In 2014, Arizona used fish poison to clear an invasive fish from Virgin River after mechanical removal methods failed. Then the red shiner came back

For years, conservationists waged a relentless battle against the invasive red shiner in the Virgin River. Initial rotenone treatments showed promise, yet the red shiner persistently returned. However, in 2021, a newly designed two-week rotenone treatment method proved effective, allowing the endangered woundfin fish to recolonize their habitat. This ongoing struggle underscores the complexities of eradicating invasive species once and for all.