South African Journal of Science
On-line version ISSN 1996-7489
Print version ISSN 0038-2353
WEPENER, V.. Application of active biomonitoring within an integrated water resources management framework in South Africa. S. Afr. j. sci. [online]. 2008, vol.104, n.9-10, pp.367-373. ISSN 1996-7489.
Because waste water and runoff from surrounding catchments are a main source of direct and continuous input of pollutants in aquatic ecosystems, the study of the effects of in-stream exposure on organisms has a high ecological relevance. However, correlating observed effects with specific pollutants or even classes of pollutants remains difficult, due to the usually unknown, complex and often highly variable composition of these source waters. By integrating multiple endpoints at different ecologically relevant levels of organization within one test organism, it is possible to gain an understanding of how different levels of organization within this organism respond to toxic exposure, and how responses at these different levels are interrelated. The use of biological markers in transplanted organisms, referred to as active biomonitoring (ABM), is demonstrated in this paper. The correct choice of bioindicator organism and suite of biomarkers makes it possible to assess the effects of wastewater and runoff water in terms of known environmental effects (such as effluents containing endocrine-disrupting chemicals or pulp mill effluent) as well as runoff water with an uncharacterized composition of contaminants (for instance storm-water runoff from industrial complexes). The applicability of ABM as a cause-effect assessment protocol is demonstrated through a case study in South Africa that relates to stressor identification within a system exposed to urban and industrial waste water. This paper proposes a multi-tiered framework that allows for the incorporation of ABM within the existing South African integrated water resources management framework.