Biology of the Smallscale Yellowfish: feeding biology and metal bio accumulation in five populations


Author: Andrew Husted

Organisation: University of Johannesburg


The general conservation status of freshwater ecosystems worldwide is poor and continues to decline at a rapid rate. This decline is a result of severe alteration of freshwater ecosystems caused by human activities. With an ever increasing human population as well as economic development, an increase in the demand for water is inevitable, as well as an increase in pollution to freshwater ecosystems. The sectors which are responsible for this are the domestic, agricultural, recreational and industrial sectors as they all depend on fresh flowing water. Aquatic ecosystems are heavily degraded on a global level by these human activities and impacts. South Africa is no different to the rest of the world. The quality of water in South African river systems has deteriorated due to increasing industrial, mining and agricultural activities in the catchments. Fish are often used as an indicator for ecological integrity as they are long-lived and therefore a good indicator of long-term exposure. Relatively little is known about Labeobarbus polylepis (Small-scale yellowfish) with reference as an indicator species as well as its feeding habits. This study consists of two components, namely the bioaccumulation of heavy metals by L. polylepis and the feeding biology of L. polylepis. Each of these components will be completed separate from one another. The first component of this study was the assessment of the water quality from five river systems in South Africa, namely the Phongola, Assegaai, Elands and Komati rivers, as well as the Ngodwana Dam. The aims for this component of the study were to evaluate the overall health of the five different populations of L. polylepis and to obtain site specific metal bioaccumulation data for each locality. Suggestions and proposals for future monitoring and management of these waterbodies were also made.

Author: Andrew Husted

Organization: University of Johannesburg

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