Appendices:

Appendix 1

LIST OF PARTICIPANTS

TECHNICAL CONSULTATION ON THE ENHANCEMENT OF SMALL WATER BODY FISHERIES IN SOUTHERN AFRICA, 25–29 January 1993, Harare, Zimbabwe

Mr.D. Bandula
SADC Fisheries Sector Coordination Unit
c/o Chief Fisheries Officer
PO Box 593
Lilongwe, MALAWI
Phone: +265-721766
Fax:+265-721117
Telex:44709 SADFISH MI

Mr. J.J.Baloyi
Dept of Research and Specialist Services
Henderson Research Station
PO Box 2004
Mazowe, ZIMBABWE
Phone:+263-75-2281

Mr. Wellington Binali
AGRITEX Fisheries Unit
PO Box 8117
Causeway, Harare, ZIMBABWE
Phone:+263-4-703820

Mr. Alan Brooks
Central & Northern Regions Fish Farming
Project
PO Box 700
Mzuzu, MALAWI
Phone:+265-332794
Fax:+265-335051

Ms. Maria do Carmo Carrilho
Fish Culture Department
CP 4590
Maputo, MOZAMBIQUE
Phone:+258-1-460011 Ext. 301/2
Fax:+258-1-460479
Telex:6196 MAGRI MO

Mr. Arne Fjaelling
Institute for Freshwater Research
S-17893 Drottningholm, SWEDEN
Phone:+46-8-759-0040
Fax:+46-8-759-0338

Mr. Daniel Jamu
ICLARM
PO Box 229
Zomba, MALAWI
Phone:+265-531274/215
Fax:+265-522559

Dr. James Kapetsky
Inland Water Resources & Aquaculture Service
Fishery Resources & Environment Division
Fisheries Department
FAO, via delle Terme di Caracalla
00100 Rome Italy
Phone:+39-6-5225-6646
Fax:+39-6-5225-3020
Telex:610181 FAO I

Dr. Ossi V. Lindqvist
University of Kuopio
PO Box 1627
SF-70211 Kuopio FINLAND
Phone:+358-71-162100
Fax:+358-71-162131
Telex:42218 KUY SF

Dr. Cecil Machena
Acting Chief Ecologist (Aquatic)
Dept of National Parks & Wildlife Management
PO Box 8365
Causeway, Harare, ZIMBABWE
Phone:+263-4-790816

Ms. Grace A. Mafwenga
Regional Fisheries Office
PO Box 3012
Arusha, TANZANIA
Phone:+255-57-3568

Mr. Freddie Magagula
Fisheries Section
Ministry of Agriculture & Cooperatives
PO Box 162
Mbabane, SWAZILAND
Phone:+268-42731 ext. 194
Fax:+268-44700
Telex:2343 AGRIC WD

Mr. Charles Makawa
Central & Northern Regions Fish Farming
Project
PO Box 700
Mzuzu, MALAWI
Phone:+265-332794
Fax:+265-335051

Ms. C. Mangwaya
Henderson Fish Farm
Dept of National Parks & Wildlife Management
PO Box 8365
Causeway, Harare, ZIMBABWE
Phone:+263-75-2281

Dr. Brian E. Marshall
Dept of Biological Sciences
University of Zimbabwe
PO Box MP 167
Mount Pleasant, Harare, ZIMBABWE
Phone:+263-4-303211 x1489

Ms. Tabeth Matiza
IUCN
PO Box 745
Harare, ZIMBABWE
Phone:+263-4-728266
Fax:+263-4-720738
Telex:22670 IUCN ZW

Mr. Wilson Mhlanga
Lake Kariba Fisheries Research Institute
Dept of National Parks & Wildlife Management
PO Box 75
Kariba, ZIMBABWE
Phone:+263-61-2936
Fax:+263-61-2938

Dr. Heimo Mikkola
Office of the FAO Representative
CP 1928
Maputo, MOZAMBIQUE
Phone:+258-1-491136, 490948
Fax:+258-1-491906
Telex:6120 FAOR MO

Mr. Trevor Mmopelwa
Fisheries Section
Ministry of Agriculture
Private Bag 003
Gaborone, BOTSWANA
Phone:+267-350502
Fax:+267-356027
Telex:2543 VET BD

Ms. Seipati Mofolo
Fisheries Section
Ministry of Agriculture
Private Bag 82
Maseru, LESOTHO
Phone:+266-322444
Telex:4441

Mr. Joseph Mutale
Department of Fisheries
PO Box 510738
Chipata, ZAMBIA
Phone:+260-62-22755
Fax:+260-62-21321
Telex:63020 AGRICO ZA

Mr. Chris Nobbs
AGRITEX Animal Production Branch
PO Box 8117
Causeway, Harare, ZIMBABWE
Phone:+263-4-707311
Telex:2455 ZW

Mr. Chris Nugent
Project ZIM/88/021
c/o FAO Representative
PO Box 3730
Harare, ZIMBABWE
Phone:+263-4-703820
Fax:+263-4-729563
Telex:26040 FAO ZW

Dr. Pierre-Denis Plisnier
FAO/FINNIDA Lake Tanganyika Research Project
PO Box 55
Mpulungu, ZAMBIA
Phone:+260-4-455188
Fax:+260-4-455055

Mr. Brian Rashidi
Central & Northern Regions Fish Farming
Project
PO Box 700
Mzuzu, MALAWI
Phone:+265-332794
Fax:+265-335051

Mr. Arjo Rothuis
Dept of Fish Culture & Fisheries
Wageningen Agriculture University
PO Box 338
6700 AH Wageningen, NETHERLANDS
Phone:+31-83-708-3307
Fax:+31-83-708-3962

Mr. Nelson Shila
Project URT/87/016
c/o FAO Representative
PO Box 2
Dar-es-Salaam, TANZANIA
Phone:+255-51-46478
Fax:+255-51-32979
Telex:41320 FOODAGRI TZ

Mr. E.S. Shoniwa
AGRITEX Fisheries Unit
PO Box 8117
Causeway, Harare, ZIMBABWE
Phone:+263-4-703820

Prof. D.F. Thys van den Audenaerde
Musee Royal de l'Afrique Centrale
B-1980 Tervuren BELGIUM
Phone:+32-2-769-5285
Fax:+32-2-767-0242

Dr. Francois Vallet
Project LIB/88/009
c/o UNDP, PO Box 358
Tripoli, LIBYA
Fax:+218-2130856 (UNDP)
Telex:20523 MBRC LY (MBRC, Tajura)

Mr. Henk van der Mheen
Project ZIM/88/021
c/o FAO Representative
PO Box 3730
Harare, ZIMBABWE
Phone:+263-4-703820
Fax:+263-4-729563
Telex:26040 FAO ZW

Mr. B.J. van Zyl
Fresh Water Fish Institute
Private Bag 2020
Mariental, NAMIBIA
Phone/fax:+264-661-361

ALCOM

Mr. Arne Andreasson
ALCOM
PO Box 3730
Harare, ZIMBABWE
Phone:+263-4-724985
Fax:+263-4-729563
Telex:26040 FAO ZW

Mr. Sam Chimbuya
ALCOM
PO Box 3730
Harare, ZIMBABWE

Mr. Francisco David e Silva
ALCOM
PO Box 3730
Harare, ZIMBABWE

Ms. Elin Elsdal
ALCOM
PO Box 3730
Harare, ZIMBABWE

Ms. Birgitta Larsson
ALCOM
PO Box 3730
Harare, ZIMBABWE

Mr. Soeren Leth-Nissen
c/o Dept of Fisheries
PO Box 510738
Chipata, ZAMBIA
Phone:+260-62-22755
Fax:+260-62-21321

Mr. Niklas Mattson
c/o ICLARM
PO Box 229
Zomba, MALAWI
Phone:+265-531274/215
Fax:+265-522412

Mr. Ulf Nermark
c/o UNDP
PO Box 54
Gaborone, Botswana
Phone:+267-350502
Fax:+267-356027
Telex:2543 VET BD

Ms. Sevaly Sen
ALCOM
PO Box 3730
Harare, ZIMBABWE

Mr. Christophe Tilquin
c/o FAO Representative
PO Box 7588
Maseru 100, LESOTHO
Phone:+266-315585
Fax:+266-310196
Telex:4237 FAOLES LO

Ms. Lena Westerlund
ALCOM
PO Box 3730
Harare, ZIMBABWE

Observers

Mr. Ron Evans
Rothmans Fish Farm
PO Box ST 98
Southerton, Harare, ZIMBABWE

Mr. Emmanuel Koro
City of Harare
PO Box 990
Harare, ZIMBABWE
Phone:+263-4-706536 x204

Dr. Hilary M. Masundire
Lake Kariba Research Station
University of Zimbabwe
PO Box 48
Kariba, ZIMBABWE
Phone:+263-61-22312
Fax:+263-61-2938

Mr. Paul Mutangabura
Africare
PO Box 308
Harare, ZIMBABWE
Phone:+263-4-42610
Telex:24666 ZW

Mr. D. Nkala
Office of the UNDP Resident Representative
PO Box
Harare, ZIMBABWE
Phone:+263-4-792681
Fax:+263-4-728695
Telex:

Mr. A. Stockseth
Office of the FAO Representative
PO Box 3730
Harare, ZIMBABWE
Phone:+263-4-723545
Fax:+263-4-729563
Telex:26040 FAO ZW

Mr. Dirk Teerlinck
BADC Regional Cooperation Section
Embassy of Belgium
PO Box 2522
Harare, ZIMBABWE
Phone:+263-4-793306
Fax:+263-4-703960
Telex:24788 AMBEL ZW

Secretariat

Mr. Boyd A. Haight
ALCOM
PO Box 3730
Harare, ZIMBABWE

Ms. Monique Maes
ALCOM
PO Box 3730
Harare, ZIMBABWE

Ms. Lorraine Weir
ALCOM
PO Box 3730
Harare, ZIMBABWE

Appendix 2

AGENDA

TECHNICAL CONSULTATION ON THE ENHANCEMENT OF SMALL WATER BODY FISHERIES IN SOUTHERN AFRICA, 25–29 January 1993, Harare, Zimbabwe

Sunday 24 January

Monday 25 January

Tuesday 26 January

Wednesday 27 January

Thursday 28 January

Friday 29 January

Appendix 3

LIST OF DOCUMENTS

TECHNICAL CONSULTATION ON THE ENHANCEMENT OF SMALL WATER BODY FISHERIES IN SOUTHERN AFRICA, 25–29 January 1993, Harare, Zimbabwe

Document No. Title

Country Posters

Small Reservoir Fisheries in Botswana

Utilisation of Small Water Bodies in Lesotho Lowlands

Dam Enhancement Survey in Malawi

Small Water Bodies in Namibia

Minor Fresh Water Fisheries in Tanzania

Small Water Bodies in Eastern Province, Zambia

Possibilities for Development of Extensive Fish Farming in Upland River Valley Systems in Western Zambia

Small Water Body Fisheries in Zimbabwe

Appendix 4

ABSTRACTS

TECHNICAL CONSULTATION ON THE ENHANCEMENT OF SMALL WATER BODY FISHERIES IN SOUTHERN AFRICA, 25–29 January 1993, Harare, Zimbabwe

by Boyd A. Haight
ALCOM, Harare

There is no official definition of a Small Water Body. A useful definition was given by Anderson at the 1987 CIFA Symposium on the Development and Management of Fisheries in Small Water Bodies:

Small Water Bodies are defined as small reservoirs and lakes of less than 10km: small ponds, canals, irrigation canals, swamps and small seasonal, inland floodplains. They also include small rivers and streams of less than 100km in length. They do not include mangroves, large coastal and inland floodplains or coastal lagoons with intensive, well established fisheries, or fish ponds.

Small Water Bodies can be classified in two broad categories, firstly, the man-made Small Water Bodies (dams, reservoirs, irrigation canals, etc.) and secondly, the natural ones (floodplains, swamps and natural ponds). Further classification can be made for example on the basis of size, average depth, and seasonality depending on use of this information. Bernacsek (1985) estimated from published statistics that there are over 19,000 small water bodies in Africa, but concluded that this a gross underestimate due to under-reporting.

The number and extent of small water bodies in the SADC region varies by country, generally increasing to the south. This corresponds with generally lower rainfall patterns and population densities. For example, Malawi and Tanzania have many hundreds of small reservoirs, while Zambia has over 1000 and Zimbabwe many thousands. Many new reservoirs are being built in Botswana. The poster session will give the most up-to-date figures for the region.

Based on FAO statistics (1989), the average annual fish catch from major lakes, hydro-electric reservoirs and major rivers in Africa is approximately 1 870 000 tons/year. It is generally recognized that many of the inland fisheries seem to approach the limits of sustainable production and a majority are over-exploited. For many years, the fisheries management in reservoirs and Small Water Bodies received little attention from fishery developers and planners. However, with the increasing competition for use of water resources and the over-exploitation of inland and marine waters, one of government's policies is to focus on management of these Small Water Bodies.

To date, the overall potential of Small Water Bodies to supply dietary animal protein to the rural areas has never been adequately evaluated. Small Water Bodies have often been neglected by fisheries developers and planners in Africa, who have either focused on large inland waters, marine fisheries or on aquaculture. On an overall basis, the potential production of these African Small Water Bodies has been roughly estimated at between 990 000 and 2 300 000 tons/year (Bellemans, 1989) or at between 1 and 3 million tons by Bernacsek (1984). These data explain the new interest of people in these Small Water Bodies.

Yields of reservoirs are highly variable as a result of geographic location, natural productivity and fisheries management. The shape of a water body provides a good guide to its potential production, although many classifications must be arbitrary and many examples will not fit in.

Throughout Africa, many of these Small Water Bodies are already fished by an unknown number of fishermen, with an unknown quantity of fish but probably at a level of subsistence. Small Water Bodies' fisheries are usually traditionally managed because of their limited access and low fishing intensity. At this level, the fishery is often open to anyone, it represents an opportunity for the poorest to obtain what may be an important supplement to their diet. They use simple traps, hooks and lines, nets and mosquito nets. Gear and implements may be manufactured by fishermen and often shared with other members of the fishing community. Choice of gear is dependent on many factors such as water depth which varies with season and the age of the fishermen.

Pierre Denis Plisnier
FAO/FINNIDA Lake Tanganyika Research Project
Mpululngu, Zambia

Based on the shape of small water bodies (<10km²), they can be classified into three main types: “lake type”, “multi-branch” and “river type” (ALCOM, pers.com). Each of those can be arbitrarily subdivided into shallow water type (<3–4 meters for example) and deep water type.

“Lake type” small water bodies are often shallow, and present a gently sloping flat land. They are often very productive.

“Multi-branch” small water bodies are characterized by a higher littoral/pelagic ratio and are generally occupied by important macrophyte communities. When shallow, those ecosystems can present a very high primary productivity.

“River-type” small water bodies are often deep, present a steep side, and often located in mountainous areas. Their productivity is generally moderate to poor depending on average depth.

The high S/V (surface area/volume ratio) of many SWB is responsible for a high heat and light budget favourable to phytoplankton production. This same ratio is also responsible for the low capacity of those ecosystems to buffer the environmental effect which acts over the surface area. The daily variation of temperature, Ph and dissolved oxygen can be extremely wide.

When shallow, the waters often get mixed completely by wind action. This allows the mixing of the nutrients favouring a high primary productivity. High biomass of plankton in shallow water can reach 500 μg chl a^-1 (LEMOALLE & al, 1981).

The resuspension of sediments by wind action in shallow waters can also induce such phenomenona as decrease in light penetration, high variation of conductivity, poor substrate condition for invertebrates.

Many small water bodies -- “lake type”, or shallow multi-branch" type -- have seasonal flooding plains responsible for important inflow of nutrients into the system and seasonal variation of the ionic content.

The relations between morpho-edaphic index and fish yields may not be very useful for SWB as their conditions of use are often not met. Dystrophy, and important fluctuations in water volume, temperature regime and conductivity can often be observed. Moreover, existing relations have not been established for the size and volume range characteristics of the SWB.

In order to assess the MSY of fisheries in SWB, it would be interesting to conduct more limnological studies in those specific ecosystems. Some of the variables to take into consideration should probably include primary productivity, total phosphorus and chlorophylle a.

The number of small water bodies being important, remote sensing studies of variables such as chlorophylle a, temperature and turbidity should be considered. This field of investigation may prove very interesting considering the relations between chlorophylle a and primary productivity (LEMOALLE and al, 981) and primary production.

by D. Thys van den Audenaerde
Musee Royal de l'Afrique Central
Tervuren, Belguim

The composition of the fish fauna in small water bodies is subject to several ecological principles.

The number of fish species inhabiting the small water body is ruled by:

• the law of Arrhenius concerning surface and species-numbers;
• the number and sizes of the different biotopes.

The interdependence with the original and inflowing river systems is maximal to very important, according to the size of the small water body.

The annual fluctuations of water level and chemical composition are most important in small water bodies.

According to the parallel S. Wright principle concerning small number populations, the numbers for stocks of different fish species can fluctuate highly from year to year.

When compared to the original riverine condition, the following modification in fish faunal composition can be expected:

• an increase inTilapiafishes proportional to the extension of breeding and feeding areas, with fluctuations according to water level and its annual fluctuation;
• a variable increase of the different Haplochromine fishes, with much fluctuation based on the availability of the specialized food;
• an increase of Schilbeids as far as a permanent pelagic biotope became permanent;
• few modifications in Mormyrids;
• at present there is almost no information available on the possibilities of small pelagic clupeids and cyprinids in small water bodies.

by C.N.Mangwaya
Department of National Parks and Wildlife Management,Harare, Zimbabwe

If fish production in small water bodies of southern Africa is to be maximized, the indigenous tilapias have certain disadvantages -- early maturity and precocious breeding,which result in overcrowding and stunted growth. Carp is being cultured by some commercial farmers in Zimbabwe. There are several pros and cons to introducing Chinese carps -- such as the grass carp, the silver carp and the big-head carp -- into small water bodies of the region. The grass carp has a remarkable growth rate (almost an average of 1 kilo per year in the tropics); it is a natural eliminator of weeds as it feeds on them. Stocking of grass carp together with indigenous omnivorous tilapia species should therefore be considered. The issues to be addressed are source of seed, stocking rates, the economics of seed production and reservoir harvesting, local demand for carp, and potential negative impact on indigenous fish species.

by James M.Kapetsky
FAO Inland Water Resources and Aquaculture Service, Rome, Italy

This paper seeks to provide a general framework to acquire the information needed to develop and manage small water bodies for fisheries and aquaculture. The general framework is in two parts. The first is a sampling framework. The emphasis here is on the first level of information, that which is needed for planning at regional and national levels. A simple sampling frame that has been developed for SWBs lists five broad categories of information: administrative, environmental, economic, social and cultural. Basic approaches to acquire this information include search of existing government records; on-the-ground surveys based on maps; and aerial or satellite remote sensing. In practice, it may be desirable to use all three approaches.

Once the first-level data are available, they can be analyzed in a number of ways. This is the analytical framework. This paper describes the use of a geographical information system (GIS) as an analytical framework for small water bodies and for fish farming. A case study from Ghana is used to illustrate a combination of approaches to analytical frameworks for SWBs.

by James M. Kapetsky
FAO Inland Water Resources and Aquaculture Service, Rome, Italy.

This paper describes the rationale, objective and preliminary results from “Strategic Assessment of Fish Farming Potential in Africa”, a study conducted by the FAO's Inland Water Resources and Aquaculture Service. The study uses spatial indicators -- such as temperature, water availability, agro-climatic zones, population distribution, social conditions and infrastructure -- to estimate fish farming potential. According to the study, 29 countries of Africa, including five in SADC -- Angola, Tanzania, Mozambique, Malawi and Zambia -- have conditions suitable for warm water fish farming.

A more rigorous application of the study to SADC will enable a review of aquaculture status and trends in the region. Such an exercise is presently being undertaken by the FAO in partnership with ALCOM. It will modify three of the seven spatial criteria -- temperature, water availability and agriculture by-products -- to take into account the conditions in southern Africa. An eighth criterion may be added -fish farm density in sub-national boundaries. A GIS (geographical information systems) map for SADC developed from the study can yield information useful also for small water body development and management.

by Niklas Mattson
ALCOM, Zomba, Malawi

Stock assessment in general is outlined and its dependence on sound sampling techniques emphasized. It is argued that the development of empirical predictive models is pivotal for efficient management to the numerous and diverse small water bodies. The information needed to modify existing models, or to create new models, can be gained by conducting comparative studies of small water bodies and their stocks. A prerequisite is the establishment of a data base of small water body characteristics. This will require sampling programmes on selected small water bodies. Parameters to be included in the data base are proposed. An example of a fish sampling technique is given, which employs a gear that is being tested and modified for use on small water bodies: the “Drottningholm” benthic multi-mesh gillnets.

by Henk W. van der Mheen
Support for Rural Aquaculture Extension
FAO, Harare Zimbabwe

Gillnet fishery in Zimbabwe is a licensed fishery. Before a licence can be issued for a certain reservoir, the potential for an increase of the fishing pressure has to be determined. Since there is a large number of dams in Zimbabwe, a simple method applicable on a large scale is required. This paper discusses the direct assessment of the fishing activities, the assessment of the fish stock, and the use of a length frequency distribution as an indicator of the fishing pressure. For AGRITEX Fisheries Unit the last method proved the most appropriate. Examples of the use of this method on different dams are discussed.

by Joseph C. Mutale
Department of Fisheries, Chipata, Zambia

Soeren Leth-Nissen
ALCOM, Chipata, Zambia

Eastern Province is characterized by more than 200 small water bodies varying in size from 4 to 30 hectares, and covering an estimated area of 1 000ha (Mattson and Mutale, 1992). The fishery potential of these SWB is significant, 50 to 200 tonnes of fish per year. Most of them were stocked in the 1960s and 1970s and are at present overfished and poorly managed.

The District Council is the administrative unit charged with issuing gillnet licences upon approval of the Department of Fisheries (DoF). The DoF recommends a stretched mesh size of 87.5mm but there is no restriction on the number of nets used by the license holder, or on the number of boats on a reservoir. No licence is needed for hook and line fishing.

In contrast to many of the other provinces in Zambia, Eastern Province has no capture fishery. Consequently, a creel survey in two small water bodies was designed in order to monitor the fishing effort, identify fishing gear used, register yields, record monthly catch data for the different fishing gear and finally to try to estimate the potential fish production of these SWBs. This paper presents preliminary results, generated over a period of 9 months (April 1992 to January 1993).

by Brian E. Marshall
Department of Biological Sciences
University of Zimbabwe, Harare.

It is useful to have some estimate of potential yield when planning a fishery, and various models have been used to predict yield from physical, chemical or low-order biological variables. Most of this work has been done on larger water bodies and their applicability to small ones depends on the degree of similarity between the two. The relationships between large and small waters are examined in this paper and the applicability of existing predictive models is considered. Some of the disadvantages of this approach are also reviewed.

by Samuel Chimbuya
ALCOM, Harare

Development and/or management of SWBs requires knowledge and recognition of both the bio-technological constraints and opportunities and the socio-economic features of the community around the reservoirs.

SWBs on the whole are man-made and suitable for multiple uses: fisheries is a secondary activity. They have well defined physical boundaries and identifiable local communities that exploit them. Due to the multiplicity of use of SWBs and the complexity of social, cultural and economic backgrounds of the different communities, development agencies should establish a dialogue with target communities in order to tailor technological interventions to the particular setting pertaining to that community.

Conventional methods of data collection are time-consuming, invariably inflexible and take a long time to produce results. The pace of change in the socio-economic environment of target communities makes conventional methods inappropriate for introducing technological interventions that respond to the needs of the community. The Rapid Rural Appraisal method, on the other hand, is designed to investigate the socio-economic features of a community and enable the planner to take into account the problems and concerns of the target community. It is iterative, innovative and interactive. Analysis of results is done in the field with the people and results are ready to use at the end of the appraisal. The flexibility and adaptability of Rapid Appraisals makes this method most suitable for assessing community interest before initiating development projects.

by Monique Maes
ALCOM, Harare

Many African countries suffer from short supply of fish for several reasons: drought, poor roads, lack of facilities for processing and preservation. Sometimes, even if fish is available, it is expensive. Based on FAO statistics (1989), the average fish catch from major lakes, hydro-electric reservoirs and major rivers is approximately 1 870 000 tons/year. It is generally recognized that it seems to approach the limits of sustainable production. The potential production of these SWB has been roughly estimated at between 1 and 3 million tons (Bernacsek, 1984). These data explain the new interest of people in SWB.

The other reasons for paying attention to these SWBs are:

• they already exist and no capital expenditure is need to create them.
• they are high in nutrient content.
• they are usually located in the rural areas of the dry zone.
• they would provide a fresh source of protein where it is most needed.
• they could provide employment for rural people.
• fishermen can cover most of the area of a Small Water Body, and
• because of their number, size and distribution throughout countries, SWB are in a position to provide fish at a low price affordable by the rural population.

This paper provides an overview of the different possibilities for managing a SWB. Three possibilities are: (i) enhancement of fisheries (ii) extensive stocking and (iii) development through aquaculture.

The management of an open fishery could be made in different ways:

• the use of supplementary feeding,
• the use of fertilizer, thus the integration of farming systems,
• protection of breeding areas,
• control of fishing gears and number of fishermen, and
• as a focus of recreational activities, leisure.

Stock enhancement is a major approach to increase in fish yield in open fisheries and is characterised by low cost and high efficiency. It can also be useful when there is a lack of fish preservation (pollution, use of wrong fishing gears). Stocking could also be useful to furnish fingerlings to rural people for their fish ponds.

Aquaculture could be done at semi-intensive and intensive levels. The difference between the two is based mainly on the quality of feeds and fertilizers and therefore on the costs. Aquaculture development could be organized through cages and pens.

by John Moehl and Bill Davies
Auburn University, Auburn, Alabama USA

Management strategies for small impoundment fish populations are reviewed, with consideration given to intensification techniques applied throughout the United States and Canada. Intensification is achieved by enhancing water fertility through liming and fertilization. The concept of balance in fish populations is used as a basis to illustrate the importance of maintaining desirable predator/prey relationships through stocking and regulating the harvest of keystone predators. Generally, harvest levels for predators are reduced when species diversity and structural complexity of the environment are increased. Case studies are presented representing contrasting climatic regions of North America which demonstrate similarities in management style. Principles and practices presented in this paper should be adaptable to management of fisheries in small water bodies over a wider range of conditions than those discussed, making them transferable to other regions.

FAO Fisheries Circular. No. 854. Rome, FAO. 1992. 69p.

The construction of reservoirs in the People's Republic of China has created more than 82 man-made water bodies which have increased the inland surface water area by more than 2 million ha. The utilization of these newly established water bodies for the development of culture-based fisheries has been demonstrated as a means of providing animal protein, employment and income for the rural population.

This document provides an insight into some major reservoir fisheries development approaches presently being practised in China. It is divided into two parts. The first includes an overall description of reservoir fisheries in China and the various approaches presently being applied. In the second part, three case studies show three fishery management strategies i.e. (i) a combination of cove and cage culture of fingerlings and table-fish in a reservoir in central China; (ii) integrated culture of fish, livestock, poultry and agriculture in a group of small reservoirs in southeast China; and (iii) application of inorganic fertilizers to enhance fish yields in small reservoirs in northwest China.

by Francisco David e Silva,
ALCOM, Harare

While all SADC countries have some kind of legislation to regulate inland fisheries, SWBs have a number of specific attributes. This paper reviews existing regulations in four SADC countries to discuss how they may facilitate or restrain action to improve the fishery utilization of small water bodies.

by Lena Westerlund,
ALCOM, Harare

This paper reviews some important considerations to be taken into account when organizing small reservoir communities for fisheries management, and illustrates how they apply to one ALCOM pilot project in Zimbabwe.

The concept of “community organization” encompasses a wide variety of organisations, from religious groups to savings clubs. In the small reservoir fisheries context, community-based organizations which exploit the resource in one way or another could be co-operatives, syndicates, limited companies or any other organizational structure. The paper focuses on groups which could both exploit and manage a natural resource.

by Franciso David e Silva
ALCOM, Harare

This paper proposes that the economics of small water bodies should be approached in two ways.

Capture fishery economic theory should be applied to larger small water bodies, while smaller water bodies where fisheries enhancement measures are (to be) applied should be treated as fish ponds. One economic criterion to select larger small water bodies which should receive priority for fishery management purposes, and indicators to assess the economic viability of enhancement measures, are suggested.

by Francios Vallet
FAO Project LIB/88/009, Libya

Small water bodies are found everywhere, providing high quality complementary food for local populations. However, the fish production of small water bodies is generally low. Specific enhancements of the physical environment and the food chain, and interventions on fishing effort and methods, can significantly improve and sustain production. Improvement of catch utilization can also benefit local people. Examples of interventions in several countries are given.

When planning and implementing enhancements, particular attention must be given to protecting the environment and fish stocks to ensure sustainable production. Enhancements should be relevant to and useable by the segments of the local population which regularly use the reservoir.

by Arne Fjaelling
Institute for Freshwater Research
Drottningholm, Sweden

The fish resource in a large number of water bodies in Southern Africa is to be utilized. An extensive inventory/exploitation program is under way within ALCOM. As part of this policy, a strategy for the implementation of appropriate fishing technology is sought. The performance characteristics of some gear for small reservoirs are given. Some considerations on fisheries management are discussed. Several factors - social, biological and physical - affect the choice of fishing gear. Some of them interact in their turn, some vary in time and space. It is concluded that at this stage it is not relevant to make specific recommendations on fishing technology. Instead it is suggested that available information is evaluated and the significance of choice of gear determined. Then a decision tree can be built that can suggest proper exploitation schemes. One way to organize a large and growing body of knowledge of this kind is by a computer assisted AI (Artificial Intelligence) system.

by U.P. Nermark
ALCOM, Harare
T.G. Mmopelwa
Fisheries Section, Ministry of Agriculture
Gaborone, Botswana

This paper describes various local fish catching methods found in the three countries, with emphasis on Botswana. The methods are categorized into net (gill net, seine, liftnet, cast net, mosquito net), hook (hook and line, rod and line, “night line”, longline), trap (basket/funnel traps, “sack-trap”, floodplain traps), herding gear (thorny branches, grass bundles, sack cloth) and others (spear, poison). It has been difficult to identify names for the various gear used, hence the paper is largely descriptive. All in all the methods are adaptations of some well documented gear types to fit local conditions.

Results from fishing with some selected gear in Botswana are presented. Selectivity, availability and cost of gear are also discussed.

by C.G. Nugent and W. Binali
Agritex Fisheries Unit, Harare

Some of the characteristics of small reservoir fisheries in the Southern African region are discussed in relation to the problems of extension. The limited size of the fisheries of each small reservoir, and the fact that these reservoirs are often thinly spread out through the region, combine to make extension communication difficult with (usually non-fishing) communities that live adjacent to these water bodies. Various options are open to government or NGOs -- more or less specialised, more or less decentralised. These approaches are discussed and compared, and particular reference is made to those used in Zimbabwe by the agricultural extension service and others.

by Heima Mikkola
FAO Representative in Mozambique and Swaziland

This paper addresses the existing relationship between fish farming/aquaculture and water-borne human diseases. It also tackles the question: is it possible that new human disease strains could be created through fish farming/aquaculture activities.?

by Birgitta Larsson
ALCOM, Harare

Of the most important and widespread diseases in the tropics, schistosomiasis, malaria and filariasis (including onchocerciasis and lymphatic filariasis) have vectors that directly depend on water for their development or as a habitat. The vectors that transmit arbo-viruses usually depend on water for their development. Micro-organisms can also disperse by contaminated water. It is therefore important to take into account the possible negative health effects in planning and implementing any water-related project. Within aquaculture the most important measures are to remove vegetation in the pond; keep ponds stocked with fish at all times; the pond should have steep (1:1) sides; no urination/defecation in or near the pond; proper hygiene must be maintained in handling and cooking products from the pond.