Biological monitoring: Streams
With over 92,000 miles of rivers and streams within its boundaries, Minnesota is a state rich in riverine resources. From streams that meander slowly through wetlands and flat plains to coldwater streams cascading down rocky gorges, the variety of stream types reflect Minnesota’s changing terrain.
Landscapes within the state transition between eastern woodlands and western prairies, and from northern coniferous forests to corn-belt plains. Minnesota contains a rare three-way continental divide near Hibbing, with water flowing in three directions to three separate seas.
Of the 10 major river basins in Minnesota: the Red and Rainy flow north into Hudson Bay; the Lake Superior Basin flows east into the Atlantic Ocean; and the remaining basins flow south into the Gulf of Mexico.
MPCA staff sampling fish with electrofishing equipment.Overall, many of Minnesota’s streams are in good shape. More than 65% of assessed streams meet water quality standards and criteria, but only about 5% of stream miles have been assessed. Pollution control efforts have been largely successful in reducing point source pollution to rivers and streams. However, past emphasis on chemical contaminants has failed to address the more insidious consequences of landscape alteration and non-point source pollution on the quality of water resources.
Watershed disturbances from urban, residential, and agricultural development can contribute to an overall decrease in the physical, chemical, and biological quality of rivers and streams. Because aquatic communities integrate the effects of all stressors in the aquatic environment, monitoring these communities is the best way to understand the relationship between human induced disturbances and aquatic resource quality.
