CORAL REEFS ASSESSMENT AN ASSESSMENT OF CORAL REEFS IN AMBON, INDONESIA By GINO VALENTINO LIMMON B. Sc., SARJANA AN ASSESSMENT OF CORAL REEFS IN AMBON, INDONESIA By GINO VALENTINO LIMMON, B. Sc. A Thesis Submitted to the School of Graduate Studies in Partial Fulr.Ilment of the Requirements for the Degree Master of Science McMASTER UNIVERSITY ©Copyright by Gino Valentino Limmon, June 1996 MASTER OF SCIENCE (1996) McMaster University (Geology) Hamilton, Ontario TITLE: An Assessment of Coral Reefs in Ambon, Indonesia. AUTHOR: Gino Valentino Limmon, B. Sc. (Hasanuddin University) SUPERVISOR: Professor Michael J. Risk NUMBER OF PAGES: x, 80 ii ABSTRACT Increasing human activity and population pressure on coastal marine resources, especially coral reefs, in Ambon have caused significant stresses on coral communities requiring careful management. A suitable environmental management strategy for this complex ecosystem, however, must be based on an accurate assessment of the state of these resources, natural variability, and the impact of human activities. Consequently, baseline research is needed to describe reef areas and to provide data about environmental changes. One control site (Tanjung Setan) and three affected sites (Hila, Wayame and Wailiha) on Ambon were observed to assess the condition ofthe reefs. Coral cover, coral growth rate, species richness and environmental parameters such as suspended particulate matter (SPM), resuspended sediment, salinity, temperature, dissolved nutrients (N03 and P04), <5 1 ~, and water clarity were measured to assess reef condition and to determine the possible causes of reefdegradation. Average coral cover in the control site (Tanjung Setan) is higher (64%) than that in affected sites: Hila (27%), Wayame (36%) and Wailiha (11%). Also, the greatest number of species was found in Tanjung Setan (101 spp.) followed by Hila (66 spp.), Wayame (62 spp.) and Wailiha (43 spp.). iii Coral growth rates show different trends from coral cover and number of species. Corals in Tanjung Setan have higher growth rate (1.61 em/year) than those in Hila (1.45 em/year) and Wayame (1.31 em/year), but corals in Wailiha show almost the same growth rate (1.57 em/year) with that in Tanjung Setan. The surprisingly rapid growth rates at W ailiha are probably caused by high nutrient availability and rapid growth of corals to keep pace with high sedimentation rates. The o1 ~ content of coral tissue was analyzed at each site to trace the sewage (nutrients) loading from the land. Relatively high ratio of o 1 ~ found in Wailiha and Wayame indicated sewage (nutrients) inputs to the reefs in these areas. In addition, limited lignin testing on corals from Wailiha showed positive results, indicating that the plywood factory adjacent to the reefinfluences the corals there. High SPM and resuspended sediment values, high dissolved nutrients and 0 1 ~ content, and turbid water in Wayame and W ailiha indicated that these reefs are under siltation and sewage (eutrophication) stress. Hila mainly suffered from physical disturbance such as fish blasting and coral collecting, suggested by bomb craters and coral fragments. Conversely, no significant evidence of human impact was found in the control site (Tanjung Setan), where SPM, resuspended sediment, dissolved nutrients, and o 1 ~ values are all low, and water clarity is very high. iv ACKNOWLEDGMENT First of all, I would like to thank my supervisor Dr. M. J. Risk for his invaluabl~ help in giving me opportunity to do research in Ambon, providing the financial support for this project, and for his encouragement and his patience in editing this thesis. Thanks also go to many other people contributing to this work in various ways. This thesis would have been impossible without the assistance and patient of them. I would like to thank; • Evan Edinger, for his help in the field work and identifying my corals • Jodie Smith, Jeff Heikoop, and Cam Tsujita, who always helped and support me with patient during my study in McMaster University • Ir. D. Noija, Ir. Ch. Sutrahitu, Ir. A. Berhitu, Didi, Lucky, Ongen, Roland, Reno, Barlef, Izaac, for their tireless helped during the field work • Dean and Staff of Fisheries Department, Pattimura University for allowing me to use their facilities • Ir. Agan pattisina and StaffofLPIU, who lending me most ofmy research equipment • The head and staff ofbasic biology lab. who allow me to use their facilities • Jamal, Noverita, Mr. Endang Saepudin, Mr. Yahya Amadjaya and family, Mr. Suarga and family, and Mr. Iman Pambagyo and family, for their support during my study in Canada • Paul, JoAnn and Kiersten, for their great companies. • My beloved family; papi, mamie, Rigo and Dionne, for their love and support To one and all, many thanks. v TABLE OF CONTENTS Page Abstract ......................................................................................................... iii Acknowldgements........................................................... .. .. .. .. v Table of Contents.......................................................................................... vi List ofTables................................................................................................. viii List ofFigure................................................................................................. tx Chapter I. INTRODUCTION I. 1. The Importance ofCoral Reefs................................................. 1 I. 2. Ecological Control on Coral reefs............................................ 2 I. 2. 1. Salinity . .. .. .. .. .. .. .. .. .. 2 I. 2. 2. Temperature................................................................ 3 I. 2. 3. Light........................................................................... 4 I. 2. 4. Dissolved Nutrients..................................................... 5 I. 3. Previous Work........................................................................ 6 I. 4. Description ofResearch Site .................................................... 7 I. 4. 1. General Description ..................................................... 7 I. 4. 2. Physical Setting........................................................... 8 I. 4. 3. Climate and Oceanography .......................................... 10 I. 5. Scope and Objectives ............................................................... 11 Chapter II. MEmODOLOGY II.1. Site Selection .......................................................................... 12 II.2. Coral Community Assessment. .............................................. 12 11.3.Growth Rates.......................................................................... 18 11.4. Coral Diversity ....................................................................... 20 II.5. Suspended Particulate Matter................................................. 20 II.6. Resuspension of Sediment...................................................... 21 II. 7. Sediment Trapped in Coral Skeleton ....................................... 23 II.8. Bottom Sediment. ................................................................... 24 vi II.9. Water Quality Analyses .......................................................... 24 IT.10. 8 1 ~ Isotope Analysis ........................................................... 25 II.11. Data Analyses ....................................................................... 26 Chapter Ill. RESULTS III.l. Coral Community Assessment.............................................. 27 ill.2. Coral Diversity.................................................................... 31 III. 3. Growth rates....................................................................... 33 ill.4. Suspended Particulate Matter............................................... 35 III.5. Resuspension of Sediment................................................... 38 III.6. Sediment Trapped in Coral Skeleton ..................................... 41 III.?. Bottom Sediment ................................................................. 42 ill.8. Water Quality Analyses ........................................................ 43 III.9. 8 1 ~ Isotope Analysis ........................................................... 47 Chapter IV. Discussion IV. 1. Coral Community assessment.. ............................................ 49 IV. 2. Coral Growth rate............................................................... 53 Chapter V. Conclusion and Recommendation V. 1. Conclusion............................................................................ 57 V. 2. Recommendation................................................................. 58 References................................................................................................. 59 Appendix A. The result oflifeform method .................. ::-............................. 69 Appendix B. List ofcoral species at each site.............................................. 72 Appendix C. Growth rate data.................................................................... 77 Appendix D. Suspended particulate matter (SPM) data............................... 79 Appendix E. The fluctuation ofNutrients content........................................ 80 vii LIST OF TABLES page Table 2-1. Lifeform categories and codes .................................................. 14 Table 3-1. Number of Species................................................................... 31 Table 3-2. Resuspended sediment value.................................................... 39 viii LIST OF FIGURES page Figures