Fish and birds survived
One of the things that people forget is that many fish wouldn't survive.
Not all fish are the same - some live in salt water, some live in fresh-water, it's hard to keep those separate during a global flood.
Just one of the reasons the flood myth is just a story, not a fact.
And the issue of not everyone being evil (esp. babies and small children) is also why the logistics of armageddon make no sense and can't be reconciled with the concept of a loving god. It doesn't give people a chance, and as the population grows the number of people that it's unfair to keeps increasing.
Again, another reason that bible stories and religious beliefs simply make no sense once you start thinking about the nitty gritty details.