Cotton-producing areas of the Central Sudan, bordered by the Blue and the White Nile, have been subjected to repeated applications of pesticides. This region is irrigated by a series of canals, the Gezira canals, which hold large amounts of fresh water. Lake Nubia at the Sudan-Egypt border is another important fresh water reservoir and fisheries ground. Fish from both the Gezira and Lake Nubia showed elevated concentrations of pesticides, suggesting that continued pesticides application would endanger the aquatic fauna of this region and the proposed fresh water fishery.