SEASONALITY, HABITATS and MICRO-HABITATS of FISH in WADEABLE STREAMS of NAKOROTUBU, RA, FIJI ISLANDS by Lekima K. F. Copeland Co
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SEASONALITY, HABITATS AND MICRO-HABITATS OF FISH IN WADEABLE STREAMS OF NAKOROTUBU, RA, FIJI ISLANDS By Lekima K. F. Copeland Cover photo: A possible new genus new species of pipefish in the family Sygnathidae found in Vucinivola stream, Nakorotubu. A thesis submitted in fulfillment of the requirements for the Degree of Master of Science in Marine Science Copyright © 2013 by Lekima K. F. Copeland School of Marine Studies Faculty of Science, Technology and Environment University of the South Pacific September, 2013 DEDICATION To my dearest grandmother Vani Tupou Koroi for her love and support & The Rosi ni Kuladrusi Samanunu Simpson ii ACKNOWLEDGEMENTS The stream flowing from the temple “Wherever the stream flows, there will be all kinds of animals and fish. The stream will make the waters of the Dead Sea fresh, and wherever it flows it will bring life” (Ezekiel 47:9). Shortly after submitting my thesis proposal to the research committee, I left to join an expedition to survey several streams originating from the highest peak in New Caledonia. In my heart I still doubted myself on whether I had the ability to undertake Master’s research. I remember lying restless in the early hours of the morning in a small hut far from civilization. Somehow this bible verse came to my mind and all I could remember was “the stream flowing from the temple” but I still could not recollect which book and verse. I switched on my head torch so that I could flip through the pages of my bible but to no avail; I still could not find it. I turned off my head torch and decided to get some sleep. Somehow my bible fell from my hands in the dark and a thought crossed my mind that I should flip it over and switch on the torch. Right before my eyes was the exact book and chapter (Ezekiel 47) I was looking for. Out of the 1220 pages in my bible it fell exactly on the page I was looking for. From that day onwards I knew that God had given his blessings for me to work on riverine fishes. To my supervisors, Professor William Aalbersberg, Aaron Jenkins, James Comley, Marika Tuiwawa and Professor Linton Winder, thank you very much for the support and guidance throughout the study. I greatly appreciate the graduate assistant scholarship given to me by Professor Aalbersberg. I would not have been able to undertake this study without a scholarship and I am especially grateful to Marika Tuiwawa for allowing me to work at the South Pacific Regional Herbarium as a graduate assistant. It has been a blessing to travel with Marika and the rest of the herbarium team to some of the most beautiful and remote parts of Fiji. iii To Aaron Jenkins, I gratefully acknowledge the work you have done on Fiji’s freshwater fishes. Thank you for sharing valuable information on Fiji’s fishes, which included the provision of the fish-dex cards, fish keys, the use of the seine nets for my study and verifying my collection. I thank James Comley who has critiqued this research from the very beginning to the end. Your insight into the experimental design and the analysis of the results has helped me immensely in completing this thesis. Thank you Professor Linton Winder for your comments on the data analysis and results chapter. My deepest recognition to the University of the South Pacific for funding this research. For the field work carried out in Nakorotubu, I would like to thank the Ra Provincial Office for allowing me to carry out the research in the province. Many thanks to the chiefs and village headmen of the following villagers, Nabukadra, Saioko and Naocabau for permission to undertake research on their qoliqoli. Especially to the Mata ni Tikina (district representative) for allowing us to stay in his house over the course of the fieldwork. Thank you Fiji Meteorological Service for providing rainfall data for this thesis. My gratitude to my field assistants from the villages; Josh, Abo and Takala. To my two cousins Samu Copeland and Pita Koroi, thanks for assisting me with the field work in Nakorotubu. To the Herbarium staff, thank you Alifereti Naikatini for helping out with the logistics in carrying out the fieldwork. To Hilda Waqa thank you for answering many questions concerning multivariate analyses using CANOCO. I gratefully appreciate the training in 2010 through the Darwin Initiative fund and thank you for allowing me to be part of that workshop. The training received helped me immensely in the multivariate component of my thesis. Dr. Sarah Pene thank you for your comments on the first draft of my thesis. The staff of the environment unit, Dr. Bale Tamata, Ron Vave and Semisi Meo, thank you for allowing me to use the Horiba meter, underwater camera and the color printer to print my field protocol sheets. Thank you Leigh Anne Buleirua for allowing me to travel iv with you guys to Nakorotubu under the COWRIE project for the first time. This visit helped me choose my sites for the study. Special thanks to Lavenia Tokalauvere and Hans Wendt for helping out with my maps. To the late Sese Gukivuli, thank you for the provisions of chemicals and water quality sampling equipment. To the staff at the administration office at IAS, Aisha Khan, Reshma Prasad, Loata Qorovarua and Rina Segran thank you for helping me out with the administration of my vote code. Special thanks to Mere Naisilisili our graphic artist for helping with several figures in my thesis; especially on the methodology figure. To the staff of Marine Studies Program at the University of the South Pacific, Nanise Bulai, Jone Lima and Shiv Sharma, thank you for allowing me to use the facilities and equipments. Special thanks to the curator of the Marine Collection, Johnson Seeto for availing his pipefish book which was very useful for the identification of my pipefish specimens. Thank you again Johnson for allocating space in the marine collection to work on my voucher specimens and an environment that was conducive for writing my thesis. To Kara Roqica and Laisiasa Cavakilaqi thank you for your vehicles during the wet and dry season sampling phase. To my friends and peers in the CRISP room, Laura Williams, Monal Lal, Viliame Waqalevu and Kelly Brown for the many discussions concerning thesis work. To my fellow GAs at IAS, Siteri Tikoca, Bindiya Rashni, Mereia Katafono, Rusiate Ratuniyata, Fulori Nainoca, Hans Wendt, Isimeli Loganimoce, Elijah Tamata and Joape Ginigini thank you for your support. To Kinikoto Mailautoka (KK) and David Boseto, thank you for sharing your knowledge on freshwater fishes with me. I remember my trip to the headwaters of the Wainibuka River in the Nakauvadra range with you KK, when I decided to try out a pretest of my thesis methodology. It was difficult because you were just critiquing me very well on my data collection only after one station. I sat there dumbfounded and stressed but the lessons learnt (two blisters on my left and right calf muscles) taught me valuable life lessons and prepared me well for data collection in Nakorotubu. Thank you KK and David for always asking me “Hey Lex, what fish is this?” and when I got it wrong you v guys would always correct and clarify things with me. This was the fastest way I could learn how to identify freshwater fishes in Fiji. Finally, to my very supportive family, especially my grandmothers Vani Koroi and Elizabeth Copeland, my mom and stepfather Litia and Venasio Ramabuke, my siblings Michael Copeland, Vani Copeland, Josephine Copeland and Patrick Ramabuke. To my cousins Arthur Sokimi, William Sokimi, Augustine Sokimi and Lycyna Sokimi; Leslie Copeland, William Copeland and Samu Copeland. To Aunty Josephine and Uncle William Sokimi, Aunty Etrina Simpson, Uncle William Copeland and Aunty Lucy Copeland and the rest of the family and friends thank you for your support thus far. God bless you all and Vinaka Vakalevu. vi ABSTRACT Research on the abiotic and biotic factors affecting fish in both large rivers and wadeable streams in Fiji is scarce. This research analyzes several mechanisms affecting fish in wadeable streams of Nakorotubu, Viti Levu, Fiji. Three streams were sampled during the wet and dry seasons and divided into lower, mid and upper reach. At each reach there were five replicate stations and within each station water quality, habitat and micro- habitat data were collected. Fish were surveyed using a combination of electrofishing and beach seine. Data were analyzed using both univariate and multivariate statistical methods to elucidate factors affecting fish communities. A total of 677 fish were caught through electrofishing; 27 species of fish from nine families were collected representing 16% of the known freshwater and brackish water fish fauna of Fiji. For statistical analysis 24 species were analyzed due to the inability to identify pipefishes in-situ to species level. All pipefish species collected were lumped into the one genus based category Microphis spp. Spatial variation in fish assemblages were identified with a total of eleven species (46% of total) confined to the lower reaches of the three streams surveyed. Other species such as Eleotris fusca, E. melanosoma, Kuhlia rupestris, Anguilla marmorata, Redigobius leveri, and Sicyopterus lagocephalus, were ubiquitous throughout the reaches. Temporal changes in fish community structure across wet and dry season were noticeable for the three streams sampled. About fifteen species (63%) were observed in both seasons, while seven species (29%) were seen only in the dry season. In contrast two species (8%) were only found in the wet season, Anguilla obscura and Glossogobius illimis.