Sediments in the Tema Harbour (Ghana): Chemical Pollution and Sedimentation Rates
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Sediments in the Tema Harbour (Ghana): Chemical Pollution and Sedimentation Rates Benjamin O. Botwe SEDIMENTS IN THE TEMA HARBOUR (GHANA): CHEMICAL POLLUTION AND SEDIMENTATION RATES Benjamin O. Botwe Thesis committee Promotor Prof. Dr Piet N.L. Lens Professor of Environmental Biotechnology IHE Delft Institute for Water Education, the Netherlands Co-promotor Prof. Elvis Nyarko Professor of Marine Environmental Science University of Ghana, Accra, Ghana Other members Prof. Dr Karen J. Keesman, Wageningen University & Research, the Netherlands Prof. Kerstin Kuchta, Technical University of Hamburg, Germany Dr Elin Vanlierde, Agentschap Informatie Vlaanderen, Brussels, Belgium Dr Leonard Ost, Deltares, Delft, the Netherlands This research was conducted under the auspices of the Graduate School for Socio-Economic and Natural Sciences of the Environment (SENSE) Sediments in the Tema Harbour (Ghana): chemical pollution and sedimentation rates Thesis submitted in fulfilment of the requirements of the Academic Board of Wageningen University and the Academic Board of the IHE Delft Institute for Water Education for the degree of doctor to be defended in public on Friday, 29 June 2018 at 01:30 p.m. in Delft, the Netherlands by Benjamin Osei Botwe Born in Accra, Ghana CRC Press/Balkema is an imprint of the Taylor & Francis Group, an informa business © 2018, Benjamin O. Botwe Although all care is taken to ensure integrity and the quality of this publication and the information herein, no responsibility is assumed by the publishers, the author nor IHE Delft for any damage to the property or persons as a result of operation or use of this publication and/or the information contained herein. A pdf version of this work will be made available as Open Access via http://repository.tudelft.nl/ihe. This version is licensed under the Creative Commons Attribution-Non Commercial 4.0 International License, http://creativecommons.org/licenses/by-nc/4.0/ Published by: CRC Press/Balkema Schipholweg 107C, 2316 XC, Leiden, the Netherlands [email protected] www.crcpress.com – www.taylorandfrancis.com ISBN ISBN: 978-1-138-32351-3 ISBN ISBN: 978-94-6343-838-4 DOI: https://doi.org/10.18174/443802 To my children, Jayden, Gideon and Davida Acknowledgements I wish to express profound gratitude to the Dutch Government for funding this PhD study at the UNESCO-IHE Institute for Water Education in Delft through Nuffic in the framework of the Netherlands Fellowship Programme (NFP-PhD. 12/316). I also wish to thank the University of Ghana for the financial support provided through the Office of Research, Innovation and Development (ORID) under the Faculty Development Fund (UGFD/7/2012- 2013/004). The logistical and technical assistance provided by the Ghana Ports and Harbours Authority is also acknowledged. I am most grateful to Prof. dr. Piet N.L. Lens (Promotor) and Prof. Elvis Nyarko (Co- Promotor), whose excellent guidance and advice have brought me this far. The staff of the Department of Marine and Fisheries Sciences at the University of Ghana are acknowledged for their support. I am also indebted to Alisa Mast and Gregory A. Wetherbee, both at the US Geological Survey, for donating a KB corer for my field sampling. I also wish to thank Jolanda Boots (Admissions Officer, UNESCO-IHE, Delft), who was instrumental in the technical matters of my PhD study at the UNESCO-IHE, Delft. Professor Ronny Blust is acknowledged for permitting me to conduct bioassay experiments at the Systemic Physiological and Ecotoxicological Research (SPHERE) laboratory of the University of Antwerp, Belgium. I received lots of encouragements from Frank and Ida van der Meulen and Cor Schipper for which I am grateful. My dear wife Janet Botwe, my brother Dr. Theophilus Botwe and my entire family are also acknowledged for their support. Furthermore, I am grateful to Mr. Bennet Atsu Foli for providing editorial assistance. Several others have contributed to the success of my PhD work in one way or the other, whose names are not mentioned. vii Abstract The Tema Harbour in Ghana has been in operation for nearly six decades and is subject to large influxes of sediments and sediment pollution due to the intense human activities in the harbour area. This thesis assessed sediment pollution in the Tema Harbour by using the standard 10-day Corophium volutator and 28-day Hediste diversicolor whole-sediment toxicity bioassays as well as chemical contaminant (DDTs, HCHs, PAHs and metal - Cd, Pb, Cr, Ni, Cu, Zn and As) data. The bioassay results showed significant C. volutator and H. diversicolor mortalities, indicating that the Tema Harbour sediments are polluted and toxic. Biota-sediment accumulation factors further revealed a high potential for bioaccumulation of the sediment-associated metals, which can have adverse implications for the food chain. Thus, the Tema Harbour sediments are unsuitable for disposal at sea without remediation. The thesis further investigated sediment accumulation rates (SARs) in the Tema Harbour by the combined analyses of sediment trap and sediment core data. The sediment cores exhibited variable bulk density profiles, indicating highly dynamic and non-steady sedimentation conditions. 7Be-derived gross-estimates of very recent sediment accumulation rates using the constant flux-constant sedimentation (CF-CS) model were in the range of 2.5-9.0 g.cm-2.y-1. These values were much lower than the estimated average settling fluxes from the sediment trap data (15.2-53.8 g.cm-2.y-1), indicating sediment resuspension plays an important role in the sedimentation process. Conventional 210Pb sediment dating models did not allow any estimation of SARs in the Tema Harbour. The 210Pb-based TERESA model, on the other hand, proved to be a good tool for quantifying sediment accumulation rates in the Tema Harbour with time-averaged values in the range of 1.4-3.0 g.cm-2.y-1 and sediment accretion rates of 1.7-3 cm.y-1. In conclusion, this study has shown that the Tema Harbour has been severely affected by anthropogenic activities, resulting in pollution of the sediments, especially those from the Fishing Harbour and the Canoe Basin. Moreover, the sediment accretion rates in the harbour may pose moderate problems for sustainable use of the harbour. There is, therefore, a need to improve sediment and environmental management in the Tema Harbour and regulate the disposal of the dredged material originating from this tropical coastal harbour. ix Abbreviations and acronyms AAS – Atomic absorption spectrometer Ace – Acenaphthene Acy – Acenaphthylene AEDE – Annual effective dose equivalent AGDE – Annual gonadal dose equivalent AL1 – Action levels 1 AL2 – Action level 2 ANOVA – Analysis of variance Ant – Anthracene BaA – Benzo[a]anthracene BaP – Benzo[a]pyrene BbF – Benzo[b]fluoranthene BCR – Community Bureau of Reference BFR – Brominated flame retardant BghiP – Benzo[g,h,i]perylene BkF – Benzo[k]fluoranthene Bq – Becquerel BSAF – Biota-sediment accumulation factor CANMET – Canada Centre for Mineral and Energy Technology CB – Canoe Basin Chr – Chrysene COEC – Chemicals of emerging concern CRM – Certified reference material DahA – Dibenz[a,h]anthracene DDD – Dichlorodiphenyldichlororethane DDE – Dichlorodiphenyldichloroethylene DDT – Dichlorodiphenyltrichloroethane DNA – Deoxyribonucleic acid DO – Dissolved oxygen EF – Enrichment factor Eh – Redox potential ENEA – Ente per le Nuove tecnologie, l‘Energia e l‘Ambiente xi Abbreviations and acronyms ERL – Effects Range Low ERLQ – Effects range low quotient ERM – Effects Range Median ERMQ – Effects range median quotient ERICA – Environmental Risk from Ionising Contaminants Assessment and Management Fla – Fluoranthene Flu – Fluorene GC – Gas chromatograph GC-ECD – Gas chromatograph with electron capture detector GC-FID – Gas chromatograph with flame ionisation detector GC-MSD – Gas chromatograph with mass selective detector GESAMP – Group of Experts on the Scientific Aspects of Marine Environmental Protection GIS – Geographic Information Systems GPHA – Ghana Ports and Harbours Authority Gy – Gray HCH – Hexachlorocyclohexane Hex – External hazard index HPAHs – High molecular weight PAHs IAEA – International Atomic Energy Agency ICP – Inductively Coupled Plasma ICP-MS – Inductively Coupled Plasma - Mass Spectrometry IFH – Inner Fishing Harbour Igeo – Geo-accumulation index IP – Indeno[1,2,3-cd]pyrene JICA – Japan International Co-operation Agency LPAHs – Low molecular weight PAHs MERMQ – Mean effects range median quotient MH – Main Harbour MTCA – Model Toxics Control Act Nap – Naphthalene NFP - Netherlands Fellowship Programme NIST – National Institute of Standards and Technology NTU – Nephelometric Turbidity Unit NUFFIC - Netherlands Organisation for International Cooperation in Higher Education xii Abbreviations and acronyms OC – Organochlorine compound OCP – Organochlorine pesticide OFH – Outer Fishing Harbour OM – Organic matter PAH – Polycyclic aromatic hydrocarbon PAH16 – 16 priority PAHs by the United States Environmental Protection Agency 210 Pbex – Excess Lead-210 210 Pbsupp – Supported Lead-210 PBDE – Polybrominated diphenyl ether PCB – Polychlorinated biphenyl PCDD – Polychlorinated dibenzodioxins PCDF – Polychlorinated dibenzofuran PCN – Polychlorinated naphthalene PDBS – Phase Differencing Bathymetric Sonar PFC – Perfluorinated chemical PFOA – Perfluorooctanoic acid PFOS – Perfluorooctane sulfonate Phe – Phenanthrene POPs – Persistent organic pollutants ppm – Parts per million PVC – Polyvinyl chloride Pyr – Pyrene RAC – Risk assessment