Is Physical Removal a Viable Management Option for Invasive Common Carp: Modeling Evidence from Distinct Ecosystem Types in North America

Physical removal is an important strategy used to reduce the abundance of invasive vertebrates but its utility has been questionable for fish. Using a modeling approach we demonstrate that the usefulness of physical removal in controlling common carp, a globally invasive fish, is strongly influenced by the ecology of invaded ecosystems. In regions with poor communities of predators that forage on carp eggs and larvae and where carp can easily recruit within systems from which they are being removed, physical removal alone is unlikely to succeed even if removal rates approach 90% of adult individuals annually. However, in regions with strong predatory communities where carp can recruit only in seasonally-unstable habitats from which the juveniles must out-migrate to join the adult population, physical removal can lead to sustained population control. In this scenario, annual removal rates as low as 30% are able to achieve the desired population control of 100 kg/ha or less. Such removal rates are often achievable by targeting winter aggregations of carp and could lead to a sustainable common carp control across large geographic areas.