Jeff, are fatheads and LMB all that you have in the pond right now?

If they pull off a spawn, with no other predators in the pond, it could be a big step in the wrong direction. Maybe you have more time to act if you get a later LMB spawn in NE Wisconsin.

If you have a steady source of water, and as davatsa suggests, you might want to consider draining.

Excerpt from Robert Crais' "The Monkey's Raincoat:"
"She took another microscopic bite of her sandwich, then pushed it away. Maybe she absorbed nutrients from her surroundings."