Trout Stream Water Monitoring
The Milwaukee River Basin is home to only 28 miles of trout stream. These unique coldwater streams can support trout and sensitive macroinvertebrates that require clean, cold water. The presence of trout generally signals good and cold water quality.
Climate change impacts put these special ecosystems at risk. In recent years, Milwaukee Riverkeeper community volunteers identified two Class II Trout streams exceeding the temperature standard, and several others showing signs of warming.
Milwaukee Riverkeeper decided to investigate the daily fluctuations of temperature and dissolved oxygen concentrations in both streams to understand the ongoing threat to these waterways. As the project continues, and we expand research to other cool and coldwater streams, we aim to identify stream reaches at most risk, potential sources of thermal pollution, and potential restoration efforts to keep these unique ecosystems healthy and cold!
Let’s Dive in a Little Deeper
How Does Climate Change Impact Coldwater Streams?
Climate change alters the environmental conditions critical for trout survival. Warmer water temperatures, declining oxygen levels, altered precipitation patterns that lead to increased periods of flooding punctuated by severe drought conditions, and extreme wet weather events that threaten stream stability are all threats to the health of coldwater streams. In addition, the loss of trees from climatic factors and pests, like the Emerald ash borer, can exacerbate warming of streams.
What Can We Do to Protect Trout Streams?
- Protect Coldwater Refuges: Identify and conserve headwaters and groundwater-fed streams that remain cool during warming periods.
- Restore Riparian Buffers: Plant trees and vegetation to provide shade, stabilize streambanks, limit runoff, and reduce sedimentation.
- Manage Water Use: Reduce water withdrawals for agriculture and industry to maintain streamflow during dry periods near these streams.
- Monitor and Adapt: Use monitoring data to adjust conservation strategies as climatic conditions change.
- Promote Climate Resilience: Advocate for policies that reduce runoff and protect water resources, as well as for removal of dams and other impediments to fish passage. In a changing climate, fish and aquatic life need to be able to freely move to a variety of habitats to survive and thrive.
