The authors estimate that during the year preceding the survey, fish farmers interviewed produced just under 7 tons of tilapia in their fish ponds, taking into account major harvests as well as intermittent harvesting. In those households where ponds were operational, this was equivalent to about 6.6 kg (landed weight) of fish per individual per year. This is slightly less than half the average quantity of fish available per person per year for the world as a whole. Each household harvested just under 60 kg during the year, from an average of almost 1 400m2 of pond(s). The physical productivity - about 4.3kg/100m2 per year equivalent - was low.
Extending the results of the above survey to the 1 418 farmers who have fish ponds in the North-Western Region (DoF, Dec. 1988), the farmed tilapia production should have reached about 50 tons during 1988, based on estimated productivity (4.3 kg/100m2/year).
This estimate is arrived at by:
assuming that the ratio between active and former farmers is the same in the Province, as in the sample;
assuming the average productivity in kg per area per year to be the same in the Province as in the sample
Table 2.1: Production in the Province 1988 (DOF)
| No. of Farmers | No. of Ponds | Total area of ponds (ha) | Total fish production in ponds (t) | |
|---|---|---|---|---|
| Solwezi | 195 | 301 | 14.9 | 6.95 |
| Kasempa | 28 | 135 | 3.5 | 2.3* |
| Mwinilunga | 1 195 | 2 189 | 108.6 | 15.72 |
* Extrapolation from a harvest of one pond only
In addition, capture fisheries from streams and rivers, particularly the Zambezi, provide substantial amounts of fish, most of the harvests remaining unrecorded. Dried fish from Zambezi is commonly sold in other parts of the Province.
Another 50 tons of fish (DoF, Solwezi) are cultured commercially by Kanzandi Mine outside Solwezi.
The ponds are earthen and supplied with water from streams or rivers through gravity flow. Three out of four ponds can be drained. Excess water is either diverted or flows via an outlet in the pond back into the river. Occasionally the fish culture activity is done in conjunction with irrigation of small garden plots. Scarcity of water for fish farming is rare in the province.
While almost all farmers report that they use fertilizers, feed or both, a few practise integrated fish farming with domestic animals. One reason is that ponds are not in the immediate vicinity of the homestead, making it difficult to watch the animals to prevent thefts and predation. The introduction of exotic species (e.g. Peking Duck) for integrated farming in the beginning of the ICARA project did not succeed.
Respondents, almost without exception, claim that they feed their fish. Three categories of feed are reported: household leftovers, maize bran and vegetable matter (in most cases cassava leaves). Household leftovers are the feed most frequently mentioned by farmers, followed by maize ban and vegetable matter. Most pond-owners appear to regularly use at least two of the three feeds.
Feed is available to most farmers throughout the year. A few report occasional lack of household leftovers, and about a third report lack of vegetable materials (e.g. cassava leaves) during the dry season (April-November).
Farmers do not have a good recall, or grasp, of how much feed they place in the pond(s) and how often. However, of those who report how often (25%) at least one in two state that they feed daily. There is little information on the quantities. The answers indicate that household leftovers (presumably, mostly vegetative materials) may amount to as much as a few kg per day. Fertilizers are reported to be used slightly less frequently than feed. Nine out of ten farmers claim they apply organic fertilizers in the form of manure, compost and non-composted vegetative matters. While the frequencies of application differ considerably from one respondent to another, it seems clear that almost half the ponds receive fertilizers in some form at least once a week.
Only a few of the farmers report that there are periods of the year when they do not have organic fertilizers of some kind available for the ponds. Manure is lacking during part of the year for 20% of the farmers. During the survey it was found that fertilizers are primarily used by farmers to grow crops and vegetables. The picture, however, is not consistent. In Mwinilunga District fertilizers are applied only to the main staple crop cassava. Its use is mostly limited to a few specific crops and to the small garden for vegetables which most households have near their homestead. The survey team concluded that in several cases manure from free-roaming animals like goats and chickens would have remained uncollected were it not for the fish ponds.
As reported for feeds, farmers have little recall of the quantities or frequencies with which they apply fertilizers to their ponds making it difficult to estimate average quantities. However, it seems that the quantities applied are larger for manure (20 kg per application) than for compost (5 kg) and vegetative materials.
Slightly fewer than half the farmers carry out intermittent harvesting. Those who do generally have larger or more ponds (1755m2 of surface area), than those who do not (who average 1065m2 per farm). When major harvests are carried out, the ponds are rarely drained. Some fish is left in the ponds thereby avoiding the need to find fingerlings (or broadstock) for restocking. Households which practise intermittent harvesting (41%) report doing so anywhere between once a week and once a month. The quantities taken out are small, averaging about .8 kg a month. Fishing is done by hook and line, and the catch used exclusively for home consumption. The major harvest, on the other hand, normally yields enough to allow a part of the fish to be sold at the pond-side to neighbours and friends.
The information collected during the survey shows that the average farmer during a year collects about 50 kg from his ponds during major harvest and just under 10 during intermittent harvests. Frequently, the 50 kg are taken in one major harvest; at the most in two. The average period between major harvests is 11 months.
Apart from the difficulties encountered in keeping fish ponds in good working condition, predators seem to be the most frequent cause of problems. As many as three in four of the farmers report problems with fish ponds. They feel it is difficult to obtain substantive help to ensure that they are kept in good shape, in spite of the extraordinary extension services provided to farmers in the Mwinilunga District, and they constitute the majority of those interviewed. In Kasampa and Solwezi Districts, such problems are understandable because extension services in these districts are poorly equipped compared to that in Mwinilunga.
In the immediate future the production of tilapia in ponds will depend upon: modifications achieved in the average physical productivity of ponds; number of ponds lost (abandoned) and number of ponds added. These possibilities will be discussed in turn. The analysis is based on the assumption that extension services will continue to function at the level it had achieved at the time of the survey.
Few farmers would like to change the manner in which they grow out fish. However, the complaint over too small fish is frequent. Several would like to introduce faster - growing types of tilapia and/or other species. Carp is the fish most often mentioned in this connection.
There is little reason to expect that within the next few years farmers on their own will be able to remove the constraints which some of them face, because fertilizers, feed and labour are at different times of the year either lacking or used for more urgent purposes. Therefore, in spite of the low physical productivity reported (less than half a ton per hectare and year), the authors do not expect that fish farmers on their own will be able to, or indeed may even have an incentive to, drastically increase the physical productivity of their ponds. As a result, growth in farmed fish production will be closely linked to an increase in (the combined water area of) fish ponds. Given the good availability of land and water in the area there appears to be considerable physical scope for this to take place.
Few of the farmers who own ponds have stopped using them. Those who have done so still have a positive attitude towards raising fish in ponds. They are generally prevented from getting back into the activity by obstacles which take major effort to remove (pond repair, water supply). Thus, the authors expect that during the next few years, the rate at which practising fish culturists will be lost, will be closely linked to the rate at which ponds become impossible to use.
However, the survey does not yield any information as to what this rate might be. It does seem likely, however, that given the natural wear and tear on pond walls and water supply channels, the rate will increase over that observed to date, unless preventive measures are taken.
Amongst present farmers about one in ten reported that he was in the process of constructing additional ponds. About the same number did not want to build more ponds. The remainder stated their intention to build additional ponds in the future. Most farmers already have two ponds. New ponds are not likely to differ markedly from the norm of the area. Therefore if those farmers who are interested in more ponds, build one or two in a year, the new ponds will increase fish production by less than 10% a year.
All the potential farmers want to have fish ponds. Lack of resources, however, has prevented them from constructing ponds, the most important constraint identified being lack of funds to pay manual labourers. In the middle of 1988, pond construction appeared to be an insurmountable hurdle for the majority. There is little reason to believe that potential farmers in the Mwinilunga district will in the near future constitute a significant source of new ponds, unless they receive grants to fund pond construction.
Thus, all in all it seems plausible that in the next few years the number of new ponds will increase at a rate somewhere between 5 and 10% (in the absence of new aid schemes). Given that there will be some loss of ponds, the farmed tilapia output is now set to grow at a rate definitely lower than 10% per year, possibly about 5%.
The survey indicates that raising tilapia in earthen ponds is hardly an activity that yields a surplus large enough to pay for pond construction, or to pay for labourers attending to fish ponds.
However, the survey also shows that in spite of the low productivity attained, the activity is important to those farmers who have ponds both as a source of food and as a source of cash. Besides, it is an activity well in line with, and complementary to, the subsistence - oriented, general farming activities of the household. Like these, pond culture of tilapia makes use of inputs available from within the farm. Rarely are inputs purchased. Thus, it makes very good economic and social sense to ensure, through Government support, that practising farmers continue to use their ponds as long as there are no obviously better things for them to do.
