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

Colorado Project


Temperature and Winter Duration Requirements for Reproductive Success in Johnny Darter, Etheostoma nigrum (Percidae), in the South Platte River Basin, Colorado

September 2018 - June 2021


Personnel

Participating Agencies

  • CO Division of Parks and Wildlife
  • Colorado Parks & Wildlife

Water temperature is a critical ecological variable and changes in water temperature and its seasonal timing may influence biological processes in aquatic ectotherms. Historically, the South Platte River Basin naturally experienced a wide range of seasonal temperatures However, urbanization and development of Waste Water Treatment Plants have contributed to warmer and more consistent water temperatures throughout the year, particularly in winter months. Less variation in seasonal temperatures could have adverse effects on native fishes that previously relied on temperature fluctuations for important biological processes, such as reproduction. Assessing the thermal requirements of warm water fishes will provide valuable information towards establishing protective winter water temperature standards in effluent-dominated streams.