May 4, 2018 - U.S Geological Survey scientists have linked urban and physical chemical stressors associated with extensive agricultural and urban development to the health of small Midwestern streams. In 2013, the USGS conducted the Midwest Stream Assessment (MSQA) by using statistical ecological methods to identify the most important stressors among the hundreds of potential physical and chemical stressors measured.

These stressors – including development along stream banks and excessive fine-grained sediment, nutrient, and pesticides – are adversely affecting the health of fish, macroinvertebrate, and/or algal communities in nearly all the 100 small streams studies across 11 Midwestern states.

The MSQA results show that no streams are pristine, there is no single stressor, and each site has a unique mix of stressors.  This suggests that improving stream conditions will require multiple approaches.  However, there are some consistent findings, as well. 

The results are summarized in this fact sheet produced by the USGS. 

For more information, contact the NAWQA Project.