SUN-DRIED SALTED FISH AS A MEANS OF REDUCING
POST-HARVEST LOSSES IN BOTSWANA

by

T.C. Mmopelwa
Senior Fisheries Officer
Ministry of Agriculture
Private Post Bag 003
Gaborone, Botswana

1. INTRODUCTION

Although large in total area, landlocked Botswana has a relatively small area of surface waters providing year-round fishing grounds. The fishery is concentrated in remote settlements in the Okavango and Chobe river systems. The region lacks in most social amenities like communications and other public utilities. Fishing is to a large extent at subsistence level and fishermen belong to the poorest sector of the communities.

The Botswana fishery suffers from lack of collection of biological and ecological information. Several estimates for the maximum sustainable yield for water bodies within the country have been made based on empirical data. These estimates indicate that the fishery is underexploited. A project to properly assess the resource potential of the national fishery and to design a strategic programme of fisheries resource management was submitted for incorporation in the Government plans of April 1991.

Of the various fish processing technologies available salting and drying has become the most widely adopted in the country. Other fish processing technologies are either less accepted for producing a product without a secure market, or relatively expensive to undertake in a rural settlement. The Okavango and Chobe areas would have enough firewood for smoking, but smoked fish is not accepted in Botswana.

2. THE PROCESS OF SALTING AND DRYING

2.1 Catching Method

The principal method of fish capture in Botswana is gillnetting. Nets are set in late afternoon to be lifted the following morning. In case of large catches nets are hauled and fish removed ashore, otherwise fish is collected and the net is left for a day or two before being moved to a potentially more productive ground. Some of the catch may be alive at the time of checking the net. The dead fish are normally at post rigor condition indicating that entangling in the net occurs both at dusk and at dawn.

2.2 Fish Handling and Cleaning

Fish in Botswana is not immediately gutted, particularly in the Okavango and Chobe area. In this region there is still a belief that removing the offals leads to a loss of fat. Fish is marketed whole, also because the time between hauling the net and marketing of the fish is relatively short.

At Shashe near Francistown, gutting is done in conjunction with descaling of the fish.

Fish destined for salting is descaled and split (in the case of tilapia) or filleted (in the case of catfish), then brushed and cleaned in river water, after which they are ready to be salted.

2.3 Salting

Rubber containers, originally manufactured as dustbins, are used for salting by the fishermen. A few drainage holes are made at the bottom. Starting with a layer of salt, alternated layers of salt and fish are placed in the container until it is full. Depending on the catches it may take up to three or four days to fill a bin. Once filled, the fish is left in the bin for two or three days before it is taken out for drying.

2.4 Sun-Drying

Sun-drying of fish is done on racks made either of chicken wire or woven reed mats mounted on poles erected on the ground. The racks are constructed at a site where enough shading, preferably from trees, can be provided to avoid direct heat from the sun. The fish dries at ambient temperature for about a week before packaging in hessian sacks. It is protected from rain throughout the drying process. The product has a moisture content of 6–7%.

2.5 Dried Salted Fish Marketing

At the time of introducing the dried salted fish technology, Botswana was being hard-hit by a record drought which lasted for seven years. The Government commissioned the Financial Assistance Programme (FAP) to help the growth of productive activities and create more jobs for the increasing labour force. Through grants under the FAP scheme fishermen acquired fishing equipment and catches went up. The salting and drying technology was extended to preserve the catches.

Unfortunately, there was no ready market for the increased production of salted dried fish. The Government decision to purchase dried salted fish to be distributed through institutional feeding programmes to those most disadvantaged by the drought, was a blessing to the fishing communities as a stable and guaranteed market was created. Government financial allocations for fish purchases grew as more fishermen entered the fishery. It is perhaps the availability of the market rather than the popularity of the product that largely contributed to the positive response of fishermen towards the dried salted fish technology.

The dried-salted fish has a salt content of 10–15%. This successfully inhibits fish spoilage, but may be a limiting factor to consumer acceptance. For consumption the salted dried fish has to be soaked in water for at least 12 hours, changing the water at least twice to reduce the salt content to about 1%.

The application of the technology described above can be considered a success. Basically the aim was to produce a long shelflife product in a remote region, so that in particular seasonal catches remain fit for local human consumption for a long time, or can be marketed when conditions allow for consumption elsewhere in the country.

The Government purchases once a month. Three factors contribute to the success:

• compared to other parts of Africa salt is relatively cheap in Botswana, where a 50 kg bag costs P 6.30 (US$ 3.37 at exchange P 1.87=US$ 1);

• catches landed are usually small and fishermen have adequate time to process them;

• the availability of a stable market provided by the Government acted as a stimulus for more fishermen to adopt the technology fast.

2.6 Constraints to the Application of Sun-Dried Salted Fish Technology

Although the use of this technology produces the desired results it is not without problems.

The most important constraint is that of salt supply. The transportation of salt to remote fishing communities poses problems as the road infrastructure is poorly developed. Where the private sector is involved in salt trade the price is normally more than double the Government subsidized price. For economic reasons fishermen then use less salt at the expense of the quality of the product.

Fishermen use prime quality fish caught at dawn for home consumption and salt fish in post rigor condition. Salting will however not improve the quality of the product.

The type of containers used is sometimes found too high. A container of the same material but lower has been suggested.

Screening for quality is normally done by Government extension staff. However, some of the staff are not adequately trained to perform efficiently, e.g., lack the ability to identify products made from bad quality fish.

There is also a lack of capability to collect enough data to assess post-harvest losses. Salted dried fish is often handled roughly. As the product does not easily pick up visual dirt storage facilities are not to required standards.

Lastly, the fact that the Government is the predominant customer and the inherent constraints this entails must be considered.

3. REFERENCES

Fisheries Unit. 1989/90 Annual Report.

Fisheries Unit. 1989. Aquaculture and human nutrition. Botswana country paper presented to the ALCOM technical consultation on the role of aquaculture in human nutrition.

NORFICO. 1987. Botswana Fisheries. Report of the fish processing and marketing consultancy (October-December 1986).

Table 1

Drying pattern for sun-dried salted fish

Source: NORFICO consultancy report, February 1987

Table 2

Moisture content of sun-dried salted fish

Source: NORFICO consultancy report, February 1987

Table 3

Nutritive value of sun-dried salted fish

Source: NORFICO consultancy report, February 1987

Table 4

Government funds allocations and fish purchases

Source: Fisheries Unit - Ministry of Agriculture