Abstract
Seawater temperature was recorded at two-hourly intervals for two years (March 2006-March 2008) by six data loggers in Diego Garcia atoll, central Indian Ocean. Loggers were substrate mounted, in two transects of 5, 15 and 25 m depth on a seaward reef and in a lagoonal pass. During the season of mixed but predominantly northwest winds, regular plunges of temperature of 5–7°C occurred with a periodicity of 1–4 days. This partly coincided with the period of greatest annual warming. Temperature fluctuations increased with increasing depth. Temperature traces are compared with HadISST1 and AVHRR satellite-derived temperature data which do not capture the deeper water temperature plunges. Reasons for the regular temperature plunges appear to include both tidal cycles and unidentified, internal waves. This is important for issues of coral refuges, complicating use of satellite-derived temperature data for planning optimal coral reef conservation areas.
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References
Berkelmans R (2002) Time-integrated thermal bleaching thresholds of reefs and their variation on the Great Barrier Reef. Mar Ecol Prog Ser 299:73–82
Brown BE, Dunne RP, Goodson MS, Douglas AE (2002) Experience shapes the susceptibility of a reef coral to bleaching. Coral Reefs 21:119–126
Coles SL, Brown BE (2003) Coral bleaching—capacity for acclimatization and adaptation. Adv Mar Biol 46:183–223
Graham NAJ, McClanahan TR, MacNeil MA, Wilson SK, Polunin NVC, Jennings S, Chabanet P, Clark S, Spalding MD, Letourneur Y, Bigot L, Galzin R, Ohman MC, Garpe KC, Edwards AJ, Sheppard CRC (2008) Climate Warming, Marine Protected Areas and the Ocean-Scale Integrity of Coral Reef Ecosystems. PLoS One 3(8): e3039, 9 pp
Kaplan DM, Largier JL, Navarrete S, Guinez R, Castilla JC (2003) Large diurnal temperature fluctuations in the nearshore water column. Estuarine, Coastal and Shelf Science 57:385–398
Lee H-J, Chao SY, Fan KL, Kuo TY (1999) Tide-Induced Eddies and Upwelling in a Semi-enclosed Basin. Nan Wan Estuar Coast Shelf Sci 49:775–787
Liu G, Strong AE., Skirving W, Arzayus LF (2005) Overview of NOAA coral reef watch program’s near-real time satellite global coral bleaching monitoring activities. Proc 9th Int Coral Reef Symp: 1783–1793
Maina J, Venus V, McClanahan TR, Ateweberhana M (2008) Modelling susceptibility of coral reefs to environmental stress using remote sensing data and GIS models. Ecol Model 212:180–199
Manzello DP, Berkelmans R, Hendee JC (2007) Coral bleaching indices and thresholds for the Florida Reef Tract, Bahamas, and St. Croix, US Virgin Islands Mar Pollut Bull 54:1923–1931
McClanahan TR, Ateweberhan M, Muhando CA, Maina J, Mohammed M (2007a) Effects of climate and seawater temperature variation on coral bleaching and mortality. Ecol Monogr 77:503–525
McClanahan TR, Ateweberhan M, Ruiz Sebastian C, Graham NAJ, Wilson SK, Bruggemann JH, Guillaume MMM (2007b) Predictability of coral bleaching from synoptic satellite and in situ temperature observations. Coral Reefs 26:695–701
McClanahan TR, Ateweberhan M, Graham NAJ, Wilson SK, Ruiz Sebastián C, Guillaume MMM, Bruggemann JH (2007c) Western Indian Ocean coral communities: bleaching responses and susceptibility to extinction. Mar Ecol Prog Ser 337:1–13
Obura DO (2005) Resilience and climate change: lessons from coral reefs and bleaching in Western Indian Ocean. Estuar Coast Shelf Sci 63:353–372
Rayner NA, Parker DE, Horton EB, Folland CKL, Alexander V, Rowell DP, Kent EC, Kaplan A (2003) Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century. J Geophys Res 108(D14):4407. doi:10.1029/2002JD002670
Sheppard CRC (2000) Coral Reefs of the Western Indian Ocean : an Overview. In: McClanahan T, Sheppard CRC, Obura D (eds) Coral reefs of the Western Indian Ocean: Ecology and conservation. Oxford University Press, Oxford, pp 3–38
Sheppard CRC, Obura D (2005) Corals and reefs of Cosmoledo and Aldabra atolls: extent of damage, assemblage shifts and recovery following the severe mortality of 1998. J Nat Hist 39:103–121
Sheppard CRC, Spalding M, Bradshaw C, Wilson S (2002) Erosion vs recovery of coral reefs after 1998 El Niño: Chagos reefs, Indian Ocean. Ambio 31:40–48
Sheppard CRC, Harris A, Sheppard ALS (2008) Archipelago-wide coral recovery patterns since 1998 in the Chagos Archipelago, central Indian Ocean. Mar Ecol Prog Ser 362:109–117
Strong AE, Gjovig KK, Kearns E (2000) Sea surface temperature signals from satellites—an update. Geophys Res Lett 27:1667–1670
Webster PJ, Moore AM, Loschnigg JP, Leben RR (1998) Coupled ocean-atmosphere dynamics in the Indian Ocean during 1997–98. Nature 401:356–360
West JM, Salm RV (2003) Resistance and resilience to coral bleaching: implications for coral reef conservation and management. Cons Biol 17:956–967
Wilkinson C (ed) (2004) Status of coral reefs of the World. Volumes 1 and 2. GCRMN. Australian Institute of Marine Science, Townsville, p 557
Wooldridge S, Done T, Berkelmans R, Jones R, Marshall P (2005) Precursors for resilience in coral communities in a warming climate: a belief network approach. Mar Ecol Prog Ser 295:157–169
Acknowledgements
I thank the several diving colleagues who helped deploy and recover these temperature loggers so effectively and the United Kingdom’s OTEP fund for some of the funding that made the work possible.
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Communicated by Geology Editor Dr. Bernhard Riegl
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Sheppard, C. Large temperature plunges recorded by data loggers at different depths on an Indian Ocean atoll: comparison with satellite data and relevance to coral refuges. Coral Reefs 28, 399–403 (2009). https://doi.org/10.1007/s00338-009-0476-x
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DOI: https://doi.org/10.1007/s00338-009-0476-x