Challenges in fisheries management in the Zambezi, one of the great rivers of Africa

Abstract

Almost all fisheries in the Zambezi River system have experienced severe declines in catch rates, loss of larger, most valuable fish species, and increased use of environmentally damaging active fishing gears. The fisheries of the Barotse, Caprivi and Kafue floodplains, and lakes Kariba (Zambian sector), Malawi and Malombe are all fished down. The concept of balanced harvesting with moderate effort has no relevance to these African inland fisheries, where rapid human population growth and lack of alternative livelihoods for small‐scale fishers means they have no choice but to continue fishing despite dwindling returns. In some areas, e.g. Liuwa Plain National Park in Zambia and conservancies in Namibia, comanagement with local communities has potential for success, but other fisheries, e.g. Lake Malombe in Malawi, are so severely fished down that there is no prospect of recovery without radical restructuring of exploitation patterns coupled with habitat restoration.

Maximizing fisheries yields while maintaining community structure

“…These findings are important, as the development of the uncontrolled fishery on the Zambian side of Lake Kariba with increasing effort, decreasing catch rates, and subsequently decreasing mesh sizes to compensate for decreasing returns is conventionally interpreted as emergent signs of overfishing. Despite producing a higher yield while conserving relative community structure, the less selective fishery in Zambia is conforming to conventional indicators of destructive and unsustainable fishing patterns such as increased use of illegal small-meshed gears, strongly reduced stock abundance, and decreased mean size of fish in catches (Tweddle et al 2015).…”

“…10). This, so-called "fishing down process" (Welcomme 1999) is generally considered as a sign of a deteriorating and harmful situation (Pauly et al 1998;Tweddle et al 2015), with the added problem that an increasing number of fishing methods become technically illegal as they target smaller and …”

Gill net catch composition and catch per unit effort in Flag Boshielo Dam, Limpopo Province, South Africa

“…Large cichlids of the genus Oreochromis for example, are the basis for commercial fisheries in the Zambezi River catchment and in Lake Liambezi Tweddle et al, 2015), while large cyprinids of the genera Labeo and Labeobarbus are harvested in small-scale fisheries in Mozambique (Booth and Weyl, 2004) and Malawi (Weyl et al, 2010). It is likely that should a small-scale gill-net fishery be developed at Flag Boshielo Dam, it would be based on species that have a proven ability to support fisheries elsewhere (Weyl et al, 2007).…”

“…The considerably higher CPUE in this mesh size was a consequence of the higher species richness and numbers of fish, which compensated for the relatively small average size of fish when compared to the larger mesh sizes. As many African inland fisheries suffer from severe overfishing, the symptoms of which include the depletion of larger, higher value species and decreasing CPUE Tweddle et al, 2015), it is essential that fisheries development be guided by the concept of sustainable natural resource utilisation (Froese et al, 2015).…”

Sustaining rural livelihoods through an integrated landscape approach

“…Similar confl icts of interest over the use of natural resources for food or their protection for the benefi t of tourism also exist in the fi eld of fi sheries management (Abbott et al, 2007;Tweddle et al, 2015). Fish stocks, located in the Zambezi River and across the fl oodplains in the Zambezi Region, suff er from overfi shing and a lack of coordinated management with cross-border Zambia.…”