Likely effects of salinity on acute copper toxicity to the fisheries of the lake George-Edward basin

Abstract

Alkaline, saline waters are common in the Western Rift Valley of East Africa, in which the lake George-Edward basin is situated. A growing copper mining industry in the area makes it important to understand the limnology of the lakes in this basin before copper pollution occurs. The fish could possibly suffer from acute (or chronic) toxicity if copper levels increase. Abiotic factors within the alkaline, saline waters of this basin reduce the acute toxic effects of copper to fish. The most important factor is salinity, which is a measure of the total dissolved mineral salts. The relatively highly concentrations of mineral salts of these waters will to reduce the effective copper ionic activity through adsorption, precipitation, and ionic interference. The high concentrations of organic compounds in the waters, also complex and chelate the ionic Cu2+, thus reducing further its effective concentration. This will therefore act as a check on the copper toxicity to the fish of the lake basin.