Minnesota lake clarity soared 600% after invasive carp were removed in 2009

Pickerel Lake in Minnesota had suffered from poor water quality and persistent algal blooms for decades, largely caused by invasive common carp dominating its shallow waters. Authorities removed the carp in 2009, triggering a dramatic ecological recovery in the lake. Following the intervention, water clarity improved by nearly 600% and native aquatic plants began to thrive again. The case underscores how tackling invasive species can be a decisive factor in restoring degraded freshwater ecosystems.