Department of Aquaculture and Fisheries Management

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Assessment of Growth Performance of Monosex Nile Tilapia (Oreochromis Niloticus) in Cages Using Low-Cost, Locally Produced Supplemental Feeds and Training Fish Farmers on Best Management Practices in Kenya
(2018) Bundi, James M.; Ngugi, Charles C.; Fitzsimmons, Kevin; Manyala, Julius; Kimotho, Ann N.; Amadiva, Judith M.; Ndogoni, Julius N.; Munguti, Jonathan
Changing technology in aquaculture has been the major driving force for increasing aquaculture production in the phase of dwindling open water stocks. The choice of technologies and their adoption still remain a focus to increase production, productivity and farm incomes. We assessed the growth of Nile tilapia using locally available materials that included cages and low cost feeds to increased tilapia production in ponds. Various interventions were used among them experimental trials where we formulated low cost diets replacing expensive fish meal. A series of four workshops were also conducted over the course of this project period under this intervention. The first workshop on the development and use of best management practices in aquaculture was held in August 2014. This workshop targeting women in aquaculture had 18 women in attendance. There were two subsequent workshops, held in March and August 2015, and attended by fish farmers from Kirinyaga County. The fourth workshop was held for two days between 2nd and 3rd October 2015. This workshop specifically targeted the youth in aquaculture aimed at training the youth on integrated cage and pond culture focusing on development of cage culture in reservoirs located in the county of Kirinyaga that are presently underutilized by the communities. Graduate support covered three female students who selected because of their previous linkage with AquaFish CRSP and excellent role they continue to play in development of aquaculture in this region. Among them two have submitted their theses for examination. We submitted five peer reviewed publications during this project period with two being specific on low cost feed and fish meal replacement. AquaFish provided funds for HCPIs and graduate students to attend National, Regional and WAS Meetings and Conferences as well. We note that farmers adopted feed technology very well and in their survey feed formulation and fish breeding were their priority. Under lesson learned, we noted that farmers required frequent visits, simple materials for reading and constant communication. They also require strategies on fish marketing such as use of cell phones applications and Aquashops.
Black Soldier Fly (Hermetia illucens) Larvae Meal as a Sustainable Protein Source for Fish Feed Production in Kenya
(SPRINGER, 2023) Opiyo, M. A.; Nairuti, R. N.; Ngugi, C. C.; Holeh, G. M.
Aquaculture has been ranked as one of the fastest-growing food sub-sectors, providing quality protein to better the livelihoods of rural communities alongside curbing malnutrition and food security globally. Nonetheless, the industry’s sustainability has been threatened by the high cost of fish feeds, which account for approximately 60–70% of the total operational costs. Fish meal (FM) has been extensively utilised as the main source of protein in the diets of farmed finfishes. However, due to declining capture fisheries and competing uses from other animal feed producers, the ingredient has become a scarce resource with limited availability and high prices. Black soldier fly larvae (BSFL) have been identified as a promising alternative protein source in fish feeds. BSFL are documented to have high nutritional content: crude protein (of up to 64% dry matter), essential amino acids, fatty acids, and other micro-nutrients which are vital for the growth of fish. BSFL meal has the potential success of replacing FM in the diets of various fish species. This chapter focuses on analysing recent research work in BSFL proximate and chemical composition, its current utilisation in fish feeds and gaps to be filled in its complete utilisation as an ingredient in commercial feed production. This information is expected to help both cottage and commercial fish feed producers utilise BSFL in feed production in Kenya and further will promote the sustainability of the aquaculture industry.
Challenges Facing the Fishing Industry in Homalime and Kendu Bay Zones of Lake Victoria in Homabay County, Kenya
(Historical Research Letter, 2015) Osamba, Joshia; Okello, Adhiambo Eunice; Parsitau, Damaris
Fishing has been an important source of livelihood for many Kenyans for many years. It is one of the oldest occupations of mankind. In Kenya, both gender have been involved in this industry while performing different roles such as fish production by the male and fish processing and marketing by the female. The roles ultimately complemented each other. The objective of the study was to establish the challenges the fisher folk have faced in the fishing industry in reference to Homalime landing bay and Kendu Bay County of Kenya. The study focused on the factors that have hindered the fishers from executing their roles as expected. Sampling was conducted in Homalime “Doho Beach” and at “Kotieno” in Kendu Bay. This took place between May 2013 and the month of August 2013. Data was obtained using a cross-sectional survey research design, quantitative and descriptive research designs. Information was collected through interviews using open-ended questions and questionnaire guides. The population of the study consisted of 1,804 registered fisher folk in Homalime and Kendu Bay by the year 2013. A number of fisher folk never registered because of various reasons although they participated fully. 586 of the fisher folk were registered in Kendu Bay while 498 were from Homalime. The fishers in both bays perceived that their challenges in the fishing industry were due to the decline of the Kenyan economy. The fisher folk could not be sustained by the income they realised from fishing activities since the daily expenses increased. Fish prices shot up lowering protein consumption among the fishing communities hence vulnerability to all kinds of diseases including diarrhea, amoeba, typhoid, cholera, malaria and HIV/AIDS. Results indicated the challenges in groups of major factors and individual factors that have hindered equitable economic growth of the fishing industry in the regions discussed in the study. Keywords: Challenges, Fisheries, Gender, Landing bays
Challenges facing the tea Sector in Nyeri County
(2015) Maina, F.N.; Mathenge, P.W; Mwathe, Z.M.; Mathenge, M.M.
Nyeri County is renowned for its production of quality tea for export. However, the sector is beleaguered by numerous problems and is not performing at its full potential. This survey was carried out to identify the issues currently affecting the sector and possible mitigating measures. Twenty-eight farmers and four key informants were interviewed. Low prices, lack of technical know-how on tea production, adverse climatic conditions, and lack of markets for purple tea were identified as major issues limiting tea sector in the county. Possible solutions are discussed in this paper.
Changes in population characteristics and diet of Nile tilapia Oreochromis niloticus (L.) from Nyanza Gulf of Lake Victoria, Kenya: what are the management options?
(Taylor &Francis, 2007-11-26) Muchiri, Muchai; Njiru, M.; Okeyo-Owuor, J. B.; Cowx, I. G.; Knaap, M. van der
Different levels of probiotics affect growth, survival and body composition of Nile tilapia (Oreochromis niloticus) cultured in low input ponds
(Elsevier, 2019) Ngugi, Charles C.; Karisa, Harrison Charo; Jumbe, James; Opiyo, Mary A.
A 7-month experiment was carried out to determine the effects of different levels of probiotics (baker’s yeast (Saccharomyces cerevisiae) and Bacillus subtilis) on Nile tilapia (Oreochromis niloticus) reared in low input ponds. Monosex male fingerlings (40 g) were randomly distributed into 28, 1.25 m3 net cages at 50 fish m−3 and fed twice daily at 3% body weight on seven isonitrogenous (28% crude protein) diets supplemented with either Saccharomyces cerevisiae (1 × 1010 CFU g−1) or Bacillus subtilis (1 × 109 CFU g−1) at different levels: Diet 0 (control); Diet 1–3 were supplemented with S. cerevisiae at 2 g kg −1 (Diet 1); 4 g kg−1 (Diet 2) and 6 g kg −1 (Diet 3) whereas Diet 4–6 were supplemented with B. subtilis at 5 g kg−1 (Diet 4); 10 g kg−1 (Diet 5) and 15 g kg−1 (Diet 6). Higher final weight (255.31 ± 3.19), Specific Growth rates (SGR) (0.77±0.01) and better Feed Conversion Ratio (FCR) (1.61 ± 0.02) were recorded in fish fed on Diet 2 followed by fish fed on Diet 5. Fish fed on probiotic- supplemented diets had significantly better growth, nutrient utilization and FCR compared to fish fed on the control diet (P < 0.05). Probiotic supplementation significantly affected the body composition of the fish (P < 0.05). S. cerevisiae led to significantly high protein (86.06%) at 4 g kg−1 (Diet 2) (P < 0.05) while B. subtilis led to significantly higher protein (89.40%) at 5 g kg−1 (Diet 4) (P < 0.05). Crude lipid and ash content were significantly lower in the fish fed on probiotic supplemented diets (P < 0.05) compared to the control. This study has demonstrated that the application of probiotics in diets of Nile tilapia in low input ponds promotes growth and enhances body composition. The two probiotics have got different effects depending on the level of application. S. cerevisiae exhibited the best performance at 4 g kg−1 while B. subtilis had the best performance at 10 g kg−1
Difficulties of fishing at Lake Naivasha, Kenya: is community participation in management the solution?
(Blackwell Publishing Asia Pty Ltd, 2010) Muchiri, Mucai; Njiru, James Murithi; Ojuok, Jacob E.; Aura, Christopher Mulanda; Kundu, Rodrick
Difficulties of fishing at Lake Naivasha, Kenya: is community participation in management the solution?
(2010) Muchiri, Mucai; Aura, Christopher Mulanda; Kundu, Rodrick; Njiru, James Murithi; Ojuok, Jacob E.
Unlike other lakes in tropical regions, Lake Naivasha exhibits low fish species diversity. The fishery is based on introduced fish species that are not native to the lake. The lake ecosystem is very fragile, as reflected in its fluctuating fish catches. The fishery almost completely collapsed in 2001, due partly to mismanagement and ignorance about needed conservation measures. The Kenyan government, like many governments around the world, recognized the need to involve fishers and other stakeholders, in order to ensure better management of the lake fisheries resources. Also referred to as collaborative management (co-management), this management approach provides the opportunity to share responsibility for managing the fishery resources between the government and the community. A total ban on fishing was imposed in February 2001, lasting for 1 year, to allow lake fish stocks to recover. This study analyses the co-management process for Lake Naivasha, and discusses the role played by the community during the fishing ban, as well as the successes and challenges encountered, and the tribulations and perceptions of the fishers regarding the new management strategy. It also comprises the first documentation of community participation in fisheries management begun for Lake Naivasha in the year 2001.
Dynamic of Stress Response in Victoria Labeo (Labeo victorianus) during transfer from the Hatchery to cages and Ponds under Differential Caged Stocking Densities
(International Journal of Science and Research (IJSR), 2012) Kuria, Gladys, M.; Ngugi, Charles, C.; Oyoo-Okoth, Elijah
Variation in fish stocking densities translate to difference in growth performance, yields and economic benefits in fish culture. Transferring fish directly from hatcheries to the cages or ponds may induce stress. We evaluated the stress response of Labeo Victoria (Labeo victorianus) in an integrated cage-cum-pond culture during transfer of fish from the hatchery to the cages and ponds at different cage stocking densities. Cages were stocked at varying densities of 10, 30, 60, 90, 120, 150 and 180 fish/m3 and suspended in a static pond of 200 m2 . The L. victorianus fingerlings of a mean weight 23.6 ± 1.8 g were stocked in the cages and the pond respectively. 20 fish were sampled during the transfer period from the hatchery to ponds and cages for analysis of primary and secondary parameters of stress response. Primary stress response occurred when fish were directly transferred to cages and ponds at stocking density ≥ 60 fish/m3 and 90 fish/m3 respectively. Parameters of secondary stress response occurred in fish transferred to the cages at stocking density ≥ 120 fish/m3 and in ponds at density ≥ 150 fish/m3 . Transfer of fish directly from the hatchery to the ponds induce primary and secondary stress.
Ecology and Management of Lake Naivasha, Kenya, in Relation to Climatic Change, Alien Species' Introductions, and Agricultural Development
(Environmental Conservation; Cambridge Journals, 1990) Harper, David, M.; Muchiri, Mucai; Mavuti, Kenneth, M.
Lake Naivasha is an important freshwater resource for Kenya's foreign-currency-earning agriculture and tourism, and for water-supply. It has always experienced extensive water-level fluctuations as a consequence of irregular rainfall patterns that are affected by continental-scale climatic events, and its communities — particularly of aquatic plants — were adapted to these changes.
Economic Gain versus Ecological Damage from the Introduction of Non-native Freshwater Fish: Case Studies from Kenya
(2008) Muchiri, Mucai; Hickley, Phil; Britton, Robert; Boar, Rosalind
Non-native freshwater fish species that have been introduced to the inland waters of Kenya are listed and the consequences of stocking such fish are reviewed. Original species composition and lake ecosystem function can be detrimentally affected but, also, the introduction of non-native species can result in significant economic benefit. In the context of impact on recipient fish communities and the performance of exploited fisheries, the merits or otherwise of alien fish species introductions are discussed with the aid of two case histories; lungfish (Protopterus aethiopicus) in Lake Baringo and a number of species, particularly carp (Cyprinus carpio), in Lake Naivasha.
Effect of Social and Economic Drivers on Success of Small Scale Fish farming in Western Kenya
(Lake Victoria Fisheries Organization, 2016) MUCHIRI, MUCAI; KUNDU, RODRICK; NJIRU, MURITHI; NYAMWEYA, CHRISPHINE
Aquaculture in Kenya provides important livelihood opportunities for the rural poor by improving the local economy as well as supplementing protein sources. Despite being one of the areas with highest aquaculture potential in the country, Western Kenya records some of the highest rates of poverty and malnutrition. This study undertook an assessment of socio-economic factors affecting small scale fish farmers in this region. Structured questionnaires were administered to 135 households through direct interviews. The relationship between fish production and variables affecting it were modeled using a multiple linear regression. The results revealed that access to road infrastructure was the most significant (p=0.00239) factor affecting fish production in the study area. Other significant factors of production include pond management level (p=0.01452), source of water for fish farms (p = 0.02029), fish feed (p=0.02241), status of fish ponds (p=0.0289) and location of ponds (p=0.029). Therefore policy planning for aquaculture development should strongly consider these factors as an important aspect of fish farming.
Exotic introductions to the fishery of Lake Victoria: What are the management options?
(2005) Muchiri, M.; Knaap, M. van; Cowx, I. G.; Waithaka, E.; Njiru, M.
Fish Growth Performance at High Altitude Environment at Karatina University, Kenya
(Global Journal of Advanced Research, 2018-10) Mugo, James Bundi; Chege, Moses Gichuho
This report entails the findings of fish growth performance project that targeted high altitude environment. One such environment is Karatina university fish ponds in Kenya. Fingerlings of Nile tilapia (Oreochromis niloticus), African catfish (Clarias gariepinus) and Common carp (Cyprinus carpio) were stocked at 3.3 fish m-2 with an average body weight of 4.9-5.6 g. Feeding was done twice a day (10.00am and 4.00pm). Stocked – an average body weight of 4.9-5.6 g. The highest final mean weight of African catfish was (785.4±g), mean weight (248.4±1.4g), mean weight gain (780.4±5.5g) and SGR (2.9%) but lowest % survival (68%). Is was clearly indicated that the African catfish is more adaptable to low water temperatures than the other two fish species. As recorded by this study, African catfish performed better than all the other fish species.The study recommended that on farm trials should be carried out to test the growth performance based on fish farmers environmental natural conditions
Growth, Survival and Nutrient Utilization of Nile Tilapia (Oreochromis niloticus) using Cyanophyceae (Arthrospira fusiformis) as Replacement of Fishmeal Based Diets
(International Journal of Science and Research (IJSR), 2014-08) Oyoo-Okoth, E.; Ngugi, C.C.; Mugo-Bundi, J.
Suitability of using cynaophyceae (Arthrospira fusiformis) to replace fishmeal (Caridina nilotica) as a main protein source in the diet of Nile tilapia (Oreochromis niloticus) was investigated at a ratios of: 25%, 50%, 75% and 100%. The five dietary treatments were tested in triplicate in static earthen ponds for 160 days. Growth, Food conversion ratio (FCR), and nutrient utilization in fish fed at 25% and 50% A. fusiformis were better than those fed 75% and 100% A. fusiformis but not significantly different (P > 0.05) from those fed with C. nilotica diets alone. Growth reduction, increased FCR and reduced nutrient utilization occurred with increasing A. fusiformis in the diet beyond 50% inclusion levels. Survival was however better at higher levels of A. fusiformis inclusion. Thus it is possible to replace up to 50% of C. nilotica with A. fusiformis in the diets of O. niloticus.
Habitat degradation and subsequent fishery collapse in Lakes Naivasha and Baringo, Kenya
(2004) Muchiri, Mucai; Hickley, Phil; Boar, Rosalind; Britton, Robert; Adams, Chris; Gichuru, Nicholas; Harper, David
Lakes Naivasha and Baringo in the eastern Rift Valley of Kenya are shallow, freshwater lakes that are subject to major fluctuations in water level and suffer from habitat degradation as a consequence of riparian activity. Lake Naivasha is approximately 160 km2, is bordered by Cyperus papyrus and its aquatic macrophytes are in a state of flux. The most significant riparian activity is the large scale production of flowers for the European market. Lake Baringo is approximately 140 km2 and lies in a semi-arid region. Its most noticeable feature is its extreme turbidity which is mainly due to excessive soil erosion resulting from deforestation and overgrazing. This turbidity has led to near extinction of submerged macrophytes and a lake bed virtually devoid of benthic fauna. Fishing pressure has added to the environmental stresses being endured by the fish populations and commercial catches have been detrimentally affected. Accordingly, periods of fishery closure are now imposed upon both lakes. Limited remedial action is feasible and some local stakeholders are attempting to introduce mitigation measures. For Lake Naivasha there is an agreed riparian owners' management plan which tackles issues such as water usage and protection of the C. papyrus margin. For Lake Baringo there is a Rehabilitation of Arid Environments initiative which promotes such activities as restoration of riparian vegetation and appropriate stock management.
Haematological Response of Rastrineobola argentea Exposed To Subchronic Doses of Inorganic Cadmium (Cd), Methylmercury and Polychlorinated Biphenyl (PCB) via Dietary Exposure Pathway
(International Journal of Science and Research (IJSR), 2012) Chemoiwa, Emily Jepyegon; Oyoo-Okoth, Elijah
Haematological indices provide information on various aspects of fish health when exposed to environmental contaminants. We evaluated the effects of cadmium, methyl mercury (MeHg), and Polychlorinated Biphenyl (PCB) on the haematological parameters of a tropical fish. One hundred and eighty (180) mature individuals of the freshwater fish Rastrienobola argentea were exposed to dietary subchronic doses of Cd (4 µg g g1 CaCl2), MeHg (0.1 CH3HgCl µg g1 ) and PCBs (0.2 µg g1). After 45 days, blood was sampled from exposed and control groups to evaluate haematological effects of contaminants on erythrocytes, total leukocytes and differential leukocytes counts, haematocrit, heemoglobin concentration, red blood cell indices, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), and mean corpuscular haemoglobin concentration (MCHC). Results showed that red blood cells counts, haemoglobin concentration, haematocrit, leukocytes, neutrophils, and mononuclear cells counts, significantly (P < 0.05) decrease between control groups compared with the Cd, MeHg and PCB tested groups. The MCV, MCH and MHC showed significant (P > 0.05) increase between control groups with the Cd, MeHg and PCB tested groups. The present study shows that changes in haematological parameters were detectable at sub-chronic exposure to contaminants, but their application in field biomonitoring using R. argentea will need more detailed studies.
Impact of aquaculture development on water quality of fish ponds in gatundu North and south sub-counties, Kenya
(International Journal of Fisheries and Aquatic Studies, 2019-06) Ngugi, CC; Kitur, Esther; Wairimu, Theuri Olive; Mwangi, BM; Nzeve, JK
Aquaculture development in Kenya has increased in the recent past due to Government support, however, information on its influence on water quality is scanty. This study looked at the influence of fish culture on water quality in fish ponds. Water samples were collected from pond inlets and fish ponds and physico-chemical parameters analyzed. Means of measured parameters at the pond inlets were; Temp(21.27±3.31 °C), DO(4.45±0.73mg/l), EC(27.38±17.21µS/cm), TDS(368.61±135.21mg/l), pH(7.31±0.45), N-NO3(2.06±2.38mg/l) and PO4-P(0.29±0.41mg/l) while mean values inside the ponds were; Temp (23.58±3.85 °C), DO(4.89±1.09mg/L), EC(34.63±19.50µScm-1) TDS(493.13±136.67mg/l), pH(7.68±0.50), NO3(2.76±2.35mg/L) and PO4-P (1.71±1.50mg/L). Values of measured parameters were within acceptable limits for aquaculture as per WHO standards. All parameters significantly increased in pond water as compared to inlet water showing that aquaculture was contributing to deterioration of the water quality in fishponds. This calls for effluent treatment, regular monitoring and sensitization of farmers on good aquaculture practices.
Increase in popularity of flavoured tea: The case of Kenyan tea industries
(2015) Mengo, N.; Mungai, J.; Huho, J.M.; Mbuthia, S.; Mungai, M.
The aim of the study was to explore the increase in popularity of flavoured tea brands as well as to investigate their marketing effects vis-à-vis non-flavoured brands. Tea is one of the most popular beverages consumed in Kenya. Over time, companies have started adding flavours to plain tea to enhance taste and create diversity of taste for the consumer. Additives may be in forms of flowers, fruits, herbs and other natural flavours added to tea to produce flavours such as jasmine tea, masala tea, lemon grass tea, and green tea. The research was done by analysing literature and administering questionnaires. Findings indicate that with increased diversity of flavours, consumers responded by changing their purchasing patterns and incorporating flavoured tea in their consumption. This in turn has increased the popularity of flavoured tea brands in the market. From these observations, it is clear that the market for flavoured tea brands is more likely to grow due to consumer satisfaction and continual creation and diversification of flavoured.
Influences of land use/cover on water quality in the upper and middle reaches of River Njoro, Kenya
(Lakes & Reservoirs: Research and management, 2007-06) Shivoga, William, A.; Muchiri, Mucai; Kibichi, Samuel; Odanga, Jethro; Miller, Scott, N.; Baldyga, Tracy, J.; Enanga, Eric, M.; Gichaba, Maina, C.
Data from 10 sampling sites along the River Njoro are used to examine the contribution of nutrients from upstream land uses draining each of the sampling sites. The data also are used to assess whether both the proportion of land uses and the size of the subwatersheds account for the variability in water quality in the River Njoro watershed. Geographical Information System analysis was used to determine the spatial distribution of land-cover types and subwatersheds contributing run-off to the sampling sites in the River Njoro. Standard Digital Elevation Model-based routines were used to establish the watershed area contributing run-off to each sampling site. Water and sediment samples were collected for chemical analysis, and the nutrient levels were related to the upstream land-use types and the size of the subwatersheds. The mid-stream portion of the River Njoro (near Egerton University) accounts for the highest nutrient contributions. The percentage contribution is magnified by additions from industrial, human settlements and agricultural land uses around the University. There is a significant decrease in nutrient levels downstream, however, indicating natural purification as the river flows through an area of large-scale farming with intense, well-preserved riparian and in-stream vegetation. Steep slopes of the land upstream of Egerton University enhance erosion and nutrient losses from those subwatersheds. Mixed small-scale agricultural and bare lands contribute over 55% of the phosphorus load to the upper and mid-reaches of the River Njoro. The size of the subwatershed accounts for about 53% of the variability in the soluble phosphorus in the river. The land-use subwatershed proportions are important for characterizing and modelling water quality in the River Njoro watershed. Upland land uses are as important as near-stream land uses. We suggest that conservation of intact riparian corridor along the river and its tributaries contributes significantly to natural purification processes and recovery of the ecological integrity of the River Njoro ecosystem.