International Journal of
Fisheries and Aquaculture

  • Abbreviation: Int. J. Fish. Aquac.
  • Language: English
  • ISSN: 2006-9839
  • DOI: 10.5897/IJFA
  • Start Year: 2010
  • Published Articles: 191

Full Length Research Paper

Zooplankton communities as an indicator of ecosystem productivity in Lake Tinishu Abaya, Rift Valley, Ethiopia

Yirga Enawgaw
  • Yirga Enawgaw
  • Department of Zoological Sciences, College of Natural and Computational Science, Addis Ababa University, P. O. Box 1176, Addis Ababa, Ethiopia.
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Brook Lemma
  • Brook Lemma
  • Department of Zoological Sciences, College of Natural and Computational Science, Addis Ababa University, P. O. Box 1176, Addis Ababa, Ethiopia.
  • Google Scholar


  •  Received: 08 March 2018
  •  Accepted: 17 April 2018
  •  Published: 31 May 2018

Abstract

The ultimate objective of this study was, to explore community structure and biomass of zooplankton in relation to key environmental drivers to bear out the productivity of Lake Tinishu Abaya. Zooplankton samples collection was carried out for a year from January to December 2016 from two sampling sites (open and shore) using 30 µm mesh size net within the euphotic depth. Biomass of zooplankton was anticipated using length-weight regressions adjusted for the representative microcrustacean and biovolume of Rotifera from linear dimensions applied to simple geometric formula appropriate to body shape. In parallel, in-situ and laboratory measurements of the various physicochemical factors were performed using the standardized method. The results of the present study are given strongly generalized that Rotifera had the highest number of species (11 species) followed by Cladocera (5 species) and Copepods (2 species). Diversity parameter, the Shannon diversity index was higher for Rotifera (2.45) than cladocerans (2.395) and copepods (2.384). The mean total biomass of copepods, cladocerans, and Rotifera were 174.4, 46.76 and 13.67 µg/L at open site and 101.8, 51.35 and 10.9 µg/L at shore site, respectively. Physicochemical factors responsible for the observed variations in the biological features of the lake generalized that the lake water was fresh, well oxygenated, slightly warm, alkaline, very turbid, and with relatively high inorganic nutrients. The presence of fairly high diversity, abundance, and biomass of zooplankton in the study shows that the ecosystem of Lake Tinishu Abaya is chemically, physically and biologically productive which supports most of the aquatic life.

Key words: Biomass, community structure, Lake Tinishu Abaya, productive, zooplankton