Before and after beaver colonization. (Image by Weber et al., 2017)
Beaver dams are helping keep the river waters cool and cozy for steelhead salmonids, as results of a new study suggest. Some studies have suggested that dams help raise water temperatures, therefore endangering heat-sensitive species. To test that theory, researchers tracked beaver dams and monitored water temperatures along 34 kilometers of the John Day River in Oregon over eight years. The team also assessed the impact of artificial beaver dams on water temperature along four reaches of Oregon’s Bridge Creek.Their findings show that the proliferation of dams has kept the water temperature below 25°C — the temperature that puts juvenile salmonids at risk. Study authors say that the dams likely reduced high stream temperatures by increasing surface water storage and connectivity with cool groundwater.
Authors:
Nicholas Weber, Nicolaas Bouwes, Michael M. Pollock, Carol Volk, Joseph M. Wheaton, Gus Wathen, Jacob Wirtz, Chris E. Jordan
Corresponding author:
Nick Weber, Fish Ecologist, Eco-Logical Research, Inc., US, Email: nick.weber@ecologicalresearch.
Original paper published in PLOS One on May 17, 2017.
