, Volume 138, Issue 1, pp 177–187

Seasonality of phytoplankton in some South Indian lakes

  • A. R. Zafar
The Sub-tropics and Tropics

DOI: 10.1007/BF00027239

Cite this article as:
Zafar, A.R. Hydrobiologia (1986) 138: 177. doi:10.1007/BF00027239


The landscape of South India is dotted with innumerable man-made lakes. They differ vastly in age, physiography, water flow characteristics, chemistry and trophic state, yet maintain a phytoplankton overwhelmingly dominated (43–93%) by blue-green algae; the subdominants are diatoms and/or Chlorococcales and euglenoids. The blue-greens apparently reach them from soils which are known to harbour a rich blue-green flora and several species in common with limnoplankton.

South Indian lakes resemble some tropical counterparts in sustaining dense phytoplankton populations all the year round and temperate dimictic ones in showing two annual growth peaks that usually occur in summer (February–May) and the post-monsoon period (October–November), in synchrony with rise in temperature. In the chemically more oligotrophic lakes, the peaks are constituted by Raphidiopsis mediterranea Skuja, Navicula cryptocephala Kütz., Melosira granulata (Ehr.) Ralfs, and others and in hypereutrophic lakes by Microcystis aeruginosa Kütz., Synechocystis aquatilis Sauv., Oscillatoria spp., Burkillia coronata West & West and Euglena acus Ehr. The bimodal seasonality in abundance of phytoplankton reflects in chlorophyll and biomass concentrations although these are not in strict synchrony with each other. At the maxima chlorophyll a and over-dry biomass may rise to 8.5 mg l−1 and 204 mg l−1 respectively in highly productive waters. The highest rate of carbon assimilation recorded in such phases is 10.6 g C m−3 d−1.

Copyright information

© Dr W. Junk Publishers 1986

Authors and Affiliations

  • A. R. Zafar
    • 1
  1. 1.Limnology Laboratory, Department of BotanyOsmania UniversityHyderabadIndia

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