School of Molecular and Life Sciences Technical Feasibility of Cultivating Local Seaweed Species in Inland Saline Water of Western Australia Ha Thi Thu Bui This thesis is presented for the Degree of Doctor of Philosophy of Curtin University April 2018 DECLARATION To the best of my knowledge and belief this thesis contains no material previously published by any other person except where due acknowledgment has been made. This thesis contains no material which has been accepted for the award of any other degree or diploma in any university. Signature: Date: 23 April 2018 STATEMENT OF ACCESS TO THESIS I, the undersigned, the author of this thesis, understand that Curtin University, Perth, Western Australia, will make it available for use within the university library and allow access to users in other approved libraries. All users consulting this thesis have to sign the following statement: ‘In consulting this thesis, I agree not to copy or closely paraphrase it in whole or in part without the written consent of the author and to make properly written acknowledgement for any assistance which I have obtained form it’. Beyond this, I do not wish to place any restriction on this thesis. Signature: i ACKNOWLEDGEMENTS I would like to express my sincere thanks to the Ministry of Education and Training (MOET) of Vietnam and Curtin International Postgraduate Research Scholarship (CIPRS) for granting me the opportunity to study and complete my PhD on Environment and Agriculture in the School of Molecular and Life Sciences (SML) (former as Department of Environment and Agriculture), Curtin University. I would also like to thank the following people who have helped me with the completion of my study: Professor Ravi Fotedar, my supervisor, for his unsurpassed support and guidance, for his support as an exceptional expert and his tireless efforts and patience in supervising me; my co-supervisor, Professor Jean-Philippe Croue and Dr. Uras Tantulo for their help with my writing. I would like to thank the SML for providing me with the necessary facilities, excellent support and an ideal environment in which to undertake this research study. My thanks go to the administration and all the teachers, staff and other colleagues at SML, particularly to Simon Longbottom, Rowan Kleindienst and Anne Barnet for their support in my working at Curtin Aquatic Research Laboratory. Thank you also to the Graduate Research School, International Centre, IO-Visa Office and Research Scholarship Office at Curtin University, for their administrative support. From deep of my heart, thanks to Dr. John Huisman, Western Australian Herbarium Curator, for his kind help, patience and time spending in identifying the local seaweed species for my study. I would like to thank Associate Professor Dr Phan Thi Van, Dr. Nguyen Huu Ninh, Dr. Nguyen Quang Huy, Dr. Tran The Muu, and Dr. Dang Thi Lua, the current and former Director of the Board of the Research Institute for Aquaculture No.1 (RIA1), and Mr. Tran Manh Tuan, Director of the Centre of Aquaculture Technology Transfer, RIA1, for offering me this great opportunity to study at Curtin University. Thanks also go to my colleagues at RIA1 for their valuable support and encouragement. I would also like to thank Dinh Quang Huy, who has been willing to help and assist me during my study. I give thanks from deep in my heart to Hoang Cong Tin, Le Van ii Ky, Mai Van Ha, Tran Duc Thien, Ong Moc Quy, Nguyen Thi Hanh, Tran Thi Anh Nguyet and others. Thanks for their kindness, for spending time with me, and for helping me in my research and sharing my personal problems that occurred during my time in Australia. I would like to thank Dr Thuy Nguyen, Dr Thomas Kalb and Dr Thang Van Nguyen for proofreading my papers, and giving me extremely helpful advice on my writing. I am very grateful to my beloved husband Trong Quoc Luu for his support, financially and spiritually, and understanding of my work. Without his assistance in my Laboratory work, I could not handle the whole burden. Thanks also to my lively daughter, Lily To Tran Luu, who did not receive enough attention from me during my study. Thanks to my family, my dad and relatives for their support. Without their boundless love, trust and encouragement, I would not have made it this far. Dedicated to the memory of my mother, Nguyen Thi Diem, and my brother, Bui Giang Nam, who always believed in my ability to be successful in the academic arena. Your love had encouraged me to complete this research. I am in debt to many people who I cannot mention here, and would like to pass on my thanks to them also. Perth, April 2018 iii PREAMBLE This study aims to evaluate the technical feasibility of culturing locally available seaweeds in inland saline water (ISW) of Western Australia and in ionically modified ISW. Although, there are lower additional input resources required for existing agricultural farmers to culture seaweed in ISW than other higher order fish, shrimp and molluscan species, there is no comprehensive published information available to culture local seaweed species under ISW environment in Western Australia. The present thesis is structured so that the information flows easily from one chapter to another within the context of some entire chapters or certain sections of the chapters have been published, therefore there is a possibility of certain duplication, particularly in terms of introduction and methodology. The thesis is organized into ten (10) chapters. Chapter 1 is general introduction to the research that includes the background information, justification of the study, the aim, and the objectives of the research. Chapter 2 reviews the relevant literature on the topic and related research areas including quality of ISW in Australia and Western Australia, and current global aquaculture practice in ISW. Information about the ionic composition and environmental factors influencing characteristics of ISW are also reviewed. This chapter also provides an overview about six studied seaweed species and their potential uses and aquaculture practices. Chapter 3 presents methodology and summarises the general methods used in the experiments, data collection, and data analysis. This chapter includes a common section of Materials and Methods of subsequent chapters. This attempts to avoid repeating of some of the common protocols followed in rest of the chapters. Selecting potentially suitable seaweeds species that could be grown in ISW was the first step in order to achieve the aim of this research. Chapter 4 describes the selection procedure for seaweeds to be investigated for their technical feasibility to culture in ISW around Perth region in Western Australia. Five genera of seaweed consist of six species representing green, red and brown seaweeds were shortlisted to be cultured in iv ISW and potassium-fortified ISW (K+ISW). These six species of seaweed are Cystophora subfarcinata, Sargassum linearifolium, Sargassum podacanthum, Ulva lactuca, Glateroupia suspectinata, Fushisunagia catenata (basionym Lomentaria catenata) (Appendix 1). As the species of Fushisunagia catenata was identified after the publication of the article on Lomentaria sp., Lomentaria catenata will be used as the name of this species throughout the thesis. Chapter 4 also explores the effects of + + two sources of K as K2SO4 and KCl to fortify ISW. Both sources of K to make 100%K+ISW result in a similar specific growth rate (SGR) for both S. linearifolium and S. podacanthum as if cultured in ocean water (OW). The remaining part of the thesis is divided into three sections. Section 1 focusses on Sargassum spp. and comprises of chapters 5 to 7. Section 2 includes Chapter 8 which describes the experiments conducted on Lomentaria catenata. Section 3 consists of Chapter 9 which containes two sections: (i) – a preliminary study of culturing Ulva lactuca in OW, and (ii) – cultural feasibility of U. lactuca in ISW. Chapter 5 investigates the productivity of Sargassum spp. in K+ISW at 100%, 66% and 33% of [K+] as in OW. Sargassum spp. can sustain a similar growth rate as in OW in K+ISW at 100% of K+ concentration. The SGR of S. linearifolium’s is higher than S. podacanthum at all K+ISW levels. The section related to the S. linearifolum in this chapter, entitled “Productivity of Sargassum linearifolium in potassium-fortified inland saline water under laboratory conditions”, is published in the journal of Aquaculture Research as a research article (Appendix 2.1). Chapter 6 focuses on the culture of S. linearifolium and S. podacanthum in 100% K+ISW and OW, which are enriched weekly by ammonium:phosphate, at the levels of 80:8, 120:12, 160:10, 200:20 and 240:24 µM. The higher nutrient supplementation in OW works better than in K+ISW in terms of Sargassum biomass, however, there is no interaction between water types (OW and K+ISW) and supplementation of nutrient levels. S. padocanthum grows better than S. linerifolium in both OW and K+ISW nutrient-enriched environment. The main segment of this chapter centered on S. podacanthum, entitled “Effects of nitrogen and phosphorus enrichment on the growth of Sargassum podacanthum cultured in potassium-fortified inland saline water” has been published in American Journal of Applied Science as a research article (Appendix 2.2). v Chapter 7 describes the research on effects of temperature and pH on the growth of S. linearifolium and S. podacanthum cultured in K+ISW. Temperature of 20–22oC and ambient water pH levels of 7.0–8.2 of K+ISW are suitable for cultivating Sargassum spp. This chapter has been published in American Journal of Applied Science as a research article entitled “Effects of temperature and pH on the growth of Sargassum linearifolium and S. podacanthum in potassium-fortified inland saline water” (Appendix 2.3).