The Ark Class ship formed part of the three-fold survival plan of the wealthy and powerful of the Petroleum Age. The other two legs of the plan were the arcologies, and space habitats.
The Californian Sea Otter, as a species, eats about 30 different types of food found throughout its range. Each individual otter, however, will only eat 3 or 4 of these foods - those it was fed by its mother as a child. It will not eat the others even if failure to do so means it would starve. Maybe other, possibly larger and more dangerous creatures and monsters, have similar habits.