Rwanda Aquaculture, Eugene Kaplan, January 19, 2002

Rwanda Aquaculture

An Assessment of Three Tilapia Farms in Rwanda

As an ancillary responsibility of my participation in a USAID/CIDCM, I examined the potential for tilapia culture in Rwanda as exemplified by three farms:

the National Research Facility at Rwasave (the research facility of the National University of Rwanda),
a large private farm at Kigembe, Gone Fishin', operated by an American, Chris Thorne,
the cage farm of the “Pecheurs de Lac Kivu.” This farm was not physically examined by me. I participated in an evaluation session of the potential for a follow-on grant for the project at USAID headquarters in Kigali, in which the farm was described.

THE PHYSICAL ENVIRONMENT

Rwanda is a small landlocked republic in central Africa located on the Equator. It lies on the eastern rim of the Albertine Rift, a western arm of the Great Rift Valley. The climate is moderate, rarely reaching above 22 degrees C, or falling below 15 degrees C. This is due to the largely mountainous nature of the topography. For this reason the country is nicknamed “The Land of a Thousand Hills.”
The largest lake in this landlocked country is Lake Kivu. There are many other lakes. These are usually irregular, taking the shape of the valleys in which they lay. Some of the larger lakes are Butera, Ruhondo, Muhazi and Mugasera.
The nation is the most densely populated in Africa, with intense cultivation on every surface, even almost vertical mountainsides. The overutilization of farmland suggests that fish farming will fill an important niche in this country.
The climate is moist. Most parts of the country receive more than 1000 mm of precipitation.

POLITICAL HISTORY AND DEMOGRAPHY

Rwanda was colonized by Germany in 1890. It was mandated to Belgium following WWI, and was granted independence in 1962. Following a period of political instability and scheming, a genocide was planned and instigated by the president, a member of one of the two dominant tribes. A civil war broke out in 1994, in which the planned genocide of one tribe was attempted. With the World inattentive, about one million Rwandans were systematically killed, and the national infrastructure wrecked. Two million Rwandans emigrated, leaving the nation without a base of technologists. Following a war crimes tribunal in Arusha, in 1995, the country has remained stable, with some incursions from the Congo in the North.
At the time of this visit efforts to repair the economy appear to have borne fruit, and signs of the previous devastation are rare. The national spirit appears to be upbeat. The National University of Rwanda remains as a beacon of hope. It is a thriving institution with a modern, extensive campus.

AQUACULTURE

The research station at Rwasave consists of 108 half-hectare/hectare ponds and an office facility, a classroom and storage facilities. A relatively sophisticated laboratory has the capacity to analyze nutrients with old generation automated analysis equipment. An ancillary laboratory is designed for plankton analysis. A building is devoted to breeding. Masculinization of tilapia is accomplished by the 17-methyl testosterone method, and breeding of Clarias is initiated by injection of whole pituitary glands harvested from live Clarias.
A number of broodstock and fingerling growout ponds are operational. It seemed to me that about 7 growout ponds are functional.
Experiments with food development are given priority. To date fertilization of ponds is the dominant method of enrichment. Azolla-based crumble has been studied. There is evidence that a formulation of blood meal and local materials has been developed at Rwasave and used for hand pelleting by the Pecheurs de Lac Kivu, a fisherman's cooperative. It has not yet been analyzed.
A three-man staff of scientists operates the facility:

Dr. Jean-Bosco Gashagaza, director
Dr. Canisius Kanangire, head scientist
Simon (?) M.A., administrator

Dr. Gashagaza, an affable man, has many years of research and consultation experience with tilapia farming in Rwanda.
Dr. Kanangire, a recent Ph.D. is a research-oriented scientist who won a million Rw F prize for his research, awarded by NUR. His specialty is fish nutrition.
Simon (?) seems to supervise the day-to-day operation of the farm.

It is my impression that the Rwasave experimental farm is operating at a low level due, I must assume, to lack of funding.

Kigembe Farm “Gone Fishin'”;

This commercial farm was designed to be a profitable enterprise. The design is based on the Chinese terrestrial animal-based enrichment technique, whereby animal wastes fall directly into the ponds from cages and enclosures placed over or near the ponds. The farm is well designed. Water flow is maintained by diverting a permanent stream, and is substantial, at least at the end of the rainy season when I visited. Water is silty, and when deemed too opaque, is diverted to upper ponds which act as settling tanks. Valve design is efficient. Water flow seems to be at an adequate exchange rate.
A report by a consultant, Adeke Benoit, written in 2000, indicates that oxygen levels in the ponds are high (ca. 8ppm). It is not clear whether the measurements were taken in functioning production ponds or in unused ponds.
Benoit and Moehl (Ph.D. thesis, 1993) mention that although temperatures rarely reach above 22 degrees C, and are far from the optimal 28 degrees C, production is not substantially affected. It is likely that growth rates are adequate because stocking rates are low, although Thorne projects harvest rates of 22,500 kg/ha/8 mos and 30,000 kg/ha/6 mos.
Thorne will attempt 4 month growout of 450-500g tilapia. (It seems that this size is acceptable in the market.) His business plan appears to be excellent. His experience as an administrator should result in an entrepreneurial approach altogether lacking in government-operated farms.
Unfortunately Mr. Thorne's farm is severely underfunded. A loan of $250,000 US is needed immediately, otherwise it is likely that the farm will fail. IT IS THE OPINION OF THIS OBSERVER THAT THE FARM IS WELL CONSTRUCTED, WELL RUN AND OPERATIONAL. A LOAN WILL MAKE THE FARM SUCCESSFUL. What Mr. Thorne lacks in formal training in pisciculture, can be made up by advice from the Rwasave farm on an extension service level. The farm is fully operational, but lacks funding for fish food, labor, debt repayment, etc.

The “Pecheurs de Lac Kivu” Cooperative cage farm

This farm was developed in response to a drastic drop in production in Lake Kivu and was instigated by the fishermen. The plan is to fence off several embayments and place enclosures and cages in them. Depths beneath the cages are approximated at ca 5m. This depth should prevent anoxia from bacterial activity beneath the cages, but just barely. The cool temperatures in the lake, which lies at about 1500m altitude, should slow down decomposition beneath the cages.
The Rwasave research station has provided a formula for pellet production, and a hand pelleter is used to prepare the food. The president of the cooperative reports growth rates of 10g - 500g in 4 mos. I feel that these values represent optimal growth rather than mean growth, especially since the fish population appears to be mixed sex.
The proposal made to USAID is for enclosure of a further embayment for fingerling production. I suggested utilization of HAPAs.

COMMENTS AND RECOMMENDATIONS

Rwanda was the site of a USAID/CRSP project until 1994, which performed considerable research. The civil war negatively affected these efforts and the trauma has not yet worn off. Several workers with CRSP were killed. My examination of the situation in Rwanda reveals a vigorous effort to sustain fish farming in that nation. Over a thousand artisanal fish farms exist. I hope that CRSP will renew its interest in Rwanda and build on its former effort .

I recommend:

The exploration of other fish species possibly more suited to the climate, eg. European or Indian carp, silver carp, etc. Potential polyculture species include tilapia, bighead carp, European carp, and silver carp. ( It is possible that silver carp may be an acceptable food to Rwandans, and its niche as a blue-green algae eater makes it desirable as a water quality maintainer). It seems to me that Clarias farming has not been accepted on a large scale in Rwanda, although it holds much promise.
The introduction of a fast growing tilapia species/strain suited to cool Rwandan temperatures. The GIFT strain of niloticus developed by ICLARM in the Philippines may be suited to the climate.

The author has experimented with O. aureus from Lake Manzala in northern Egypt and found it to grow at a faster rate than a strain of niloticus at less-than-optimal temperatures.

An attempt to recruit the current chicken feed factory to manufacture pelleted feeds should be made. It will be necessary to encourage the factory to purchase an extrusion machine and a pelleting machine. Binder is necessary. Above all, the proper formulation will be needed. The Rwasave station can provide formulation and analysis, but not prices. Fish and chicken feed producers in Belgium have the computer capacity to prepare cost-benefit analyses of different formulations. The use of pelleted feed will permit more intensive fish farming and higher profits for large commercial farms which may supplant or coordinate activities with the artisanal farmers. In Jamaica, for example, large tilapia producers provide pelleted food and fingerlings to small farmers and then buy back the product when it reaches market size.

The author has succeeded in the above effort in Cote D'Ivoire. Over time pelleted food can be achieved in Rwanda.

Cage farming is an alternative useful to developing nations. The numerous deep lakes in Rwanda provide an opportunity to explore this option.

Respectfully submitted,

Eugene Kaplan, Ph.D.
Axinn Distinguished Professor of Conservation and Ecology emeritus
Director, Hofstra University Marine Laboratory emeritus
Director, Hofstra University Aquaculture Program
January 19, 2002

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