The area sampled is part of Kunene River along the Namibia Angola border. Four stations were sampled along the Kunene River, plus Olushandja Dam (Etaka) that directly receive water from the Kunene River via the Kallueque- Oshakati Canal. The four stations along the river are: Hippo Pools, just downstream of Ruacana Hydropower Station, Swartboisdrifft, further downstream of Ruacana, Epupa, immediately upstream of the falls and Otjinugua, further downstream of Epupa Falls (Figure 1). These are among some other stations that have been sampled along the Kunene River for many passed years.