2.1 Description of the study site
The study was undertaken in the upper Kabompo River, located on the border of Kalumbila and Mwinilunga districts in Zambia. Kalumbila District includes major mining towns in the Northwestern Province (Figure 1). The study area lies approximately 60 km from the source of the Kabompo River (12.1845°S, 25.1765°E to 12.3691°S, 25.0442°E). The upper Kabompo is part of the Kabompo River and is one of the main tributaries of the Zambezi River. It originates at an altitude of approximately 1,500m above mean sea level (amsl) in the highlands which forms the watershed between the Zambezi and Congo rivers. It flows in a general south-westerly direction from the highlands through flatter areas immediately before entering the narrow deep valley known as Kabompo Gorge at Wushingi Hills. Within the Kabompo Gorge the river course disappears below rocks and boulders (creating a natural barrier during dry season) and flows underground for approximately 1.5km where it reemerges below a major drop-off in the river gorge approximately 40-50m in elevation. The upper Kabompo River channel including floodplain during peak rain season is up to 1km wide in this upper section of the river, and numerous tributaries join the Kabompo River between the river and the villages. The average water temperature is about 25oc across the study area. The study site was chosen because of its frequent fishing activity and high fish diversity. The fishery (covering all the native species caught in this study) is also of economic importance to local communities as a livelihood and a source of brood fish for the Aquaculture Breeding Programme.