Department of Aquaculture and Fisheries Management

Permanent URI for this collectionhttps://dspace.njala.edu.sl/handle/20.500.144402/158

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    Anthropogenic pollution impact on physico-chemical characteristics of Lake Kivu, Rwanda
    (African Scholarly Science Communications Trust, 2012-08-03) Olapade, Olufemi Julius
    Anthropogenic activities such as industrial effluent, domestic and agricultural waste disposal constitute major sources of pollution in water. The effects of these pollutants on the physico- chemical properties of Lake Kivu, Rwanda were investigated at three locations (Gisenyi, Kibuye and Cyangugu) between February 2005 and December 2006. Water samples used for physico- chemical analysis were collected from 12 stratified points on the lake. Samples collected were analysed and interpreted using appropriate international procedures. The physico -chemical properties measured were temperature, conductivity, pH, transparency, salinity, total alkalinity, dissolved organic matter (DOM), total dissolved solids (TDS), dissolved oxygen (DO), biological oxygen demand (BOD), nitrate – nitrogen, phosphate – phosphorus and sulphate. Mean water temperature measured (24.7 + 0.58 o C) was highest in Kibuye and lowest (24.5 + 0.31 o C) in Cyan gugu. The lake water was moderately hard with mean total alkalinity values of 88.1 ± 1.63mgL -1 ; 79.7 ± 2.36mgL -1 and 81.0 ± 2.46mg L -1 recorded in Gisenyi, Kibuye and Cyangugu respectively; salty and alkaline with mean pH values of 8.87 ± 0.07 in Gisenyi; 8.86 ± 0.06 in Kibuye and 8.91 ± 0.06 in Cyangugu. Total dissolved solids (TDS) level in the lake was above the 500mg L -1 prescribed by WHO while the mean biochemical oxygen demand (BOD) reading was within the range for unpolluted or moderately polluted lake. Water from the lake showed mineralization with mean conductivity values ranging from 1058 - 1184μS cm -1 in Gisenyi; 1058 - 1147μS cm -1 in Kibuye and 1031 - 1116μS cm -1 in Cyangugu. The mean dissolved oxygen values were below the 5mgl -1 limit recommended by WHO for fresh water fish species. SO 4- -2 and NO 3 – N concentration in the lake water does not constitute any serious health risk to both man and the aquatic organisms it supports. However, there is the need to constantly monitor the lake water to mitigate any build up of the ions to a hazardous level.
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    Economic Assessment of Integrated Fish Farming (Fish-Rice-Piggery) in Sierra Leone
    (Science Publishing Group, 2015) Olapade, Olufemi Julius
    The present study evaluates the profitability and environmental effect of integrated fish cum rice and piggery production at Njala University, Sierra Leone. The research carried out between June and November, 2014 consists of the pigsty (2.5m × 11m), a maggoty and integrated pond (395.2m2) sown with 0.94kg NERICA 19 rice at spacing of 20cm inter - rows and 5cm intra - rows. The pond was stocked with Clarias gariepinus juveniles (mean weight 25.6± 1.78g) at the density of 4.8fish per m2.Water quality parameters viz., temperature, pH, Dissolved oxygen, NO3-N, NH3/NH4, hardness and alkalinity were determined in the pond and were found to be within the recommended range for the culture of tropical fish. Economic analysis of the adaptive research gave a negative incremental benefit and Net Present Value (NPV) in both the first and second year of production. The sensitivity analysis evaluation shows that the enterprise is fairly sensitive to price fluctuation (-46.02%) and highly sensitive to survival rate of the fish and the scale of production of the pigs. Increasing scale of production and selling at market price will greatly enhance profitability and short term payback of costs.
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    Environmental and Economic Impact of Fish cum Rice and Poultry Production Integration System
    (2015-04-14) Olapade, Olufemi Julius
    The economic viability and environmental friendliness of integrating fish with rice and poultry was evaluated in a fish pond (520m 2 ); a paddy platform (8 x 25m 2 ) sown with 1.00kg NERICA 19; a poultry house (3.5 x 11m in dimension) and a maggoty. Integrated pond was stocked at 1.923 fish per m 2 (25g mean weight) while 400 day-old broilers were housed. Water quality parameters determined were within recommended range for the culture of tropical fish species and statistically non-significant (p < 0.05). The synergy gave positive Net Present Value NPV of Le 18,520,661.51 (US\$4,161.95) in the third year; a benefit-cost ratio of 1.23 and two year payback. Sensitivity calculated was 23.6% an indication of the sensitivity of the investment to survival rate. Integrating fish with rice and poultry is environment friendly, and economically viable with potential to create employment, augment income and improve the living standard of sub Saharan poor population.
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    Growth Performance and Hematology of the African Catfish ( Clarias gariepinus Burchell, 1822) Juveniles Fed Graded Level of Anisophyllea Laurina R. Br. Ex. Sabine ( Monkey Plum ) Seed Meal
    (2015-04-14) Olapade, Olufemi Julius
    Anisophyllealaurina seed meal (ASM)in this study partially replacedfish meal(FM). Isonitrogenous and isocaloricdiets (40% crude protein) containing0%, 25%, 50%, 75%, 100% ASMwere formulated. Clariasgariepinus juveniles (32.72 ± 0.32) stocked at 10 fish/50L troughs fed twice daily for 98 daysutilized effectively the formulated diets for growth.Mean weight gained (MWG) washighest at 0%and 25% butdecreased as ASM increased.Specific growth rate (SGR), Protein efficiency ratio (PER), Protein intake (PI) were significant (p<0.05) at 0% and 25% inclusion. Survival rate (%SR)was unrelated totreatment - highest at 0% and 100% (97%SR)and least at 75% (90%SR).Carcass protein, packed cell volume and haemoglobin counts were statistically the same at 25%, 50%, 75% and 100% inclusion. Since C. gariepinusperform better at 25%ASM inclusion it is recommended as the level of replacement for FM in fish diets.
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    Nutritional Evaluation of Defatted Groundnut Cake meal with Amino acid as Protein Supplement in African Catfish (Clarias gariepinus Burchell, 1822) Juveniles Diet
    (2018-12-15) Olapade, Olufemi Julius
    Background and Objective: Fish feed constitute about 60% of fish production costs and this is because fishmeal (FM) which is the major protein feedstuff in fish feed is in excessive demand by other agricultural production sectors thus leading to increase in its price.Researching into alternative way of attenuating FM in fish feed production becomes necessary.Consequently, in this paper, the effect of feeding Clarias gariepinus juveniles with diets supplemented with defatted groundnut cake (DGNC), lysine (L) and methionine (M) was studied for 56 days.Materials and Methods: Fish of an initial mean body weight of 34.4±0.548g were fed the trial diets at inclusion levels of 0, 25, 50, 75 and 100%.The diet with 0% DGNC and 100% fishmeal served as the control.The experimental fish held in 56 L troughs were fed treatment diets in triplicate group of 20 fish per replicate at 5% body weight twice daily.Water parameters measured according to standard methods were pH, temperature, conductivity and NH 3 .Dissolved oxygen was not determined because the experiment was completely flow-through.Results: At the end of the feeding trial, fish fed with the control diet recorded the highest mean weight gain (17.33±1.53),followed by fish fed diet 2 (14.33±0.58).Protein intake and survival rate were not significantly different (p<0.05) but protein efficiency ratio was significantly different among dietary treatments.Feed Conversion Ratio (FCR) was highest at diets 1, 2 and 3, respectively and were not statistically different (p<0.05).The water quality parameters monitored in the trial were within recommended range and were not affected by the supplemented diets.Conclusion: It can be concluded that, substituting FM with DGNC, L and M at 25 and 50% inclusion will not compromise growth performance and feed utilization of the fish and neither will it significantly lower the water quality of the culture environment.
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    Occupational hazards, risk and injuries of fish processors in Tombo a coastal fish landing site, Sierra Leone, West Africa
    (Academic Journals, 2021-06-30) Olapade, Olufemi Julius
    Fish and fish products bear potential hazards and risks of public health concern. A preliminary study of hazards, injuries and risks among fisherfolk in Tombo, Sierra Leone, West Africa was carried out on November 2018. Sixty subjects from among the organized fish processor groups were interviewed with semi-structured questionnaire. Results obtained from the study were analyzed with Microsoft Excel and presented in tables and charts. The results of the study indicated that females (56.7%) were more involved in fish processing than males (41.7%); and the active age of these processors fell in the age range of 35-45 years. Married people (71.7%), dominated singles, widowed and divorced put together. Dominant religion in the study area was Islam and Christianity. Smoking (hot and cold), frying, packing, icing, filleting, seasoning or the combination of two or more according to the subjects was the prevailing processing methods used by processors in Tombo. Inherent hazards, injuries and risks reported by the respondents included high blood pressure, cardiovascular disease, nervous tension, insomnia, skin disease, bronchitis or asthma, muscular problems or those of the joint, long-term neck and back pains, eye problem, typhoid, malaria, and hearing problem caused by environmental noise. To mitigate the hazard and risks associated with fish processing in Tombo, training on appropriate fish handling and processing techniques; the provision of appropriate handling and processing equipment by responsible stakeholders were considered according to the subjects rational options. Key words: Occupation, hazards, injuries, risks, fish processors, Tombo, Sierra Leone.
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    The Role of International Donors in Aquaculture Development in Africa
    (IntechOpen, 2020-05-15) Olapade, Olufemi Julius
    Aquaculture, one of the fastest food production sectors in the world, has received and continues to receive funding from international donors and funding agencies since its introduction in Africa. The sector plays a key role in many emerging economies because of its potential to contribute to increased food production and at the same time help reduce pressure on fish resources. In spite of huge natural resources and a high demand for fish and fishery products, aquaculture production in Africa has yet to catch up with major players globally. Increased aquaculture production is hoped will greatly complement current efforts aimed at achieving the United Nations Millennium Development Goals (MDGs), especially the eradication of extreme poverty and hunger, reduction in child mortality, improvement of maternal health, prevention of diseases, promotion of gender equity and women empowerment. Africa however is the only region of the world where the present level of per capita fish consumption has declined over the past decades as populations grow. Researchers have adduced reasons for the setback to the development of Africa aquaculture. The unanswered question however is “Has donors’ support further the course of aquaculture development in Africa?”