These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Fridge Logic: So, the environment is destroyed to the point that part of the ocean is on fire and whole cities have sunk into the ocean. What does mankind decide to do? Go whaling! Could be Fridge Brilliance if most of the land animals are killed off and whales are one of the last sources of food, but then you see that we still have Polar Bears, animals that are in danger of extinction now.
Also, how is Moby Dick still alive? This movie takes place in the future. How far is up to debate, but New York looks like it's been under for a while. And he would have been well over a hundred even in modern times!
There have been cases of live whales found with antique, 200 year old harpoons lodged in them. They can last for quite a while, although his longevity is indeed improbable.