|PD/A CRSP Twentieth Annual Administrative Report
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MOU No. RD009A
Oregon State University, Corvallis, Oregon
|James R. Bowman||US Principal Investigator|
|Christopher Langdon||US Principal Investigator|
|Tom Popma||US Principal Investigator (through September 2001)|
|Karen L. Veverica||US Principal Investigator|
|Nancy Gitonga||Host Country Principal Investigator|
|John Kinyanjui||Host Country Research Associate/Head of Station, Sagana Fish Farm (through January 2002)|
|Bethuel Omolo||Host Country Research Associate/Head of Station, Sagana Fish Farm (from January 2002)|
|Mucai Muchiri||Host Country Principal Investigator|
|Charles C. Ngugi||Host Country Principal Investigator|
|Rachel Kamau||Graduate Student (from May 2002)|
|Norman Munala||Graduate Student (from May 2002)|
|Daniel Omwansa||Graduate Student (from May 2002)|
|John Rauni||Graduate Student (from May 2002)|
|James Bundi||Undergraduate Student (Partially CRSP funded)|
|Daniel Ochola||Undergraduate Student (Partially CRSP funded)|
|Geoffrey Mwangi||Undergraduate Student (Partially CRSP funded)|
|Emmy Amwayi||Undergraduate Student (Partially CRSP funded)|
|Joseph Onyango||Undergraduate Student (Partially CRSP funded)|
The following Ninth Work Plan investigations were completed in the reporting period:
This subcontract was awarded funding to conduct the following Tenth Work Plan investigations:
Note: 10PDR3 and 10NSR5 commenced in Year 2 of the Tenth Work Plan. The published work plans appear in the forthcoming Addendum to the Tenth Work Plan.
MacWere, E., 2002. Comparison of tilapia and Clarias polyculture yields and economic benefits resulting from a locally available animal feed (pig finisher pellet), agricultural by-product (rice bran), and a pelleted test diet in fertilized ponds. M.S. thesis, Moi University, Eldoret, Kenya.
Ngugi, C., J. Macharia, and J. Rasowo. Comparative study of hatching rates of catfish eggs on different substrates. Presented to First National LVEMP Scientific Conference at Nairobi, Kenya, 1519 October 2001.
Ngugi, C., J.O. Manyala, and T. Mboya. Fish introduction and their impact on the biodiversity and the fisheries of Lake Victoria. Presented to the First National LVEMP Scientific Conference at Nairobi, Kenya, 1519 October 2001.
Aquaculture America 2002 at San Diego, California, 2730 January 2002. (Bowman, Gitonga, Langdon, Muchiri, Veverica)
PD/A CRSP Annual Meeting at San Diego, California, 31 January 2002. (Bowman, Muchiri)
Africa Regional Expert Panel Meeting at Nairobi, Kenya, 8 July 2002. (Gitonga, Muchiri, Ngugi)
Sixth Central American Symposium on Aquaculture at Tegucigalpa, Honduras, 2224 August 2001. (Popma)
Research conducted by the PD/A CRSP at Sagana Fish Farm has identified 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. It also allows project personnel to work with and train the fisheries extension officers, complementing the experience the extension officers gain through formal training activities.
On-farm trials were conducted in two phases in two different parts of Kenya. Thirty farmers were selected to participate in the trials in Central Province and Eastern Province, Kenya in 1999 and 2000. A pre-trial workshop was held in December 1999 to discuss and select management schemes for testing. 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 2.0 fish m-2 for tilapia, 0.2 fish m-2 for catfish stocked with tilapia, and 1.0 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. 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 annualized revenues (NAR) exceeding KSh 250,000 ha-1 yr-1; the average was KSh 310,832 ha-1 yr-1. Farmers also concluded that increasing the size of their ponds would contribute to increases in production.
In western Kenya (Rift Valley and Western Provinces), 28 ponds were stocked following pre-trial workshops. Twenty-one of these had harvested their fish and five remained to be harvested by the time of the post-trial workshop (two ponds that had dried up during the course of the trials were eliminated). Five ponds had gross annualized production of less than 5.0 t ha-1 yr-1, but the overall average was 7.4 t ha-1 yr-1. Yields from this trial were 163 to 873% higher than yields reported for the year proceeding the trial. The average increase was 420%. Net annualized revenue (not counting fingerling costs) averaged KSh 487,270 ha-1 yr-1, which was higher than for the Central and Eastern Provinces. Seventy-six percent of the ponds netted over KSh 250,000 ha-1 yr-1. When fingerling costs were included, average NAR was KSh 431,368 ha-1 yr-1. Although farmers had not kept detailed records of their expenditures during previous years, many of them claimed enormous increases in net revenues because they had never made money from their fishponds before. Better results, compared to previous fish yields, were achieved by 80% of the farmers who participated in the trials.
These trials have helped farmers and extensionists to gain a better understanding of pond management. Application of feed and fertilizers stood out as the most important management technique learned by the farmers. According to participating farmers, at least 1,000 people in each of the two regions got to know about the trials. In the region containing the Central and Eastern Provinces, 28 new ponds had been constructed and 31 new farmers had reportedly begun growing fish during the time of the trials. In the western region, 24 new farmers reportedly began culturing fish during the trial period.
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. This training program, undertaken under the Ninth Work Plan by the PD/A CRSP Kenya Project, has sought to improve training and to provide a cadre of trainers who have extensive practical fish production experience.
Full scholarship support was provided for two M.S. students under this activity, one at Moi Universitys Chepkoilel Campus, Eldoret, Kenya, and the other at Auburn University, Alabama. Stipends were provided to allow graduate and undergraduate university students to work at Sagana Fish Farm to conduct thesis research and gain valuable field experience, and a small research project program has allowed the station staff to further their professional development and carry out their own research, which is expected to have a positive impact on station management.
A series of five short courses for personnel of the Kenya Fisheries Department (FD) was begun in 1999 and concluded in 2000. In the first four sessions of the series, more than 80 FD staff received two weeks of training in pond construction methods and pond management techniques, and in the final session an additional 26 persons (24 fisheries officers and two outside-funded participants) received three weeks of advanced training in pond construction, pond management, and business planning.
Following requests from farmers, a program of farmer education days was developed to complement the short-course training undertaken in this activity. During the first half of 1999, five farmer education days were held in which 107 farmers and 40 extensionists participated. All districts in the Central Province were covered, and one district each from the Eastern and Rift Valley Provinces was included. The farmer education days were continually improved, following feedback from farmers. A one-day farmer field day, sponsored by the World Bank (Lake Victoria Management Project), was held in April 2002 in which 20 fish farmers from Kisumu District were trained in pond construction and management techniques. Four additional farmer field days for 31 farmers, including fisheries extension workers, were conducted at Moi University and at Sagana Fish Farm in August 2002.
This activity was undertaken at the request of the Kenya Fisheries Department to provide in-service training for Kenyan fisheries officers and to support Kenyan university students in graduate and undergraduate aquaculture programs. Fisheries officers need in-service training to learn about pond design and construction and about current aquaculture techniques so that they can transmit this information to fish farmers. Selected university students receive support for more in-depth aquaculture studies; some of them will become fisheries officers and fill the extension role in the future. The training activity was planned for one year, beginning on the first of May 2002 and concluding on 30 April 2003.
Support for four graduate students began in May 2002, when they enrolled at Moi Universitys Chepkoilel Campus in Eldoret, Kenya to begin their studies. These students are currently involved in coursework and in developing their research proposals; at least two of them will be conducting aspects of the Clarias fingerling production research described in another PD/A CRSP investigation (see Techniques for the production of Clarias gariepinus fingerlings as baitfish for the Lake Victoria Nile Perch Longline Fishery, 10NSR5, facing page). In addition, five undergraduate students have received stipend support for aquaculture work conducted in association with their special projects. Three three-week training sessions for fisheries officers will be conducted under this activity. The first was scheduled for 12 to 31 August 2002 in Eldoret, while the second and third sessions will be conducted in mid -November 2002 and by April 2003, respectively. These courses focus on pond design and construction and on pond management techniques and business plan preparation for commercial aquaculture.
Clarias gariepinus is widely distributed throughout Africa, is highly valued as a food fish, and has a high potential for aquaculture. It has also become increasingly important as a baitfish in the Lake Victoria Nile Perch Fishery, which is of enormous economic importance in Kenya, Uganda, and Tanzania because of its foreign currency earnings and the employment it provides for people near the lake. The annual demand for fingerlings has been estimated to be between 1.5 and 15 million. Fishers have traditionally captured C. gariepinus fingerlings from Lake Victoria for use as bait using small-mesh beach seines and mosquito nets, but beach seining is highly destructive to the spawning habitats of native cichlids and is illegal. The development of practical pond production methods for C. gariepinus fingerlings could contribute to the supply of bait fish for lake fisheries and help protect spawning habitats, while at the same time providing a highly profitable business for fish farmers. Spawning of C. gariepinus is easily performed with simple hatchery techniques, but further work is needed to increase survival during the fry-to-fingerling stage using methods that do not require electricity or high levels of inputs. Basic studies on larval stocking densities, provision of shade in rearing ponds, and length of grow-out period are also required.
The objective of this particular set of experiments is to determine the effects of a shading regime, larval stocking density, and larval grow-out period on the production of C. gariepinus fingerlings in earthen ponds. Each set of experiments will be conducted in 12 to 24 ponds of 100 to 150 m2 in area. Initial fertilization will be with urea and diammonium phosphate at 10 kg N ha-1 and 4 kg P ha-1 plus cow manure at 500 kg ha-1, applied two days prior to stocking; repeat doses will be applied at the initial dose on days 7, 14, and 21. Trout feed (36% protein) will be added twice daily at a rate of 10 kg ha-1 d-1 beginning on the fourth day. Treatments in the pond shading experiments are expected to be 25, 50, 75, and 100% coverage of the pond surface using cut sedges. For the stocking density and grow-out period experiments, larvae will be stocked at three densities (20, 50, and 100 larvae m-2) for two different grow-out periods (21 and 42 d) in a 3 x 2 factorial design with three or four replicates per treatment. Supplies for this research are currently being acquired, and test runs will be conducted from August through October; in-pond research is expected to begin by December 2002.
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