Eradication efforts catalyze rapid evolution in an invasive predatory fish

Area of Science:

• Ecology
• Evolutionary Biology
• Conservation Biology

Background:

• Invasive species management is costly and often fails due to species adaptation.
• Evolutionary adaptation to control measures can prevent eradication.
• High mortality can drive life-history evolution even without a direct selective agent.

Purpose of the Study:

• To investigate the evolutionary response of invasive smallmouth bass to a long-term suppression effort.
• To determine if intensive control drives adaptive evolution in invasive species.
• To understand the role of evolutionary adaptation in the failure of invasion control.

Main Methods:

• Analysis of annually collected ecological and genetic data over 20 years.
• Monitoring population size, age structure, and maturation rates of smallmouth bass.
• Genomic analysis to identify allele frequency changes in response to selection pressures.

Main Results:

• Intensive manual suppression doubled annual mortality but led to a larger bass population.
• The population shifted towards younger, earlier-maturing individuals.
• Significant allele frequency changes were observed in genomic regions linked to maturation and growth.

Conclusions:

• High mortality imposed by control efforts can drive rapid, adaptive evolution in invasive species.
• Evolutionary adaptation, specifically earlier maturation and increased growth, undermined the smallmouth bass suppression program.
• Future invasion control strategies should incorporate genetic monitoring and adaptive management to account for evolutionary responses.