Application of multivariate statistics and toxicity indices to evaluate the water quality suitability for fish of three rivers in the Kruger National Park, South Africa

• Published in: African journal of aquatic science Vol. 40; no. 3; pp. 247 - 259
• Main Authors: Gerber, R, Wepener, V, Smit, NJ
• Format: Journal Article
• Language: English
• Published: Grahamstown Taylor & Francis 03.07.2015; Taylor & Francis Ltd
• Subjects: ammonium compounds; aquatic toxicity index; data collection; Environmental protection; fish; Freshwater; Letaba River; Luvuvhu River; metals; multivariate analysis; National parks; nutrients; Olifants River; orthophosphates; principal component analysis; Rivers; Statistics; Toxicity; turbidity; water quality; water quality assessment; South Africa, Northern Prov., Luvuvhu R; South Africa; South Africa, Mpumalanga, Kruger Natl. Park; South Africa, Letaba R
• DOI: 10.2989/16085914.2015.1073139
• ISSN: 1727-9364; 1608-5914

The water quality of the Olifants, Letaba and Luvuvhu rivers within the Kruger National Park was assessed for their suitability to sustain fish populations. Since water quality assessments result in huge datasets, principal component analysis and an aquatic toxicity index (ATI) were employed to reduce these to more manageable indices. Water quality changed over time, with metal concentrations decreasing, and high flows resulted in increased concentrations of suspended metals. The ATI indicated that metals had no major effect on lowering index values in any of the rivers, and that these values were affected by turbidity in both the Olifants and Letaba rivers, whilst nutrients such as ammonium and orthophosphates negatively affected index scores in the Luvuvhu River. Water quality has improved from the 1990s to 2011.