A limnological study of factors affecting algal biodiversity in the Hartbeespoort Dam by GUSTAVE OLOLO 920303106 MINOR DISSERTATION Submitted in the partial fulfilment for the requirements for the degree MAGISTER SCIENTIAE in AQUATIC HEALTH FACULTY OF SCIENCE UNIVERSITY OF JOHANNESBURG Supervisor: Dr. Richard Greenfield Co-Supervisor: Prof. Victor Wepener OCTOBER 2013 1 Acknowledgment I would like to thank God almighty, the provider for everything He makes possible for me along this study period. I also would like to express my heartfelt appreciation to: Dr. Richard Greenfield, my supervisor, for his assistance, academic guidance and motivational support throughout the duration of my studies. Prof. Victor Wepener, my co-supervisor for his constant support, his advice, financial support and proof reading of my dissertation. The Faculty of Sciences, The Department of Zoology at the University of Johannesburg for the use of facilities and equipment. Mrs E. Fisher and Mr B.Rufaro (Spectrum) for their support during this project. My Fellow research colleagues, P. Nakarmi, S. Kanga, A. Lesiba, R. Gerber, R.Tate, O.T. Olubambi, V. Maboko, L. Kruger, N. Dumisile and L. Lungile for their help and academic support. To my Family, for all their continuous support, love and for their belief in me. To my Beloved Daughter Avomo Ololo Rebecca Louisia. To my Dear Mother Andjolo Marie-Louise. 2 Table of Contents Declaration ............................................................................................ Error! Bookmark not defined. Acknowledgment .................................................................................................................................... 2 Table of Contents .................................................................................................................................... 3 List of tables ............................................................................................................................................ 6 List of figures .......................................................................................................................................... 7 Abbreviations and Acronyms .................................................................................................................. 9 Glossary ................................................................................................................................................ 10 Abstract ................................................................................................................................................. 12 Chapter 1 Introduction ................................................................................................................... 13 1.1 Background ........................................................................................................................... 13 1.2 Problem Statement and Hypothesis ...................................................................................... 14 1.3 Aim and objective of the study ............................................................................................. 15 Chapter 2 Literature Review .......................................................................................................... 16 2.1 Cyanobacteria ........................................................................................................................ 16 2.2 Aquatic macrophytes ............................................................................................................. 18 2.3 Chlorophyll-a ........................................................................................................................ 18 2.4 The process of eutrophication ............................................................................................... 19 2.5 Environmental factors influencing algal bloom formation .................................................. 19 2.5.1 Temperature .................................................................................................................. 20 2.5.2 pH .................................................................................................................................. 20 2.5.3 Turbidity and light penetration ...................................................................................... 20 2.5.4 Nutrients ........................................................................................................................ 21 2.6 The Harbeespoort Dam ......................................................................................................... 21 2.6.1 History, construction and usage .................................................................................... 21 2.6.2 Water quality ................................................................................................................. 22 Chapter 3 ............................................................................................................................................... 24 3 Materials and Methods .......................................................................................................................... 24 3.1 Study area and Sampling points ............................................................................................ 24 3.2 Physical parameters ............................................................................................................... 26 3.3 Nutrients analysis .................................................................................................................. 26 3.4 Metals in water and total suspended solids (TSS)................................................................. 26 3.5 Chlorophyll-a quantification ................................................................................................. 26 3.6 Algal identification and quantification .................................................................................. 27 3.7 Statistical analysis ................................................................................................................ 27 Chapter 4 Results and Discussion .................................................................................................. 28 4.1 Physical water quality parameters ........................................................................................ 28 4.1.1 Temperature ........................................................................................................................ 28 4.1.2 Dissolved oxygen (DO)....................................................................................................... 30 4.1.3 Electrical conductivity (EC) ................................................................................................. 32 4.1.4 Total suspended solids (TSS) ............................................................................................... 34 4.1.5 pH values .............................................................................................................................. 35 4.2 Chemical water quality parameters ....................................................................................... 36 4.2.1 Total phosphorus ........................................................................................................... 37 4.2.2 Nitrate and nitrite .......................................................................................................... 39 4.2.3 Ammonium ................................................................................................................... 42 4.3 Trace metals .......................................................................................................................... 44 4.4 Chlorophyll-a (Chl-a) quantification .................................................................................... 47 4.5 Phytoplankton population ..................................................................................................... 49 4.5.1 Cyanophyta (Blue green algae) ..................................................................................... 50 4.5.1.1 Microcystis aeruginosa ................................................................................................. 50 4.5.1.2 Anabeana sp. ................................................................................................................. 50 4.5.1.3 Oscillatoria sp. .............................................................................................................. 50 4.5.1.4 Arthrospira sp. .............................................................................................................. 51 4.5.1.5 Cylindrospermopsis sp. ................................................................................................. 51 4.5.2 Chrysophyta (Yellow green algae) ................................................................................ 51 4 4.5.2.1 Melosira granulate ........................................................................................................ 51 4.5.2.2 Cyclotella sp. ................................................................................................................. 51 4.5.3 Chlorophyta (Green algae) ............................................................................................ 51 4.5.3.1 Oocystis sp. ................................................................................................................... 51 4.5.3.2 Scenedesmus sp. ...........................................................................................................