by Ian Hinze
The spraying of endosulphan insecticide over the Okavango Delta in May 2001 in an attempt to control the range of tsetse-fly (which causes sleeping sickness in man). A meeting held in Maun on October 19, 2000, Botswana's Ministry of Agriculture announced the spraying of some 7,180 sq. kilometers. endosulphan is a poisonous substance known to kill fish as well as insects and is believed to be a real threat to a number of bird species. The proposed dose of endosulphan is double what was used in the 1970s.
Conservation groups have been raising awareness of the consequences and are calling on the government of Botswana for an Environmental Impact Assessment (EIA). The general public can express its concern by writing polite letters to the president (Private Bag 001, Gaborone, Botswana) or to the Minister of Agriculture (Private Bag 003, Gaborone).
The Okavango Delta is a site of high conservation value, and wide-scale area spraying adversely affect biodiversity. Many waterbirds occur in the area, and scientists believed many breeding fish-eaters may suffer. The slaty egret, for example, which is a globally threatened species, is largely confined to Botswana, neighboring Namibia and Zimbabwe. Its stronghold is the Okavango Delta, but the endosulphan may kill the fish it feeds on.
There is also concern for the welfare of insectivores and finches. If the spraying kills the insects, these birds, and insect-eating animals, may have to find other prey or starve to death. Also, any bird eating an insect sprayed with endosulphan may ingest the chemical.