Will the Okavango survive as Africa�s remaining wilderness?
Correspondent | Tuesday March 25, 2014 14:54
For now, the delta is still the face of Botswana and one of Africa’s remaining wildernesses. It is described by researchers as the world’s largest continental alluvial fan covering 22,000km2.
Like in Serengeti, human activity is threatening the ecosystem of this virgin land. There is spraying of toxic chemicals and the proliferation of lodges, some of which are only accessible by boat. Another concern is the ever increasing number of people looking for opportunities in the area. Observers say this could result in the delta being overpopulated and losing its wilderness component to become another Serengeti. Tourists are not helping by feeding the animals when they are not supposed to.
I recall one incident during my tour in the Chobe National Park in which an elephant called ‘Huwie’ was killed in Savuti for attacking a wildlife camp to eat oranges. British researcher, Susan Cooper, said some tourists in Savuti admired the elephant and started feeding it oranges, saying it was cute. After the tourists had left, the elephant attacked the wildlife camp, to look for more oranges and it was killed.
Cooper who was researching on spotted hyenas was traumatised by the death of the elephant, saying if it were not for the tourists, it would not have been killed. She warned that while we need tourists, some have hidden agendas that can destroy the industry. She was following a pack of 15 hyenas which had been fed at one stage or another. Cooper said each time she approached the hyenas at night, they stopped hunting, expecting her to feed them. She lamented the state of affairs, saying if remedial measures are not put in place, the delta would lose its value as a tourist destination.
On another front, the delta needs to be freed from the grip of an aquatic plant called Savinia Molesta. The weed has created swamps by a process of silting and blocking the flow of water on some river channels.
Peter Smith, who stayed and worked in the Okavango most of his life said the weed came to Africa from Brazil a century ago by an ardent lover of nature for ornamental purposes and it has since spread like wildfire. Other sources say the weed came from Kariba. Hence it is sometimes called Kariba weed.
Smith said the weed is threatening to block the remaining channels of the delta. In the 1970s, the Ministry of Agriculture employed people to remove the weed from the blocked channels by hand without success.
Realising that the plant was winning the battle, the government came up with a new strategy of introducing insects to feed on the plant with the hope of exterminating it. Informed sources say the insects were bought from Brazil. But upon their release at designated sites in the Okavango, birds descended on them and wiped them out in no time. This was a humiliating blow to the government and ever since, there has been no attempt to remove the weed. Concerned groups are suggesting the imposition of stricter regulation on movement of boats in the delta because they unwittingly transport the weed.
Smith who has extensively researched on the plant says Salvinia grows faster than any vegetation because it reproduces by propagation and not by pollination. It forms a thick layer on the surface of water, depleting oxygen and suffocating aquatic life, especially fish. It is spread and transported along the Okavango and Chobe by hippos and boats traversing the delta. Under normal conditions, Salvinia can form a two feet thick mat freely floating on the surface of water without being attached to the ground. In extreme cases, the mat completely conceals the river, becoming dangerous to wildlife, especially buffalos which are reported to be drowning unaware of the depth of the river.
In a battle that threatened the delta ecosystem, the government used toxic chemicals between 1970 and 1990 as a last resort to exterminate the Tse-tse fly in the Okavango. Residues of chemicals such as endosulfan and DDT brought are still found in plants, fish and water in the delta. Researchers have particularly raised concern about the use of endosulfan and DDT because they persist in the environment and human body after spray. Endosulfan attacks the central nervous system, causing over-stimulation, headache, nausea, vomiting seizure and in extreme cases, unconsciousness and death.
A research report by Lesego, Mmualefe from the Chemistry Department in Rhodes University shows the same results of chemical residues in water, plants and fish in the Okavango. Although they had not sampled humans for the research, they could not rule out finding equally shocking results in human bodies. This could mean that people who depend on fish in the Okavango are exposed to danger because as one researcher puts it, “residues found in fish could also be found in its predator”.
Another research report by O. Serumola and M. Mbongwe expresses the same sentiments about the danger of being exposed to toxic chemicals. They attribute this to lack of appropriate legislation for control of imports especially chemicals. By implication, this means that a number of chemicals which have been banned in other countries due to unacceptable human and environmental health reasons are still marketed and used in Botswana.
Serumola and Mbongwe say the management of chemical substances in Botswana could be lax because it is dispersed in different ministries. The Ministry of Health for example has the responsibility of assessment of environmental and occupational health hazards which includes chemicals and gives clearance for chemical licensing.
The Ministry of Minerals, Energy and Water Affairs is responsible for all environmental issues related to mining and the monitoring of waste water, emissions from industries and sewage treatment plants.
The Ministry of Commerce and Industry is responsible for issuing licenses to manufacturers and importers of chemicals. The Ministry of Agriculture is responsible for pesticide use and regulations.
At a UNDP organised seminar held in Francistown in 2012, an official from the Ministry of Agriculture said all the pesticide outlets in the country are under obligation to remove the expired toxic chemicals from their shelves and send them to the ministry for safe custody at Sebele. It was clear even from his presentation that the outlets are not complying and the expired products could end up at the regional landfill or exposed in open and public places.
There is evidence that toxic chemicals are in the wrong hands. The chemicals are weapons of mass destruction because they also kill untargeted species. The use of the chemicals, especially spraying is as deadly as dropping a bomb in the delta.
Birdlife Botswana suggests that the use of harmful chemicals or pesticides should be regulated and that the products should be removed from the market as it is done in other countries.
MORERI GABAKGORE