
Poisoning smallmouth bass in Fossil Creek
Crews last week used chemicals to kill smallmouth bass in a 2.5-mile-long stretch of Fossil Creek, invaders that had already spawned and so threatened to wipe out one of the premier refuges for endangered native fish in the Southwest.
The six-man crew spent weeks netting perhaps 100-300 native fish to move upstream, before using a chemical to kill all the fish remaining in the final 2.5 miles of the stream before it merges with the Verde River.
They set up a dispenser to inject Rotenone into the water, a chemical that essentially smothers any gill-breathing creature. Laboratory tests have shown that the chemical can cause Parkinson’s-like symptoms in laboratory animals. However, the concentrations used to kill the fish in a stream remain far below those levels. The chemical breaks down quickly into harmless byproducts. In addition, the crews released a second chemical that neutralized any lingering traces once it had killed all the fish in that 2.5-mile stretch of stream. Source
This scenario is difficult to judge because it is always best to preserve native species. Sometimes it is a losing battle and you can’t fight invasive species because they sometimes overwhelm a habitat or they can establish an equilibrium leading to minimal disruption of native species.
It is sad to see the poisoning of our favorite species in Fossil Creek but I suspect that if there was a predator that threatened to wipe out the smallmouth bass, we would feel the same way.


