A study into the anthropogenic impacts affecting the Elands River, Mpumalanga. BY MARTIN FERREIRA DISSERTATION SUBMITTED IN FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE MAGISTER SCIENTIAE IN AQUATIC HEALTH IN THE FACULTY OF SCIENCE AT THE UNIVERSITY OF JOHANNESBURG SUPERVISOR: PROF. JHJ VAN VUREN CO – SUPERVISOR: PROF. V WEPENE ACKNOWLEDGEMENTS Met dank en lof aan my Almagtige Skepper en Hemelse Vader, want “ ’n mens kan sy voornemens hê, maar die laaste word daaroor kom van die Here af ” (Spreuke 16:1) I would like to thank and acknowledge with appreciation the following people and institutions: My parents and my sisters, for their continuous love and support, especially my farther who has given me every opportunity to better myself. My supervisors Professor Van Vuuren and Professor Wepener for their leadership and support. A special thank you to prof Vic whose door is always open for all students, no matter how small the problem. Gordon O’Brien for his leadership and giving me this opportunity. The WRC and the University of Johannesburg for providing funding and equipment to complete the study. I would also like to thank my Paper Mill study team: Wynand, Cameron, Irene and Riaan. You started out as my colleges and ended up being great friends. Oom Giel and Tannie Louisa for everything they have done for me, and making it possible for me to complete my studies. A final thank you to Maryke Coetzee for loving me, supporting me and putting up with me despite myself. - 2 - TABLE OF CONTENT List of Tables 7 List of Figures 10 Summary 17 Opsomming 21 CHAPTER 1: GENERAL INTRODUCTION 1.1 Introduction 25 1.1.1 The River Health Program 26 1.1.2 The Reserve 28 1.1.3 EcoClassification and EcoStatus 29 1.2 Aim and Objective 30 1.3 References 31 CHAPTER 2: LITERATURE SURVEY AND SITE SELECTION 2.1 Introduction 33 2.1.1 The River Health Program 34 2.1.2 The Reserve 34 2.1.3 A New Approach for the management of rivers 35 2.2 The Study Area 36 2.3 SAPPI and the Elands River 38 2.4 Biomonitoring 40 2.4.1 Water Quality 41 2.4.2 Sediment 44 2.4.3 Habitat 45 2.4.4 Riparian Vegetation 47 2.4.5 Ichthyofauna 51 2.4.6 Macro Invertebrates 54 2.5 Site Selection 57 - 3 - 2.6 References 67 CHAPTER 3: WATER QUALITY 3.1 Introduction 76 3.2 Materials and Methods 77 3.2.1 Field Surveys 77 3.2.2 Laboratory Analysis 78 3.2.3 Statistical Analysis 78 3.3 Results and Discussion 79 3.4 Conclusion and Recommendations 99 3.5 References 100 CHAPTER 4: SEDIMENT, HABITAT AND RIPARIAN VEGETATION 4.1 Introduction 104 4.2 Materials and Methods 106 4.2.1 Physical and Chemical Characteristics of Sediment 106 4.2.2 Habitat Quality Indices 107 4.2.3 Riparian Vegetation 108 4.2.3 Statistical Analysis 108 4.3 Results and Discussion 108 4.3.1 Sediment 108 4.3.2 Habitat Quality 114 4.3.3 Riparian Vegetation 118 4.4 Conclusion and Recommendations 126 4.5 References 127 CHAPTER 5: ICHTHYOFAUNA 5.1 Introduction 132 5.2 Materials and Methods 133 - 4 - 5.2.1 Field Surveys 133 5.2.2 Spatial and Temporal Analysis 134 5.2.3 The FAII 135 5.3 Results and Discussion 135 5.3.1 Spatial and Temporal Analysis 135 5.3.2 Biotic Indices 151 5.4 Conclusion and Recommendations 155 5.5 References 157 CHAPTER 6: INVERTEBRATES 6.1 Introduction 161 6.2 Materials and Methods 162 6.2.2 SASS 162 6.2.1 Spatial and Temporal Analysis 163 6.2.3 Laboratory Analysis 165 6.3 Results and Discussion 165 6.3.1 Spatial and Temporal Analysis 165 6.3.2 Biotic Indices 178 6.4 Conclusion and Recommendations 191 6.5 References 193 CHAPTER 7: ECOCLASSIFICATION 7.1 Introduction 197 7.2 Materials and Methods 199 7.2.1 Macro Invertebrate Response Assessment Index 199 7.2.2 Fish Response Assessment Index 199 7.2.3 Rating, Ranking and Weighting 200 7.3 Results and Discussion 201 7.3.1 Macro Invertebrate Response Assessment Index 201 - 5 - 7.3.2 Fish Response Assessment Index 203 7.4 Conclusion and Recommendations 204 7.5 References 205 CHAPTER 8: GENERAL CONCLUSION AND RECOMMENDATIONS 8.1 Conclusion 207 8.2 Recommendations 209 APPENDIX A 211 - 6 - LIST OF TABLES Table 2.1 Typical analysis of acid bleach effluent generated during the activities of the Ngodwana pulp and paper mill. Table 2.2 Examples of industry practices that fall within a Category I industry. Table 2.3 Criteria used in the assessment of habitat integrity. Table 2.4 Vegetation species found in the Riparian zone of Resource Unit 2 (Roodewal, Doornhoek, Waterval Boven, Blouboshkraal) T = tree; S = shrub; R = reed; F = herbaceous; G = grass. Table 2.5 Vegetation species found in the Riparian zone of Resource Unit 4 (Roodewal BB2, Houtboschoek, Elandshoek & Ngodwana) T = tree; S = shrub; R = reed; F = herbaceous; G = grass. Table 2.6 The present ecological state if the fish in the Elands River within resource unit 2. Table 2.7 Present ecological state of the invertebrate communities of the Elands River within resource unit 2. Table 3.1 Nutrient and system variables results for the high flow survey (March 2005). Data (in mg/l unless otherwise stated) represents results of once of sampling. Table 3.2 Nutrient and system variables results for the low flow survey (June 2005). Data (in mg/l unless otherwise stated) represents results of once of sampling. Table 3.3 Results (mean ± standard deviation) obtained by Labware laboratories for system and nutrient variables during high flow conditions (3 Jan 2005 – 9 May 2005). Table 3.4 Results (mean ± standard deviation) obtained by Labware laboratories for system and nutrient variables during low flow conditions (27 June 2005 – 24 Oct 2005). Table 3.5 Examples of industry practices that fall within a category I industry. - 7 - Table 3.6 Reference conditions for average monthly water temperature (°C) and dissolved oxygen (mg/l). Table 3.7 Reference conditions for average monthly electrical conductivity (µs/cm). Table 3.8 Reference conditions for selected water quality variables (pH units and mg/l). Table 3.9 Reserve conditions for average monthly electrical conductivity (mS/m). Table 4.1 Physical and chemical characteristics of the sediment collected during high flow conditions. Table 4.2 Physical and chemical characteristics of the sediment collected during low flow conditions. Table 4.3 The method applied in assigning ecological classes based on the results of habitat indices applied in the study. Table 4.4 Results (IHAS and HQI scores and ecological classes) of the habitat quality indices during high flow conditions. Table 4.5 Results (IHAS and HQI scores and ecological classes) of the habitat quality indices during low flow conditions. Table 4.6 Vegetation species found in the Riparian zone at sites on the Elands and Crocodile Rivers (species name in bold indicate non – endemic species). Table 5.1 Results (FAII score, ecological classes and abundances) of ichthyofaunal species collected during high flow conditions. Table 5.2 Results (FAII score, ecological classes and abundances) of ichthyofaunal species collected during low flow conditions. - 8 - Table 5.3 The contribution of the various taxa to the similarity within groups (determined by using SIMPER) for both flow regimes. Table 5.4 The FAII scoring system applied in this study for assigning ecological classes. Table 6.1 Biotopes and sampling duration of the biotopes that were included in this study. Table 6.2 The contribution of the various taxa to the similarity within groups (determined by using SIMPER). The groups were determined using Bray-Curtis cluster analysis and NMDS. Table 6.3 The invertebrate scoring system (SASS 5) results and the method applied in assigning ecological classes in this study. Table 6.4 Result for SASS 5 (SASS score, number of taxa found and the average score per taxa) as recorded during high flow conditions. IHAS scores are calculated with 100 as a maximum score. Table 6.5 Result for SASS 5 (SASS score, number of taxa found and the average score per taxa) as recorded during low flow conditions. Table 6.6 Abundances of invertebrate families collected during high flow conditions (S – Stones; VG – vegetation). Families indicated in grey represent indicator families. Table 6.7 Abundances of invertebrate families collected during low flow conditions (S – Stones; VG – vegetation). Families indicated in grey represent indicator families. Table 7.1 MIRAI results (EC and ecological class) for the site on the Elands and Crocodile Rivers for both flow regimes. Table 7.2 FRAI results (FRAI % and ecological class) for the site on the Elands and Crocodile Rivers for both flow regimes. - 9 - LIST OF FIGURES Figure 2.1 Elands River Comprehensive Reserve Determination Study Surface Water Resource Units. The main study area falls within resource unit 2. Figure 2.2 Besides the Sappi Ngodwana mill there are various other impacts on the Elands River, often occurring on the tributaries associated with the Elands River. Figure 2.3 Photograph of ER 1 (Hemlock) the characteristic cobble beds (A) and interspersing pools (B). Figure 2.4 Photograph of ER 2 (Ryton Estates) and the site too shows the typical cobble beds and pools. Figure 2.5 The photograph shows site ER 3 (Bambi bridge) down stream of the Ngodwana mill and springs. Figure 2.6 Photograph of site ER 4, before the confluence with the Lupelule River (A) upstream and (B) downstream.