Identifying factors that harm fish and other stream life is a key part of the watershed restoration and protection projects being carried out by the MPCA under Minnesota’s Clean Water Legacy Amendment.
The MPCA will be working in several streams throughout Minnesota each year to gauge stream health. Many streams suffer from stressors that harm fish and other aquatic life. These stressors may also affect recreation such as swimming and fishing.
Elements of stream health
The MPCA and local partners examine several interrelated factors to identify stressors. The goal is to maintain conditions in healthy streams and fix problems in unhealthy streams.
The agency studies the following factors and the relationship among them:
Stream connections, such as dams, culverts and tile drainage
Hydrology, including stream flow and runoff
Stream biology, such as fish and bugs
Water chemistry, including oxygen levels, nutrient levels and temperature
Stream channel assessment, mainly erosion
What conditions stress our streams?
StreamStressors-4Too much sediment
Soil and other matter in water can make it hard for fish and other aquatic life to breathe, feed and reproduce. Sediment can also cover spawning areas and fill in parts of streams.
Aquatic life needs oxygen dissolved in the water to breathe and survive.
Stream temperature affects metabolism and the ability to get oxygen, especially for species such as trout.
Lack of habitat
Habitat affects all aspects of survival for fish and other aquatic life. Habitat encompasses places to live, food to eat, places to reproduce and means of protection.