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Aquatic Sciences

, Volume 61, Issue 4, pp 293–306 | Cite as

Nitrogen deficiency, phosphorus sufficiency, and the invasion of Lake Kinneret, Israel, by the N2-fixing cyanobacterium Aphanizomenon ovalisporum

  • Moshe Gophen
  • Val H. Smith
  • Aminadav Nishri
  • Stephen T. Threlkeld

Abstract:

Historically, the phytoplankton community of Lake Kinneret, Israel, has been dominated by the dinoflagellate Peridinium gatunense and other edible species that are important in the lake's food web. However, major changes have occurred both in external nutrient loading and in the water column chemistry of the lake since the mid-1980's. Epilimnetic particulate nitrogen: particulate phosphorous (PN : PP) ratios have declined, and measurements of seston chemistry suggest that the intensity of seasonal nitrogen limitation has increased. The phytoplankton community also was altered in 1994 and 1995 by a lake-wide summer invasion of the nitrogen-fixing cyanobacterium Aphanizomenon ovalisporum. This abrupt change in phytoplankton community structure is consistent with the development of conditions increasingly N-deficiency and P-sufficiency in the water column, which should favor cyanobacterial dominance.

Key words: Aphanizomenon, cyanobacteria, N-deficiency, P-sufficiency, N : P ratios, Lake Kinneret. 

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Copyright information

© Birkhäuser Verlag, 1999

Authors and Affiliations

  • Moshe Gophen
    • 1
  • Val H. Smith
    • 2
  • Aminadav Nishri
    • 1
  • Stephen T. Threlkeld
    • 3
  1. 1.Kinneret Limnological Laboratory, Israel Oceanographic and Limnological Research Co., P. O. B. 345, Tiberias, Israel 14102IL
  2. 2.Department of Systematics and Ecology, and Environmental Studies Program, University of Kansas, Lawrence, KS 66045, USA US
  3. 3.Department of Biology, University of Mississippi, University, MS 38677, USA US

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