The development of a toxicity database using freshwater macroinvertebrates, and its application to the protection of South African water resources

Palmer, C.G. and Muller, W.J. and Gordon, A.K. and Scherman, P-A. and Davies-Coleman, H.D. and Pakhomova, L. and De Kock, E. (2004) The development of a toxicity database using freshwater macroinvertebrates, and its application to the protection of South African water resources. South African Journal of Science, 100 (11 & 12). pp. 643-650. ISSN 0038-2353




There is a growing international trend towards the protection of freshwater resources from pollution by imposing instream guidelines and specified waste-discharge conditions. Current methods for devising freshwater quality guidelines are based on species sensitivity distributions (SSDs) that are used to identify pollutant concentrations, ensuring the protection of a modelled percentage of species (95% protection is a common goal). SSDs are derived from the toxicity test results of as many taxa as possible for each polluting substance. Waste-discharge licences can be for single substances, specified in terms of chemical concentrations, and derived in conjunction with instream guidelines; or for complex mixtures, specified in terms of toxic units. In both cases toxicity test results are the core data used. The emphasis on SSDs calls into question the species constituting the test populations. It is likely that SSDs based in part on the responses of local organisms will achieve superior site-specific ecological protection. Until the early 1990s, there were very few data on the tolerances of South African freshwater organisms. In the intervening decade, the Unilever Centre for Environmental Water Quality at Rhodes University has developed a toxicity database that, to date, records the responses of 21 South African freshwater taxa to 26 single-substance pollutants or mixtures. This is the most comprehensive database of South African toxicity responses available and has been used in the drawing up of methods and guidelines to protect water resources. This paper aims to make these data available and to describe applications of the data using selected case studies.

Item Type:Article
Additional Information:Rhodes Centenary issue
Uncontrolled Keywords:water pollution, South Africa, freshwater quality, freshwater organisms, toxicity tests
Subjects:Y Unknown > Subjects to be assigned
Divisions:Research Institutes and Units > Institute for Water Research (IWR)
ID Code:129
Deposited By: Rhodes Library Archive Administrator
Deposited On:18 Aug 2005
Last Modified:06 Jan 2012 16:17
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