THE EFFECT OF SUBLETHAL CONCENTRATIONS OF NATURAL SUSPENDED SILT ON ROUTINE OXYGEN CONSUMPTION BY MOZAMBIQUE TILAPIA (OREOCHROMIS MOSSAMBICUS)

Abstract

Exposure of adult Oreochromismossambicusto sublethal concentrations (5 to 20 g silt ℓ⁻¹) of natural silt from the Phalaborwa Barrage altered routine oxygen consumption by causing increased rates of oxygen consumption. This indicates that sublethal levels of suspended silt result in a significant (p<0.05) increase in oxygen consumption by the exposed fish due to an increase in metabolic rate associated with increased activity and stress. Any species unable to compensate for this increase in energy expenditure over time would not be able to sustain itself.