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Marine heatwaves threaten global biodiversity and the provision of ecosystem services

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The global ocean has warmed substantially over the past century, with far-reaching implications for marine ecosystems1. Concurrent with long-term persistent warming, discrete periods of extreme regional ocean warming (marine heatwaves, MHWs) have increased in frequency2. Here we quantify trends and attributes of MHWs across all ocean basins and examine their biological impacts from species to ecosystems. Multiple regions in the Pacific, Atlantic and Indian Oceans are particularly vulnerable to MHW intensification, due to the co-existence of high levels of biodiversity, a prevalence of species found at their warm range edges or concurrent non-climatic human impacts. The physical attributes of prominent MHWs varied considerably, but all had deleterious impacts across a range of biological processes and taxa, including critical foundation species (corals, seagrasses and kelps). MHWs, which will probably intensify with anthropogenic climate change3, are rapidly emerging as forceful agents of disturbance with the capacity to restructure entire ecosystems and disrupt the provision of ecological goods and services in coming decades.

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Fig. 1: Global patterns of MHW intensification, marine biodiversity, proportions of species found at their warm range-edge and concurrent human impacts.
Fig. 2: Ecological impacts of MHWs as determined by a meta-analysis of responses to eight prominent MHW events.
Fig. 3: Impacts of MHWs on foundation species.

Data availability

Daily 0.25° resolution NOAA OISST V2 data are provided by the NOAA/OAR/ESRLPSD, Boulder, Colorado, USA, at Data on human impacts and marine biodiversity are available from NCEAS ( and Aquamaps (, respectively. Coral bleaching records were extracted from the NOAA Reef Watch programme (, giant kelp biomass data were sourced from the Santa Barbara Coastal Long-term Ecological Research (SBC-LTER) programme ( Additional data are available from the corresponding author upon request.

Change history

  • 18 March 2019

    In the version of this Letter originally published, the following ‘Journal peer review information’ was missing “Nature Climate Change thanks Jennifer Jackson and Paul Fiedler for their contribution to the peer review of this work.” This statement has now been added.


  1. 1.

    IPCC Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) (Cambridge Univ. Press, 2013).

  2. 2.

    Oliver, E. et al. Longer and more frequent marine heatwaves over the past century. Nat. Commun. 9, 1324 (2018).

    Article  Google Scholar 

  3. 3.

    Frölicher, T. L., Fischer, E. M. & Gruber, N. Marine heatwaves under global warming. Nature 560, 360–364 (2018).

    Article  Google Scholar 

  4. 4.

    Chen, I.-C., Hill, J. K., Ohlemüller, R., Roy, D. B. & Thomas, C. D. Rapid range shifts of species associated with high levels of climate warming. Science 333, 1024–1026 (2011).

    CAS  Article  Google Scholar 

  5. 5.

    Burrows, M. T. et al. Geographical limits to species-range shifts are suggested by climate velocity. Nature 507, 492 (2014).

    CAS  Article  Google Scholar 

  6. 6.

    Cardinale, B. J. et al. Biodiversity loss and its impact on humanity. Nature 486, 59–67 (2012).

    CAS  Article  Google Scholar 

  7. 7.

    Pecl, G. T. et al. Biodiversity redistribution under climate change: Impacts on ecosystems and human well-being. Science 355, eaai9214 (2017).

    Article  Google Scholar 

  8. 8.

    Coumou, D. & Rahmstorf, S. A decade of weather extremes. Nat. Clim. Change 2, 491–496 (2012).

    Article  Google Scholar 

  9. 9.

    Perkins, S. E., Alexander, L. V. & Nairn, J. R. Increasing frequency, intensity and duration of observed global heatwaves and warm spells. Geophys. Res. Lett. 39, L20714 (2012).

    Article  Google Scholar 

  10. 10.

    Meehl, G. & Tebaldi, C. More intense, more frequent, and longer lastingheat waves in the 21st century. Science 305, 994–997 (2004).

    CAS  Article  Google Scholar 

  11. 11.

    Trenberth, K. E., Fasullo, J. T. & Shepherd, T. G. Attribution of climate extreme events. Nat. Clim. Change 5, 725–730 (2015).

    Article  Google Scholar 

  12. 12.

    Oliver, E. C. J. et al. The unprecedented 2015/16 Tasman Sea marine heatwave. Nat. Commun. 8, 16101 (2017).

    Article  Google Scholar 

  13. 13.

    IPCC Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (Cambridge Univ. Press, 2012).

  14. 14.

    Hobday, A. J. et al. A hierarchical approach to defining marine heatwaves. Prog. Oceanogr. 141, 227–238 (2016).

    Article  Google Scholar 

  15. 15.

    Garrabou, J. et al. Mass mortality in Northwestern Mediterranean rocky benthic communities: effects of the 2003 heat wave. Glob. Change Biol. 15, 1090–1103 (2009).

    Article  Google Scholar 

  16. 16.

    Wernberg, T. et al. An extreme climatic event alters marine ecosystem structure in a global biodiversity hotspot. Nat. Clim. Change 3, 78–82 (2013).

    Article  Google Scholar 

  17. 17.

    Smale, D. A. & Wernberg, T. Extreme climatic event drives range contraction of a habitat-forming species. Proc. R. Soc. Lond. B 280, 20122829 (2013).

    Article  Google Scholar 

  18. 18.

    Mills, K. E. et al. Fisheries management in a changing climate lessons from the 2012 ocean heat wave in the Northwest Atlantic. Oceanography 26, 191–195 (2013).

    Article  Google Scholar 

  19. 19.

    Cavole, L. M. et al.Biological impacts of the 2013–2015 warm-water anomaly in the Northeast Pacific: winners, losers, and the future. Oceanography 29, 273–285 (2016).

    Article  Google Scholar 

  20. 20.

    Chavez, F. P. et al. Biological and chemical consequences of the 1997–1998 El Niño in central California waters. Prog. Oceanogr. 54, 205–232 (2002).

    Article  Google Scholar 

  21. 21.

    McCabe, R. M. et al. An unprecedented coastwide toxic algal bloom linked to anomalous ocean conditions. Geophys. Res. Lett. 43, 366–376 (2016).

    Article  Google Scholar 

  22. 22.

    Pearce, A. F. & Feng, M. The rise and fall of the ‘marine heat wave’ off Western Australia during the summer of 2010/2011. J. Mar. Syst. 111–112, 139–156 (2013).

    Article  Google Scholar 

  23. 23.

    Bond, N. A., Cronin, M. F., Freeland, H. & Mantua, N. Causes and impacts of the 2014 warm anomaly in the NE Pacific. Geophys. Res. Lett. 42, 3414–3420 (2015).

    Article  Google Scholar 

  24. 24.

    Hughes, T. P. et al. Spatial and temporal patterns of mass bleaching of corals in the Anthropocene. Science 359, 80–83 (2018).

    CAS  Article  Google Scholar 

  25. 25.

    Benthuysen, J. A., Oliver, E. C. J., Feng, M. & Marshall, A. G. Extreme marine warming across tropical Australia during austral summer 2015–2016. J. Geophy. Res. Oceans (2018).

  26. 26.

    Borenstein, M., Hedges, L. V., Higgins, J. P. T. & Rothstein, H. R. Introduction to Meta-Analysis (John Wiley & Sons, Ltd, Chichester, 2009).

  27. 27.

    Moore, J. A. Y. et al. Unprecedented mass bleaching and loss of coral across 12° of latitude in Western Australia in 2010–11. PLoS ONE 7, e51807 (2012).

    CAS  Article  Google Scholar 

  28. 28.

    Smith, T. B., Glynn, P. W., Maté, J. L., Toth, L. T. & Gyory, J. A depth refugium from catastrophic coral bleaching prevents regional extinction. Ecology 95, 1663–1673 (2014).

    Article  Google Scholar 

  29. 29.

    Vargas, F. H., Harrison, S., Rea, S. & Macdonald, D. W. Biological effects of El Niño on the Galápagos penguin. Biol. Conserv. 127, 107–114 (2006).

    Article  Google Scholar 

  30. 30.

    Poloczanska, E. S. et al. Global imprint of climate change on marine life. Nat. Clim. Change 3, 919–925 (2013).

    Article  Google Scholar 

  31. 31.

    Somero, G. N. The physiology of climate change: how potentials for acclimatization and genetic adaptation will determine ‘winners’ and ‘losers’. J. Exp. Biol. 213, 912–920 (2010).

    CAS  Article  Google Scholar 

  32. 32.

    Harvey, B. P., Gwynn-Jones, D. & Moore, P. J. Meta-analysis reveals complex marine biological responses to the interactive effects of ocean acidification and warming. Ecol. Evol. 3, 1016–1030 (2013).

    Article  Google Scholar 

  33. 33.

    Pearce, A. et al. The ‘Marine Heat Wave’ off Western Australia During the Summer of 2010/11 Fisheries Research Report No. 222 (Department of Fisheries, 2011).

  34. 34.

    Wernberg, T. et al. Climate driven regime shift of a temperate marine ecosystem. Science 353, 169–172 (2016).

    CAS  Article  Google Scholar 

  35. 35.

    Halpern, B. S., Selkoe, K. A., Micheli, F. & Kappel, C. V. Evaluating and ranking the vulnerability of global marine ecosystems to anthropogenic threats. Conserv. Biol. 21, 1301–1315 (2007).

    Article  Google Scholar 

  36. 36.

    Marba, N. & Duarte, C. M. Mediterranean warming triggers seagrass (Posidonia oceanica) shoot mortality. Glob. Change Biol. 16, 2366–2375 (2010).

    Article  Google Scholar 

  37. 37.

    Liquete, C. et al. Current status and future prospects for the assessment of marine and coastal ecosystem services: a systematic review. PLoS ONE 8, e67737 (2013).

    CAS  Article  Google Scholar 

  38. 38.

    Cavanagh, R. D. et al. Valuing biodiversity and ecosystem services: a useful way to manage and conserve marine resources? Proc. R. Soc. Lond. B (2016).

  39. 39.

    Cai, W. et al. Increased frequency of extreme La Nina events under greenhouse warming. Nat. Clim. Change 5, 132–137 (2015).

    Article  Google Scholar 

  40. 40.

    Cerrano, C. et al. A catastrophic mass-mortality episode of gorgonians and other organisms in the Ligurian Sea (North-western Mediterranean), Summer 1999. Ecol. Lett. 3, 284–293 (2000).

    Article  Google Scholar 

  41. 41.

    Ñiquen, M. & Bouchon, M. Impact of El Niño events on pelagic fisheries in Peruvian waters. Deep Sea Res. Pt 2, 563–574 (2004).

    Article  Google Scholar 

  42. 42.

    Thomson, J. A. et al. Extreme temperatures, foundation species, and abrupt ecosystem change: an example from an iconic seagrass ecosystem. Glob. Change Biol. 21, 1463–1474 (2015).

    Article  Google Scholar 

  43. 43.

    Brown, B. E. Suharsono. Damage and recovery of coral reefs affected by El Niño related seawater warming in the Thousand Islands, Indonesia. Coral Reefs 8, 163–170 (1990).

    Article  Google Scholar 

  44. 44.

    Edwards, M. S. Estimating scale-dependency in disturbance impacts: El Niños and giant kelp forests in the northeast Pacific. Oecologia 138, 436–447 (2004).

    Article  Google Scholar 

  45. 45.

    Whitney, F. A. Anomalous winter winds decrease 2014 transition zone productivity in the NE Pacific. Geophys. Res. Lett. 42, 428–431 (2015).

    Article  Google Scholar 

  46. 46.

    Glynn, P. W. El Niño-associated disturbance to coral reefs and post disturbance mortality by Acanthaster planci. Mar. Ecol. Prog. Ser. 26, 395–300 (1985).

    Article  Google Scholar 

  47. 47.

    Le Nohaïc, M. et al. Marine heatwave causes unprecedented regional mass bleaching of thermally resistant corals in northwestern Australia. Sci. Rep. 7, 14999 (2017).

    Article  Google Scholar 

  48. 48.

    Hughes, T. P. et al. Global warming and recurrent mass bleaching of corals. Nature 543, 373 (2017).

    CAS  Article  Google Scholar 

  49. 49.

    Rodrigues, L. C., van den Bergh, J. C. J. M., Loureiro, M. L., Nunes, P. A. L. D. & Rossi, S. The cost of Mediterranean sea warming and acidification: a choice experiment among scuba divers at Medes Islands, Spain. Environ. Res. Econ. 63, 289–311 (2016).

  50. 50.

    Prideaux, B., Thompson, M., Pabel, A. & Anderson, A. C. in CAUTHE 2017: Time For Big Ideas? Re-thinking The Field For Tomorrow (eds Lee, C., Filep, S., Albrecht, J. N. & Coetzee, W. J. L.) (Department of Tourism, University of Otago, Dunedin, 2017).

  51. 51.

    TEEB The Economics of Ecosystems and Biodiversity Ecological and Economic Foundations (Kumar, P., ed.) (Earthscan, London and Washington, 2010).

  52. 52.

    García Molinos, J. et al. Climate velocity and the future global redistribution of marine biodiversity. Nat. Clim. Change 6, 83–88 (2016).

    Google Scholar 

  53. 53.

    Kaschner, K. et al. AquaMaps: Predicted Range Maps for Aquatic Species (2015);

  54. 54.

    Jones, M. C. & Cheung, W. W. L. Multi-model ensemble projections of climate change effects on global marine biodiversity. ICES J. Mar. Sci. 72, 741–752 (2015).

    Article  Google Scholar 

  55. 55.

    Halpern, B. S. et al. Spatial and temporal changes in cumulative human impacts on the world’s ocean. Nat. Commun. 6, 7615 (2015).

    CAS  Article  Google Scholar 

  56. 56.

    Halpern, B. S. et al. A global map of human impact on marine ecosystems. Science 319, 948–952 (2008).

    CAS  Article  Google Scholar 

  57. 57.

    Deser, C., Alexander, M. A., Xie, S.-P. & Phillips, A. S. Sea surface temperature variability: patterns and mechanisms. Annu. Rev. Mar. Sci. 2, 115–143 (2009).

    Article  Google Scholar 

  58. 58.

    Ready, J. et al. Predicting the distributions of marine organisms at the global scale. Ecol. Modell. 221, 467–478 (2010).

    Article  Google Scholar 

  59. 59.

    Wallace, B. C. et al. OpenMEE: Intuitive, open-source software for meta-analysis in ecology and evolutionary biology. Methods. Ecol. Evol. 8, 941–947 (2017).

    Article  Google Scholar 

  60. 60.

    Del Re, A. A practical tutorial on conducting meta-analysis in R. Quant. Meth. Psych. 11, 37–50 (2015).

    Article  Google Scholar 

  61. 61.

    Kaplan, I., Halitschke, R., Kessler, A., Sardanelli, S. & Denno, R. F. Constitutive and induced defenses to herbivory in above-and-below ground plant tissues. Ecology 89, 392–406 (2008).

    Article  Google Scholar 

  62. 62.

    Gurevitch, J., Morrison, J. A. & Hedges, L. V. The interaction between competition and predation: a meta‐analysis of field experiments. Am. Nat. 155, 435–453 (2000).

    Google Scholar 

  63. 63.

    Gurevitch, J., Morrow, L. L., Wallace, A. & Walsh, J. S. A meta-analysis of competition in field experiments. Am. Nat. 140, 539–572 (1992).

    Article  Google Scholar 

  64. 64.

    Guo, L. B. & Gifford, R. M. Soil carbon stocks and land use change: a meta analysis. Glob. Change Biol. 8, 345–360 (2002).

    Article  Google Scholar 

  65. 65.

    Rosenberg, M. S. & Goodnight, C. The file-drawer problem revisited: a general weighted method for calculating fail-safe numbers in meta-analysis. Evolution 59, 464–468 (2005).

    Article  Google Scholar 

  66. 66.

    Rosenberg, M. S., Adams, D. C. & Gurevitch, J. Metawin: statistical software for meta-analysis v.2 (Sinauer Associates, 2000).

  67. 67.

    Cavanaugh, K. C., Siegel, D. A., Reed, D. C. & Bell, T. W. SBC LTER: Time Series of Kelp Biomass in the Canopy from Landsat 5, 1984−2011 (2014);

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Concepts and analyses were developed during three workshops organized by an international working group on marine heatwaves ( Workshops were primarily funded by a University of Western Australia Research Collaboration Award to T.W. and a Natural Environment Research Council (UK) International Opportunity Fund awarded to D.A.S. (NE/N00678X/1). D.A.S. is supported by an Independent Research Fellowship (NE/K008439/1) awarded by the Natural Environment Research Council (UK). The Australian Research Council supported T.W. (FT110100174 and DP170100023), E.C.J.O. (CE110001028) and M.G.D. (DE150100456). N.J.H. and L.V.A. are supported by the ARC Centre of Excellence for Climate Extremes (CE170100023). M.S.T was supported by the Brian Mason Trust. P.J.M. is supported by a Marie Curie Career Integration Grant (PCIG10-GA-2011–303685) and a Natural Environment Research Council (UK) Grant (NE/J024082/1). S.C.S. was supported by an Australian Government RTP Scholarship. This work contributes to the World Climate Research Programme Grand Challenge on Extremes, the NESP Earth Systems and Climate Change Hub Project 2.3 (Component 2) on the predictability of ocean temperature extremes, and the interests and activities of the International Commission on Climate of IAMAS/IUGG.

Author information




D.A.S. and T.W. conceived the initial idea. All authors contributed intellectually to its development. D.A.S., T.W., E.C.J.O. and N.J.H. co-convened the workshops. E.C.J.O. led the development of the M.H.W. analysis, which was supported by N.J.H., L.V.A., J.A.B., M.G.D., M.F., A.J.H., S.E.P.-K., H.A.S. and A.S.G. The meta-analysis of ecological impacts was conducted by M.T., B.P.H., S.C.S., M.T.B. and P.J.M. D.A.S. led manuscript preparation with input from all authors.

Corresponding author

Correspondence to Dan A. Smale.

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The authors declare no competing interests.

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Journal peer review information: Nature Climate Change thanks Jennifer Jackson and Paul Fiedler for their contribution to this work.

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Supplementary Figures 1–5, Supplementary Table 1

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Smale, D.A., Wernberg, T., Oliver, E.C.J. et al. Marine heatwaves threaten global biodiversity and the provision of ecosystem services. Nat. Clim. Chang. 9, 306–312 (2019).

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