ISSN 2736-1756
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 13 (4), pp. 001-011, April, 2019. © International Scholars Journals
Full Length Research Paper
Seasonal variation in the diversity and abundance of phytoplankton in a small African tropical reservoir
ADON Marie Paulette*, OUATTARA Allassane and GOURENE Germain
Université d’Abobo - Adjamé, UFR Sciences et Gestion de l’Environnement, Laboratoire d’Environnement et de Biologie Aquatique, 02 BP 801 Abidjan 02, Côte d’Ivoire.
Accepted 23 February, 2019
Abstract
Phytoplankton species composition and seasonal changes were investigated in the shallow reservoir of Adzopé. Taxonomic composition, diversity and abundance of phytoplankton were studied at 4 stations from May 2008 to February 2009, in relation to physical and chemical factors (temperature, conductivity, dissolved oxygen, transparency, pH, nutrients) and climatic factor (rainfall). The phytoplankton comprised 144 taxa, mainly Chlorophyta (29.45% of taxa), Euglenophyta (29.45%) Bacillariophyta (23.97%) and Cyanobacteria (10.27%). Phytoplankton density values were greatest during the transition season (short rainy season), lower during the dry seasons, and extremely lower during the long rainy season (mean value 356 105 cells/l, 44 105 cells/l and 35 105 cells/l respectively). Abundance was dominated by Anabaena constricta Szafer (Geitler) and Microcystis aeruginosa (Kütz.) Kütz. The diversity index varied between 2.1 bits/cells in long rainy season and 4.6 bits/cells in short dry season. The redundancy analysis (RDA) demonstrated a separation between the long rainy season and the other seasons due to the influence of the flood pulse.
Key words: Phytoplankton, shallow reservoir, species dominance, West Africa.