by
M.I. Van der Lingen
Chief Ecologist
Branch of Aquatic Ecology
Department of National Parks and Wildlife Management
Zimbabwe
Abstract |
| Multipurpose use covering recreation, fisheries and tourism is the aim in many main river impoundments. Experience in developing management plans is broadly outlined. Attention is given in particular to fisheries management, introduction of appropriate species, aquatic weed control, water quality control and potential for intensive culture. |
Résumé |
| La plupart des projets d'endiguement de cours d'eau importants répondent à des objectifs multiples qui embrassent à la fois les activités récréatives, la pêche et le tourisme. L'auteur dresse un bilan général de l'expérience acquise dans le domaine de l'élaboration des plans d'aménagement, notamment en mettant l'accent sur l'aménagement halieutique, l'introduction d'espèces appropriées, la lutte contre les mauvaises herbes aquatiques, le contrôle de la qualité des eaux et les possibilités de culture intensive. |
There are three main river basins in Zimbabwe, namely (Figure 1):
The Zambezi basin in the north in which the major impoundments are:
Lakes McIlwaine and Robertson, on the Hunyani River near Salisbury, the capital city.
The Sabi-Lundi basin in the southeast, draining into the two rivers, the Sabi and the Lundi. The major impoundments here are:
Lake Manjirenje on the Chiredzi River.
The Limpopo basin in the south and southwest, on which there are a number of medium-sized impoundments (see Figure 1).
In addition, there are rivers flowing west into Botswana and eastward into Mozambique. There are no natural lakes in Zimbabwe, but as a result of river basin planning and management over many years, 4.6 × 109 m3 of water is impounded. This volume is about 25 percent of the mean annual run-off (Thornton, 1980). A total of 120 dams, which are classified as large dams by the International Commission on Large Dams (ICOLD), and a great number of smaller dams have been built. Thirty four of these have been studied, to some degree, by limnologists. Of these, Lakes Kariba Kyle and the Hunyani Lakes (McIlwaine and Robertson) have received the greatest attention.
Major upstream dams have modified the flows of the Zambesi, Sabi and Lundi Rivers, but there were no floodplain fisheries to any extent on these rivers. There were, however, traditional fisheries on the major rivers.
Figure 1 Zimbabwe showing main river basins
In this essay it is proposed to discuss the larger lakes from the aspects of potential and the problems encountered in management.
Table 1 shows the variations in characteristics of the main lakes - all man-made.
Table 1
| Parameter | Lake | |||
| McIlwaine | Robertson | Kyle | Kariba | |
| Water surface temp. °C | 16–24 | 16–24 | 16–27 | 17–32 |
| Altitude (m above MSL) | 1 400 | 1 350 | 1 000 | 484 |
| Surface area at FSL ha | 2 630 | 8 100 | 9 105 | 510 000 |
| Maximum depth m | 27 | 23 | 56 | 119 |
| Mean depth m | 9.5 | 5.7 | 14.6 | 29.5 |
In addition to the purpose for which the impoundments were primarily built, they also fulfil other very important functions.
Food supply - Smaller impoundments provide a protein source locally. Larger impoundments with an established fishing industry provide a contribution to national food supply. Kariba is a good example; on this lake a multimillion dollar commercial fishing industry and a sport fishing have developed.
Recreation - There is both water-based and outdoor recreation in the surrounding area, where this is developed as a recreational area. The importance of recreation is exemplified by the fact that very often the investment in boats, facilities and amenities is of such a size that subsequent management of the water is as much directed to this end as to the primary purpose. Recreation aspects are:
In the planning stage, account must be taken of the secondary possibilities. For example, the building of jetties, clearing of certain areas of trees and the allocation of land, must be done around the perimeter for fisheries and amenity purposes.
In planning the secondary use of impoundments, size and special characteristics of the area are taken into account to determine whether the area is of national, regional or local importance.
Nationally important waters are generally over 2 000 ha; planning is by state authorities and the administration through the Department of National Parks and Wildlife Management. Provision is made for commercial fishing, sport fishing and nature experience, and the surrounding land area used for game sanctuaries, camping, picnicking, nature trails, etc.
Regionally and locally important waters are administered at those levels, authority being vested in local Government bodies.
The overall aim is the optimum exploitation of the entire resource for food production, tourism, recreation and, of course, the primary purpose of irrigation, hydro-electric power or whatever it may be. In planning reservoir construction the impact, both negative and positive is assessed.
The problems encountered are basically of five kinds:
Scientific problems, those posed in trying to understand the system. Comparative studies and typological comparisons with local relevance are of importance here;
Maintenance problems, those relating to maintenance of the water for general purposes, such as, aquatic vegetation control, siltation, water pollution, and eutrophication;
Management problems arising from needs of particular aspects, such as, water supply and recreation;
Associated ecological problems resulting from the creation of the impoundment, flooding of spawning and food beds; downstream effects of the dam, such as, loss of floodplain fisheries, and
Multipurpose-use conflict problems, resulting from the diversity of uses which may at times be in conflict, such as, commercial fishermen's nets versus anglers, and so on.
Some specific problems are detailed further.
Most lakes created by damming mainstream rivers have been well colonized by riverine fish which adapt to varying degrees to the new environment. Populations can be affected by both river conditions and by fish movements prior to final closure by the dam wall. For example, in Lake Robertson on the Hunyani River very few tigerfish (Hydrocynus vittatus) are found. Prior to closure the river had been affected by pollution from pulp mill effluent, which killed or caused the withdrawal of the Hydrocynus population.
It can also happen that seasonal downstream migration might result in the absence of one element or another.
Lake McIlwaine rapidly became highly eutrophic in the early 1960s due to the addition of treated sewage effluent. Marshall (1978) reports that the total dissolved salt increased from 70 micromhos in 1959–61 to 130 in 1968–70. Sewage diversion on a significant scale started in the early 1970s and the total dissolved solids had dropped to about the 1959–61 levels by 1974–76. Dense blooms of blue-green algae occurred, and although fish production was high, there was large fish kills every year from 1969 to 1973 when deoxygenated water in the bottom rose to the surface, due to overturn caused by various factors. The dense algal growths could in fact have been limiting production due to their shading effect. A slight drop in catches has been observed since 1976.
In Lake Kariba, productivity of the waters in the vicinity of river inflows is higher than in other areas. Years of high rainfall, when the rivers bring in large amounts of nutrients, are good years for the sardine fishery. It has been suggested that localized fertilization would lead to increased catches of sardine, and there may well be a good case for judicious introduction of nutrients into the open waters of the lake using treated effluent, provided there are no health problems.
In Lake Kariba the fluctuation of water level in the 1960s, as the lake filled, may possibly have prevented the establishment of aquatic macrophytes.
Below Lake McIlwaine there have been fish kills due to the discharge of H2S laden hypolimnetic water.
A noticeable feature below many dams in times of spilling is the massing of fish attracted by the inflowing water. These fish are best cropped and used either for food or restocking other waters.
The problem is either one of too much or of too little.
McIlwaine during 1971 - large areas were covered with water hyacinth, Eichhornia crassipes, which proliferated rapidly after a year of low water and with a relaxation of control measures. Mechanical removal was ineffective and the problem was solved only by aerial spraying of the worst affected areas over a period of time, portions only being done at any one time. This prevented large amounts of rotting vegetation at any one time, but was primarily dictated by considerations of water quality. In the aerial spraying, 2–4D was used and subsequent spraying by boat.
The measures were completely successful and the ongoing control by a permanently employed Weed Control Unit has prevented any re-emergence of the problem.
Lake Kariba - Salvinia molesta covered some 25 percent of the lake surface area in 1962, declining to 15 percent from then to 1971. By 1973 it had dropped to 5 percent and in 1979 was less than 2 percent. The grasshopper, Paulinia acuminata, was introduced in 1971, and Mitchell and Rose (1979) attribute the decline of the Salvinia directly to the Paulinia. Marshall and Junor, however, conclude in the light of other evidence, that Paulinia was not the main agent and indeed the decline may have occurred anyway. My view is, that as in so many situations, a complexity of factors has operated together. It is significant that even before the Paulinia were introduced, the Salvinia was reduced to such an extent that, except occasionally in one or two isolated areas, it was not a problem. Furthermore, work by Mitchell (1976) showed that Salvinia has a positive effect in providing a substrate for fish food organisms and cover for several species at a time when submerged macrophytes were sparse.
At Lake Kyle, the problem is a paucity of aquatic vegetation. Despite stable water levels over recent years, aquatic vegetation has not become established, due in great measure to the presence of the herbivorous tilapia, Tilapia rendalli. In this lake, investigations are going forward aimed at the establishment of ‘artificial’ reefs and cover, using rocks, brushwood, old fishing nets and other artefacts.
Angling and commercial fishing:
There is a range here from apparent competition for the same species and occupation of the same area, i.e., shallow water, to a situation of no contact as in the Kariba sardine fishery where deep waters are exploited for a fish of no angling importance. To a large measure the conflict is really one between boats of sport fishermen and gillnets of commercial fishermen.
In small lakes there is frequently no room for an organized continuing commercial fishery, although subsistence and even economic fishing by rod and line for nonsporting species, is important.
Due regard must be paid to the sport fishing. For example, the tigerfish, Hydrocynus vittatus, in Lake Kariba as a sport fish is worth a great deal of money, generating employment services and attracting tourists.
The problem is overcome by zonation of areas where different activities have stated pre-eminence.
Lake Kariba:
Zonation on Lake Kariba caters for:
National Park areas on the lake shore where wildlife, tourism and game-viewing are paramount;
Areas near holiday centres where water sports are paramount and commercial fishing is not allowed;
Commercial fishing areas zoned for concessions and other fishermen separately:
Sport fishing areas, and
River areas closed to commercial fishing.
On the smaller lakes which are heavily utilized for recreation and angling on weekends, commercial fishing is generally prohibited over weekends and holidays. The system adopted has served to minimize conflict, but, of course, there are still problems from time to time.
The only case involving resettlement of any number of people is the Lake Kariba settlement of 22 000 people which was accomplished peacefully on new land with provision for assistance until they became established.
Many of the people return periodically to the lake shore to fish for varying periods during the year. Many are more or less permanently settled along the shore. The previous subsistence fishing has now become economic fishing, but there are still many who fish on a small scale.
Fish
Over 100 species of fish occur in Zimbabwean waters. The most important for commercial fishing are:
Sarotherodon mortimeri
Sarotherodon mossambicus
Sarotherodon macrochir
Tilapia rendalli
Clarias gariepinus
Labeo spp.
Hydrocynus vittatus
Mormyrid spp.
Limnothrissa miodon
Fish are marketed fresh, deep frozen and often dried or smoked in smaller quantities generally for local consumption. Canned Hydrocynus and Limnothrissa are recent new arrivals on the market. The Limnothrissa catch is mainly sun-dried and sold throughout the country.
Gear
Gillnets from 5 cm to 15 cm and beach seines are used widely. The Limnothrissa fishery uses encircling seine nets (purse seines and lamparas) and lift nets. Traditional methods such as, basket traps, and rod and line fishing are responsible for a good deal of the subsistence catch. Commercial fisheries are of the restricted entry type with a limited number of licences being granted. In many of the tribal areas the local community fishes, and the is arranged through tribal authorities. Statistics of catches are returned by larger operators. On Lake Kariba and elsewhere where there are a large number of peasant fishermen, a system of sampling and recording catches at landings is in operation. In regard to the major lakes the following specific points may be mentioned:
Lake Kariba
Two inshore concession areas; all other fishing areas by fishermen locally resident; total number of self-employed fishermen increased from 1962 to a high of 1 000 in 1966 and thereafter declined, the war situation being partly responsible. Numbers at present (1980) are about 500; open water industrial fishery operating from three main centres on the lake
Lake McIlwaine
One concession company which has operated the fishery for the past 25 years and many rod and line subsistence anglers. There is also a significant sport fishery.
Lake Robertson
Two concession fishery companies; again, many subsistence anglers.
Lake Kyle
This is under reconsideration and a maximum of two companies are recommended. The previous history of fishing by up to 14 fishermen has proved difficult to control, and inefficient. Rod and line subsistence fishermen and sport angling is important.
Other Waters
Waters under control of local authorities. May have commercial, artisanal and subsistence fisheries established.
Introductions
The introduction of species not occurring in a water body is a highly controversial issue. Since all the water bodies in Zimbabwe are in any case artificially created, it is hardly possible to think seriously of the ecological integrity of such waters. Nevertheless, great care is required in deciding on introductions. The Limnothrissa, introduced to Lake Kariba in the final event by Zambia (after combined efforts were no longer possible due to political events), has been a great success.
A cyprinid from the Limpopo, Engraulicypris brevianalis, has been introduced to lakes in the Sabi, Lundi and Limpopo system and has assisted in developing the black bass potential of these waters by its value as a forage fish.
Sarotherodon macrochir has become the most important commercial species in the Hunyani Lakes and in Lake Kyle, having been introduced in the mid-1950s to Zimbabwe from Zambia.
Haplochromis codringtoni has recently been introduced into the two Hunyani Lakes, where it will utilize mollusc populations.
The introduction of Sarotherodon macrochir into Kariba in 1959–62 cannot be judged to have been successful (van der Lingen, 1973) as this fish does not form any measurable part of the catch.
As a general policy stocking has been carried out where this is indicated, using fish occurring in the particular river system if they do not occur at the dam sites.
Introduction of the Largemouth Black Bass, Micropterus salmoides, has been made for sport fishing and has been moderately to very successful in many lakes above 1 000 m.
Some problems in development
In our experience it is not desirable to create vast capital expenditure for most of our fisheries (fishing for Limnothrissa excepted). Traditional ways and methods developed from them in regard particularly to boats, are most appropriate.
On Lake Kariba small fishing villages, from which fishermen operate in rowing boats or dugout canoes, provide an adequate basic pattern. Regular visits by powered and refrigerated or ice-carrying boats, which convey the fish to market, are a necessary part of the system. Overmechanization can rapidly lead to an ecological imbalance. The kapenta or Limnothrissa fishery is, however, a fishery which requires high capital input in terms of expensive boats and gear. However, even here the dangers of overcapitalization can occur.
Some figures are given in the following:
| Limnothrissa - Lake Kariba | ||||||
| t | ||||||
| 1974 | 500 | |||||
| 1975 | 650 | |||||
| 1976 | 1 050 | |||||
| 1977 | 1 200 | |||||
| 1978 | 2 780 | |||||
| 1979 | 4 880 | |||||
| Total recorded landings 1979 (all species) | ||||||
| Lake Kariba | 5 560 | |||||
| Lake Kyle | 55 | |||||
| Hunyani Lakes | 450 | |||||
| Estimated total landings - commercial, subsistence, sporting, 1979 | ||||||
| Kariba | 5 800–6 000 | |||||
| Kyle | 80– 100 | |||||
| Hunyani Lakes | 600 | |||||
| Others | 2 530 | |||||
| Total | 9 000–10 000 | |||||
As new water bodies are created by damming rivers they will add to the fisheries production. There are many such schemes on the drawing boards. However, it will be necessary to expend effort on developing more intensive fisheries in river basin planning. Intensive culture associated with irrigation comes readily to mind. The use of fish cages in reservoirs is also an avenue needing exploration. Increased catches will be possible from more intensive management of medium-sized waters. This may involve the setting-up of hatcheries in some cases so that populations are not dependent on uncertain natural factors for annual recruitment. Furthermore, judicious use of means of enhancing productivity in keeping with the overall use of the water body may be considered.
Multipurpose use of large and medium-sized water bodies in river management planning presents many problems, but also the possibility of the best use of these bodies;
Basic limnological and hydrobiological research is an important basis for understanding and management. Much can be learnt from comparable studies elsewhere;
Development of the fishing must take into account sociological and human factors and patterning development on that in more industrialized parts of the world can be counter productive;
River basin planning should take account of the fisheries potential of the reservoirs created, but also the possibility of intensive fish culture associated with irrigated agriculture, and
Each water and each country has unique possibilities and problems, but sharing the thoughts and impressions with others can only be of great advantage and is essential.
van der Lingen, M.I., 1973 Lake Kariba: early history and south shore. Geophys.Monogr.Ser., (17):132–42
Marshall, B.E., 1978 An assessment of fish production in an African man-made lake (Lake McIlwaine). Trans.Rhod.Sci.Assoc., 59(3):12–21
Marshall, B.E. and F.J.R. Junor, Ecological aspects of the decline of Salvinia molesta in Lake Kariba (in press)
Mitchell, S.A., 1976 The marginal fish fauna of Lake Kariba. Kariba Stud., 8:109–22
Mitchell, D.S. and D.J.W. Rose, 1979 Factors affecting extent of Salvinia molesta on Lake Kariba. PANS, 25:171–7
Thornton, J.A., 1980 A review of limnology in Zimbabwe, 1959–79. Natl.Water Quality Surv.Ser., Salisbury, (1):85 p.
by
J.J. Chaika
Fisheries Department
P.O. Box 593
Lilongwe, Malawi
Abstract |
| Malawi is fortunate in having been endowed with four lakes and a number of perennial rivers. The fisheries supported by these waters are considered in three categories: large-scale producers, characterized by heavy capital investment and mechanization; small-scale producers with low capital investment and a low level of organization, and a fishery for ornamental fishes for export. Small-scale producers, the traditional fishermen, accounted for about 80 percent of the total catch in 1978. |
| Development of fisheries, and the need for regulatory management, both for large-scale and small-scale producers, have been conditioned by a number of factors which relate to the human population distribution, national and regional economics, geography, and the general productivity of lake and river fisheries. At present, the best potential for development of fisheries lies in the north and for this reason management regulations can be somewhat relaxed there for the present. |
Résumé |
| Le Malawi a la chance de compter sur son territoire quatre lacs et un certain nombre de cours d'eau permanents. Les pêcheries qui exploitent cet ensemble de ressources se répartissent en trois secteurs: pêche industrielle, caractérisée par l'importance des investissements et de la mécanisation; pêche artisanale, très peu organisée, avec de faibles investissements et enfin pêche des poissons ornementaux destinés à l'exportation. En 1978, le secteur de la pêche artisanale, utilisant les méthodes traditionnelles, a fourni environ 80 pour cent de l'ensemble des prises. |
| La planification du développement de la pêche et la réglementation indispensable de l'exploitation industrielle et artisanale des ressources halieutiques doivent tenir compte d'un certain nombre de facteurs liés à la répartition démographique, aux données économiques nationales et régionales, à la géographie et à la productivité générale de la pêche dans les lacs et les rivières. Pour le moment, les pêcheries offrant les meilleures perspectives de développement sont celles situées au nord, ce qui explique la souplesse relativement plus grande à l'heure actuelle des règlements de mise en valeur concernant cette région. |
Malawi is fortunate for having been endowed with four lakes and several perennial rivers. All the lakes have lucrative fisheries. However, of the many rivers, only the River Shire has for several years attracted the attention of the Fisheries Department.
The fisheries have been classified into three categories: commercial fishery, ornamental (tropical) fishery and the traditional fishery. In this paper the commercial fishery will be called “large-scale producers” characterized by heavy capital investment and mechanization. The traditional fishery will be called “small-scale producers” and characterized by small capital investment in each unit, with a low level of organization. Vessels in use are small and usually individually owned and fishing relies on labour intensive operation (Proude, 1978). The aquaria fishery is intermediate and is for the export market for live fish.
Small-scale producers caught 80 percent of edible fish in 1978. The total income to the fishermen amounted to Mlwi.K 7 312 320.00. The large-scale producers landed 14 percent of edible fish valued at Mlwi.K 1 057 500.00. The ornamental fishery exported only 131 780 fish at a value of Mlwi.K 210 219.00.
The development trend of the fisheries has not been even throughout the country. It is my intention in this paper to appraise some of the factors that have led to the uneven development and growth of the fisheries.
In a development planning exercise, background data are an essential prerequisite to ensure a balanced multidisciplinary approach. The Fisheries Department has been compiling data on total catches of fish since 1960 (Table 1). Proude (1973) advocates that the data should cover information on the fisheries resources. The information should ideally cover the present species caught and whether they are fully utilized, or offer scope for greater exploitation. The data should also be broken down by fishing areas, weight of fish caught and seasonal variations. He further states that information on location of fishing centres, the numbers of fishermen involved and the numbers and types of fishing gears should be compiled.
Attention has also been paid to the shore facilities for handling and processing fish. Since underdevelopment is commonly associated with lack of capital, special attention has been given to ownership and the credit structure. Proude (1973) advises that attention should also be accorded to the capability of the infrastructure to deal with any increase in fish landings. He also suggests a study of distribution channels and the location of fish marketing centres, their capacities and potential and the preferences of consumers.
Malawi is divided into nine principal fishing areas. It is not an accident that the areas are divided as such; each one has characteristic geographical features. The northern region portion of the lake is deeper than the central and the southern portions. The deepest point is about 704 m. The shoreline is generally rocky with steep cliffs. Likoma/Chizumulu Islands are enclaves in Mozambique; the water is relatively shallow. The centre designated as Nkhota Kota and Domira Bay, on the map is fairly deep in comparison to the southern portion designated as the southwest and east arms. The Nkhota Kota and Domira Bay and south-west and east arms have generally pockets of sandy shorelines interrupted in a few spots by either rocky promotories or reeds. Lake Malombe is an expansion of the Upper Shire River and the area is very different from the Lower Shire River system, which is basically floodplain. Lake Chiuta and Lake Chilwa are closed basins and saline.
Table 1
Fish production and beach prices of fish landed in all waters of Malawi, 1960–78
| Year | Production by area | Total production and value | ||||||
| Lake Malawi | L. Malombe Upper Shire | Lake Chilwa | Lake Chiuta | Lower Shire | Landed weight | Beach price (1 kg) | Landed value | |
| 1960 | - | - | - | - | - | 5.8 | ||
| 1961 | - | - | - | - | - | 7.9 | ||
| 1962 | 9.3 | 1.8 | 0.5 | - | - | 11.6 | ||
| 1963 | 7.4 | 2.6 | 3.3 | 0.5 | 0.5 | 13.7 | ||
| 1964 | 6.2 | 1.1 | 5.3 | 0.5 | 0.5 | 13.1 | ||
| 1965 | 6.5 | 1.5 | 8.9 | 2.0 | 2.0 | 18.9 | 5.3 | 1 002.0 |
| 1966 | 0.8 | 2.9 | 7.3 | 1.5 | 1.5 | 17.5 | 5.5 | 962.5 |
| 1967 | 5.4 | 4.0 | 3.3 | 1.7 | 1.7 | 14.4 | 5.0 | 720.0 |
| 1968 | 7.8 | 7.8 | 0.9 | 2.3 | 2.3 | 18.0 | 5.5 | 990.0 |
| 1969 | 24.2 | 5.3 | 2.9 | 0.1 | 9.2 | 41.7 | 8.8 | 3 669.6 |
| 1970 | 43.6 | 6.4 | 4.2 | 1.1 | 11.0 | 66.3 | 8.4 | 5 569.2 |
| 1971 | 54.0 | 5.0 | 3.6 | 0.9 | 9.7 | 73.2 | 7.1 | 5 197.2 |
| 1972 | 57.0 | 3.1 | 5.3 | 1.4 | 17.3 | 84.1 | 8.4 | 7 064.4 |
| 1973 | 53.7 | 5.3 | 1.9 | 0.8 | 9.8 | 69.4 | 8.8 | 6 107.2 |
| 1974 | 52.2 | 4.2 | 3.1 | 0.9 | 9.7 | 70.1 | 8.8 | 6 168.8 |
| 1975 | 47.2 | 8.1 | 2.8 | 0.7 | 12.1 | 70.9 | 11.2 | 7 940.8 |
| 1976 | 36.5 | 6.1 | 21.2 | 1.8 | 9.3 | 74.9 | 10.0 | 7 490.0 |
| 1977 | 33.9 | 6.4 | 20.8 | 1.5 | 5.6 | 68.2 | 10.0 | 6 820.0 |
| 1978 | ||||||||
A summary census of fishing centres for 1975 shows that there were a total of 310 fishing beaches. On Lake Malawi 141 were recorded, of these five were used by large-scale producers. Of the five centres used by large-scale producers, four centres are managed by the Government through the Fisheries Department, the fifth centre is used by parastatal organizations. Four of the five centres are situated in the southern half of Lake Malawi. Of the 305 centres used by small-scale producers, 73 percent were recorded in Nkhota Kota/Domira Bay and Southwest and east arms. In Lake Malombe and the Upper Shire, 42 centres were recorded. Lake Chilwa had 27 fishing centres. Lake Chiuta and the Lower Shire River each had 10 and 90 fishing centres, respectively.
The definition of the fisheries here encompass the fishermen, their fishing crafts and fishing gears and the quantities and species of fish caught.
Large-scale producers are engaged in a highly mechanical fisheries characterized by capital intensive investments. There are at present 12 trawlers and four ringnets. Two trawlers and the four ringnets are operated by a parastatal organization, and fish landing is also managed by the organization.
The remaining trawlers are operated by private owners. The latter were created by the Government through a fishing loan; they transact their affairs on Government-managed fish markets, where there are also fuel and minor repair services.
In terms of employment, the private-owned trawlers (pair trawlers unit) each employs nine fishermen which adds to a total of 90 fishermen for the whole fleet. The total employment in the large-scale producers' sector is relatively small.
To avoid a localized overfishing, each fishing unit has been assigned to a fishing area. Their ratio of fishing effort to total catch is closely watched. Effort is in unit of number of boat days. At present four trawlers fish in area A, three fish in area D, three fish in area G and one has just started to fish in the north (Figure 1). Since 1968 the state of the trawl fishery and total production is as shown in Table 2. Area A is now exclusively for the four pair trawlers owned by private individuals. A Sarotherodon fishery using ringnets is permitted. The Sarotherodon ringnet fishery uses 102 mm mesh-size nets, therefore, it is not detrimental to the trawler fishery.
The population of fishermen in the small-scale producers has increased from 5 663 men in 1975 to 11 133 men in 1978. At the same period, the number of fishing crafts has only increased from 5 431 in 1975 to 5 889 in 1978 (Table 3). There were more fishermen with their own fishing crafts than those without fishing crafts in 1978. There was a high percentage of fishermen in Lake Malombe/Upper Shire River and in the northern region without fishing crafts of their own (Table 4).
There is a strong tendency in the central (Nkhota Kota/Domira Bay) and in the southern portion of Lake Malawi (Southeast arm and Southwest arm), including Lake Malombe and the Upper Shire River to use plank boats. This tendency is more prominent in the Southeast arm, Southwest arm in Lake Malombe, and the Upper Shire River (Table 5). The situation may reflect the difference in economic growth between the fishing areas. The difference in economic growth may itself suggest differences in the fisheries, in the predominent species exploited and the prices that different species of fish fetch at the beach. Table 6 shows the annual estimated catches of various species during 1978. Data from Lake Chiuta and Lake Chilwa are missing.
Table 7 shows the total estimated catches by various fishing gears during 1977. The information may assist in revealing the reasons for differentiation in the economic growth of the nine fishing areas.
Figure 1 Large-scale producers' fishing areas in the southern portion of Lake Malawi
Table 2
Annual total catch from large-scale producer trawlers and catch per unit effort
| Area | A | B | Southwest arm | Domira Bay | Total | ||||||||
| Company | Parastatal | Private | cpue | Parastatal | Private | cpue | Private | cpue | Private | cpue | t | ||
| P1 | P2 | P1 | P2 | ||||||||||
| Year | |||||||||||||
| 1968 | 548 | 3.8 | 548 | ||||||||||
| 1969 | 843 | 365 | 3.6 | 2.2 | 1 208 | ||||||||
| 1970 | 561 | 1 268 | 3.9 | 2.7 | 1 829 | ||||||||
| 1971 | 406 | 1 079 | 2.5 | 1.3 | 1 485 | ||||||||
| 1972 | 174 | 807 | 1.4 | 1.2 | 78 | 2.1 | 1 059 | ||||||
| 1973 | 791 | 1.6 | 2 060 | 4.6 | 269 | 1.8 | 59 | 1.4 | 3 179 | ||||
| 1974 | 2 105 | 2.3 | 3 601 | 5.7 | 667 | 2.3 | 301 | 1.3 | 6 674 | ||||
| 1975 | 1 998 | 1.6 | 3 521 | 5.7 | 1 096 | 3.4 | 63 | 1.0 | 6 678 | ||||
| 1976 | 1 650 | 1.2 | 4 266 | 723 | 1.5 | ||||||||
| 1977 | 871 | 0.7 | 4 154 | 614 | 1.3 | 2 949 | 2.3 | ||||||
| 1978 | 1 047 | 1.1 | 857 | 1.1 | 722 | 0.7 | |||||||
| 1979 | 1 571 | 1.2 | 3 195 | 4.7 | 182 | 0.6 | 505a | 0.1 | |||||
P1 = Parastatal organization
P2 = Privately owned fishing units
a Data for one unit available up to May
Table 3
Comparison of increase of fishermen (1975 and 1978), and change in the numbers of fishing crafts: 1975–78. Data from Fisheries Department Statistics
| Area/year | Fishermen | Changes in numbers of fishing crafts | Total | ||||
| 1975 | 1978 | 1975 | 1976 | 1977 | 1978 | ||
| Northern region | 2 667 | Data not available | 623 | 800 | 1 423 | ||
| Likoma/Chizumulu Is. | 260 | 195 | 425 | 158 | 205 | 983 | |
| Nkhota Kota/Dormira Bay | 2 552 | 1 740 | 880 | 544 | 1 449 | 1 038 | 3 911 |
| Southwest arm | 1 008 | 388 | 277 | 697 | 761 | 2 123 | |
| Southeast arm | 1 567 | 1 658 | 1 432 | 1 101 | 1 154 | 5 345 | |
| Lake Malombe/Upper Shire | 396 | 878 | 470 | 485 | 410 | 362 | 1 727 |
| Lake Chiuta | 180 | 198 | . . . . . . . . . . . Data not available. . . . . . . . . . . | ||||
| Lake Chilwa | 597 | 657 | |||||
| Lower Shire | 1 938 | 2 158 | 1 840 | 1 653 | 1 668 | 1 569 | 6 730 |
| Total | 5 663 | 11 133 | 5 431 | 4 816 | 6 106 | 5 889 | 22 242 |
Some data missing
Table 4
Fishermen with and without fishing crafts for 1978
| Area | 1978 | ||
| Fishermen with crafts | Fishermen without crafts | Percentage of fishermen without fishing crafts | |
| Northern region | 1 713 | 954 | 36 |
| Likoma Island | 205 | 55 | 21 |
| Nkhota Kota/Domira Bay | 1 295 | 445 | 26 |
| Southwest arm | 761 | 247 | 25 |
| Southeast arm | 1 154 | 413 | 26 |
| Lake Malombe/Upper Shire | 362 | 516 | 59 |
| Lake Chiuta | . . . . . . . . . . . . . Data not available . . . . . . . . . . . . . | ||
| Lake Chilwa | |||
| Lower Shire | 1 569 | 589 | 27 |
| Total | 7 059 | 3 219 | 31 |
Table 5
Changes from dugout canoes to plank boats with or without seagull outboard engines between 1977–79. Data from Fisheries Department Statistics
| Area | 1977 | 1978 | 1979 | ||||||
| Canoe | Boat without engine | Boat/engine | Canoe | Boat without engine | Boat/engine | Canoe | Boat without engine | Boat/engine | |
| Northern region/Likoma Island | 1 622 | 14 | 9 | Data not available | 1 104 | 6 | 9 | ||
| Nkhota Kota/Domira Bay | 1 457 | 63 | 130 | 978a | 37 | 140 | 1 001 | 56 | 149 |
| Southwest arm | 530 | 39 | 131 | 394 | 9 | 79 | 427 | 24 | 91 |
| Southeast arm | 649 | 243 | 178 | 699 | 242 | 231 | 613 | 238 | 201 |
| Lake Malombe/Upper Shire | 98 | 193 | 133 | 175 | 220 | 87 | 39 | 188 | 83 |
| Lake Chiuta | |||||||||
| Lake Chilwa | |||||||||
| Lower Shire | |||||||||
Table 6
Annual estimated catches of fish by species in 1978 (weight in t) Data from Fisheries Department Statistics
| Area | Sarotherodonspp. | Mixed small Haplochromisspp. | Unmixed Haplochromis spp | Catfish | E. sardella | Other species | Total |
| Northern region | 87 | 57 | 351 | 582 | 79 | 326 | 1 482 |
| Likoma Island | 2 | 29 | 2 313 | 366 | 14 | 50 | 2 774 |
| Nkhota Kota/Domira Bay | 339 | 1 214 | 431 | 881 | 17 | 480 | 3 362 |
| Southwest arm | 3 412 | 487 | 513 | 2 064 | 1 228 | 855 | 8 559 |
| Southeast arm | 3 956 | 602 | 710 | 903 | 214 | 266 | 6 652 |
| Lake Malombe/Upper Shire | 5 425 | 249 | - | 259 | - | 126 | 6 059 |
| Lake Chiuta | . . . . . . . . . . . Data not available . . . . . . . . . . . | - | |||||
| Lake Chilwa | - | ||||||
| Lower Shire | 1 236 | - | - | 3 671 | - | 650 | 5 557 |
| Total | 14 457 | 2 639 | 4 318 | 8 726 | 1 552 | 2 753 | 34 445 |
Table 7
Annual estimated catch by gear in the fishing areas for 1977 Data from Fisheries Department Statistics
| Area/Gear | Northern region | Likoma Island | Nkhota Kota Domira Bay | Southwest arm | Southeast arm | L. Malombe/Upper Shire | Lake Chiuta/Lake Chilwa | Lower Shire |
| Gillnets | 695 | 332 | 1 134 | 4 972 | 4 020 | 4 302 | 8 | |
| Beach seines | 48 | - | 919 | 455 | 833 | 1 467 | 4 | |
| Purse seines | 215 | 2 162 | 721 | 471 | 1 147 | 47 | - | |
| Longlines | 142 | 42 | 75 | 27 | 77 | 3 | Data | 1 |
| Fish traps | 1.0 | - | 0.5 | 20 | 0.9 | 0.03 | not | 3 |
| Handlines | 0.07 | 5 | 5 | 27 | - | - | available | - |
| Scoop nets | 4 | - | 8 | - | - | 3 | 2 | |
| Other gears | - | - | - | - | - | - | 0.2 | |
| Mosquito nets | 62 | 13 | 2 | 812 | 139 | 30 | - |
Fish traps, handlines and scoop nets do not seem to be effective fishing gears in Lake Malombe, Lake Malawi and the Upper Shire River. Fishing in the Lower Shire River is conducted in the floodplains.
Fishing in Lake Malombe and the Upper Shire River is basically with gillnets and beach seines and mosquito nets being the next relatively effective gears. Longlining and purse seining are very important in the north where the lake is very deep with steep sides. Purse seining is also important in the centre and south (Table 6). But gillnets are the major fishing gears in southeast arm and southwest arm.
Gillnets in the Nkhota Kota/Domira Bay, Southwest arm, Southeast arm and Lake Malombe mainly exploit Sarotherodon spp. Beach seines mainly catch Sarotherodon spp., which are abundant in the above-mentioned fishing areas. Purse seines are used to catch the semipelagic unmixed Haplochromis spp. Little wonder that this is the major gear used in the north.
This information on its own does not tell reasons for the differential evolution in the fishing craft. A look at the differences in the beach prices of the species may explain the reasons for the differences in the economic growth in the nine fishing areas (Table 7).
Sarotherodon spp. fetch relatively high prices in all the fishing areas, Likoma Island is the only exception, where Eugraulicypris sardella and other species fetch high prices.
Large-Scale Producers
The parastatal organizations have carrier boats which ferry fish as they are caught from the trawlers to the factory. The factory has refrigeration facilities and ice plants. The fish is washed, weighed in standard boxes and either kept in refrigerators or in ice. The unmixed Haplochromis spp. are sometimes sun-dried. Some catfish of the species Bagrus meriodinalis are filleted and smoked. Recently, the organization started to package the unmixed Haplochromis spp. and E. sardella in polythene bags and freeze them.
The sale of fish is usually by wholesale to fishmongers who sun-dry them and later sell them in urban and rural markets. Sometimes the organization has contracts for supply of dried fish, this is why it sun-dries the fish. Smoked filleted catfish are sold to hotels. The fresh fish in bags are exclusively for urban markets where they are sold in supermarkets.
Individually-owned pair trawlers are the creation of the Government, which initially provided credit facilities. They operate on Government-managed markets. Formerly, the Government also used to supply fuel and repair services on credit. Fish is kept in ice boxes the whole day in boats and sold to fishmongers in the evening. Fishmongers usually sun-dry the fish. Once dry, the fishmongers either take the fish to urban or rural markets to sell it on retail, or at wholesale price.
Small-Scale Producers
The small-scale producers generally do not stay out for long hours, therefore, their fish is always in good condition. The fish are sold immediately on landing either at wholesale or retail prices, depending on the size of the catch and demand. Processing is either by sun-drying or smoking. Buyers who have trucks usually take the fish on ice to urban markets. This is done with Sarotherodon spp. only and it is practised only in the southern fishing areas of Southwest arm, Southeast arm, Lake Malombe and the Upper Shire River.
Table 8
Average beach prices of the species caught in the nine fishing areas (1978) (in Tambala/kg)a
| Species/Area | Sarotherodon spp. | Mixed Haplochromis spp. | Unmixed Haplochromis spp. | Catfish | Eugraulicypris sardella | Others | Average price |
| Northern region | 17 | 28 | 7 | 15 | 9 | 5 | 14 |
| Likoma Island | 6 | - | 7 | 8 | 14 | 15 | 10 |
| Nkhota Kota/Domira Bay | 14 | 6 | 10 | 11 | - | 12 | 11 |
| Southwest arm | 14 | 9 | 6 | 10 | 3 | 9 | 9 |
| Southeast arm | 13 | 6 | 6 | 9 | 7 | 9 | 8 |
| Lake Malombe/Upper Shire | 12 | 5 | - | 8 | - | 8 | 8 |
| Lake Chiuta | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Data not available . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . | ||||||
| Lake Chilwa | |||||||
| Lower Shire | 13 | - | - | 11 | - | 9 | 11 |
| Average price | 13 | 11 | 7 | 10 | 8 | 10 | 10 |
Marketing of fish at wholesale prices is easier in the centre and south than it is in the north. This is evidenced by the difficulties the new individually-owned pair trawler experiences in the north. There are three obvious reasons for this. The road condition in the north is poorer than in the centre and south. Some of the roads are impassable during the rainy season. The estates and urbanization in the south and a rapidly growing population in the centre induced by the transfer of the capital city of Lilongwe has created higher population densities, and thus the south and centre have larger populations than the north. Figure 1 shows the movement of fish from the fishing areas to the markets. The width of the arrows signify the relative quantities of fish delivered to respective main markets.
Since 1975 the Fisheries Department has been empowered by a Parliamentary act to license gillnets, beach seines, chilimira nets and mosquito nets. Licensing was first started in Lake Malombe, the Upper Shire River, the Southeast arm and the Southwest arm. Later it was introduced to Nkhota Kota/Domira Bay, Lake Chilwa and the Lower Shire River. These are areas of high catches. The fisheries are also fairly intensive, especially in Lake Malombe, the Upper Shire River, Southeast arm, Southwest arm, and Nkhota Kota and Domira Bay. The licensing has just started in the northern region although it is not enforced as strictly as is done in the centre and south. This in itself has persuaded me to think of the north as an area of active fisheries development, while the centre and the south are areas of regulatory fisheries management. The implication of fisheries management here is to allow a balanced growth of the fisheries.
A boat-building project is soon to be in operation in the northern region. This, with the leniency in the enforcement of the laws, may encourage fishermen in the north to modernize.
Fisheries planning is very different from agricultural planning. The difference comes about because here we are dealing with a resource which is hidden under water, therefore, inventory taking presents a special problem (Hamlisch, 1973). Yet data are prerequisite to planning. It is the data which provide guidelines for the choice of development projects - where, when, how and in what order to implement. Consequently, development as a process of improvement with respect to a set of values or transformations of human beings, i.e., modernization (Coleman and Nixson, 1978) will depend on how a fisheries planner analyses the information in front of him. It is clear from the Malawi case study that there are many interlocking factors that govern the trend of fisheries development. The identification of the trend will allow the designing of the future desired objectives and the construction of a plan. It is noted here that the fisheries have not been modernized in the north probably because of lack of a nearby boat-building project. This has led to less fish being caught and consequently higher prices of fish. A boat-building project, which is soon to be started in the area, is intended to correct this situation. The Malawi Fisheries Department seems to have several objectives for developing the fisheries resources of the country.
The introduction of credit facilities for the trawl fishery and running of boat-building yards supports this. Bigger and safer boats also improve working conditions of fishermen. The development of the ornamental fishery is intended to contribute to the flow of foreign exchange to the national economy. While the management regulations are supposed to minimize conflicts among different fisheries and to prevent irrational use of the resources.
Coleman, D. and F. Nixson, 1978 Economics of change in less developed countries. Oxford, Philip Allan
Hamlisch, R., 1973 Fisheries planning to meet economic and social objectives with special reference to countries bordering the Eastern Central Altantic. J.Fish.Res. Board Can., 30(12)Pt.2:2276–81
Proude, P.D., 1973 Objectives and methods of small-scale fisheries development. J.Fish.Res. Board Can., 30(12)Pt.2:2190–5
