Browsing by Author "Kimirei, Ismael"

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    Variability in pelagic fish catches and the physic- chemical parameters in Kigoma area, lake Tanganyika, Tanzania.
    (University of Dar es Salaam, 2005) Kimirei, Ismael
    The short term variability in pelagic fish catches and physic-chemical parameters in Kigoma bay, Lake Tanganyika were studied between January and December 2003. This study revealed both daily and seasonal variability in pelagic fish catches and limological environment, nutrients generation into the photic zone and hence primary production was found to depend on the hydrodynamics linked to seasonal wind runs in the lake region. Catch per unit effort (CPUE) and catch composition of the main fishery species fluctuated seasonally and were dominated by Stolathrissa tanganicae. Two spawning maxima, March-May and October-December, were found for S. tanganikae while recruitment took place during the dry season (July-September). Fluctuations in environmental parameters were found to correlate with fish catches. Air temperature, water transparency and conductivity were found to significantly affect pelagic fish catches. Density- dependant and density-independent effects on reproduction and recruitment success were hypothesized to cause the observed variability in pelagic fish catches in Kigoma Bay, Lake Tanganyika. Recommendations on the pelagic fisheries management actions and environmental monitoring needs are put forward.