ARBA MINCH UNIVERSITY SCHOOL OF GRADUATE STUDIES DEPARTMENT OF BIOLOGY The Impact of Water Hyacinth (Eichhornia crassipes) on Composition and Abundance of Macrophytes and Phytoplanktons, and on Water Quality in Lake Abaya, Southern Ethiopia By BEDILU BEKELE MENGISTU Advisor DIKASO UNBUSHE (Ph.D.) A THESIS SUBMITTED TO THE DEPARTMENT OF BIOLOGY IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE MASTERS OF SCIENCE DEGREE IN BIOLOGY (BOTANICAL SCIENCE) FEBRUARY 2014 ARBA MINCH I ARBA MINCH UNIVERSITY SCHOOL OF GRADUATE STUDIES DEPARTMENT OF BIOLOGY The Impact of Water Hyacinth (Eichhornia crassipes) on Composition and Abundance of Macrophytes and Phytoplanktons, and on Water Quality in Lake Abaya, Southern Ethiopia A THESIS SUBMITTED TO THE DEPARTMENT OF BIOLOGY IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE MASTERS OF SCIENCE DEGREE IN BIOLOGY (BOTANICAL SCIENCE) APPPROVED BY: ADVISORS: 1. DIKASO UNBUSHE (Ph.D.) Sign date EXAMINORS INTERNAL NAME EXTERNAL NAME CHAIR PERSON NAME I Declaration I, undersigned, declare that the information provided in this thesis is an original work and that it has not been presented in other universities or collage, seeking for similar degree or other purposes. All sources of materials used in this thesis have been dully acknowledged Bedilu Bekele Sign date Advisor: 1. Dikaso Unbushe (Ph.D.) Sign date II Dedication This work is dedicated to our planet which is found at most vulnerable condition facing towards pollution the physical environment leading to extinction of the biotic treasures. III TABLE OF CONTENTS Contents pages Declaration .................................................................................................................................................... II Dedication .................................................................................................................................................... III TABLE OF CONTENTS ............................................................................................................................. IV LIST OF FIGURES ..................................................................................................................................... VI LIST OF TABLES ...................................................................................................................................... VII LIST OF APPENDICES ............................................................................................................................ VIII ACRONYMS .................................................................................................................................................. IX ACKNOWLEDGEMENT ................................................................................................................................... X ABSTRACT ..................................................................................................................................................... XI 1. INTRODUCTION .................................................................................................................................... 1 1.1 Background ..................................................................................................................................... 1 1.2 Statement of the problem .............................................................................................................. 4 1.3 Objective of the study ..................................................................................................................... 5 1.3.1 General Objective ........................................................................................................................ 5 1.3.2 Specific objectives ........................................................................................................................ 5 2. LITERATURE REVIEW ..................................................................................................................... 6 2.1 Wetland definition and classification system ........................................................................... 6 2.2 Role of wetlands ....................................................................................................................... 7 2.3 Threats to wetlands .................................................................................................................. 8 2.4 The consequence of wetlands loss ........................................................................................... 9 2.5 Ethiopian wetland classification system ................................................................................. 11 2.6 Wetlands and water ................................................................................................................ 12 2.7 Vulnerability of wetlands to invasive species ......................................................................... 13 2.8 Taxonomy, behaviors, distribution of water hyacinth (Eichhornia crassipes) ........................ 13 2.8.1 Distribution of water hyacinth ................................................................................................ 15 2.8.2 Adverse Impact of water hyacinth on wetland ecosystem ..................................................... 15 2.8.3 Beneficial impact of water hyacinth .......................................................................................... 21 3. MATERIALS AND METHODS ........................................................................................................ 23 3.1 Description of study area ........................................................................................................ 23 IV 3.1.1 Location of the study area ....................................................................................................... 23 3.1.2 Climate .................................................................................................................................... 26 3.1.3 Plant and animals life of the study area ................................................................................. 27 3.1.4 Population and socioeconomic condition .............................................................................. 27 3.2 Design of the study area ......................................................................................................... 27 3.3 Data collection ........................................................................................................................ 27 3.3.1 Macrophyte data collection .................................................................................................... 27 3.3.2 Phytoplankton data collection ................................................................................................ 28 3.3.3 Water quality data collection .................................................................................................. 28 3.4 Data analyses .......................................................................................................................... 28 3.4.1 Macrophyte distribution and abundance data analyses .......................................................... 28 3.4.2 Phytoplankton distribution and abundance data analyses .................................................... 29 3.4.2.1 Waterbio physicochemical property analyses ...................................................................... 29 4. RESULTS AND DISCUSSION ......................................................................................................... 31 4.1 Abundance, composition and distribution of macrophytes ................................................... 31 4.2 Distribution and abundance phytoplankton ........................................................................... 39 4.2 Water bio physicochemical parameter measurements .......................................................... 43 5. CONCLUSIONS AND RECOMMENDATIONS ............................................................................. 50 5.1 Conclusions ............................................................................................................................. 50 5.2 Recommendations................................................................................................................... 51 6. REFERNCES .......................................................................................................................................... 52 7. APPENDICES ........................................................................................................................................ 58 V LIST OF FIGURES Figure 1Macrophytes and their location ......................................................................................... 3 Figure 2 Stepwise invasion process ................................................................................................ 4 Figure 3 Production of fish and other crustaceans decline due to shrinkage of wetlands ........... 10 Figure 4 Map of Ethiopian wetlands, rivers and lakes.................................................................. 12 Figure 5 Morphology of the flower of water hyacinth ................................................................. 14 Figure 6 Cascading effect of water hyacinth ................................................................................ 20 Figure 7 Map of Ethiopia showing location of the study area ...................................................... 24 Figure 8 Landsat satellite image showing location of sampling