Abstract
This study sought to understand why/when sand islands formed off the north coast of Viti Levu Island (Fiji), how they subsequently developed, and what is likely to happen to them in future. During fieldwork in 2010 and 2016, six groups of sand islands were mapped and their sub-surface stratigraphy analysed; radiocarbon ages were obtained for 16 samples. All islands rise from emerged bevelled reefal platforms 0.55 m below msl on average. Radiocarbon ages from sediments overlying these platforms suggest they emerged above low-tide level around AD 1300. Once emerged, mangroves and/or seagrass beds developed on platform surfaces, allowing sediment to accumulate. Interior sand islands developed and grew to occupy most of the emerged platforms, pushing mangroves and seagrasses to their margins. Recent sea-level rise has seen island shorelines recede; Severe Tropical Cyclone Winston (February 2016) caused profound changes to the form of some and led to deposition of rubble banks along their fringes. This study contributes evidence for the origin, development and likely prospects of such sand islands under a changing climate. It has implications for the future sustainability of coastal ecosystems in such regions and for the livelihoods of the peoples who depend upon them.
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References
Albert S, Leon JX, Grinham AR, Church JA, Gibbes BR, Woodroffe CD (2016) Interactions between sea-level rise and wave exposure on reef island dynamics in the Solomon Islands. Environ Res Lett 11:054011. https://doi.org/10.1088/1748-9326/11/5/054011
BOM (2014) Climate variability, extremes and change in the Western tropical Pacific: new science and updated country reports. Pacific-Australia climate change science and adaptation planning program technical Report. Australian Bureau of Meteorology (BOM) and Commonwealth Scientific and Industrial Research Organisation (CSIRO), Melbourne,
Bronk-Ramsey C (2017) OxCal v4.3.2. Oxford radiocarbon accelerator unit,
Chang YT, Du L, Zhang SW, Huang PF (2013) Sea level variations in the tropical Pacific Ocean during two types of recent El Nino events. Glob Planet Change 108:119–127. https://doi.org/10.1016/j.gloplacha.2013.06.001
Church JA, Clark PU, Cazenave A, Gregory JM, Jevrejeva S, Levermann A, Merrifield MA, Milne GA, Nerem RS, Nunn PD, Payne AJ, Pfeffer WT, Stammer D, Unnikrishnan AS (2013) Sea level change. In: Stocker TF et al (eds) Climate change 2013: the physical science basis working group I contribution to the fifth assessment report of the intergovernmental panel on climate change. Cambridge University Press, Cambridge, pp 1137–1308
Collen JD, Garton DW (2004) Larger foraminifera and sedimentation around Fongafale Island, Funafuti Atoll, Tuvalu. Coral Reefs 23:445–454. https://doi.org/10.1007/s00338-004-0396-8
Dangendorf S, Marcos M, Woppelmannc G, Conrad CP, Frederikse T, Riva R (2017) Reassessment of 20th century global mean sea level rise. Proc Natl Acad Sci U S A 114:5946–5951. https://doi.org/10.1073/pnas.1616007114
Davis WM (1920) The islands and coral reefs of Fiji. Geogrl J 55:34–45, 200–220, 377–388
Duvat V (2018) A global assessment of atoll island planform changes over the past decades. WIREs Clim Change e557. https://doi.org/10.1002/wcc.557
Duvat VKE, Magnan AK, Wise RM, Hay JE, Fazey I, Hinkel J, Stojanovic T, Yamano H, Ballu V (2017) Trajectories of exposure and vulnerability of small islands to climate change. Wiley interdisciplinary reviews-climate Change. 8:UNSP e478. https://doi.org/10.1002/wcc.478
Duvat V, Pillet V, Volto N, Krien Y, Cece R, Bernard D (2019) High human influence on beach response to tropical cyclones in small islands: Saint-Martin Island, Lesser Antilles. Geomorphology 325:70–91. https://doi.org/10.1016/j.geomorph.2018.09.029
Eyre BD, Cyronak T, Drupp P, De Carlo EH, Sachs JP, Andersson AJ (2018) Coral reefs will transition to net dissolving before end of century. Science 359:908–911. https://doi.org/10.1126/science.aao1118
Fisk GW, Haines PE, Toki BF (2017) Coastal environments under a changing climate - what if resilience building is not enough? In: Filho WL (ed) Climate change adaptation in Pacific countries. Springer, Berlin, pp 417–431
Fosberg FR (1957) Description and occurrence of atoll phosphate rock in Micronesia. Am J Sci 255:584–592. https://doi.org/10.2475/ajs.255.8.584
Fujita K, Nagamine S, Ide Y, Umezawa Y, Hosono T, Kayanne H, Yamano H (2014) Distribution of large benthic foraminifers around a populated reef island: Fongafale Island, Funafuti Atoll, Tuvalu. Mar Micropaleontol 113:1–9. https://doi.org/10.1016/j.marmicro.2014.08.008
Gibbons JRH (1981) The biogeography of Brachylophus (Iguanidae) including the description of a new species, Brachylophus vitiensis, from Fiji. J Herpetol 15:255–273. https://doi.org/10.2307/1563429
Hamburger MW, Everingham IB, Isacks BL, Barazangi M (1988) Active tectonism within the Fiji platform, Southwest Pacific. Geology 16:237–241. https://doi.org/10.1130/0091-7613(1988)016<0237:atwtfp>2.3.co;2
Hong E, Dade WB, Chang YC, Chan SY (2010) Geomorphic evolution of a Barrier Island reflects the history of natural sediment supply and human intervention in Taiwan. J Coast Res 26:53–58. https://doi.org/10.2112/08-1008.1
Kemp AC, Horton BP, Donnelly JP, Mann ME, Vermeer M, Rahmstorf S (2011) Climate related sea-level variations over the past two millennia. Proc Natl Acad Sci 108:11017–11022. https://doi.org/10.1073/pnas.1015619108
Kench PS (2014) Developments in coral reef and reef island geomorphology. Geomorphology 222:1–2. doi: https://doi.org/10.1016/j.geomorph.2014.05.018
Kench PS, Owen SD, Ford MR (2014) Evidence for coral island formation during rising sea level in the Central Pacific Ocean. Geophys Res Lett 41:820–827. https://doi.org/10.1002/2013gl059000
Kench PS, Ford MR, Owen SD (2018) Patterns of island change and persistence offer alternate adaptation pathways for atoll nations. Nat. Commun 9:#605. https://doi.org/10.1038/s41467-018-02954-1
Kronen M, Vunisea A, Magron F, McArdle B (2010) Socio-economic drivers and indicators for artisanal coastal fisheries in Pacific island countries and territories and their use for fisheries management strategies. Mar Policy 34:1135–1143. https://doi.org/10.1016/j.marpol.2010.03.013
Kumar R, Nunn PD, Field JS, de Biran A (2006) Human responses to climate change around AD 1300: a case study of the Sigatoka Valley, Viti Levu Island, Fiji. Quat Int 151:133–143. https://doi.org/10.1016/j.quaint.2006.01.018
Kumar SK, Chandrasekar N, Seralathan P, Sahayam JD (2012) Diagenesis of Holocene reef and associated beachrock of certain coral islands, gulf of Mannar, India: implication on climate and sea level. J Earth Syst Sci 121:733–745. https://doi.org/10.1007/s12040-012-0183-9
Ladd HS, Hoffmeister JE (1927) Recent negative shift in the strand line in Fiji and Tonga. J Geol 35:542–556. https://doi.org/10.1086/623443
Mangubhai S, Erdmann MV, Wilson JR, Huffard CL, Ballamu F, Hidayat NI, Hitipeuw C, Lazuardi ME, Muhajir PD, Purba G, Rotinsulu C, Rumetna L, Sumolang K, Wen W (2012) Papuan Bird's head seascape: emerging threats and challenges in the global center of marine biodiversity. Mar Pollut Bull 64:2279–2295. https://doi.org/10.1016/j.marpolbul.2012.07.024
McKoy H, Kennedy DM, Kench PS (2010) Sand cay evolution on reef platforms, Mamanuca Islands, Fiji. Mar Geol 269:61–73. https://doi.org/10.1016/j.margeo.2009.12.006
McLean R, Kench P (2015) Destruction or persistence of coral atoll islands in the face of 20th and 21st century sea-level rise? Wiley Interdiscip. Rev. Clim. Chang 6:445–463. https://doi.org/10.1002/wcc.350
Mengel M, Levermann A, Frieler K, Robinson A, Marzeion B, Winkelmann R (2016) Future Sea level rise constrained by observations and long-term commitment. Proc Natl Acad Sci U S A 113:2597–2602. https://doi.org/10.1073/pnas.1500515113
Miyata T (1984) Geologic development of Viti Levu, Fiji. In: Sugimura A (ed) Sea-level changes and tectonics in the middle Pacific: report of the HIPAC project in 1981, 1982 and 1983. Kobe University, Kobe, pp 57–62
Montaggioni LF, Pirazzoli PA (1984) The significance of exposed coral conglomerates from French Polynesia (Pacific Ocean) as indicators of recent relative sea-level changes. Coral Reefs 3:29–42. https://doi.org/10.1007/bf00306138
Morrison AE, Cochrane EE (2008) Investigating shellfish deposition and landscape history at the Natia Beach site, Fiji. J Archaeol Sci 35:2387–2399. https://doi.org/10.1016/j.jas.2008.03.013
Nerem RS, Beckley BD, Fasullo JT, Hamlington BD, Masters D, Mitchum GT (2018) Climate-change-driven accelerated sea-level rise detected in the altimeter era. Proc Natl Acad Sci U S A 115:2022–2025. https://doi.org/10.1073/pnas.1717312115
Nunn PD (1990) Coastal processes and landforms of Fiji - their bearing on Holocene Sea-level changes in the south and West Pacific. J Coast Res 6:279–310
Nunn PD (1994) Oceanic Islands. Oxford
Nunn PD (1998a) Pacific Island landscapes : landscape and geological development of Southwest Pacific Islands, especially Fiji, Samoa and Tonga. Institute of Pacific Studies, University of the South Pacific, Suva, Fiji
Nunn PD (1998b) Sea-level changes over the past 1,000 years in the pacific. J Coast Res 14:23–30
Nunn PD (2007) Climate, environment and Society in the Pacific during the last millennium. Elsevier, Amsterdam
Nunn PD (2012) Na koronivalu ni Bā: upland settlement during the last millennium in the Bā River valley and Vatia peninsula, northern Viti Levu Island, Fiji. Asian Perspect 51:1–21
Nunn PD (2013) The end of the Pacific? Effects of sea level rise on Pacific Island livelihoods. Singap J Trop Geogr 34:143–171. https://doi.org/10.1111/sjtg.12021
Nunn PD, Peltier WR (2001) Far-field test of the ICE-4G model of global isostatic response to deglaciation using empirical and theoretical Holocene Sea-level reconstructions for the Fiji Islands, southwestern Pacific. Quat Res 55:203–214
Nunn PD, Kohler A, Kumar R (2017) Identifying and assessing evidence for recent shoreline change attributable to uncommonly rapid sea-level rise in Pohnpei, Federated States of Micronesia, Northwest Pacific Ocean. J Coast Conserv 21:719–730. https://doi.org/10.1007/s11852-017-0531-7
Otvos EG, Carter GA (2008) Hurricane degradation-barrier development cycles, northeastern Gulf of Mexico: landform evolution and island chain history. J Coast Res 24:463–478. https://doi.org/10.2112/06-0820.1
Perry CT, Kench PS, Smithers SG, Riegl B, Yamano H, O'Leary MJ (2011) Implications of reef ecosystem change for the stability and maintenance of coral reef islands. Glob Chang Biol 17:3679–3696. https://doi.org/10.1111/j.1365-2486.2011.02523.x
Petchey F, Anderson A, Hogg A, Zondervan A (2008) The marine reservoir effect in the Southern Ocean: an evaluation of extant and new ΔR values and their application to archaeological chronologies. J R Soc N Z 38:243–262. https://doi.org/10.1080/03014220809510559
Reimer PJ, Bard E, Bayliss A, Beck JW, Blackwell PG, Ramsey CB, Buck CE, Cheng H, Edwards RL, Friedrich M, Grootes PM, Guilderson TP, Haflidason H, Hajdas I, Hatte C, Heaton TJ, Hoffmann DL, Hogg AG, Hughen KA, Kaiser KF, Kromer B, Manning SW, Niu M, Reimer RW, Richards DA, Scott EM, Southon JR, Staff RA, Turney CSM, van der Plicht J (2013) INTCAL13 and MARINE13 radiocarbon age calibration curves 0-50,000 years cal BP. Radiocarbon 55:1869–1887
Robb KF, Nunn PD (2012) Nature and chronology of prehistoric settlement on the Vatia peninsula, northern Viti Levu Island, Fiji. J Isl Coast Archaeol 7:272–281. https://doi.org/10.1080/15564894.2011.614320
Robb KF, Nunn PD (2014) Vatutāqiri: an immense stone-walled fortification on the Vatia peninsula, northern Viti Levu Island, Fiji. People Cult Oceania 30:1–19
Rodriguez AB, Yu W, Theuerkauf EJ (2018) Abrupt increase in washover deposition along a transgressive barrier island during the late 19th century acceleration in sea-level rise. In: Moore L, Murray B (eds) Barrier dynamics and response to changing climate. Springer, Berlin, pp 121–145
Selig ER, Frazier M, O'Leary JK, Jupiter SD, Halpern BS, Longo C, Kleisner KL, Sivo L, Ranelletti M (2015) Measuring indicators of ocean health for an island nation: the ocean health index for Fiji. Ecosystem Services 16:403–412. https://doi.org/10.1016/j.ecoser.2014.11.007
Shkol'nik EL, Baturin GN, Zhegallo EA, Nikolaev SD (2006) Phosphogenesis on selected low atolls in the near-equatorial part of the Western Indian Ocean. Oceanology 46:242–255. https://doi.org/10.1134/s0001437006020111
Stoddart DR (1971) Geomorphology of Diego Garcia atoll. Atoll Res Bull 149:7–26
Valmonte-Santos R, Rosegrant MW, Dey MM (2016) Fisheries sector under climate change in the coral triangle countries of Pacific Islands: current status and policy issues. Mar Policy 67:148–155. https://doi.org/10.1016/j.marpol.2015.12.022
Veitayaki J, Tawake A, Aalbersberg W, Rupeni E, Tabunakawai K (2003) Mainstreaming resource conservation: the Fiji locally-managed marine area network and national policy development. In: Jaireth H, Smyth D (eds) Innovative governance, indigenous people. Local Communities and Protected Areas. Ane Books, New Delhi, pp 105–124
Walsh KJE, McBride JL, Klotzbach PJ, Balachandran S, Camargo SJ, Holland G, Knutson TR, Kossin JP, Lee TC, Sobel A, Sugi M (2016) Tropical cyclones and climate change. Wiley Interdisciplinary Reviews-Climate Change 7:65–89. https://doi.org/10.1002/wcc.371
Webb AP, Kench PS (2010) The dynamic response of reef islands to sea-level rise: evidence from multi-decadal analysis of island change in the Central Pacific. Glob Planet Chang 72:234–246. https://doi.org/10.1016/j.gloplacha.2010.05.003
Woodroffe CD (2008) Reef-island topography and the vulnerability of atolls to sea-level rise. Glob Planet Change 62:77–96. https://doi.org/10.1016/j.gloplacha.2007.11.001
Woodroffe CD, Samosorn B, Hua Q, Hart DE (2007) Incremental accretion of a sandy reef island over the past 3000 years indicated by component-specific radiocarbon dating. Geophys Res Lett 34:L03602. https://doi.org/10.1029/2006gl028875
Yamano H, Kayanne H, Chikamori M (2005) An overview of the nature and dynamics of reef islands. Glob Environ Res 9:9–20
Yamano H, Cabioch G, Chevillon C, Join JL (2014) Late Holocene sea-level change and reef-island evolution in New Caledonia. Geomorphology 222:39–45. https://doi.org/10.1016/j.geomorph.2014.03.002
Acknowledgements
The original research was funded by the G. Unger Vetlesen Foundation as a part of a study by PN of last-millennium climate-society interactions on tropical Pacific Islands. PN, AM and PD received funding from the University of the Sunshine Coast to enable the second phase of field/analytical research. We are grateful to Fiona Petchey (University of Waikato) for recalibrating the first group of radiocarbon ages, so that all those shown in Table 2 are presented consistently.
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Nunn, P.D., McKeown, M., McCallum, A. et al. Origin, development and prospects of sand islands off the north coast of Viti Levu Island, Fiji, Southwest Pacific. J Coast Conserv 23, 1005–1018 (2019). https://doi.org/10.1007/s11852-019-00707-w
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DOI: https://doi.org/10.1007/s11852-019-00707-w