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Hydrobiologia

, Volume 110, Issue 1, pp 47–55 | Cite as

A quantitative study of the phytoplankton in the Blue and White Niles at Khartoum

  • Faisal Sinada
  • A. G. Abdel Karim
Article

Abstract

The variation in numbers of the major planktonic algae in the surface waters of the Blue Nile and White Nile were followed for 29 months (August 1968–December 1970). In terms of biomass, the phytoplankton was dominated by diatoms and blue-green algae; other groups were of minor importance. High phytoplankton densities occurred during winter in both rivers, and during summer in the Blue Nile, with values in the latter river greater than in the former. Melosira granulata and its variety angustissima and Anabaena flos-aquae var. intermedia f. spiroides were the most important taxa in the two Niles. Melosira distans and Attheya zachariasi, which are reported for the first time in the present study, preponderated at certain times in the Blue Nile. Microcystisflos-aqua which had been a minor component of the phytoplankton in both rivers during the early 1950s, showed a profuse growth in the Blue Nile. Lyngbya limnetica, Anabaenopsis cunningtonii and A. tanganyikae, which constituted important components of the phytoplankton in the early 1950s, either disappeared or maintained themselves in reduced numbers during the present study. This change in the algal flora of the two Niles may be attributed to the construction of the Roseres dam across the Blue Nile in 1966 and to the invasion of the White Nile by Eichhornia crassipes in 1957.

Keywords

Sudan algae Blue Nile plankton ecology tropical rivers White Nile 

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References

  1. Berner, L. M., 1951. Limnology of the Lower Missouri River. Ecology 32: 1–12.Google Scholar
  2. Karim, A. G. A., 1967. Algal flora of certain gravel pits in the Thames Valley, U.K. Hydrobiologia 30: 577–599.Google Scholar
  3. Lakshminarayana, J. S. S., 1965. Studies on the phytoplankton of the River Ganges, Veranasi, India. Hydrobiologia 25: 119–137; 138–164.Google Scholar
  4. Prowse, G. A. & Talling, J. F., 1958. The seasonal growth and succession of plankton algae in the White Nile. Limnol. Oceanogr. 3: 223–238.Google Scholar
  5. Sinada, F. & Abdel Karim, A. G., 1984. Physical and chemical characteristics of two African lakes: The Blue Nile and the White Nile at Khartoum. Hydrobiologia (this volume).Google Scholar
  6. Talling, J. F. & Rzóska, J., 1967. The development of plankton in relation to hydrological regime in the Blue Nile. J. Ecol. 55: 637–662.Google Scholar
  7. Utermöhl, H., 1931. Über des umgekehrte Mikroskop. Arch. Hydrobiol. 22: 643–645.Google Scholar
  8. Venkateswarlu, V., 1969. An ecological study of the algae of the River Moosi, Hyderabada (India) with special reference to water pollution. III. The algal periodicity. Hydrobiologia 34: 533–560.Google Scholar

Copyright information

© Dr W Junk Publishers 1984

Authors and Affiliations

  • Faisal Sinada
    • 1
  • A. G. Abdel Karim
    • 1
  1. 1.Department of Botany, Faculty of ScienceUniversity of KhartoumSudan

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