How come there aren't only carnivorous animals left on earth if noah's ark actually existed?

cooping up every animal and putting them on one boat would be very difficult as it would be very cramped and on the boat there would be herbivores and carnivores within close proximity of each other and as anyone knows carnivores only eat meat so would eat other carnivores and they would eat the herbivores on the boat and since there were apparently 2 of each animal on the boat the weaker, non-predators would be wiped out pretty fast. it would also mean the extinction of that breed since they were the only ones left as the whoooooole earth was flooded. how do christians explain this?