Nile tilapia (Oreochromis niloticus) is the species of choice for tilapia culture worldwide due to its fast growth and robust nature.
Genetic development to improve the species, such as the latest strains of GIFT tilapia, has elevated growth rates by about 60%. A commercial strain reaches about 500g in weight in eight months, while an indigenous Mozambican tilapia (O. mossambicus) takes 11 to 14 months to attain the same weight.
This has great implications for economic viability.
Most African countries where Nile tilapia is not indigenous have accepted the fact that the benefits of the improved strains outweigh its conservation threats.
While this has undoubtedly had conservation implications, the positive spin-off has been that many thousand of tons of farmed fish are now available in these countries, reducing the pressure on marine fish stocks, and helping to provide protein in protein-poor areas.
A balancing act
Zambia has managed to balance the need of both commercial fish production and conservation, with national parks such as Luangwa and Kafue where Nile tilapia are present in the rivers. However, the country also has World Heritage sites such as Lake Bangweulu where Nile tilapia are not present.
The country has a thriving aquaculture industry, with some farms harvesting over 100t a month.
In Mozambique, the government has accepted the fact that the country is effectively ‘downstream from everywhere’, with most rivers crossing the country flowing across national borders to the south, west and north.
Therefore, the fish found in them are not protected from invasion by natural barriers. The country’s government has thus adopted a pragmatic approach to stimulate aquacultural development, and the best Nile tilapia strains have been distributed.
South Africa finds itself 25 years behind the rest of Africa with a ‘game park’ mentality prevailing and environmental agencies striving to ‘preserve’ rather than ‘conserve’.
In addition, suffocating legislation effectively prevents serious investment in aquaculture. If this ‘protective legislation’ was achieving what was intended, there would be some measure of compensation, but the reality is very different.
Nile tilapia are extant in all river catchments shared with our neighbours, and preventing Nile tilapia culture will not change this. It is notable that aquaculture has attracted more legislation than any other agricultural enterprise, including the proposed new Aquaculture Bill.
The constitutional right to farm is fundamentally threatened by this legislation and must be challenged.
Despite the documented presence and continuing spread of Nile tilapia in these catchments, the Department of Environmental Affairs and Tourism (DEAT) has place a moratorium on farming this species in the three most climatically suitable provinces, even if present in the river on a farm.
Reality must prevail: marine fish stocks need replacement. DEAT should authorise tilapia farming in all regions in these catchments, and concentrate on safeguarding O. mossambicus in places where sanctuaries can realistically be established, as was done in establishing our national parks for game.
The coastal rivers and estuaries of the Wild Coast would provide ideal sanctuaries, as O. mossambicus survives here with cool temperature and high salinity tolerances that naturally exclude Nile tilapia.
More details in the next article.