HR: 1340h
AN: B13B-0228    [Abstracts]
TI: Determining Impacts of Confined Animal Feedlot Operations (CAFOs) on the Water Quality and Periphyton Community in two Mid-Michigan Streams
AU: * Oemke, M P
EM: oemke@alma.edu
AF: Alma College, 614 W. Superior St., Alma, MI 48801 United States
AU: Borrello, M C
EM: borrello@alma.edu
AF: Alma College, 614 W. Superior St., Alma, MI 48801 United States
AU: Snowden, L
AF: Alma College, 614 W. Superior St., Alma, MI 48801 United States
AU: Farley, A
AF: Alma College, 614 W. Superior St., Alma, MI 48801 United States
AB: Confined Animal Feedlot Operations or CAFOs are suspected of having serious impacts on adjacent streams either from direct discharges of animal wastes or from surface runoff carrying animal wastes after rain events. These inputs often contain high levels of nutrients, particularly nitrogen and phosphorus. In some cases other particular chemical constituents in the animal waste, like ammonia nitrogen may adversely affect resident stream biota. We investigated two streams adjacent to two CAFOs in mid-Michigan. Sites were sampled upstream of the CAFO influence and downstream of each facility. Geochemical analyses showed high concentrations of nitrate nitrogen and total nitrogen at both upstream and downstream locations of both streams. This indicates that upstream nutrient inputs had already impacted the study streams, making separation of CAFO inputs hard to separate from the already existing high inputs of nutrients from other routine agricultural practices. Coliform bacteria concentrations were also determined throughout the summer, using the Coliscan rapid detection method to separate E.coli from total coliforms. E.coli is the bacterium associated with human fecal contamination and is routinely measured to determine compliance with Michigan's Water Quality Standard of 130 cfu's/100ml. E.coli are also routinely found in warm-blooded animal waste. High levels of E.coli were enumerated from both downstream CAFO locations. Measured E. coli concentrations downstream of the CAFOs were well above the State of Michigan's standard. At one site over 80% of samples exceeded the state's standard and 20% of samples exceeded the standard at the other downstream location. The attached periphyton community was sampled using glass slides as artificial substrates exposed for 28 days at each sampling location. Dramatic changes were reported in diatom species dominance and in community species composition. For example the diatom species, Cocconeis placentula var. euglypta, comprised over 40% of the upstream diatom community, yet comprised $< $5% of the downstream CAFO impacted diatom community. This study indicates the usefulness of associating a biological component with simultaneous measurements of traditional water quality parameters. CAFOs may have a much greater impact on the stream periphyton community than just accelerating plant growth from excess nutrients. Changes in stream water chemistry had significant impacts on the species and structure of the attached algal community. The chemical parameters; total phosphorus, ortho-phosphorus and ammonia nitrogen appeared to be the most sensitive of those measured, in detecting the possible influences of feedlot inputs on overall stream water quality
DE: 4845 Nutrients and nutrient cycling
DE: 1860 Runoff and streamflow
DE: 0345 Pollution--urban and regional (0305)
DE: 0400 Biogeosciences
DE: 0614 Biological effects
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting