Noahs ark is a physical impossibility

I have to wonder how many animals were on board and what the food amount would be.. these are my loose calculations...
there are about 18,000 land species of animals.. this includes birds, amphibians and mammals,
lets say that 50% of these are clean and 50% unclean
9,000 x 7 for the clean animals= 63,000
9,000 x 2 for the unclean animals= 18,000
= 91,000
How many of the unclean animals could survive off eating the dung of the clean animals, (which cities in the states and canada save millions by feeding there sewage to pigs?)... that takes care of the hugest brunt of the dung... we are also dealing with genetically superior beings, not just the humans being supperior but also the animals and the food, they would metabolise better than what we do today, most likely there was alot of sleeping going on here, so in a state of rest they most likely would not have needed to eat as much as if they were active.
Noah did bring food aboard the ship so I would assume that there was enough to feed the creatures through the whole time of there stay, and again the unclean 18,000 animals would have eaten the dung of the clean, so that leaves only 63,000 clean animals to feed...
My question is how do we figure out the superior levels of genetics that are taking place at this time... and I wonder if there was any fasting taking place throughout the 371 days they were on board the ship...

When you take into account the decree of God stating that mans years would only be 120 years in Genesis 6, and when you do the math of the numbers there it took 1000 years for this decree to come in force...
God used the environment to effect us, and as is observable environment does effect us in way of our health and not only ours but our offspring.
And for the fish I will give you the genetically superior..
My question to you is where than would all the salt come from to make the water to salty?
With the amount of water that would be upon the earth in that time I am sure the amount of salt would be pretty well on scale.And I think that going from 2 or 7 of each species to make all the species on earth now is a far lesser cry than all of this coming from a single ameoba in the primordial soup...