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


Participating Agencies

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

Theses and Dissertations Publication Date
Baum, C.M. Temperature and winter duration requirements for reproductive success in Johnny Darter Etheostoma nigrum in the South Platte River basin, CO. Master's Thesis (47 pp), Colorado State University, Fort Collins, CO July 2021