Mikael N. Ekandjo (CFRT)
Gosbert Hamutenya (SFRB)
The full report is available on request
The Kunene River originates in the Bie plateau, close to Huambo at about 1750 meters above sea level. The upper 400 km are relatively steep, whereas the middle section has a lower gradient forming a marshy floodplain. When meeting the Namibian border at Ruacana, the river forms a 120 m waterfall and the remaining distance to the sea is steep with a gradient of 1:447. From Ruacana the fast flowing river forms the border between Angola and Namibia. (Tvedten et al 1994) Due to the low population density and the fact that the Himba and Zemba that inhabit the area along the lower Kunene do not utilise the fish as food, the fish stocks are presently not exploited to any significant degree (Tvedten et al 1994, Hay et al, 2008). According to Tvedten et al, (1994), the proposed second hydropower scheme on the lower Kunene River may have an impact on the current situation of freshwater fisheries exploitation as the construction work may brings in fish eater populations from other regions that may influence the local Himba/Zemba communities to start eating fish. In Total 46 fresh water fish species were found in the Namibian part of the Kunene River in the past years. Of those 46, five are endemic to the Kunene River (Hay et al, 2008).
The biological assessment of fish species have been carried out over years. To date, there are data available since 1994, however due to budgetary constraint; this survey was not conducted during 2013. It is therefore a tradition that a similar survey is carried out each and every year during the same season and at designated stations. This is done so that data recorded are comparable to those collected other years. These surveys are carried out, focussing on the biological assessment of the fishery of each river system. This includes species composition, sizes in terms of length and weight as well as reproductive stages. This specific report will mainly focus on species composition at various stations, catch per unit effort (CPUE) and lastly will compare this survey’s fish catches to that of December 2012.
1.1. Study areaThe 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.
Fig.1. A map showing a study area with various stations sampled (adopted from Hay et al, 2008)
Table 1. A table showing sampling stations and their GPS coordinates
2. MATERIALS AND METHODS
2.1. Materials used
• Two panels of gill nets consisting eleven different mesh sizes were used in this survey.
• The eleven different mesh sizes (12, 16, 22, 28, 35, 45, 57, 73, 93 118 and 150 mm) of 10 m length, multifilament brown gill nets.
• A 10 m drag net was used to sample smaller fishes that are not caught in gillnets A GRAMI GPS with 5 m accuracy was used to record the positions of sampled sites.
• A boat mounted with a 25hp engine was used in the river to set nets.
• Two 4x4 cars were used to felly equipments and personnel’s
• A total of six personnel were involved in this survey
• Pasgear habitat and record forms were used to record the data
• Plastic bags and mesh tags were used to carry and indentify catches from each net separate respectively.
1. Mikael N Ekandjo (CFRT, Rundu)
2. Gosbert Hamutenya (SFB: Rundu)
3. Erasmus P. Haimene (FRT: Epalela)
4. David Kandunge (FRT: Onavivi)
5. Ismael Kapuka (FRT: Epalela)