Cooperative Fish and Wildlife Research Units Program: Iowa
Education, Research and Technical Assistance for Managing Our Natural Resources

Iowa Project

Age Structure & Growth of Invasive Common Carp Populations in the Malheur National Wildlife Refuge

July 2011 - December 2011


Participating Agencies

  • US Geological Survey

The goal of this project is to formulate a comprehensive, long-term carp control strategy for restoring the ecosystem health of the Malheur National Wildlife Refuge. Although short term carp reductions have occurred, no long-term control of this species has ever been achieved. Invasive carp have contributed significantly to the degradation of water bird habitat at the Refuge for over 50 years. Their presence is impacting the Pacific flyway bird populations. This will be accomplished by: • Refuge will begin identifying factors e.g., basic population status and dynamics of Refuge’s carp populations. Since age structure and growth are key components that need to be determined before effective evaluation and control can take place, the Refuge will collect associated dorsal fin spine and otolith samples necessary as a foundation for a control strategy. These calcified tissue samples, which reveal a fish’s age and history of growth rate over its lifetime, will be sent to the IA Coop F&W Research Unit for analysis. • IA Coop Unit has technical training, specialized equipment, and experience necessary to process these samples and do follow-up analysis to generate age structure and growth rate estimates.