HR: 09:15h
AN: NB41C-04    [Abstracts]
TI: Factors influencing the uptake of nutrients in streams within the New York City water-supply source areas.
AU: * Newbold, D
EM: newbold@stroudcenter.org
AF: Stroud Water Research Center, 970 Spencer Road, Avondale, PA 19311 United States
AU: Kaplan, L
EM: lakaplan@stroudcenter.org
AF: Stroud Water Research Center, 970 Spencer Road, Avondale, PA 19311 United States
AU: Bott, T
EM: tlbott@stroudcenter.org
AF: Stroud Water Research Center, 970 Spencer Road, Avondale, PA 19311 United States
AU: Jackson, J
EM: jkjackson@stroudcenter.org
AF: Stroud Water Research Center, 970 Spencer Road, Avondale, PA 19311 United States
AU: Aufdenkampe, A
EM: aufdenkampe@stroudcenter.org
AF: Stroud Water Research Center, 970 Spencer Road, Avondale, PA 19311 United States
AU: Dow, C
EM: cdow@stroudcenter.org
AF: Stroud Water Research Center, 970 Spencer Road, Avondale, PA 19311 United States
AB: The uptake of nutrients was measured in each of ten streams within the water supply source areas for New York City, once each year between 2000 and 2002. Uptake lengths were estimated from the conservative-tracer-corrected downstream attenuation of short-term (1-2 h) nutrient releases. Uptake lengths correlated with stream size and were converted to uptake velocities (V_f) for further analysis. V_f of phosphate, with a mean of 0.018 mm/s, fit Michaelis-Menten uptake kinetics with a half-saturation of 7 μg/L background phosphate. V_f of ammonium, with a mean of 0.58 mm/s, did not correlate with background ammonium concentration, but fit an uptake curve that used total dissolved nitrogen as the substrate, with a half-saturation of 1 mg/L. V_f of glucose and arabinose were not related to background concentrations. V_f for all four nutrients correlated with community respiration (CR) from diel oxygen variation. For phosphorus uptake, however, CR was collinear with background phosphorus. V_f for ammonium correlated with the macroinvertebrate-based Water Quality Score and V_f for both ammonium and phosphate correlated with some molecular tracers of anthropogenic sources. These results point to nutrient uptake as a sensitive integrator of water quality, ecosystem metabolism, and community structure.
DE: 0400 Biogeosciences
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly