Estuaries and Coasts

, Volume 34, Issue 1, pp 78–89

Temperature Control on Soluble Reactive Phosphorus in the Lower Mississippi River?

  • Shuiwang Duan
  • Rainer Amon
  • Thomas S. Bianchi
  • Peter H. Santschi
Article

DOI: 10.1007/s12237-010-9284-3

Cite this article as:
Duan, S., Amon, R., Bianchi, T.S. et al. Estuaries and Coasts (2011) 34: 78. doi:10.1007/s12237-010-9284-3

Abstract

Soluble reactive phosphorus (SRP) has recently been shown to be one of the limiting nutrients for the growth of phytoplankton in the northern Gulf of Mexico. We show here that during the past decade, SRP concentrations in the lower reaches of North America's largest river, the Mississippi River, were highest in summer and lowest in winter and positively correlated with water temperature. Upstream data showed this coupling to increase in a downstream trend in the Mississippi main stem. Water quality data analysis and phosphorus mass balances were conducted to examine the controls of this relationship. The results showed that the positive SRP–temperature correlation in the Mississippi River system was largely a result of gradual dilution of SRP-enriched upper Mississippi River waters, which contributed most to the Mississippi River during summer, by SRP-depleted waters from the Ohio and other tributaries. Particle buffering and organic matter mineralization might play a role in the observed SRP–temperature relationship, but their importance relative to tributary effects is not quantified. Future work on the seasonal dynamics of SRP in large river systems needs to consider the effects of both tributary dilution and in situ processes.

Keywords

Soluble reactive phosphorus Temperature Mississippi River Dilution effect Particle buffering 

Supplementary material

12237_2010_9284_MOESM1_ESM.docx (74 kb)
Electronic Supplementary Material (ESMCorrelations between SRP concentration of the Mississippi River at Thebes and St. Francisville and SRP concentration or percentage of water contribution from upstream tributaries. USGS sites for the Mississippi River and primary tributaries are shown in Fig. 1 (DOCX 74 kb)

Copyright information

© Coastal and Estuarine Research Federation 2010

Authors and Affiliations

  • Shuiwang Duan
    • 1
    • 3
  • Rainer Amon
    • 1
  • Thomas S. Bianchi
    • 2
  • Peter H. Santschi
    • 1
  1. 1.Department of Marine SciencesTexas A&M University at GalvestonGalvestonUSA
  2. 2.Department of OceanographyTexas A&M UniversityCollege StationUSA
  3. 3.Chesapeake Biological LaboratoryUniversity of Maryland Center for Environmental ScienceSolomonsUSA

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