Imagine that humans develop starflight and go to an ocean planet. For millions of years they watch over this planet from their boats on the surface. Every few thousand years they fish all the fish to death and wait for fish to evolve again from the life that's left.
Finally, after said millions of years, a brave fish flops his way up onto one of the boats in reverse scuba gear. Why are you doing this, he begs. Why do you wipe out all fish in the ocean every fifty thousand years.
Well, the million year old human boat admiral says, some day those fish will evolve into land animals, and overfish all the fish in the ocean to death. We're trying to prevent that by only killing most of the fish in the ocean.
But now that you're here, we're going to give you three choices: you can blow up all the boats and also kill all the lungfishes that sometimes survive on land, plus you'll poison the seas and cause mass die-offs. Or you can become supreme captain of all the boats. Or you can turn all fish into fishboats because you brought along a nine-volt battery to plug into our boat engine.
No matter what happens all your fish friends are going to be stuck in a pond, **** you