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Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/3481

Authors: Beteal, Assefa
Advisors: Seyoum Mengistou(Dr.)
Keywords: Benthic macroinvertebrate
Ekman grab
Shannon diversity index,
Copyright: Jan-2010
Date Added: 25-Jul-2012
Publisher: Addis Ababa University
Abstract: Studies on the benthos of Lake Hayq were carried out at three stations from November, 2008 to April, 2009. Bottom samples were collected by using an Ekman grab (225cm2). Determination of total organic matter of littoral and profoundal samples was done using an oven and a muffle furnace. Communities of benthic fauna were reported from the lake in relation to the type of bottom substrates and aquatic macrophytes. The benthic macroinvertebrates of the bottom near to the emergent and submerged vegetation and the vegetation-free region of the lake were identified and their distribution in the lake was recorded in relation to the total organic matter and texture of the bottom sediment. Mollusks were found to be the most numerous of all benthic communities (mean number 52306individual/m-2). The Dipetra larvae were next with Chironomidae accounting the highest number. Bottom samples taken from near the vegetated regions of the lake were found to have a silt texture and the vegetation-free zone was sandy in texture. The result shows that near vegetated regions of the lake bottom had higher organic matter content than the bottom of the non-vegetated region. The sub-littoral region had highest richness (d = 2.13) while, the highest diversity (H = 1.8), evenness (J (e) = 0.209) and community density (43673.77 ind|m2) were in the littoral region. It was observed that most benthic taxa of Lake Hayq were concentrated in the littoral and sub littoral region in association with macrophytes. The littoral and sub littoral zone can therefore be considered as a site of good habitat and breeding ground for macroinvertebrates. Since there is considerable dependence of many commercial fish species on the invertebrate fauna as food resource, there is need to investigate further the biology and ecology of the benthic organisms and weed beds. It is also important that lake management should maintain the integrity and health of the macrophytes of the lake.
Description: A thesis submitted to the School of Graduate Studies, Addis Ababa University in partial fulfillment of the requirements for the degree of Master of Science in Biology (Fisheries and Aquatic sciences)
URI: http://hdl.handle.net/123456789/3481
Appears in:Thesis - Biology

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