The influence of suspended silt on oxygen consumption by the redbreast tilapia, Tilapia rendalli (Boulenger,1896)
- 1) Department of Zoology and Research Unit for Aquatic and Terrestrial Ecosystems, Rand Afrikaans University, P.O. Box 524, 2006, Auckland Park, South Africa
The routine oxygen consumption of redbreast tilapia, Tilapia rendalli exposed to silt from the Phalaborwa Barrage was investigated under controlled laboratory conditions. Exposure of adult fish to sublethal concentrations of silt did alter routine oxygen consumption by causing increased rates (53–77% from initial) of oxygen consumption. This indicates that sublethal levels of suspended silt concentrations results in an increase in oxygen consumption by the fish due to an increase in metabolic rate associated with increased activity and stress. From the laboratory experiments, it can therefore be predicted that sublethal releases from the Phalaborwa Barrage will stress the resident fish populations. However, the extent of the impact on the fish population will depend on factors such as frequency, duration and severity of exposure as well as the species in question. Long term monitoring of the fish population below the Phalaborwa Barrage is therefore essential.
- 1 - sciences appliquees, technologies et medecines
- 2 - sciences biologiques et medicales
- 3 - sciences biologiques fondamentales et appliquees. psychologie
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