PD/A CRSP Nineteenth Annual Administrative Report
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MOU No. RD009A (OSU)
Subcontract No. RD010A-08 (AU)
Oregon State University, Corvallis, Oregon
|Jim Bowman||US Principal Investigator, US Regional Coordinator|
|Christopher Langdon||US Principal Investigator|
Auburn University, Alabama
|Tom Popma||US Principal Investigator|
|Karen Veverica||US Principal Investigator|
|Bethuel Omolo||Graduate Research Assistant (Kenya; CRSP funded)|
Fisheries Department, Nairobi, Kenya
|Nancy Gitonga||Host Country Principal Investigator|
|John Kinyanjui||Host Country Research Associate and Head of Station, Sagana Fish Farm (from September 2000)|
|Japhet Ngatuni||Host Country Research Associate and Head of Station, Sagana Fish Farm (through August 2000)|
Moi University, Eldoret, Kenya
|David Liti||Host Country Principal Investigator|
|Mucai Muchiri||Host Country Principal Investigator|
|Charles Ngugi||Host Country Principal Investigator|
|Robinson Mugo||Graduate Research Assistant (partially CRSP funded)|
|Enos Mac'Were||Graduate Student (partially CRSP funded)|
|Robert Olendi||Graduate Student (partially CRSP funded)r|
|Victoria Boit||Undergraduate Student (August 2000 through March 2001)|
|Maria Fungomeli||Undergraduate Student (August 2000 through March 2001)|
|Karen Lerimoi||Undergraduate Student (from December 2000)|
|Bernard Maundu||Undergraduate Student (August 2000 through March 2001)|
|Jedidah Atieno Nyongayo||Undergraduate Student|
|Barua Tsuma||Undergraduate Student (from December 2000)|
Bunda College, Lilongwe, Malawi
|Jeremy Likongwe||Host Country Principal Investigator|
|Lucius Chimwala||Undergraduate Student (through December 2000)|
|Kenneth Chaula||Undergraduate Student (through December 2000)|
International Center for Living Aquatic Resources Management (ICLARM), Zomba, Malawi
|Daniel Jamu||Host Country Principal Investigator|
University of Nairobi, Nairobi, Kenya
|Patricia Mwau||Graduate Student (through January 2001; partially CRSP funded)|
|Hellen Njeri||Undergraduate Student (from September 2000)|
Kenyatta University, Nairobi, Kenya
|Paul Wamwea Wabitah||Undergraduate Student (through January 2001)|
Nyanchwa College of Science and Technology, Kisii, Kenya
|Lucy Wambui||Undergraduate Student (from September 2000)|
Auburn University, Alabama
Sagana Fish Farm, Sagana, Kenya
Kenya Project research is conducted at Sagana Fish Farm, in Central Province, in collaboration with the Kenya Fisheries Department under a Memorandum of Understanding between Oregon State University (OSU) and the Fisheries Department of Kenya's Ministry of Agriculture and Rural Development. In the last two years, additional MOUs have been established with Moi University and with companion site institutions in Malawi.
Research activities in this reporting period addressed aquaculture development constraints and research priorities identified in the Continuation Plan 1996. These included optimization of production/management strategies through more efficient use of supplemental feeds, conducting training activities in basic pond management practices, regionalizing the benefits of the CRSP research program through outreach activities, and establishing a companion site.
The following Ninth Work Plan investigations continued into the current reporting period:
This MOU and subcontract were also awarded funding to conduct the following Ninth Work Plan investigation:
Note: The schedule for 9ATR1 has been modified. The schedule and methods for 9FFR2 were modified. The methods for 9ADR3 were modified. Revised schedules and methods appear in the Addendum to the Ninth Work Plan. The investigations listed above were collaborative projects between OSU and Auburn University (AU). The study 9FFR2, "Fish yields and economic benefits of tilapia/Clarias polyculture in fertilized ponds receiving commercial feeds or pelleted agricultural by-products," was a collaborative project among OSU, AU, and the University of Arkansas at Pine Bluff (UAPB; under Subcontract No. RD010A-13). The following report submitted by OSU and AU addresses objective 1, locally available and lower-cost feeds. The 9FFR2A report submitted by UAPB addresses objective 2, the relative contribution of natural food (see p. 59). 9FFR6 was approved after the publication of the Addendum to the Ninth Work Plan. The work plan for this investigation will appear in the Second Addendum to the Ninth Work Plan.
Among their regional outreach activities, the Kenya Project researchers had contact with the director of the Uganda Wetlands and Resource Conservation Association (UWRCA) to discuss the possibilities for training for Ugandans in aquaculture at Sagana. They also met with George Onyango, the Task Coordinator of the Lake Victoria Environmental Management Programme (LVEMP), to discuss issues concerning the strengthening of extension services.
Bowman and other Kenya Project participants made new contacts at the Forum for Organic Resource Management (FORMAT) when they presented a paper titled "The Use of Organic Resources in Research and Development Activities." They also established a relationship with the German Development Service (which supports the Sagana Jua Kali Association) when they provided information on integration of fish farming with other agricultural activities.
The Sagana researchers have developed a linkage with the University of Nairobi's Department of Hydrobiology for doctoral studies on Labeo by staff member Dorothy Ogony.
CRSP researchers communicated with the Museums of Kenya regarding a student who was studying killifishes through Luc de Vos. The researchers also utilized Moi University's departments of Agriculture and Chemistry when giving student demonstrations of some analyses for which the Sagana laboratory is not equipped.
Liti and Fisheries Officer Raphael Mbaluka visited several reservoirs in Kitui District, Eastern Province, to assess the awareness of the community regarding fish farming. Following the visit they received requests to have some of the reservoirs stocked. CRSP researchers stocked Karia Reservoir, which is run by the local community, with fingerlings and gave an on-site seminar on the role of fish in protein supplementation.
The researchers have also presented demonstrations on the processing and preparation of fish, e.g., gutting and cooking, for the Ruthagati community in Nyeri District.
CRSP researchers helped Sagana Women's Group in the construction and management of fish ponds, and they have provided them with information on feeding practices.
At the World Aquaculture Society (WAS) Annual Conference in Orlando, Florida, Gitonga established contact with Peter Edwards of the Asian Institute of Technology (AIT), Thailand, and discussed possibilities for future training of Kenyan Fisheries Department personnel at AIT. She and Ngugi also met with CRSP researcher Kevin Fitzsimmons (University of Arizona) during the WAS conference to discuss possible future collaboration on training for Eritrean students. Such training could include components at Sagana Fish Farm as well as the University of Arizona.
Mugo, Mac'Were, Veverica, and Fisheries Officer George Owiti visited Western Kenya in December 2000 to view fingerling production sites for a CRSP investigation and a pond construction site of one of the trainees. During the trip, the group collected endemic killifishes (Notobranchius spp.) along the roadside. The fish were taken to Moi University for identification and follow-up work, as well as to Sagana where Mugo made observations on spawning and egg hatching.
Sagana received visits from various officials, academics and others, including:
Liti presented lectures to students from the University of Nairobi and Moi University at Sagana during August and October 2000. He discussed phytoplankton dynamics in Sagana fish ponds and their role in fish nutrition and water quality management, methods available for managing the prolific breeding of O. niloticus (e.g., production of monosex population through hand-sexing and sex reversal), and the role of fertilizer and supplementary feeds in fish production.
Amadiva and Fulanda made a presentation in a workshop organized by the Forum for Organic Resource Management and Agricultural Technologies (FORMAT) held 19 to 21 September 2000 in Village Market, Nairobi.
Liti and Gichuri arranged a seminar at Sagana for Moi University students from 31 September to 2 October 2000. The discussions centered around common diseases and parasites in warmwater fish, fertilization and supplemental feeding as strategies for increasing fish production, and different methods used in seed production of Clarias gariepinus and O. niloticus at Sagana.
Fulanda presented a seminar at Sagana met with agriculture/aquaculture extension agents from Embu District, Kenya (Eastern Province), on 3 November 2000 to provide them with information on general aspects of fish farming.
Sagana provided local schools with information pertinent to their National Examinations. The researchers hosted institutions ranging from primary schools to universities, and visited the site between August and November 2000. The average attendance for a visit was 30 students and teachers.
Two Austrian students from the University of Technology, Vienna, and the University of Agriculture, Vienna, conducted research related to masters degrees at Sagana between May and August 2001. They worked under the supervision of Liti and their Austrian advisors, who visited Kenya briefly between May and July 2001.
Mwau, P., 2000. Nutrient dynamics with special reference to nitrogen and phosphorus in tilapia (Oreochromis niloticus)/catfish (Clarias gariepinus) polyculture ponds at Sagana Fish Farm, Central Kenya. M.S. thesis, University of Nairobi, Nairobi, Kenya.
Liti, D., E. MacWere, and K. Veverica. Growth
performance and economic benefits of Oreochromis
niloticus and Clarias gariepinus polyculture in fertilized
tropical ponds. Poster presented to the Aquaculture
America 2001 at Orlando, Florida, 2125 January 2001.
Veverica, K., D. Mirera, and G. Matolla. Optimization of phosphorus fertilization rate in freshwater tilapia production ponds in Kenya. Presented to Aquaculture America 2001 at Orlando, Florida, 2125 January 2001.
Aquaculture America 2001 at Orlando, Florida,
2125 January 2001. (Bowman, Gitonga, Liti, Ngugi, Veverica)
PD/A CRSP Annual Meeting at Orlando, Florida, 26 January 2001. (Bowman, Gitonga, Liti, Ngugi, Omolo, Veverica)
An experiment was conducted for 180 days at Sagana Fish Farm, Kenya, to evaluate the performance of two formulated pellet feeds and a locally available rice bran. A polyculture of Oreochromis niloticus and Clarias gariepinus in fertilized tropical ponds was used. Twelve 800-m2 ponds were used, and each pond was limed at a rate of 20,000 kg ha-1 and stocked at a rate of 19,375 ha-1 with sex-reversed male O. niloticus and 625 ha-1 with C. gariepinus. The fish were fed daily at a rate of 2% body weight. Two formulated diets were compared with rice bran in three treatments that were replicated four times. The composition of the diets was as follows: Pig finisher pellet (PFP): crude protein 12.5%, lipids 10.9%, crude fiber 15.1%; Rice bran (RB): crude protein 6.5%, lipid 10%, crude fiber 37.9%; Test diet pellet (TDP): crude protein 12.5%, lipid 13.1%, crude fiber 14.1%. Diammonium phosphate (DAP) and urea were used at rates of 8 kg P ha-1 wk-1 and 20 kg N ha-1 wk-1, respectively. After one month urea input was reduced from 2.7 to 2.2 kg pond-1 to allow for the nitrogen contributions from the feed and to maintain the inputs at 35 kg N ha-1 wk-1 in the ponds. Water quality analyses showed no significant differences (P > 0.05) among treatments in the parameters measured. Exceptions were alkalinity, pH, and dissolved oxygen (DO), which were significantly (P < 0.05) different among treatments. The lowest dawn DO level (0.9 mg l-1) was recorded in the PFP treatment, while the highest afternoon value (9.9 mg l-1) was recorded in the RB treatment. The lowest pH value of 7.9 was recorded in PFP, while the highest value (8.3) was recorded in the RB treatment. The overall range of monthly mean total alkalinity was 98.0 to 118.8 mg CaCO3 l-1, and the lowest value was observed in the RB treatment. The phytoplankton community was dominated by green algae in the beginning of the culture period but later by the blue-greens towards the end of the experiment. The overall mean diversity index of phytoplankton was 0.7, and values were not significantly different (P > 0.05) among treatments. Gross primary production ranged from 0.1 to 11.5 g C m-2 d-1. However, the values were also not significantly different (P > 0.05) among treatments. The RB treatment gave significantly (P < 0.05) lower values in fish growth rate and annualized net fish yield (0.69 g d-1 and 5,000 kg ha-1, respectively) than both PFP (1.17 g d-1 and 9,298 kg ha-1, respectively) and TDP (1.15 g d-1 and 8,828 kg ha-1, respectively). The feed conversion ratio was highest in the RB treatment. There were no significant differences (P > 0.05) in survival rates and relative condition factors among the treatments. Profitability analysis by using partial and enterprise budgets revealed that locally available pig finisher pellets were the most profitable followed by rice bran at the local market price of US$1.17 kg-1 fish. At a higher price of US$1.56, PFP would still be the best choice, followed by TDP, while RB would be the least profitable. The net returns were positive for all the treatments. However, RB had the lowest break-even price and the least investment cost.
A series of five highly successful short courses was conducted by the Kenya Project of the PD/A CRSP for Kenya Fisheries Department personnel during the period of the Ninth Work Plan. Activity leaders responsible for planning and carrying out these short courses felt constrained by a lack of training materials relevant to the aquaculture situation in Kenya. Although they were able to develop some materials and to borrow others for use in these courses, they did not have teaching modules specifically suited to Kenya on topics such as pond construction, composting, pond production of mixed-sex tilapia, fish nutrition, or production by species, all of which are key for the type of training currently needed in Kenya.
This activity was proposed to begin work on the development of such training modules. A faculty member from the Moi University Department of Fisheries spent eight weeks at Auburn University, Alabama, while beginning to develop training modules for use in future training sessions in Kenya. Three complete modules were developed, and work on nine others was begun. A digital camera and a new computer, to be used for continued work on module development back in Kenya, were provided. Over 1,800 slides and photographs suitable for use in training courses were digitized and saved to disk for further work in Kenya. While in the US, the participant was also able to attend and participate in the annual conference of the World Aquaculture Society (Aquaculture America 2001) and the Annual Meeting of the PD/A CRSP, as well as to visit commercial fish-farming operations in western Alabama. This activity was conducted between 16 January and 15 March 2001.
Research conducted by the PD/A CRSP at Sagana Fish Farm has begun to identify alternative management practices and technologies that may be suitable in the region, but it should not be assumed that results obtained under controlled experimental conditions at Sagana are directly transferable to farms in the area. On-farm testing is therefore a logical step in transferring research-based technologies to the farm. On-farm testing of various alternatives allows farmers to assess their costs and benefits under local conditions as well as to receive instruction and training in basic pond management skills. Such trials also allow project personnel to work with and train the fisheries extension officers who are involved in the trials at the various locations, thus complementing the training they receive through "regular" training activities.
Thirty farmers were selected to participate in on-farm trials in four districts in Central Province and one in Eastern Province, Kenya, in 1999 and 2000. A pre-trial workshop including farmers, extension agents, Kenyan and US CRSP personnel, and students working on research projects at Sagana was held in December 1999 to discuss and select management schemes for testing, to agree on how the trials would be conducted, and to plan for proper record keeping during the trial period. Fifty-two ponds were stocked with monosex male tilapia (Oreochromis niloticus), mixed-sex tilapia, and/or catfish (Clarias gariepinus) between January and March 2000. Stocking densities were 2 fish m-2 for tilapia, 0.2 fish m-2 for catfish stocked with tilapia, and 1 fish m-2 for catfish stocked alone. Management schemes tested included high, medium, and low management levels. Ponds were sampled for fish growth at four- to six-week intervals, and farmers kept records of input type and weight, input costs, pond water additions, fish mortality, and fish sampling data. A post-trial workshop was held in March 2001 to summarize and evaluate the results of the trials. As a result of their participation in these trials, farmers learned that improved management can indeed lead to increased production, something that they were not convinced of prior to the trials. The average increase in fish harvested during these trials was 330% (3.5 T ha-1, as compared with an estimate of just over 1 T ha-1 prior to the trials). Almost two-thirds of the ponds gave net revenues exceeding 250,000 KSh ha-1 yr-1; the average being 310,832 KSh ha-1 yr-1. Farmers also concluded that increasing the sizes of their ponds would further contribute to increases in production.
Phase two of the trialsin the western region of Kenyabegan with a visit to the six districts' headquarters in December 2000. In May 2001 a pre-trial farmers workshop was held at the Bungoma Farmers Training Center to discuss and select management options suitable to the farmers. Ponds for the western region trials were stocked in May and June, and the first sampling visits were conducted in August. The trials are ongoing as of this report. As in Central and Eastern provinces, a post-trial workshop will be held to evaluate the results of these trials.
Lack of technical training has been cited as a major reason for the low output of fish ponds in Kenya. The lack was observed at all levels, from the lowest-level extension agent through university levels. The training program undertaken by the Kenya Project in Kenya seeks to improve training and to provide a cadre of trainers who have extensive practical fish-production experience.
This year the Kenya Project continued scholarship support for two M.S. students, one at Moi University's Chepkoilel Campus, Eldoret, Kenya, and the other at Auburn University, Alabama. Small stipends for student research conducted at Sagana Fish Farm have allowed undergraduate as well as graduate-level university students to remain longer to complete projects and gain valuable field experience.
The series of short courses for personnel of the Kenya Fisheries Department (FD), begun in 1999 and 2000, was concluded this year with the fifth and final course planned under this activity. In this series of courses, more than 80 FD staff received two weeks of training in pond construction methods and pond management techniques, and an additional 26 persons (24 Fisheries Officers and 2 outside-funded participants) received three weeks of advanced training in pond construction, pond management, and business planning. Additional farmer field days for approximately 50 farmers are also planned for later in 2001.
The establishment of companion sites was proposed as a way of expanding CRSP efforts in each region by assisting with needed research at sites other than CRSP host country sites and verifying the results of CRSP research at its host country sites. For the Ninth Work Plan the Kenya Project set out to identify and establish at least one companion site in the Africa region and to design and implement investigations at that site in support of the goals and needs of both the PD/A CRSP and the companion site. Discussions in 1999 between CRSP Kenya Project personnel and ICLARM-Malawi (Zomba, Malawi) and Bunda College of Agriculture (near Lilongwe) led to an agreement to collaborate. With oversight from Daniel Jamu, Director of ICLARM-Malawi, two studies were conducted between May 2000 and January 2001, one at the National Aquaculture Center near Zomba, and the second at Bunda College, Lilongwe. Reports on these two studies, are included in this volume (See 9ADR4A, "Effect of Stocking Size and Nutrient Inputs on Productivity of Oreochromis shiranus in Ponds," and 9ADR4B, "Studies on Potential Use of Salinity to Increase Growth of Tilapia in Aquaculture in Malawi." An additional spin-off study conducted by a Bunda College student, "Tilapia rendalli Fry Production under a Tilapia rendalli/Oreochromis shiranus Polyculture: The Role of Competition and Predation," may be requested from the Program Management Office.
A study to investigate the effects of three different stocking sizes (5, 10, 20 g) and two isonitrogenous input regimes (maize bran × urea and napier grass × urea) on the production of Oreochromis shiranus was conducted between June and November 2000 at the Malawi National Aquaculture Center. Six treatments (three stocking sizes × two input regimes), each in triplicate, were used in the study. Inputs were applied to ponds stocked with fish at the three stocking sizes such that each input regime supplied 20 kg N ha-1 wk-1. Fish were stocked at 2 fish m-2 and sampling (mean weight of 100 fish) was conducted biweekly. Water quality parameters (dissolved oxygen, pH, electrical conductivity, and Secchi disk visibility) were measured weekly, and total ammonia nitrogen and chlorophyll a were measured biweekly. The experiment was conducted over a period of 150 days.
The two isonitrogenous input regimes did not significantly affect fish net yield and growth rate. There were significant differences (P < 0.05) in fish growth rate and net yield between treatments. The highest fish growth rates and production (net yield) were achieved in ponds when fish were stocked at 5 g and either input regime was used, while ponds stocked with 20-g fingerlings and supplied with either napier grass × urea or maize bran × urea had the lowest net mean yield. There were significant differences (P< 0.05) in gross margins between treatments, with treatments where fish were stocked at 5 g and napier grass × urea were applied giving higher gross margins than the rest of the treatments. Mean fish survival rate was not significantly different between treatments. Results from this study suggest that stocking Oreochromis shiranus at 5 g results in higher fish production and gross margins compared to stocking larger fish. The results further show that under conditions where inorganic fertilization is used, substituting napier grass for maize bran increases profitability without affecting overall fish yield.
In a series of studies conducted in Malawi to determine the effects of different salinity concentrations on survival, growth, feed conversion, reproduction, and whole-body composition of five taxonomic groups of tilapiaOreochromis shiranus chilwae (Lake Chilwa strain), O. shiranus chilwae (Bunda College strain), O. karongae, O. shiranus shiranus, and Tilapia rendalliit was observed that the first three species grew faster in 10 salinity and would be recommended as potential candidates for brackishwater aquaculture in Malawi. T. rendalli and O. shiranus shiranus grew faster in fresh water (0 salinity) and are unsuitable for brackishwater aquaculture. With the exception of O. shiranus chilwae (Lake Chilwa strain) and O. shiranus chilwae (Bunda College strain), all species had lost carcass protein at the end of the study, suggesting that they used tissue protein as an additional energy source for osmoregulation and homeostasis. Salinity tolerance varied ontogenetically in almost all the above taxonomic groups, with younger individuals tolerating salinity longer than larger individuals. This study has also shown that the range of T. rendalli and O. shiranus shiranus would effectively be limited by salinity. The interactive effect of salinity and water temperature was not investigated in this study since all experiments were conducted at room temperature and ambient photoperiod. Temperature, however, has an influence on salinity tolerance, and in that light, we strongly recommend further investigations on the combined influence of the two abiotic factors (salinity and temperature) since they fluctuate together in nature, and their fluctuations may positively or negatively influence growth and reproductive performance of the above cichlids.
The goal of the Kenya Project's regional outreach activity has been to promote contact and communication among aquaculture research and extension personnel and organizations throughout the region. This was originally intended to be achieved mainly through participation at regional meetings and conferences, not only by presenting papers but also through participation in planning and organizing the meetings. It was hoped that such participation would help promote the dissemination of information emanating from PD/A CRSP research, help conference participants learn about fish culture practices and research priorities and activities in Kenya and in neighboring countries, and encourage the establishment of regional linkages among research and extension programs in the region. Several CRSP participants attended the Annual Conference of the World Aquaculture Society and the Annual Meeting of the PD/A CRSP in Orlando, Florida, in January 2001. This was followed by visits to research facilities at Auburn University and commercial operations in West Alabama.
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