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 works in several streams each year to gauge stream health around the state. 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 relationships 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?
Too 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.
Low oxygen. Aquatic life needs oxygen dissolved in the water to breathe and survive.
Temperature. 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.
Too many nutrients. Excess nutrients, such as phosphorus and nitrates, can be toxic to aquatic life and cause algal blooms.
Technical guidance and reports
Local partners may find this technical guidance useful for stressor identification work.
Stressors to biological communities in Minnesota's rivers and streams (wq-ws1-27)
Stressor identification technical guidance (wq-iw1-44)
Stressor Identification Report Template (wq-ws5-00)
Aquatic biota stressor and best management practice selection guide (wq-ws1-26)
Stressor reports
Anne River TMDL Project Stressor Identification Report
Bluff Creek TMDL Biological Stressor Identification
Bois de Sioux Watershed Stressor Identification Report (wq-ws5-09020101a)
Brown's Creek Impaired Biota TMDL - Stressor Identification
Buffalo River Watershed Biotic Stressor Identification
Cannon River Watershed Stressor Identification Report
Cedar River Watershed Stressor Identification Report (wq-ws5-07080201a)
Chippewa River Watershed Biotic Stressor Identification Report (wq-ws5-07020005a)
Clearwater River Watershed Stressor Identification Report (wq-ws5-09020305a)
Coon Creek Stressor Identification Report
Crow Wing River Watershed Stressor Identification Report
Des Moines River Watershed Stressor Identification Report (wq-ws5-07100001a)
Elm Creek Watershed Stressor Identification Report
Grand Marais Creek Watershed Stressor ID report
Groundhouse River Stressor Identification Report
Grove Creek Stressor Identification Report
Hawk Creek Watershed Biotic Stressor Identification
Kettle River Watershed Stressor Identification Report (wq-ws5-07030003)
Lac qui Parle River Watershed Stressor ID Report (wq-ws5-07020003a)
Lake of the Woods Watershed Stressor Identification Report (wq-ws5-09030009a)
Lake Superior North Stressor Identification report (wq-ws5-04010101a)
Lake Superior South Watershed Stressor Identification report (wq-ws5-04010102a)
Leech Lake River Watershed Stressor Identification Report (wq-ws5-07010102a)
Le Sueur River Watershed Biotic Stressor Identification Report
Little Rock Creek Stressor Identification Report (wq-iw8-09m)
Little Sioux River Watershed Biotic Stressor Identification Report
Long Prairie River Watershed Stressor Identification Report
Lower Big Sioux River Watershed Biotic Stressor Identification Report
Lower Red River of the North watershed stressor Identification
Lower St. Croix Watershed Biotic Stressor Identification Report (wq-ws5-07030005a)
Marsh River Stressor Identification Report (wq-ws5-09020107a)
Minnesota River - Headwaters Watershed Stressor Identification Report (wq-ws5-07020001a)
Mississippi River - Brainerd Watershed Stressor Identification Report (wq-ws5-07010104a)
Mississippi River - Grand Rapids Watershed Stressor Identification Report (wq-ws5-07010103a)
Mississippi River - Headwaters Watershed Stressor Identification Report (wq-ws5-07010101a)
Mississippi River - La Crescent Stressor Identification Report (wq-ws5-07040006a)
Mississippi River - Lake Pepin Stressor Identification report (Cycle 2) (wq-ws5-07040001a)
Mississippi River - Lake Pepin Tributaries Biotic Stressor Identification
Mississippi River - Reno Stressor Identification Report (wq-ws5-07060001a)
Mississippi River - St. Cloud Stressor Identification Report
Mississippi River - Sartell Watershed Stressor Identification Report (wq-ws5-07010201)
Mississippi River - Winona Watershed Biotic Stressor Identification Report
Mud Creek (Snake River Watershed) Stressor Identification Report (wq-iw6-11n)
Mustinka River Watershed Stressor Identification Report
Nemadji River Watershed Biotic Stressor Identification Report
Nine Mile Creek Stressor Identification Report (wq-ws5-07020012a)
North Fork Crow River Watershed Biotic Stressor Identification Report (wq-ws5-07010204b)
North Fork Crow River Watershed Stressor Identification report (wq-ws5-07010204d)
Otter Tail River Watershed Stressor Identification Report (wq-ws5-09020103a)
Pine River Watershed Stressor Identification Report
Pomme de Terre River Watershed Biotic Stressor Identification Study
Rainy River Headwaters Stressor Identification Report (wq-ws5-09030001a)
Redeye River Watershed Stressor Identification Report
Red Lake River Watershed Stressor Identification Report
Rock River Watershed Biotic Stressor Identification Report
Root River Watershed Stressor Identification Report
Roseau River Watershed Stressor Identification Report (wq-ws5-09020314a)
Rum River Watershed Stressor Identification Report (wq-ws5-07010207)
Sand Creek Stressor Identification Report (wq-ws5-07020012b)
Sand Hill River Watershed Biotic Stressor Identification Report
Sauk River Watershed Stressor Identification Report
Shell Rock River Watershed Biotic Stressor Identification Report
Shingle Creek and Bass Creek Biotic Integrity Stressor ID
Snake River Watershed Stressor Identification Report (wq-ws5-09020309a)
Snake River Watershed Stressor Identification update (wq-ws5-07030004)
South Fork Crow River Watershed Stressor Identification Report (wq-ws5-07010205a)
St. Louis River Watershed Stressor ID Report (wq-ws5-04010201a)
Two Rivers Watershed Stressor Identification Report (wq-ws5-09020312a)
Upper Big Sioux River Watershed Biotic Stressor Identification Report
Upper Iowa River Watershed Stressor Identification Report (wq-ws5-07060002a)
Upper/Lower Red Lake Watershed Stressor Identification Report (wq-ws5-09020302a)
Upper Red River Stressor Identification Report (wq-ws5-09020104a)
Upper St. Croix River Watershed Stressor Identification Report (wq-ws5-07030001)
Vermilion River Watershed Stressor Identification Report (wq-ws5-09030002a)
Vermillion River Watershed Stressor Identification Report (wq-ws5-07040001)
Wild Rice River Watershed Stressor Identification Report (wq-ws5-09020108a)
Wapsipinicon River Watershed Stressor Identification report (wq-ws5-07080102a)
Watonwan River Watershed Stressor Identification Report (wq-ws5-07020010a)
Winnebago River Watershed Stressor Identification Report (wq-ws5-07080203a)
Yellow Medicine River Watershed Biotic Stressor Identification
Zumbro Watershed Stressor Identification Report (wq-ws5-07040004a)