist? The rain would have diluted the salt water and killed all of the organisms (sea weed, fish, whales … everything)? In addition, the salt water would have mixed with the fresh water in the lakes and rivers and killed all of the fresh water organisms. TODAY, if you take one organisms from fresh to saltwater, or reverse, it dies. Why didn’t all of the aquatic organisms on earth die?

A few minutes later-
Many of your answers disagree with what I learned in the bible as the bible said that the water covered the entire earth. In addition, are some of you saying that god can stop the mixing of fresh and salt water? C’mon, makes no sense.
Regarding CVO’s answer … that is one of the dumbest things I’ve ever read. First of all, if you took biology, you learned about diffusion … the salt water and fresh water do NOT layer and that is clear as rivers flow into the ocean and mix. In addition, I’ve not ever read anything other than in your response that shows that fresh/salt water ORGANISMS, not just fish, can ADAPT. Beside, what I’ve read about evolution is that an organism can’t adapt but some are born already adapted and THAT is why they survive, not because they made some sort of decision to change their genetics. Your level of ignorance does not help answer my question.

BTW, how about some scientific reference regarding putting freshwater fish in salt water and they survive? … you must be kidding.
For Doma …
Things adapted? So, did they change their genetic make up and grow things? Did the fish decide to grow wings and fly over the flood? I don’t get it … how does something adapt in 40 days? If things can adapt, I’m going to grow at least a foot and join the NBA to make six million a year!

In addition, if sin caused genetic defects, where in the bible are genetic defects described? Did the bible talk about DNA and genes? Did the bible talk about dominance and recessiveness … did the bible talk about multiple alleles or co-dominance or incomplete dominance or it that just your twist on some phrase in the bible … oh, and which one so that I can determine MY twist on that same section.
Royal Racer … OH C’MON!! You MUST be kidding! Just where in your fantasy book does it say THAT?! That’s a totally new one.