It's very likey the main reason that small businesses like local restaurants, bakeries, etc. fail. People start them based on a fantasy and don't know how to watch the hard realities of expenses and income. But like gravity, there's no escaping those unless you are already wealthy enough for it all to just be a hobby.
If the fish are in a natural reserve, then you pretty much pit your soil on the line. We're missing that detail here and treating it as if this is the difference between one lake or another
"To run your business with your personal romance of how things should be versus how they are is literally the great vulnerability of business."