A review on the potential of aquaculture development in Kenya for poverty alleviation and food security

On the global scene, aquaculture accounts for about 50% of total fish production amounting to about 80 million metric tonnes. It is estimated that another 40 million metric tonnes of aquatic food will be required by the year 2030. Today, fish farming represents the fastest growing sector of food production. Moreover, aquaculture has a major role to play in the achievement of the first three Sustainable Development Goals on poverty, hunger, food security and healthy lives of people from developing countries. This is significant especially in the developing countries where poverty and malnutrition are a reality. However, in sub-Saharan Africa, per capita fish production from aquaculture is still below world production levels. In Kenya, inland capture fisheries accounted for over 90% of the total national fish production while marine capture fisheries contributed about 5% in the last decade. Kenya has one of the fastest growing human populations in the world indicating that the demand for fish and fish products will continue to rise, increasing the gap between supply and demand. Currently, aquaculture only produces about 24,000 metric tonnes of fish annually compared to an annual average of 178,000 metric tonnes from natural fisheries. The dominant cultured species include: Nile tilapia (Oreochromis niloticus), African catfish (Clarias gariepinus), rainbow trout (Onchorhynchus mykis) and common carp (Cyprinus carpio). Culture systems commonly used are static ponds and raceway systems. In addition, the country is endowed with numerous aquaculture resources ranging from favorable climatic conditions to vast water resources. In the year 2009, the Kenyan government took steps to enhance aquaculture production through an Economic Stimulus Programme. This has increased the contribution of aquaculture in Kenya to 11.0% of the total fish production. This paper discusses the growth and development of aquaculture in Kenya during the last 50 years and the impact of government support to the sub-sector. The paper also proposes strategies for ensuring that Kenya becomes one of the leading producers of fish from aquaculture in Africa.Key words: Fish production, capture fisheries, culture systems, Economic Stimulus Programme, aquacultur

Can Integrated Livestock-Fish Culture be a Solution to East Afircan's Food Insecurity? A Review

Integrated livestock-fish culture approach envisages the integration of fish farming with cattle, sheep, goats, poultry, pigs or rabbit husbandry in a design allowing wastes from one system to be used as inputs in another system. The aim is to conserve resources while increasing farm returns. This paper reviews integrated livestock-fish culture in Asia and some African countries towards stimulating growth in East Africa’s livestock-fish integration practices. Livelihood challenges and current status of integrated livestock-fish culture in some segments of East Africa are discussed. Economic analyses of integrated livestock-fish farming in selected places are presented. Challenges facing integrated livestock-fish aquaculture in the region include: government neglect of aquaculture sector, weak aquaculture research and applications, political interferences as well as social and religious challenges. Poor publicity, poor infrastructure, lack of clear legislations and policies and high illiteracy among potential fish farmers have also been mentioned as bottlenecks to the growth of integrated fish farming in the region. So far, fish-poultry integration is the most popular across Africa and Asia while fish-cattle integration is unpopular in many countries. Livestock manure as source of organic fertilizer for fish ponds and biogas production can help reduce cost of investment in purchasing inorganic fertilizers. With the present high cost of pelleted fish feeds, integrated fish farming stands to reduce the cost of feeding fish while simultaneously increasing the yield, leading to high economic returns. This paper concludes that livestock-fish integration is one of the most practicable solutions to food insecurity and malnutrition in the East African community despite its current poor status. In fact, it could be the forgotten asset that can guarantee present and future aquaculture sustainability in the region. The paper recommends capacity building among stakeholders to recognise integrated aquaculture as a ‘self feeding’ biotechnology unit, which deserves special attention in East Africa.Key words: livestock-fish culture, integration, East Afric

Cost-Benefit Analysis and Growth Effects of Pelleted and Unpelleted On-Farm Feed on African Catfish (Claries Gariepinus Burchell 1822) in Earthen Ponds

Fish feed constitutes 40-60% of the total operational costs of a fish farm. Commercial feeds are often too expensive for rural fish farmers. Consequently, farmers use non-conventional and locally available fish feed ingredients including agro-industrial by-products. These feeds have not led to increased pond productivity due to poor processing, higher fibre content, and anti-nutritional factors that limit nutrient bio-availability. Farmers have not embraced processing of fish feeds because the cost-effectiveness of processing has not been clearly demonstrated. The African catfish (Clarias gariepinus) is an important farmed fish in sub-Saharan Africa hence the need for research on its nutrition and growth performance. The growth performance and cost-benefit of using pelleted diets formulated from locally available feed ingredients on C. gariepinus were evaluated in a rural African setting. The experiment included diets that differed in the ingredients and form used (pelleted and un-pelleted). Four isocaloric and isonitrogenous diets were formulated from freshwater shrimp (Caridina nilotica), rice bran (Oryza sativa) and wheat bran (Triticum aestivum). The diets were C. nilotica and wheat bran pelleted (CWBp), C. nilotica and wheat bran un-pelleted (CWBup), C. nilotica and rice bran pelleted (CRBp), and C. nilotica and rice bran un-pelleted (CRBup). The diets were fed to C. gariepinus fingerlings (mean initial weight 1.75±0.03g), in triplicates for 5 months. The pelleted diets showed significantly better performance (P<0.05) compared to the un-pelleted diets. Fish grew to a weight of 266.77±6.21g on CWBp, 224.9±3.91g on CRBp, 211.38±4.46g on CWBup and 190.87±4.47g on CRBup. Cost benefit analysis of the pelleted and un-pelleted diets indicated positive net returns of US$180.1 for CWBp, US$142.5 for CRBp, US$126.8 for CWBup and US$ 115.5 for CRBup. The CWBp had significantly higher net returns than the other diets. This paper demonstrates that although on-farm pelleting of diets adds extra cost of labour, pelleted diets are cost-effective and should be incorporated as an essential part of on-farm feed production.Key words: Catfish, feed, pelleting, cost-effectiveness, pon

NUTRITIVE VALUE AND AVAILABILITY OF COMMONLY USED FEED INGREDIENTS FOR FARMED NILE TILAPIA (OREOCHROMIS NILOTICUS L.) AND AFRICAN CATFISH (CLARIAS GARIEPINUS, BURCHELL) IN KENYA, RWANDA AND TANZANIA

ABSTRACT Commonly utilized feed ingredients for culture of Nile tilapia (Oreochromis niloticus) and African catfish (Clarias gariepinus) from Kenya, Tanzania and Rwanda were collected over a period of six months (January -June 2010) and evaluated for their nutritive composition through proximate analysis. Most of the fish feed ingredients were found in all the three countries except a few that were unique to one or two countries as detailed in the results. Feed ingredients of animal origin exhibited significantly (P<0.05) higher crude protein levels (407 -635 g/kg DM) compared to the feed ingredients of plant based origin. Freshwater shrimps (Caridina nilotica) contained the highest crude protein levels of 635 g/kg DM. Feed ingredients of animal origin had low ether extracts (EE) with an exception of Omena fish (Rastrineobola argentea). Crude fibre (CF) was generally higher on feed ingredients of plant origin and ranged between 55-368 g/kg DM while Nitrogen Free Extracts (NfE) and ash content were higher in the feedstuffs of plant origin with an exception of maize bran which had the lowest value. Omena fish and freshwater shrimp had higher ash content of 182 and 228g/kg DM compared to other feed ingredients of animal origin, which may indicate contamination with soil particles during drying process. Based on the feed ingredient availability, potential competition with other human uses, content of crude protein and crude fibre and the feasibility of removal of anti-nutritional factors, C. nilotica, blood meal, meat and bone meal, were identified as most promising sources of animal based protein. Cotton (Gossypium spp) and sunflower (Helianthus annuus) seed cakes provided the best option as source of processed plant based protein. Leaves of gallant soldier (Galisonga parviflora), sweet potato (Ipomoea batatus), cassava (Manihot esculenta) and papaya (Papaya carica) were identified as high potential feedstuffs of plant origin either processed or in raw form for small-scale fish farming. We recommend that in well fertilized semiintensive ponds, maize (Zea mays), wheat (Triticum aestivum) and rice (Oryza sativa) bran may be utilized where available to supplement natural pond food

Competitive Interactions between Invasive Nile Tilapia and Native Fish: The Potential for Altered Trophic Exchange and Modification of Food Webs

Recent studies have highlighted both the positive and negative impacts of species invasions. Most of these studies have been conducted on either immobile invasive plants or sessile fauna found at the base of food webs. Fewer studies have examined the impacts of vagile invasive consumers on native competitors. This is an issue of some importance given the controlling influence that consumers have on lower order plants and animals. Here, we present results of laboratory experiments designed to assess the impacts of unintended aquaculture releases of the Nile tilapia (Oreochromis niloticus), in estuaries of the Gulf of Mexico, on the functionally similar redspotted sunfish (Lepomis miniatus). Laboratory choice tests showed that tilapia prefer the same structured habitat that native sunfish prefer. In subsequent interspecific competition experiments, agonistic tilapia displaced sunfish from their preferred structured habitats. When a piscivore (largemouth bass) was present in the tank with both species, the survival of sunfish decreased. Based on these findings, if left unchecked, we predict that the proliferation of tilapia (and perhaps other aggressive aquaculture fishes) will have important detrimental effects on the structure of native food webs in shallow, structured coastal habitats. While it is likely that the impacts of higher trophic level invasive competitors will vary among species, these results show that consequences of unintended releases of invasive higher order consumers can be important

Selection for growth of Nile tilapia (Oreochromis niloticus L.) in low-input environments

Nile tilapia,Oreochromis niloticus,is one of the most important species farmed in the world and is the mainstay of many resource-poor fish farmers. The majority of its culturing is carried out in semi-intensive systems with a wide array of pond inputs from the farm. These systems are characterized by poor fish growth and low yields. Studies have shown that only a small percentage of the nutrient input in these systems is converted to harvestable products. Efficient breeding programs are needed to improve the overall nutrient use efficiency of fish in low-input fertilized ponds. Selection for improved growth has typically been doneunder favorable conditions often resulting in breeds which demand more resource than can be provided on the traditional fish farms, thus increasing cost of production. In this research, the feasibility of direct improvement of the growth of Nile tilapia in low-input conditions was investigated.This study demonstrates good prospects for setting up sustainable breeding programs for resource poor tilapia farming conditions without requiring expensive supplementary protein pellets. An experiment on early growth showed that Nile tilapia juveniles can be grown at the same rate with or without supplementary feeds.There was also a substantial heritability and response to selection for body weight at harvest after two generations of selection. We found little scope for selecting for improvement of cold tolerance in juveniles, but that cold tolerance could be improved by prior acclimatization. Body weight was highly genetically correlated with body measurements indicating that when needed, alternative traits for measurement of growth can be used. The high response and short generation times in Nile tilapia indicate that farmers can reap the benefits of genetic improvement at early stages of the program.This study found significant evidence for genotype by environment interaction indicating that the selection environment can affect the results of selection. Because poverty alleviation and food security are primary goals in the developing world, the initiation and implementation of cheaper breeding programs will ensure that the genetically improved materials are accessible to the rural fish farmer. Selection for improved growth in low-input conditions should be carried out in low-input environments especially because of low cost of inputs. Appropriate breeding goals need to be set-up with the involvement of the local farmers to ensure that the resulting breed meets the requirements of local farmers. To fully benefit from improved breed programs, farmers should also enhance pond water quality and improve fish nutrition

Effect of C/N ratio levels and stocking density of Labeo victorianus on pond environmental quality using maize flour as a carbon source

The main obstacle in developing intensive fish culture is waste management which is detrimental to the environment. To mitigate environmental impacts associated with effluent discharge, measures should be put in place to avoid deterioration of the pond environment. The addition of carbon materials into culture facilities while manipulating the levels of carbon and nitrogen ratios is one of the best strategies of controlling ammonia and nitrite in ponds. This study was carried out in 18 hapas suspended in six, 150 m2 earthen ponds to investigate the effects of C/N ratios (10 and 20) and stocking density (10, 15 and 25 fish m- 2) on water quality, sediment quality and growth of Labeo victorianus. All treatments were carried out in triplicate during a time period of 72 days. A locally formulated and prepared feed containing 30% crude protein with a C/N ratio of 10 was applied. Maize flour was used as the carbohydrate source for manipulating C/N ratio and applied to the water column separately from the feed. Increasing C/N ratio from 10 to 20 reduced (P <0.001) the total ammonia nitrogen (TAN), nitrite–nitrogen (NO2–N) and nitrate–nitrogen (NO3–N) in the water column and total nitrogen in the sediment (P <0.001). It also raised sediment pH, organic matter and total phosphorus (P <0.001). The lowest protein efficiency ratio (PER), specific growth rate (SGR) and the highest food conversion ratio for the feed were recorded with a C/N ratio of 10 (P <0.05). Based on highest growth, survival, production and net benefits, C/N ratio of 20 and a stocking density of 25 fish m- 2 are optimal. Therefore, carbohydrate addition in L. victorianus culture is a promising option for sustainable aquaculture