Assessment of Heavy Metals Impact in the Ecosystem in Bandon Bay at Surat Thani Province and Using the Oyster as a Biological Index Unchalee Roekdee A Thesis Submitted in Partial Fulfillment of the Requirements for the Doctor of Philosophy in Environmental Management Prince of Songkla University 2015 Copyright of Prince of Songkla University ii Thesis Title Assessment of Heavy Metals Impact in the Ecosystem in Bandon Bay at Surat Thani Province and Using the Oyster as a Biological Index Author Miss Unchalee Roekdee Major Program Environmental Management _____________________________________________________________________ Major Advisor Examining Committee: ......................................................................... ...................................................Chairperson (Assoc.Prof. Dr Somtip Danteravanich) (Asst. Prof. Dr. Supatra Davison) ....................................................Committee Co-advisor (Asst. Prof. Dr. Somtip Danteravanich) ......................................................................... ....................................................Committee (Assoc. Prof. Dr. Sirusa Kritsanapuntu) (Asst. Prof. Dr. Sirusa Kritsanapuntu) ....................................................Committee (Dr. Oramas Suttinun) ....................................................Committee (Asst. Prof. Dr. Chalinda Ariyadet.) The Graduate School, Prince of Songkla University, has approved this thesis as partial fulfillment of the requirements for the Doctor of Philosophy Degree in Environmental Management. ......................................................................... (Assoc. Prof.Dr. Teerapol Srichana) Dean of Graduate School iii This is to certify that the work here submitted is the result of the candidate’s own investigations. Due acknowledgement has been made of any assistance received. ........................................................Signature (Asst. Prof. Dr. Somtip Danteravanich) Major Advisor ........................................................Signature (Miss Unchalee Roekdee) Candidate iv I hereby certify that this work has not been accepted in substance for any degree, and is not being currently submitted in candidature for any degree. ...............................................................Signature (Miss Unchalee Roekdee) Candidate v Thesis Title Assessment of Heavy Metals Impact in the Ecosystem in Bandon Bay at Surat Thani Province and Using the Oyster as a Biological Index Author Miss Unchalee Roekdee Major Program Environmental Management ABSTRACT This study was conducted using secondary data, a field survey and laboratory analysis to investigate the problem of heavy metal contamination in Bandon Bay, Surat Thani, Thailand. It was estimated that the amounts of Cd, Cr, Pb, Cu, Mn and Zn discharged from inland into Bandon Bay were 10.4, 26.2, 47.1, 66, 156 and 423 ton per year, respectively. A survey of heavy metal concentrations in seawater and sediments in Bandon Bay during 2011-2012 at 7 points along the bay revealed to have risks of Pb and Cd contamination of sediments. The study implied that cockle harvesting in the bay had a significant impact on seawater quality. In laboratory experiments, it was found that the association of heavy metals in terms of Cd and Pb with seawater and sediments was caused by adsorption and desorption reactions during mixing of resuspended sediment particles in seawater which caused changes to the heavy metal concentrations in seawater. Oysters were examined as potential bioindicator and found to be better suited for Cd than for Pb contamination. For this purpose their growth was observed at three locations over 9 months. It was found that the highest growth of oysters were at Kradae. The Cd accumulation rates in oysters were 0.103-0.280 mg/kg per month (wet weight), those for Pb were 0.03-0.065 mg/kg per month (wet weight). Based on these results, 1.15 kg of Cd and 0.29kg of Pb were removed from Bandon Bay by harvesting the oysters accumulating Cd and Pb. The results of the ecological risk study indicated the risk that Cd and Pb accumulated in sediments and contaminated oyster, particularly in Chaiya, Kradae and Tatong. Furthermore, the study examined the economic impact of oyster contamination by heavy metals and, finally, measures to control the heavy metal pollution problem, included of continue heavy metal monitoring, in particular use of oyster as biomonitoring for Cd and Pb, zoning of aquatic culture, use of good practice protocol for oyster cultivation, control generation sources and further research were recommended. vii CONTENTS Title Page ABSTRACT v ACKNOWLEDGEMENT vi CONTENTS vii LIST OF TABLES x LIST OF FIGURES xiii CHAPTER 1 INTRODUCTION 1 1. Background and Rationale 1 2. Objectives 4 3. Literature Review 4 3.1 The study area: Bandon Bay in Surat Thani Province 4 3.2 Oysters 7 3.3 Basic information of heavy metals 13 3.4 Heavy metals contamination in Bandon Bay ecosystem and the Gulf of 28 Thailand. 3.5 The use of oyster as a biological index for heavy metal 30 contamination. 3.6 Risk assessment 35 3.7 Mathematical model and analysis used for environmental system 42 approach. 2 RESEARCH METHODOLOGY 43 1. Scopes of the study 43 2. Instruments, Materials and Chemicals 45 2.1 Instruments 45 2.2 Equipment and accessories 45 2.3 Chemicals 46 viii Title CONTENTS (CONT.) Page 3. Methodology 46 3.1 Reviews of secondary data 47 3.2 Field survey and experimental study 48 3.3 Determine heavy metals contamination profile in Bandon Bay and 58 assessment of economic impact and risk of heavy metals contamination in Bandon Bay ecosystem 3.4 Recommendation for environmental management 60 3 RESULTS AND DISCUSSION 61 1. Fact and Profile of Heavy Metals in Water and Sediments in the Tapi 61 River and Bandon Bay: Data from Reviews 1.1 Water quality in the Tapi River and Bandon Bay 61 1.2 Sediment quality in the Tapi River and Bandon Bay 64 1.3 Sources of heavy metals and their draining to the Tapi River and 65 Bandon Bay 1.4 Assessment of heavy metals load discharged from inland into 72 Bandon Bay 2. Heavy Metals Concentration Levels in Seawater and Sediments in 75 Bandon Bay, Investigated during 2011-2012 2.1 Quality control of heavy metals in seawater and sediments analysis 75 2.2 Water quality and heavy metals of seawater in Bandon Bay 76 2.3 Sediment characteristics and heavy metal contamination at Bandon 86 Bay 3. Association of Heavy Metals in Sediments and Seawater: A Case Study 97 by Observation in Laboratory Experiments and Field Observation. 3.1 Water quality effects of cockle harrowing activities in Bandon Bay: A 97 case study using field work observation 3.2 Effects of sediment disturbance on water quality: A case study by 99 laboratory investigation 4. Heavy Metal Accumulation in Oysters Cultured in the Coastal Areas 109 of Bandon Bay ix Title CONTENTS (CONT.) Page 4.1 oysters’ growth rate at the study area 109 4.2 Cadmium and lead accumulation in oysters 110 5. Cd and Pb Contamination and Accumulation Profiles in Bandon Bay 116 6. Ecological and Health Risk Assessment for Heavy Metals Pollution in 119 Bandon Bay. 6.1 Ecological risk 119 6.2 Health risk 121 7. Economic Impact Evaluation 126 8. Recommendations for Measures to Control the Heavy Metal 127 Contamination Problem in Bandon Bay 4 CONCLUSION 129 REFERENCES 133 APPENDIX 147 VITAE 157 x LIST OF TABLES Table Page 1 Concentration of some heavy metals in marine animal from 26 different areas. 2 Details of study points in this study 49 3 Parameters and method used to analyze of seawater, sediments, 53 and oyster samples 4 Mining data of Surat Thani province in 2012 66 5 Oil palm plantations in Surat Thani province in 2010 67 6 Rubber plantations in Surat Thani province in 2010 68 7 Potential sources of heavy metal pollution from rubber and oil palm 69 plantations 8 Wastewater generation rates used in this study to calculate 70 wastewater generation by point sources. 9 Amount of shrimp farms in 2010 - 2011 at Bandon Bay, Surat Thani 72 province. 10 Wastewater characteristics concerning heavy metals 73 11 Estimated heavy metal amounts discharged from point sources to 73 Bandon Bay 12 Recovery test and detection limits of heavy metals in seawater 75 samples 13 Recovery test, CRM determination and detection limit values of 76 each heavy metal in sediment 14 Results of seawater quality at Bandon Bay determined in 2011- 78 2012. 15 Heavy metal concentrations in seawater at Bandon Bay as 85 determined in this study. 16 pH, TS, VS, organic matter, N, P and moisture content in sediment 88 samples at Bandon Bay. xi LIST OF TABLES (CONT.) Table Page 17 Characteristics of sediments at Bandon Bay during dry and rainy 88 seasons 18 Statistical test results of heavy metal concentrations in sediments 94 of Bandon Bay. 19 Comparison of the heavy metal concentrations in sediments obtained 96 in this study with the report of the PCD in 2006 and the Canadian Sediment Quality Guidelines for the Protection of Aquatic Life (2002) 20 Seawater quality characteristics at before, during and after cockle 98 harvesting 21 Results of the laboratory test on seawater quality after disturbing 100 the sediment once a day over 30 days, case of Kradae samples 22 Results of the laboratory test on seawater quality after disturbing 101 the sediment once a day over 30 days, case of Chaiya samples 23 Results of the laboratory test on seawater quality to determine 102 heavy metals in Kradae and Chaiya samples over 30 days of sediment disturbance 24 Concentrations of Cd and Pb in sediments