NEWS NOTES ON SUSTAINABLE WATER RESOURCES  USGS Report on Midwest Stream Quality Assessment

NEWS NOTES ON SUSTAINABLE WATER RESOURCES  USGS Report on Midwest Stream Quality Assessment              Healthy streams and the fish and other organisms that live in them contribute to our quality of life. Extensive modification of the landscape in the Midwestern United States, however, has profoundly affected the condition of streams. Row crops and pavement have replaced grasslands and woodlands, streams have been straightened, and wetlands and fields have been drained. Runoff from agricultural and urban land brings sediment and chemicals to streams. What is the chemical, physical, and biological condition of Midwestern streams? Which physical and chemical stressors are adversely affecting biological communities, what are their origins, and how might we lessen or avoid their adverse effects?  The analysis includes the following topics:  Biological Conditions: Algae, Invertebrates, FishHabitat Alteration: Loss of riparian zone, Sediment, Nutrient enrichmentContaminants: Pesticides in water, Contaminants in sedimentEcological Models  What have the results of the MSQA told us about stream quality in the Midwest and about which stressors are most important?   First, there are no pristine streams in the region, as indicated, for example, by a minimum of 28 pesticides detected in water at any site.   Second, no single stressor or stressor type is responsible for all of the changes to the biological communities—for almost every stream and every measure of biological condition, many stressors, both physical and chemical, are implicated. Further, each site has a unique mix of stressors, as illustrated by the site scorecards on the Regional Stream Quality Assessments (RSQA) website. These findings suggest that improving stream conditions across the region will require multiple approaches. In spite of this complexity, there are some consistent findings across sites and biological communities. Habitat, in particular excess fine sediment and the condition of the channel and riparian zone, are important to all biological communities. Pesticides, specifically the triazine herbicides and the pyrethroid insecticides, are affecting algae and invertebrates. Lastly, managing for one group of stressors by, for example, preserving or restoring riparian-zone buffers along streams might reduce other stressors as well.   This study will also be linked on the 2018 Reports Page 02 of the Sustainable Water Resources Site at  Tim SmithSustainable Water Resources CoordinatorGovernment Web Site, Water Resources Site,