Stream Water Quality and Fish Communities in an Urbanized Watershed of the Lower Mississippi River Basin

Little information is available on effects of urbanization on stream ecosystems in the Lower Mississippi River Basin. Base flow water samples were collected and analyzed monthly from four urban and four suburban streams from June 2011 to December 2013. Fish communities were assessed twice (October and March) each year during this period by backpack electrofishing. In the urban subwatersheds, dense residential housing, commercial buildings, and surface runoff from streets and highways were the primary stressors.  In contrast, stressors in suburban subwatersheds included lawn/pasture and scattered residential housing.  In urban streams, we generally found that water temperature, conductivity, dissolved oxygen, and pH were greater compared to suburban streams.  Conversely, turbidity and major nutrient species were generally lower in urban streams compared to suburban streams. We collected 978 specimens and recorded 13 species from the urban streams compared to 655 specimens and 20 species in the suburban streams.  In general, mosquitofish were strongly associated with conditions in urban streams.  Both bluegill and green sunfish were associated with a wide range of conditions found in both urban and suburban streams. Species such as spotted bass, large mouth bass, redfin pickerel, and golden shiner were only observed in the suburban streams.