Browsing by Author "Omondi Reuben"

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    Colonization Patterns of Benthic Macroinvertebrates in Fertilized And Non-Fertilized Earthen Fish Ponds
    (International Journal of Aquaculture and Fishery Sciences, 2018) Orwa Patrick; Omondi Reuben; Chemoiwa Emily
    International Journal of Aquaculture and Fishery SciencesISSN: 2455-8400CC By022Life Sciences Group Citation: Orwa PO, Omondi R, Chemoiwa EJ (2018) Colonization patterns of benthic macroinvertebrates in fertilized and non-fertilized earthen fish ponds. Int J Aquac Fish Sci 4(3): 022-026. DOI: http://doi.org/10.17352/2455-8400.000039http://doi.org/10.17352/24558400.000039DOIanAbstractStudy conducted in Kwanza, Trans-Nzoia County to determine the colonization pattern of benthic macroinvertebrates in earthen fi sh ponds. This was done to ascertain the right stocking time of ponds when the natural fi sh food is in plenty. Two ponds were used for this study; one was treated with organic manure while the other was not fertilized. Sampling for physico-chemical parameters were then taken immediately after fi lling the ponds and repeated weekly for six weeks while benthic macroinvertebrates were fi rst sampled after week 1 and repeated weekly for six weeks. The results obtained were compared between the two treatments and per treatment over time. There were signifi cant differences in most parameters over the weeks and between the treatments. Attainment of suitable conditions for stocking was however at week 3 for fertilized and week 4 for the non-fertilized contrary to the usual two week period advised by most procedures
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    Haematological Response of African Catfish (Clarias Gariepinus Burchell 1822) Fingerlings Exposed to Different Concentrations of Tobacco (Nicotiana Tobaccum) Leaf Dust
    (International Scholarly Reseach, 2013-09-17) Safina M. Musa; Aura Christopher Mulanda; Ogello Erick Ochieng; Omondi Reuben; Charo-Karisa Harrison; Munguti Jonathan Mbonge
    The present study set out to investigate the haematological effects of tobacco leaf dust on African catfish, Clarias gariepinus, fingerlings, with a mean weight of 3.01 ± 1.25 g using “static renewal bioassay system” during a 120-hour bioassay exposure period. Water quality parameters such as pH and dissolved oxygen significantly decreased while total alkalinity and conductivity increased significantly in the exposed media, compared to the control test. Leucocytes counts increased significantly while erythrocytes counts decreased significantly with increasing concentration of tobacco dust. Packed cell volume significantly reduced with increase in the concentration of tobacco dust. Haematological examination showed that there was destruction of the erythrocytes production, and the concentration of haemoglobin was much lower in the exposed fish compared to the control depicting an anaemic condition. The results could provide baseline information for the safe limits of using tobacco leaf dust in fish ponds; hence 1.56 g L−1 concentration of tobacco leaf dust was recommended for pond preparation for Clarias gariepinus fingerling stocking. For better survival rates, the fish should only be introduced in the pond after three days of tobacco application.
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    Illegal Unregulated and Unreported Fishing: Methods and Increasing Trends in Lake Naivasha, Kenya
    (WILEY ONLINE LIBRARY, 2021) Morara George N.; Njiru M. James; Getabu M. Albert; Omondi Reuben; Lewo Ruth; Obegi Beatrice; Mwangata Raymond
    Illegal, unregulated and unreported (IUU) fishing is a negative social vice that adversely affects global capture fishery production. The inadequate disclosure of IUU methods and trends in fishery waters hampers management actions to curb illegal fishing activities. Seldom have empirical studies been conducted on IUU methods and their trends in Lake Naivasha. Therefore, this study analysed data on the fisheries monitoring, control and surveillance (MCS) during 2012 to 2018 to test for the significance of trends, and compare the enforcement plans to seizures of illegal fishing gear in the lake. The IUU fishing methods included both the types of equipment and the means used to perpetrate illicit capture or acquisition of fish from the lake. The results indicate a 37% reduction of MCS enforcement patrols during 2018 compared to 2012, and a 16% to 100% upsurge in the quantity of seized IUU fishing items. Illegal fishing boats potentially threaten the fishery of Lake Naivasha with an additional fishing effort of 22% above the 176 licensed boats. An average of 10,700 fishing nets seized per year has the potential fishing intensity of 74 gillnets/km2 against an ideal intensity of 12 gillnets/km2. The frequencies of MCS patrols in Lake Naivasha exhibit no particular trends and likely ineffective in deterring the upsurge of IUU activities, or the evolution of new illegal fishing methods. An increased seizure of illegal fishing boats, outboard engines and gillnets could imply their rampant use in IUU fishing activities. These findings merit a multi-stakeholder participatory approach to identifying the MCS weaknesses and opportunities for sharing resources to strengthen the fishery management efforts in Lake Naivasha.
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    Survival and Avoidance Response of the Freshwater Gastropod Melanoides Tuberculatus (Muller) to Different Concentrations of Tobacco Waste.
    (Wiley online library, 2011-11) Ochieng Eric; Omondi Reuben; Opiyo Mary A.; Charo-karisa Harrison; Muguti Jonathan; Aura christopher Mulanda
    The Gastropod Melanoides tuberculatus plays a significant role in hampering fish larval production in earthen ponds. This study investigated use of tobacco waste to assess behavioural and survival responses of M. tuberculatus at different concentrations of tobacco waste solution of 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75 and 2 g L−1. Mean escape time varied significantly among concentrations (P < 0.05). Escape time decreased in 1-, 2- and 3-day-old solutions. Percentage survival decreased significantly with increasing concentrations of tobacco waste solution and exposure time (P < 0.05). Concentrations of 1.75 g L −1 and 2.0 g L−1 had high hazard ratios and low survival rates of gastropods and were the most effective in eradication of M. tuberculatus, hence recommended dose for preparing ponds for stocking. We conclude that tobacco waste solution can be used for control of M. tuberculatus.