WATER QUALITY AND FISH COMMUNITY CHARACTERISTICS IN
URBAN AND AGRICULTURAL STREAMS IN PART OF THE UPPER
MISSISSIPPI RIVER BASIN, 1997

Kathy E. Lee, Phil J. Talmage, Joe C. Stauffer, and Jesse P. Anderson 
Upper Mississippi River, National Water Quality Assessment Program, U.S.
Geological Survey, Mounds View, MN, 55112

The U.S. Geological Survey conducted a study to characterize differences in
water quality and fish communities in streams draining predominately
agricultural and urban areas in part of the Upper Mississippi River Basin.
Sampling was conducted during August and September of 1997 in 20 streams
draining agricultural areas and 13 steams draining urban areas. Agricultural
streams were divided into two groups based on the density of trees in the
riparian area. Ten streams had dense wooded-riparian cover (wooded
agricultural streams) and 10 streams had sparse wooded-riparian cover (open
agricultural streams). All urban streams had dense wooded-riparian cover.
Water samples were collected once from each stream during low flow for
analysis of nutrients, suspended sediment, dissolved organic carbon, and
herbicides. Dissolved oxygen concentrations were measured at each site during
a 48-hour period to determine stream primary productivity. Fish were sampled
by electrofishing in stream reaches that were 20 to 24 times the mean channel
width. Instream habitat characteristics were also measured at each stream.
Agricultural streams had greater nitrite plus nitrate nitrogen and suspended
sediment yields, and lesser dissolved ammonia and dissolved organic carbon
yields than urban streams. Herbicides were detected more frequently, and at
higher concentrations, in agricultural streams. Primary productivity was greater
in open agricultural streams than urban or wooded agricultural streams.
Instream habitat (woody debris, boulders, undercut banks, and macrophyte
beds) serves as cover for fish. Total instream habitat cover was greater in
wooded agricultural streams than in urban or open agricultural streams. An
index of biotic integrity (IBI), which is a measure of fish community health,
was calculated for each stream. Fish IBI scores were greatest at wooded
agricultural streams. Instream habitat, water quality, and land use may all have
an influence on fish IBI scores.

Keywords: Fish, IBI, Water Quality, Land Use, Minnesota


Kathy Lee, U.S. Geological Survey, WRD,2280 Woodale Drive, Mounds
View, Minnesota 55112
Phone: 612-783-3254; FAX: 612-783-3103; email: klee@usgs.gov
Platform presentation only