How much energy does a dolphin burn in a day?
Not only what’s the caloric cost, but can a dolphin afford to forever be dodging boats? That’s so much effort. And how many burned calories keep a mammal warm in cold seawater? How much lost biomass—that’s sea life in this context— is too much before a dolphin can’t get enough to eat?
How do you even measure that, anyway?
You go where you know there are dolphins, and you ask them nicely.