Results of the first hydroacoustic survey of the Ugandan waters of Lake Victoria

Tumwebaze, R. and Getabu, A. (1999) Results of the first hydroacoustic survey of the Ugandan waters of Lake Victoria. In: Tweddle, D. and Cowx, I.G. (eds.) Report on third Fisheries Data Working Group (FIDAWOG) workshop held at the Triangle Hotel, Jinja, 29 March to 1 April 1999. Jinja, Fisheries Data Working Group of the Lake Victoria Fisheries Research Project, pp. 91-97. (LVFRP Technical Document,6)

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Abstract

A lakewide hydroacoustic research programme was designed in the Ugandan waters of Lake Victoria in order to ascertain the status of fish stocks. Data obtained from the hydroacoustic surveys were complemented with by catch data from multi mesh gillnets and frame trawls to validate acoustic estimates. Fish were distributed over the whole survey area, though the densities and species composition varied from place to place. Echo traces showed the fish formed schools during daytime and became more dispersed towards evening. Approximately equivalent indices of abundance were estimated for Rastrineobola argentea and Haplocromines. The distribution of the freshwater prawn, Caridina nilotica and the lakefly Chaoborus sp. was patchy. Dense swarms of Chaoborus larvae were observed to disperse from the lake bottom as the night approached thus assuring echo-traces formed by fish on the echogram and making their interpretation difficult. Caridina nilotica were observed to form dense echo-traces at the thermocline

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• Results of the first hydroacoustic survey of the Ugandan waters of Lake Victoria. (deposited 14 Jul 2010 08:56)[Currently Displayed]

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