SS4.09 Does Intentional Nutrient Fertilization (N,P And Fe) Foster C Sequestration and/or Increased Fish Fertilization?
Date: Tuesday, June 11, 2002
Time: 11:00:00 AM
Location: Colwood
 
RoseKN, Sierra Nevada Aquatic Research Laboratory, University of California, Santa Barbara, USA, rosekimmer@hotmail.com
Jellison, R, , Marine Science Institute, University of California, Santa Barbara, USA, jellison@lifesci.ucsb.edu
Dawson, D, R, Sierra Nevada Aquatic Research Laboratory, University of California, Santa Barbara, USA, dawson@icess.ucsb.edu
Melack, J, M, Bren School of Environmental Science and Management, University of California, Santa Barbara, USA, melack@lifesci.ucsb.edu
 
HIGH NATURAL RATES OF NUTRIENT LOADING TO A MONTANE RESERVOIR (CROWLEY LAKE, CA)
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Crowley Lake, Mono County, California (area, 17 km2; mean depth, 9 m) lying in the Long Valley Caldera is a valuable aquatic resource. It is the premier trout fishery in the eastern Sierra Nevada and the largest reservoir in the Los Angeles aqueduct system. In summer, large cyanophyte blooms impair recreational uses and water quality. We measured nutrient inputs via seven tributary streams originating in alpine and subalpine catchments (total area, 985 km2) and passing through grazed lands and light urban development. On two of the tributaries, large natural spring systems contain high concentrations of nitrogen, phosphorus, and arsenic and constitute the major source of stream loading (>90% of P). Measured stream inputs of phosphorus are approximately in balance with reservoir exports, in contrast to nitrogen where exports are nearly three times the measured inputs. Thus, nitrogen fixation is a likely additional source of N.