Dramatic Collapse of Common Carp (Cyprinus carpio) in the Upper Mississippi River System

Common Carp are a widespread invasive species that are often difficult to control or eradicate. Two long-term monitoring programs in the Upper Mississippi River System have records of Common Carp populations for three to six decades, and these surveys reveal a dramatic, widespread, and enduring collapse. Using the method of multiple working hypotheses, we consider several possible explanations for the collapse, including native predators, resource exhaustion, abiotic limitations, management actions, disease, and the passenger concept of invasive species. Trends in catch rates and population size structure suggest disease offers the most compelling explanation, suggesting that Common Carp populations worldwide may be vulnerable to similar collapses.