Browsing by Author "Outa, Nicholas"
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Item A review on the status of some major fish species in Lake Victoria(2019-09-17) Outa, Nicholas; Yongo, Edwine; Keyombe, Jameslast; David, NamwayaLake Victoria, the second largest freshwater lake in the world supports a huge flora and fauna with a large human population around the Lake. The Lake is a source of food (fish), water for domestic use and crop and livestock production, transportation, tourism among others. Due to its varied uses, human intervention within the lake and its catchment has caused several ecological changes in the recent years with profound effects on the resource resources. One of the most notable change is the reduction and risk of extinction of some fish species, including the endemic tilapiine species (Oreochromis esculentus and O. variabilis), catfishes (Xenoclarias eupogon), haplochromines and cyprinids (Labeo victorianus and Barbus altinialis) within the lake. The reduction in biodiversity and extinctions within the lake has been ascribed to the introduction of alien fish species (Nile perch (Lates niloticus) and Nile tilapia (O. niloticus) into the lake, habitat loss and the cultural eutrophication. These changes if left unchecked will have devastating effects on the lake’s resources and at large to people living around the lake and beyond who depend on the lake for their livelihood. There is, therefore, an urgent need for management measures based on sound scientific research to be taken in order to curb the loss of ichthyodiversity within the lake and to save livelihoods of the direct and indirect dependents of the lakeItem Current Fish Feed Status and Development of New Feeding Technologies for Aquaculture Growth and Development in Kenya: Rapid Review(2023-12-18) Mungai, Daniel; Omondi, Argwings; Omweno, Jacob; Outa, Nicholas; Munguti, JonathanAquaculture has emerged as a promising sector for addressing the ever-increasing demand for fish protein in Kenya, where over 50% of fish consumption is reliant on imports. However, the sustainable growth and development of aquaculture in Kenya are significantly influenced by the availability and quality of fish feed, which constitutes over 50% of the total production costs. The current fish feed status in Kenya is characterized by several challenges, including limited avail-ability of high-quality feed ingredients, high feed costs, and inconsistent feed quality and nutrient composition. These challenges pose significant constraints to the efficient production of healthy and marketable fish, limiting the full potential of aquaculture growth in Kenya. To address these challenges, efforts are being made towards the development of new feed formulations and feeding technologies that can improve the efficiency and sustainability of fish feed production in Kenya. This includes the utilization of locally available feed ingredients, such as agricultural by-products and aquatic macrophytes, to develop cost-effective and nutritionally balanced feed formulations. Moreover, research is underway to optimize feed processing techniques, such as extrusion, pelleting, and encapsulation, to improve feed quality, stability, and digestibility. Additionally, innovative feeding methods, such as automated feeding systems and precision feeding, are being explored to minimize feed wastage and maximize feed utilization, thereby enhancing fish growth and reducing production costs. The development of new feeding technologies for aquaculture growth and development in Kenya holds great potential to address the challenges associated with fish feed availability, quality, and cost. By optimizing feed formulations, processing techniques, and feeding methods, the aquaculture sector in Kenya can improve its productivity, profitability, and sustainability. However, further research, investment, and collaboration among stakeholders, including government, research institutions, feed manufacturers, and farmers, are essential for the successful implementation and adoption of these new feeding technologies to drive the growth and development of aquaculture in Kenya.Item Ecological implications of Rastrineobola argentea (omena) fishery: A rapid assessment of bycatch diversity at Dunga Beach, Lake Victoria, Kenya(2022-06-01) Outa, Nicholas; Ogello, Erick; Okinyi, Walter; Mungai, Dan; Iteba, JacobRastrineobola argentea (omena) is the second most important species in the fisheries of Lake Victoria after Nile perch. However, its fisheries have negative impacts on the ecology of the lake especially because of the high numbers and diversity of bycatch resulting from the fishery. This study conducted a rapid assessment in Dunga beach in Kisumu, Kenya to identify and quantify the bycatch and to collect information on the fishermen’s perceptions of the bycatch from the omena fishery. All the boats reported bycatches of different species and different sizes. The bycatches comprised of Lates niloticus, Haplochromis spps, Clarias gariepinus, Protopterus aethiopicus, Synodontis. The smallest bycatch recorded was Haplochromis spp (3.3 cm; 3g) while the largest fish bycatch was Protopterus aethiopicus (1.5 m; 2.4 kg). Other bycatch recorded were freshwater shrimps and molluscs. 80% of the fishermen suggested the provision of alternative livelihoods as a measure to reduce the pressure on omena fishery while 12% recommended stricter rules on gears implemented. A total of 99% of the fishers reported that they do not return bycatch into the lake but rather sell them together with the main catch (omena). The implications of this on the ecological functioning of the lake is predicated on the negative impacts on the trophic interactions in the ecosystem.Item Food Safety Knowledge, Attitudes and Practices Of Fish Handlers in Kirinyaga County Markets, Kenya(2023) Kyule, Domitila Ndinda; Mburu, Saimon Wambui; Munguti, Jonathan; Obiero, Kevin; Abwao, Jacob; Ndegwa, Daniel; Outa, Nicholas; Ogello, ErickFish and fish products have high nutritional value and are important in supplementing human diet. Fish products have little or no cholesterol and saturated fat, but instead have omega 3 and low-fat content essential for human health. Despite the high nutritional value of fish products, their consumption is hindered significantly by setbacks such as spoilage and foodborne diseases that spread through contamination in the fish supply chain. The objective of this study was to evaluate fish vendors' attitudes, knowledge, and practices on food safety in selected markets in Kirinyaga County that included Sagana, Tebere, Mwea, Ndia, Kianyaga, and Kerugoya markets. A structured questionnaire was administered to 54 fish vendors to collect information on fish safety, spoilage, risk factors, personal hygiene, food contamination, type of hazards, foodborne diseases and attitudes towards training on food safety. Statistical Package for Social Sciences (SPSS) version 22.0 was used to analyze the data from the respondents. The relationship between fish vendors’ demographic characteristics and risk factors was assessed using Spearman’s rank correlation coefficient. The majority of the fish vendors had a positive attitude towards education in hygiene practices (56%). There was a positive correlation between education and fish vendors' awareness of fish foodborne diseases at p<0.05. The study revealed that fish foodborne diseases awareness was positively influenced by respondents' level of experience and age. Moreover, there was also a significant (p˂ 0.05) positive correlation on the awareness of fish foodborne diseases with hygiene and food safety. Majority of the fish handlers had average level of knowledge, attitude and hygiene practices for food safety. These findings presented a foundation for formulating policies to increase food safety and hygiene practices of fish handlers in the region, thereby preventing foodborne diseases and postharvest losses. The results of this study can also form a basis for an in-depth research for students and researchers in various disciplines such as public health, marketing, community development and more.Item Freshwater Integrated Multitrophic Aquaculture (FIMTA) technology in Lake Victoria(2021-01-17) Outa, NicholasThe decline in capture fisheries of the world has necessitated the production of fish under different aquaculture systems to bridge the gap in demand. Aquaculture contributes about 50% of fish consumed worldwide. Today, the total annual fish production in Kenya is estimated at about 150,000 metric tons, against an annual demand of 500,000. With the ever-increasing human population and demand for fish, technologies to improve aquaculture production must be embraced to bridge fish supply gap and to achieve nutritional sufficiency. One of these technologies is cage aquaculture which is the rearing of fish(es) in water bodies like dams, lakes, ponds and reservoirs in floating enclosures that allow free flow and exchange of water between the cage the outer water body. The frames of the cages can be made from bamboo, metal or High-Density Poly Ethylene (HDPE). With the challenges associated with pond aquaculture such as competition for land with other uses and susceptibility to floods, cage aquaculture has gained recognition and is rapidly expanding in Kenya and the world over. In Kenya, for example, the use of cages to produce fish is relatively new and is being practised in Lake Victoria in the five riparian Counties of Migori, Homabay, Kisumu, Siaya and Busia (Anjejo, 2017). These cages have several negative impacts on the lakes environment as highlighted below.Item Impacts of Covid-19 Pandemic and Adaptive Strategies to Build Resilience in the Kenyan Aquaculture Sector(2022-10-08) Munguti, Jonathan; Iteba, Jacob; Outa, Nicholas; Kirimi, James; Mungai, Daniel; Kyule, Domitila; Obiero, Kevin; Ogello, Erick, OchiengThis study examines the impacts of the Covid-19 pandemic and adaptive strategies to build resilience among stakeholders and actors in the aquaculture value chain in Kenya. Prior to the pandemic, Kenya's aquaculture sector had progressed from a minor player to a key component of the country's fish food system. Fish and fishery products have become the most heavily traded food commodity in the Kenyan markets. The results indicate the pandemic had significant impacts on the access to aquaculture inputs, fish trade, and socio-economic livelihoods of the aquaculture value chain stakeholders and actors during the two whole years. Thus, initial and longer-term adaptive measures, in particular by private sector players and government agencies, can contribute to building resilience to multiple shocks and stressors among stakeholders and actors in the aquaculture sector. Some measures include a government incentive package to overcome the damage to the fisheries and aquaculture sector, improve farming operations and win the market trust and adopt new methods such as intelligent sensors, camera systems and automated or remotely controlled monitoring/feeding strategies to reduce labour intensity. Such measures and policies can cushion the sector against future shocks occasioned by such pandemics.Item Modèle de diapositives du Module I de l'Atelier ouvert destiné aux pairs évaluateurs pour l'Afrique(2023-01-05) Munene, Aurelia; Saderi, Daniela; Havemann, Johanna; Obanda, Johanssen; Owango, Joy; Ngugi, Joyce Wangari; Korzec, Kornelia; Outa, Nicholas; Dine, Roseline Dzekem; Dia, Aboubakry; Onwuchekwa, GodwynsCe modèle de diapositive, disponible en format .pdf et .pptx, a été développé dans le contexte d’un projet financé par le Wellcome Trust et vise à piloter une série d’ateliers en trois parties intitulée Atelier ouvert aux pairs évaluateurs pour l’Afrique. Ce jeu est le deuxième des deux diapositives du module I à notre disposition. Vous trouverez des détails sur l’atelier et des informations sur la façon de gérer votre propre version de l’atelier dans le Guide du formateur. Divulgation : ces traductions ont été effectuées par Roseline Dzekem Dine. Ce contenu constitue un modèle. Il est destiné à être adapté au public et à la culture, tous les exemples utilisés peuvent ne pas être pertinents ou appropriés.Item Occurrence and prevalence of fish parasites and the interaction with water quality parameters in selected small water bodies in western Kenya(2022-02-08) Mziri, Venny; Outa, NicholasWater quality and the environment greatly influence the existence and proliferation of parasites in the water and consequently, fish. This can have profound implications on aquaculture within the water bodies. Few studies have been conducted on parasite aggregations about the water quality in small water bodies in Kenya. This study assessed the suitability of selected Small Water Bodies (SWBs) for aquaculture as regards fish parasites by assessing the relationship between the occurrence and prevalence of parasites to water quality, water depth, land use, and shoreline habitat type. Standard protocols and procedures were used in the collection, analysis of water quality, and assessment of fish specimens for parasitology. White spot disease, (a parasite with economic significance) was in 4 of the 6 SWBs studied and had varying prevalence rates ranging between 10% to 20%. Clinostomum, a zoonotic parasite was also recorded in one of the SWBs sampled in this study. Additionally, the study realised some significant differences in the water quality from the various selected SWBs (p˂0.05), which could be a pointer to the noted diversities in the parasite communities. The findings of this study indicated that there was a strong positive correlation (r2 > 0.8) between some parasites (Ichthyopthirius multifiliis, Clinostomum spp., Procamallanus, and Camallanus) and some water quality parameters (temperature, turbidity, Soluble Reactive Phosphorous, Total Phosphorous, and Silicates). In light of the increase in focus on fisheries and aquaculture as key drivers of the blue economy and food and nutrition security, and as the country explores new frontiers for investment in aquaculture in SWBs, the water quality and consequent habitat features such as depth and land use, need to be addressed before investment.Item Open Peer Reviewers in Africa Workshop Module I Template Slides(2022-10-04) Munene, Aurelia; Saderi, Daniela; Havemann, Johanna; Obanda, Johanssen; Owango, Joy; Ngugi, Joyce Wangari; Korzec, Kornelia; Outa, Nicholas; Onwuchekwa, GodwynsItem Reviewing the Status of Turtles in Kenyan Aquatic Ecosystems: Threats and Current Conservation Efforts(2022-07-16) Ogello, Erick; Kinga, Jeniffer; Mwanzia, Janet; Outa, Nicholas; MUTHOKA, MAVINDUTurtles are ancient repltiles with significant economic, ecological and social values to humanity. Due to the high demand for commercialized sea turtle products, turtles have been classified under ‘Critically Endangered’, ‘Endangered’ or ‘Vulnerable’ by the World Conservation Union. The long-term survival of turtles is contingent on the protection of nesting areas and the education of local communities on their conservation and importance. Pollution, loss of nesting grounds, bycatch in fishing, poaching, and climate change contribute to the decrease of turtles. If these causes are left unchecked, they may have devastating effects on the turtle population. Long-term monitoring is therefore essential for gaining a thorough understanding of turtle population dynamics and assessing the efficiency of conservation measures. We conducted a review of the most recent literature to guide future research, emphasizing the basic biology of turtles with a focus on the Kenyan situation. The review has revelaed that Kenya is home to a variety of turtles, including both marine and freshwater turtles. The green turtle (Chelonia mydas), hawksbill turtle (Eretmochelys imbricata), loggerhead turtle (Caretta caretta), Olive Ridley turtle (Lepidochelys olivacea), and leatherback turtle (Dermochelys coriacea) are some of the marine turtles found in Kenyan waters. The paper further discusses the importance of turtles, the risks they face, presents conservation measures as well as what can be done to raise their survival rates. This review proposes that government, non-governmental organizations and community must devote special attention to the development and execution of scientifically sound, conservation measures to reduce activities that place turtles under threat.Item Socio-economic consequences of imported frozen tilapia in the Kenyan aquaculture value chain: Strategies for optimizing local unexploited potential(2022-10-18) Ogello, Erick; Outa, NicholasThe capture fisheries production sector, which is the main source of consumed fish in Kenya has been declining over the years, causing a huge deficit in fish supply in the local market. Even though aquaculture has been fronted as a stop-gap measure, there are still eminent fish supply gaps, prompting the importation of frozen tilapia, mainly from China. However, imported fish has attracted numerous socioeconomic debates between proponents and opponents of fish imports, almost in equal measure. This study investigated the socio-economic consequences of imported tilapia in the local fish market and the value chain linkages in Kisumu County. Primary data were collected using direct interviews with pre-set questionnaires fed into Open Data Kit (ODK) platform, and observations from 60 randomly selected fishermen and 60 fish farmers, 100 fish traders and 96 households. Key Informant Interviews (KII) and Focused Group Discussions (FGDs) were also conducted. About 57% of the respondents processed and traded on imported frozen tilapia, 27% of them traded on fish from capture fisheries, and 16 % traded on fish from the local aquaculture sector. Imported tilapia was the cheapest at Ksh. 200/kg compared to the locally produced tilapia at Ksh. 320/kg. At least 62 % of the households in Kisumu consumed imported tilapia regularly due to lower prices and availability. About 46 % of the respondents have gained direct employment and experienced improved socio-economic status because of the imported fish, of which 71 % are youth and women. However, about 40% of the respondents reported multiple job losses and degraded socio-economic status due to poor market for the locally produced tilapia, whether from the capture or culture sector. The study concluded that the importation of frozen tilapia can potentially reduce socio-economic returns from the local fisheries and aquaculture value chains. A rational approach is to optimize local fish production to saturate the local market and potentially out-price the imported frozen tilapia. Appropriate government policies tackling the importation of fish into the country can also help reduce the negative impacts of these imported fish on the local fish market systems.Item The impacts of introduced species on lake ecosystems: A case of Lakes Victoria and Naivasha, Kenya.(2019-10-09) Outa, Nicholas; Mungai, Dan; Keyombe, James, LastFish and other aquatic organisms have been introduced into new environments for various reasons. Provision of sports fishery, supplemental to stocks, to fill empty niches, control weeds, and disease vectors and even create a commercial fishery are some of the reasons why fish species are introduced into new ecosystems. Lake Victoria and Lake Naivasha in Kenya have seen several introductions as discussed in this paper. In Lake Victoria for example, some of the species introduced include Nile perch, Lates niloticus, Nile tilapia, Oreochromis niloticus, Tilapia zilii, and Oreochromis esclentus among others. The most successful introductions have been that of the Nile perch, Nile tilapia and water hyacinth. Lake Naivasha too has witnessed a number of introductions into its fisheries too. Some of the successful introductions into the lake are those of the Common carp, Cyprinus carpio, the largemouth bass, Micropterus salmoides, the Nile tilapia, O. niloticus and Louisiana red swamp crayfish, Procambarus clarkia. Aside from the fish species mentioned, some invasive plant species have also been introduced into these two lake ecosystems. Of notable success and impacts have been the water hyacinth, Eichhornia crassipes and Nile cabbage, Pistia stratiotes. These introductions have had both negative and positive impacts on the fisheries and the ecology of the two lakes. Some of the impacts have been predation on the native species by the introduced species like in the case of Nile perch and largemouth bass in Lake Victoria and Naivasha respectively. Competition for resources and hybridization with the native species has also been witnessed in the case of the tilapiines in the two lakes with undesirable results. Blockage of navigation routes caused by the invasive plants has been a major problem in the two lakes sometimes leading to massive postharvest losses by the fishermen. On the other hand, some introduced species have led to an increase in fish landings as well as utilization of the niches that were initially vacant within these ecosystems. It can therefore be concluded that introduced species often have more negative effects on the native species and therefore such introductions should be based on sound scientific research in order to minimize their effects within the new environments.Item The status of research on Lake Victoria fisheries: Historical and current data on fisheries and the lake environment(2019-09-20) Outa, Nicholas; Mungai, Dan; Ogello, ErickLake Victoria which is the second largest freshwater lake in the world supports a large population living around it through provision of food; fish and employment; both directly and indirectly. Due to its varied uses, human intervention within the lake and its catchment has caused several ecological changes in the recent years which have had profound effects on its resources. Historical and recent data within the lake show an enormous change in the diversity of the fish species as well as environmental and ecological changes. Some of the reasons cited for the changes in biodiversity within the lake are: the introduction of alien fish species like Nile perch (Lates niloticus) and Nile tilapia (Oreochromis niloticus) into the lake, habitat loss and the cultural eutrophication. Several research projects like Lake Victoria Management programme (LVEMP) and Lake Victoria Fisheries Organization (LVFO) have been formed to help address some of these problems with varied levels of success. There is therefore an urgent need for management measures based on sound scientific research to be taken in order to curb this loss of ichthyodiversity within the lake and to save the livelihoods of the people who are dependent on the lake. Owing to the importance of the lake to the livelihoods of the people around the lake and beyond, there is need for concerted effort by all stakeholders in trying to halt the degradation and other negative environmental and ecological changes within the lake. Ecosystem approach to conservation is the way forward in the management and sustainable utilization of the fisheries and other resources within the lake.Item شرائح المراجعين المفتوحة في إفريقيا للوحدة التدريبية الأولى(2023-01-06) Munene, Aurelia; Saderi, Daniela; Havemann, Johanna; Obanda, Johanssen; Owango, Joy; Ngugi, Joyce Wangari; Korzec, Kornelia; Outa, Nicholas; Yahia Mohamed Elkheir, Lamis; Salem Youssef, Mohamed; Namoune, Rachida; Onwuchekwa, Godwynsتم تطوير مجموعة شرائح القوالب هذه، المتوفرة بتنسيق pdf و pptx ، في سياق مشروع ممول من Wellcome Trust لتجربة سلسلة من ورش العمل المكونة من ثلاثة أجزاء تسمى Open Peer Reviewers in Africa. هذه المجموعة هي الأولى من مجموعتين - مجموعة شرائح قالب الوحدة الثانية المتاحة هنا. يمكن العثور على تفاصيل حول ورشة العمل ومعلومات حول كيفية تشغيل نسختك الخاصة من ورشة العمل في دليل المدرب. (https://doi.org/10.5281/zenodo.7509683) بيان الإفصاح عن المعلومات الإفصاح: هذا المحتوى عبارة عن نموذج ويهدف إلى تكييفه مع الجمهور والثقافة ، وقد لا تكون جميع الأمثلة المستخدمة ذات صلة أو مناسبة.