FAO.org

Stocking of reservoirs is one of the management interventions that can be used to increase fish production. Zimbabwe has around 12 000 man-made reservoirs and many of these have been stocked with fish in the past. Species were selected in order to increase production or because they were preferred by consumers or as sports fish.

In 1991/1992, Zimbabwe experienced its worst drought on record and many reservoirs dried up, with loss of their fish stocks. These fish stocks would not easily recover naturally because it is difficult for most species to re-enter the reservoirs from downstream. Fish from the reservoirs, especially in the communal areas, are an important source of protein for the local communities. A special programme was launched to restock the dried-up dams in the country.

The most appropriate method to restock the reservoirs in Zimbabwe was to catch fish in reservoirs that had not dried up, and release them into the dams that had lost their fish stocks. Special transport equipment was produced. During the first six months of the restocking exercise, 383 reservoirs were restocked. With three teams fully operational, up to 100 reservoirs could be restocked each month. Restocking was effective for 64% of the reservoirs. Stocking rates varied between 0.3 and 36 kg/ha, and monitoring of the restocked reservoirs one year after stocking showed that these level were sufficient to re-establish a population of mixed tilapia species.