Growth,mortality and recruitment of silver cyprinid (Rastrineobola argentea) in the open waters of Lake Victoria,Kenya |
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| Authors: | Edwine Yongo Julius Manyala Simon Agembe |
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| Affiliation: | Department of Fisheries and Aquatic Sciences, University of Eldoret, Eldoret, Kenya |
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| Abstract: | This study investigated the growth, mortality and recruitment of Rastrineobola argentea in Lake Victoria on the basis of length–frequency data collected during the period 2014–2015. The asymptotic length (L ∞ ) had a mean (±SE ) value of 53.50 ± 0.50 mm SL , growth curvature (K ) of 0.81 ± 0.06 year?1, total mortality (Z ) of 2.96 ± 0.12 year?1, a natural mortality (M ) of 1.23 ± 0.06 year?1, a fishing mortality (F ) of 1.74 ± 0.07 year?1, an exploitation rate (E ) of 0.59 ± 0.01, a growth performance index (?′ ) of 3.36 ± 0.02 and a length at 50% capture (L 50) of 28.25 ± 0.43 mm SL . The fish exhibited a peak breeding during the months of May and August. The Beverton and Holt relative yield‐per‐recruit model indicated mean (±SE ) indices as 0.37 ± 0.01 for optimum sustainable yield (E 0.5), 0.76 ± 0.01 for maximum sustainable yield (E max) and 0.66 ± 0.01 for economic yield (E 0.1). Compared with previous studies, there is a great decline in the sizes of R. argentea stocks in Lake Victoria. Thus, management measures should include restriction on illegal seine nets <10 mm mesh size and re‐enforcement of a fishing ban or a closed season. |
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| Keywords: | growth mortality
Rastrineobola argentea
recruitment |
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