While I'm no fan of bullheads, conventional wisdom says that a healthy population of LMB can help keep their numbers in check. Same is said about Green Sunfish.

So, don't just think you have to start from scratch just because those fish are present.

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."