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Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/1823

Title: Impact of fisheries and water quality changes on the management of Lake Chamo.
Authors: Zerihun, Dejene
Advisors: Dr. Demeke Admasu
Copyright: 2008
Date Added: 19-Dec-2008
Publisher: Addis Ababa University
Abstract: This study has been conducted in the most southern Ethiopia’s Great Rift Valley lake, Lake Chamo. A survey of fish landing sites and fishing gears used in the fishery were made. A total of 51 landing sites were identified. Twenty three of them were major (having more than 10 fishermen per day) and 20 were permanent. There were four kinds of gears on the lake during the study period: Nile Perch nets, Tilapia nets, hook & lines and beach sien nets. The most commonly used gear was tilapia net accounting for nearly 72.8 % of the deployed gears, followed by Nile perch net, which constituted 13.7%. Hook & lines cover 10.2 % and beach seines 3.8 %. Almost 87 % of the Tilapia nets and 94 % of the Nile perch nets had a mesh sizes smaller than the recommended mesh size at least by four cm. The analysis of the composition of the landing showed that only three species were important in the landing: O. niloticus, L. niloticus and C. gariepinus. O. niloticus was dominating the fisheries, accounting for more than 94% by number. L. niloticus account 2.1 % and that of C. gariepinus was 3.3 %. The length composition of the landing was used to estimate landing of immature fish. The result shows only 2.2 % of the catch of O. niloticus and only 5.7 % of the Nile perch catch were mature. Surplus production models were also used to assess the harvest condition. The maximum sustainable yield and optimum effort estimated by the Schaefer model were 4697 tons and 1461 gears, while the Fox model estimated 3990 tons and 1111 gears. The determination coefficients were r2=0.9687 for the Fox and r2=0.8589 for the Schaefer model. These results suggest that the resource is overexploited. The assessment of the water quality status of the lake by taking some physico-Chemical parameters showed no threat for fish population.
Description: A thesis submitted to the school of Graduate studies of the Addis Ababa University in Partial fulfillment of the requirements for the degree of Master of Science in Environmental science
URI: http://hdl.handle.net/123456789/1823
Appears in:Thesis - Environmental Sciences

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