HR: 10:30h
AN: NB22F-01    [Abstracts]
TI: Assessment of Aquatic Biological Communities Along a Gradient of Urbanization in the Willamette Valley Ecoregion, Oregon and Washington.
AU: * Waite, I R
EM: iwaite@usgs.gov
AF: U.S. Geological Survey Oregon Water Science Center, 10615 S.E. Cherry Blossom Dr., Portland, OR 97216 United States
AU: Arnsberg, A
AF: U.S. Geological Survey Oregon Water Science Center, 10615 S.E. Cherry Blossom Dr., Portland, OR 97216 United States
AU: Carpenter, K D
AF: U.S. Geological Survey Oregon Water Science Center, 10615 S.E. Cherry Blossom Dr., Portland, OR 97216 United States
AU: Rinella, F
AF: U.S. Geological Survey Oregon Water Science Center, 10615 S.E. Cherry Blossom Dr., Portland, OR 97216 United States
AU: Sobieszczyk, S
AF: U.S. Geological Survey Oregon Water Science Center, 10615 S.E. Cherry Blossom Dr., Portland, OR 97216 United States
AU: Wigger, I
AF: U.S. Geological Survey Oregon Water Science Center, 10615 S.E. Cherry Blossom Dr., Portland, OR 97216 United States
AU: Sarantou, M
AF: U.S. Geological Survey Oregon Water Science Center, 10615 S.E. Cherry Blossom Dr., Portland, OR 97216 United States
AB: From late 2003 through summer 2004, the U.S. Geological Survey's National Water Quality Assessment Program sampled 28 streams within the Willamette Basin to investigate effects of urbanization on aquatic biology (fish, macroinvertebrates and algae), habitat, and water chemistry. The 28 watersheds fall along an urban land use gradient index (0 to 100, lowest to highest) based on land use and census data developed for this region. Watershed areas range from 13 to 96 square kilometers and contain greater than 20 percent of the Willamette Valley ecoregion. Ten streams were sampled for water chemistry six times during study period. The other 18 streams were sampled twice for water chemistry-once during high sustained flow, and once during summer low flow. The data will be analyzed to determine relationships to the urban gradient index and for possible detection of threshold responses. Preliminary results indicate that 57 percent of the most urbanized streams contained nonnative fish species, but only 43 percent contained salmonids. Conversely, nonnative fish species were present in 14 percent of the least urbanized streams, whereas salmonids were present in 79 percent of these streams. Population density and water chemistry variables were highly correlated with fish assemblage patterns among sites.
DE: 1824 Geomorphology (1625)
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly