Teller Lake in Boulder has been taken over. Somebody introduced a number of goldfish into the water some years ago, and there are now thousands of them.
The native fish are being starved out, and so the illegal aliens now dominate the waters. Their fish and wildlife service folks see only a couple of options: draining the lake and rebuilding from scratch (which would create a huge, stinking mess as well) or electroshock.
That latter option's going to be a lot more expensive than the former option, but it's really the better move; shocked fish float to the surface, which allows people to selectively net out the goldfish for uses as fertilizer or feed while permitting remaining native fish to eventually recover and swim on their merry way.
