Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

Phosphate Dynamics in an Acidic Mountain Stream: Interactions Involving Algal Uptake, Sorption by Iron Oxide, and Photoreduction

Cathy M. Tate, Robert E. Broshears and Diane M. McKnight
Limnology and Oceanography
Vol. 40, No. 5 (Jul., 1995), pp. 938-946
Stable URL: http://www.jstor.org/stable/2838633
Page Count: 9
  • More info
  • Cite this Item
Phosphate Dynamics in an Acidic Mountain Stream: Interactions Involving Algal Uptake, Sorption by Iron Oxide, and Photoreduction
Preview not available

Abstract

Acid mine drainage streams in the Rocky Mountains typically have few algal species and abundant iron oxide deposits which can sorb phosphate. An instream injection of radiolabeled posphate (32PO 4) into St. Kevin Gulch, an acid mine drainage stream, was used to test the ability of a dominant algal species, Ulothrix sp., to rapidly assimilate phosphate. Approximately 90% of the injected phosphate was removed from the water column in the 175-m stream reach. When shaded stream reaches were exposed to full sunlight after the injection ended, photoreductive dissolution of iron oxide released sorbed 32P, which was then also removed downstream. The removal from the stream was modeled as a first-order process by using a reactive solute transport transient storage model. Concentrations of 32P mass-1 of algae were typically 10-fold greater than concentrations in hydrous iron oxides. During the injection, concentrations of 32P increased in the cellular P pool containing soluble, low-molecular-weight compounds and confirmed direct algal uptake of 32PO 4 from water. Mass balance calculations indicated that algal uptake and sorption on iron oxides were significant in removing phosphate. We conclude that in stream ecosystems, PO4 sorbed by iron oxides can act as a dynamic nutrient reservoir regulated by photoreduction.

Page Thumbnails

  • Thumbnail: Page 
938
    938
  • Thumbnail: Page 
939
    939
  • Thumbnail: Page 
940
    940
  • Thumbnail: Page 
941
    941
  • Thumbnail: Page 
942
    942
  • Thumbnail: Page 
943
    943
  • Thumbnail: Page 
944
    944
  • Thumbnail: Page 
945
    945
  • Thumbnail: Page 
946
    946