9. FISH PRODUCTION STRATEGIES

9.1 Fish production potential in reservoirs

The SWB inventory identified 369 functional small water bodies in the Lesotho lowlands. This figure includes four moderately silted dams greater than 10ha and numerous medium and smaller reservoirs.

If we define a reservoir as being suitable for carp culture if the average depth is at least 1m and surface area from 0.02 to 10ha, then a total reservoir area of 84ha suitable for carp culture is identified. Based on a production level of 1,000–1,500 kg/ha already experienced in fish ponds during the early 1980s, we estimate a yield of 85–125 tonnes from the smaller water bodies. This estimate does not include the four largest reservoirs which are considered below.

Commercial inland gillnet fisheries have been practised for about 10 years in South Africa. The two most active provinces are the Orange Free State (OFS) and the Cape Province. In the latter Province, estimated yields in 1984 varied between 73.3 kg/ha/yr for the productive Gamkapoort dam (682ha) to 28.6 kg/ha/yr for the Kammanasie dam (349ha; Durham & Ramsay, 1992).

Table 9.1, on catch data from the three main gillnet fisheries in the OFS (Bloemhof, Koppies and Kalkfontein dams), shows that large reservoirs in the South African highveld yield between 10 and 35kg/ha/yr.

Table 9.1. Commercial gillnet fishery of dams in the Orange Free State, 1982–1992

(Source: OFS Nature Conservation, Bloemfontein, South Africa).

Calculated yields are in accord with an estimate of 50kg/ha/yr advanced for productive dams (van der Mheen, 1993b) but below the estimated yields ranging from 30 to 200 kg/ha/year for shallow and small impoundments proposed by Dunn (1989). Dunn's upper estimate may be excessive for Lesotho conditions.

Lesotho's lowland reservoirs are much smaller than the ones built in the OFS. However, fish population growth and recruitment are not influenced by the critical water level fluctuation which often occurs in dams in South Africa. A higher yield could therefore be expected in Lesotho reservoirs, and estimates from 10 to 70 kg/ha/yr could be made. It means that 147ha of the four major reservoirs (chap.5) could produce from 1.5 to 10 tonnes/yr.

Lastly, on the basis of a production level of 2 tonnes/ha almost reached in 1979, the present 26ha fish ponds have the potential to produce at least 52 tonnes. This latter figure added to the total fish production potential estimated from fish culture in small reservoirs and the fisheries yield from the largest dams, could lead to a potential production from 140 to 200 tonnes in areas currently under water.

9.2. Selection of strategies

Information obtained from fish stock assessment, fisheries activity monitoring and local gear improvement will lead to the final output of the present project: management options to enhance fish production in lowland reservoirs.

It is important to bear in mind that the options proposed assume a sustained subsistence handline fishery operating in the dam -- except when fish culture is practised. Improved hook and line methods have shown that a significant amount of fish could be caught by local fishermen (Chap.8). If a local fisherman uses suitable techniques, a total harvest of 50 kg per fisherman during the four fishing months (January-April) could be easily expected. This subsistence fishery must therefore be controlled by licensing.

Strategies presented in Chapter 9.5. follow a standard framework as described below. Information on fish culture is included as a possible option although this management policy was not investigated over the period of project implementation.

Target groups which could be involved and/or could take advantage from fisheries activities are listed respectively under “participants” and “beneficiaries”.

Before initiating any strategies, there are preconditions which must be fulfilled. Above all, control and ownership of the dam have to be clarified. According to the level of inputs provided by the participants, important economic factors such as market or value of final product, participant's capital, input availability and local infrastructure must be taken into consideration. Various parameters must be studied: physical, e.g. reservoir size; biological, e.g. target species; and technical, e.g. gear technology. The level of knowledge of participants is also an important selection criterion for success in the management option chosen. Finally, reservoirs are selected and prioritized for each management proposal with respect to the above criteria.

Three main enhancement options are proposed to increase the fish production from each strategy: fish stocking, protected breeding areas and closed fishing seasons. These three recommendations are extracted from an exhaustive package drawn up during the Technical Consultation on Enhancement of Small Water Body Fisheries in Southern Africa held in Harare in January 1993 (Haight, 1994).

Fish stocking

Fish stocking policy should be seen from different angles with respect to reservoir size and location.

Reservoirs smaller than 10ha are shallow and turbid impoundments which should be stocked only with common carp and catfish. The situation is more debatable for larger and deeper reservoirs. If the dam has been built in a catchment which has a small ephemeral river or no recognizable inlet, Labeo umbratus may be an additional species to be stocked with the two latter species.

Reservoirs belonging to a well-established river system should be approached with a nature conservation policy. Stocking with indigenous species like Barbus aeneus or Labeo capensis is advisable since their spawning success depends on climatic conditions (sporadic floods). Further, these two latter species are excellent fighting fish, much appreciated by sport fishermen. They offer an interesting potential for gillnet fisheries.

The 2ha Maseru fish hatchery currently produces 5,000–10,000 common carp and hundreds of catfish fingerling. However, these seeds are widely available on the local market. For instance, in 1993–94, the fish hatchery at Vervoerd dam (OFS) produced 80,000 catfish and 60,000 carp fingerlings. Following the present demand, it is intended to double the production in the next season. Labeo capensis is also bred at the hatchery where 10,000 fingerling were produced in 1993–94. Breeding of B.aeneus is still at an experimental stage but has yielded promising results (W. Koen, pers. com.).

A different stocking rate can be advised relative to the level of production which is related to the main use of the dam. A higher yield may be supported in dams like Thaba-Phatsoa (25ha), which is used mainly for livestock watering and household consumption than in dams built for municipal water supply (e.g. Maqalika or Rasebala dams).

It may be possible at a later stage to improve fish production by introducing species to occupy vacant ecological niches. In lowland reservoirs there are no specific phytoplankton feeders. The smallmouth yellowfish is the major consumer of zooplankton in the lake. However, it exploits this resource only during the first phases of its life history, visually selecting the largest individuals (chapter 6.3.3). No species which filter open water searching for phytoplankton or small zooplankton are found.

Studies should be carried out to investigate possibilities of introducing new species to exploit this vacant niche. Silver carp (Hypophthalmichthys molitrix, Valancienne, 1844) which was successfully reproduced artificially in Lesotho during the 1980s (Chondoma, 1988), could be an interesting alternative species.

Lastly, any proposal to introduce fish predators should be carefully weighed before it is implemented. Fish stocks in small water bodies would not be able to support the activity of an efficient predator even if, in the conditions that prevail in the Lowlands, its hunting success is limited by the high water turbidity.

Protection of breeding areas

The protection of breeding areas needs particular attention. Shorelines in most lowland reservoirs are readily accessible and suitable for netting or angling. Important ecological zones are polluted, being disturbed by urban activities or by uncontrolled fishing. Controls are needed to ensure the survival of breeding stocks.

9.3. Part-time commercial gillnet fishery

9.3.1. Definition and framework

The strategy is to develop a part-time commercial fishery with the objective of offering a low-priced product aimed at the immediate local market. Framework: 1 outlines the procedures needed to install a part-time commercial fishery in the Lowlands.

Framework 1: Part-time commercial gillnet fishery in reservoirs.

Pre-conditions:

- Ownership/control:
Control of dam clear
Commitment to control the reservoir

- Economic:
Market for fish (fresh or dried operation has to be profitable,
Capital for purchase of boat, gear, cool box, etc.

- Physical/biological/technical:
species:Labeo spp., yellowfish, common carp, catfish
Mean depth >3m
Reservoir> 20ha
Size max 1 gillnet/10ha (gillnet size 3×30m or similar)
Minimum stretched mesh size: 93mm

- Level of knowledge of participants:
Use of gillnets
Basic skills in financial management
Basic skills in marketing

Risks: Failure to monitor catches or regulate fishing gear could make the fishery unsustainable.

Priority reservoir:
Access to reservoir closed for unlicensed gillnet fishermen
Reservoir not used for water supply

Enhancement options:
Introduction of species to occupy vacant ecological niches (e.g. phytoplankton eater)
Stocking of existing species
Protection of breeding areas
Closed fishing season

Selected dalx: Thaba Phatsoa, Magalika and Rasebala dams

9.3.2. Economic viability of part-time entrepreneurs

We summarize below the results from a preliminary economic simulation exercise about the profitability of a part-time gillnet fishery carried out for a four-month period (January to April). For this exercise, we assume that

1. fishermen, a team of two, live around Maseru and have a vehicle to carry a boat and to transport fish to the market;

2. the estimated reservoir yield is 30kg/ha/yr;

3. a third of the catch is sold at the landing site. The price for the fish, M3 at landing site and M4 at the market place, is slightly lower than one tendered by the Fisheries Section (M4,50; Table 6.1)

Table 9.2 is on the exploitation of a unique dam located in a peri-urban area. Table 9.3 is about a “rotating fishery” involving the four larger reservoirs in the Lesotho Lowlands.

In the first simulation, the fishermen go fishing once a week during the four-month fishing period. The net monthly revenue from harvesting Maqalika dam is about M1,500 (M750 per fisherman).

A “rotating fishery” exploiting the four larger dams allows more rational use of investment. The key question is to determine the quantity of fish which could be sold in a short period at the local markets (Maseru, Mafeteng and Leribe town). We assume this amount to be 500 kg of fish. Since the fishermen are supposed to set six nets and harvest 120 kg of fish per night, they should not fish more than four consecutive days at the same site. They would make a real profit from this activity; milage is not an important factor, because of the short distance between dams (max. distance 110km). Their total monthly income can be estimated to be about M3,500 during the fishing season.

A “rotating fishery” could be sustained as a part-time activity. Fishermen are supposed to fish 34 days during the fishing period to harvest the four dams. They can fish twice over the week-end for 16 weeks (our simulation) or reduce fuel cost by fishing one or two more days during each fishing trip. It is important to note that fisheries control of selected dams is the responsibility of different local authorities (Water Branch -- Maqalika and Rasebala dams; Ministry of Agriculture --Sebaboleng dam; local chief -- Thaba-Phatsoa dam).

The fishermen will not get “rich” with this activity but will derive a regular seasonal income. This can be an important supplement to a farmer who normally gets a lump sum of money only once a year after harvest. The importance of saving money should be stressed. A lack of proper financial management, not decline in catches, could be the main reason for the failure of “rotating fishery”.

Table 9.2

Estimated revenues from a part-time commercial gillnet fishery in Maqalika dam

Table 9.3

Estimated revenues from a part-time rotating gillnet fishery in four lowland reservoirs.

To avoid over-exploitation, fishing effort should be limited. The community should understand and accept the fact that only a few fishermen can net the dam. It is essential that the inhabitants of the whole area should give their support and approval to these fishermen, otherwise poaching is likely to become excessive. From Chapter 8, it would appear that gillnets offer good prospects of commercial success. Such a fishery would be based primarily on harvesting the most abundant fish in larger reservoirs, Labeo spp. in Maqalika dam or smallmouth yellowfish in Thaba-Phatsoa dam.

Finally, it is important to warn people that a dam not intensively fished holds a large biomass of fish. When net fishing starts, the catches are often high. However, after some time (just three months in small impoundments) catches will fall and stabilize at a lower level (van der Mheen, 1993b).

9.3.3. Potential for fishery products

In Southern Africa, meat is by world standards relatively cheap, and high quality sea fish is available in abundance and at low cost from the Atlantic and Indian Oceans. Freshwater fisheries therefore must be able to compete with both 1xat and sea fish.

Little research has been done on the acceptability of freshwater fish in markets near reservoirs or on the price that such fish can command (Chapter 7.6.). In the absence of reliable market information, a detailed appraisal cannot be made of the potential for a commercial fishery; but some tentative comments can be offered.

Sun-drying

The fish fauna in the lowlands of Lesotho is dominated by the carp family which includescommon carp, Barbus sp. and Labeo sp. Their skeleton is characterized by numerous fine forked bones in the flank muscles which require special preparation before cooking.

In many African countries, the main method of preparing fish is sun-drying. Cyprinid fish prepared in this way are very popular. It is likely that such a product would be the major outlet for any commercial fishery in the Lesotho lowlands.

A fishery based on salted and dried fish for local sale need not entail great capital expenditure. This type of fisheries would be viable at a lower level of turnover than one based on the sale of fresh fish, unless the latter were sold direct from the landing site. Further, in view of the lack of refrigeration facilities in Basotho households, a dried product would have the advantage that it could be bought in quantity when money is available and stored for later consumption.

The climate of Lesotho, characterized by a high rate of evaporation, is ideal for air-drying.

Smoking

Smoked catfish fillet could offer a high-quality product for the urban market.

Canning process

The canning process presents the same advantages that dried and salted products offer. Advantage of the infrastructure at the National Basotho Cannery, Lesotho, can be taken to enhance canning.

Limited canning operations are carried out in Zimbabwe and Zambia on a small scale. Canning has been tried in the past in Malawi and Tanzania, but production costs proved to be an obstacle in both cases (Reynolds, 1993).

9.4. Recreational fishery

Another lucrative activity deriving from reservoir exploitation is sport fisheries. This could turn out to be important in Lesotho where tourism development has great potential.

As mentioned in Chapter 8, the four species which occur regularly in Maqalika and Sebaboleng dams are attractive to anglers. The most important of these is the common carp. The other species sought after by anglers are the Orange River labeo, smallmouth yellowfish and sharptooth catfish. These two latter species have particularly good angling potential and accept a variety of baits.

Framework 2: Recreational fishery in reservoirs

Definition: Fishing for pleasure with rod and reel.

Participants: Individuals

Beneficiaries: Rural and urban fish consumers
- owner/controller of dam

Pre-conditions:

- Ownership/Control:
Ownership of dam should be well-established
Owner/controller should be based near the dam in order to issue fishing permits
There should be no gillnet fishery.

- Physical/biological/technical factors:
Species: Labeo spp, yellowfish, common carp, catfish, largemouth bass
Mean depth:> 2m
Surface area:>3 ha.

- Economics:
Main use of dam should not be for water supply.
Participants should be willing to pay for permits.

Risks:
Unlimited access may result in overfishing.
Lack of control of litter etc. may result in shoreline and water pollution.
Both these factors may affect the catches from sports fishing and thus lower the revenue from it.

Enhancement Options:
Stocking of existing species for sport fishing
Introduction of closed seasons
Protection of breeding areas

Priority Reservoirs: Those found in scenic areas.

Selected Dams: Raleting, Thaba Phatsoa, Mejametalana, Morija dams and Luma lake

9.5. Unmanaged fishery

Many reservoirs are situated in open rural or urban areas. Controlling their exploitation is problematic, partly because their ownership is often unclear.

Framework 3: An unmanaged fishery

9.6. Fish culture

Beyond the 26ha of fish ponds built in the Lesotho lowlands, the small water body inventory (Chapter 5) reveals an interesting potential in reservoirs ranging from 0.02ha to 10 ha in surface area and between 0.8 and 3m in depth. Such reservoirs could be used to culture fish. No relevant data are available about production achieved from such undrainable ponds in this southern African area.

The two species proposed are the common carp and the sharptooth catfish already stocked in several reservoirs.

9.6.1. Extensive fish culture

Framework 4: An extensive fish culture in reservoirs

Pre-conditions:

- Ownership/control:
Ownership of the dam should be clear.
Owners should be committed to control the fishery.

- Physical/Biological/Technical:
Species to be stocked: common carp, catfish
Fingerlings of >8cm (>30gr) available
Surface area of reservoir < 10 ha
Mean depth of reservoir < 6m
Batch harvesting and fishing gear available

- Economic:
Market exists for fish species stocked
Participants willing to pay for fingerlinlx
Profitability of system demonstrated

- Level of knowledge of participants:
Basic knowledge on stocking
Basic skills in fish husbandry
Basic skills in financial management
Basic skills in marketing

Risks: Sabotage, theft, unreliable supply of fingerlings, limited or non-existent access to extension advice.

Priorities: - Surface area: 3 – 10 ha.
- Perennial reservoirs

Selected dams: Mejematalana, Thaba-khupa, Rakolo 1 & 3, Leshoele 2 & 3, Borokhoaneng, Agric College Maseru, Motloi dams and Luma lake.

9.6.2. Semi-intensive fish culture

Framework 5: A semi-intensive fish culture in reservoirs

Pre-conditions:

- Ownership/control:
Ownership of dam should be clear.
Owners should be committed to control the fishery.
Only owners should be allowed to fish

- Physical/Biological/Technical:
Species to be stocked: common carp, catfish
Fingerlings of >8cm (>30gr) available
Size of reservoir < 3 ha
Mean depth of reservoir = 0.8–3
Low water level fluctuations
Batch harvesting and fishing gear available
Reservoirs not used for drinking water

- Economic:
Market exists for species stocked
Local availability of fertiliser/waste products
Participants willing to pay for fingerlings and fertilizers
Profitability of system demonstrated

- Level of knowledge of participants:
Training in fish culture techniques
Basic skills in financial management
Basic skills in marketing

Risks: Sabotage, theft, unreliable supply of fingerlings and fertilizers, limited or non-existent access to extension advice.

Priorities: Surface area: 1 – 3 ha.
Reservoirs close to urban centres

Selected dams: Borokhoaneng, Agriculture College Maseru, Motloi, Rakolo 3, Leshoele 3 dams.

9.6.3. Intensive fish culture

Framework 6: An intensive fish culture in reservoirs

Pre-conditions:

- Ownership/control:
Ownership and control of the dam should be clear.
Only owners should be allowed to fish.

- Physical/Biological/Technical:
Species to be stocked: common carp, catfish
fingerlings of >8cm (>30gr) available
Size of reservoir < 3ha
Mean depth of reservoir= 0.8–1m
Low water level fluctuations
Batch harvesting gear available
Reservoir not used for drinking water

- Economic:
Market exists for fish species stocked
Participants willing to pay for fingerlings and other inputs
Local availability of fertiliser/waste products
Local availability of artificial feeds (or can be transported)
Profitability of system demonstrated

- Level of knowledge of participants:
Training in fish culture techniques for carp and catfish
Financial management skills
Marketing skills

Risks: Sabotage, theft, unreliable supply of fingerlings, unreliable supplies of feed and fertiliser; limited or non-existent access to extension advice

Priorities: Access to reservoir closed (e.g. fenced and/or guarded)
Reservoirs close to urban centres
Size of reservoir ≤ 1ha

Selected dams: Leshoele 3, JTC, Agric college Maseru, Motloi dams.

9.7. Integrated fish-cum-duck farming

A possible alternative to the semi-intensive system described above is integrated fish farming. In this system, the duck house is sited on the pond embankments in such a way that the animal wastes and washings are diverted into the SWB for recycling. The fish not only utilize spilled animal feed but also directly feed on fresh animal excreta which is rich in nutrients. Surplus excreta supports the growth of planktonic fauna. Fertilizers and supplementary feed are not used, resulting in drastic cost reduction (Kumar, 1992). Framework 7 provides the background information needed to implement such activities.

Since fish-cum-duck farming is still at an experimental stage in rural fish ponds in Lesotho, no relevant estimates are available on fish and duck meat production.

Framework 7: Fish-cum-duck farming in reservoirs

Pre-conditions:

- Ownership/control:
Ownership and control of dam should be clear. Only owners should be allowed to fish.

- Physical/Biological/Technical:
Species to be stocked: common carp, catfish
Fingerlings of >8cm (>30g) available
Size of reservoir < 3 ha. Mean depth of reservoir < 2m
Low water level fluctuations
Batch harvesting and fishing gear available
Reservoir not used for drinking water

- Economic:
Market exists for fish and duck species stocked
Participants willing to pay for fingerlings, ducklings and other inputs
Local availability of artificial feeds for ducks (or can be transported)
Profitability of system demonstrated
Level of knowledge of participants:
Training in fish culture techniques for carp and catfish
Training in duck-keeping, financial, management and marketing skills.

Risks: Sabotage, theft, unreliable supply of fingerlings, unreliable supplies of feed and fertiliser; limited or non-existent access to extension advice.

Priorities: Access to reservoir closed (e.g. fenced and/or guarded Reservoirs close to urban centres

Selected dams: Borokhoaneng, Agricultural College Maseru, Motloi, Rakolo 3, Leshoele 2 & 3 and Thaba khupa (if partitioned).