Letter | Published:

Risk maps for Antarctic krill under projected Southern Ocean acidification

Nature Climate Change volume 3, pages 843847 (2013) | Download Citation

Abstract

Marine ecosystems of the Southern Ocean are particularly vulnerable to ocean acidification1. Antarctic krill (Euphausia superba; hereafter krill) is the key pelagic species of the region and its largest fishery resource2. There is therefore concern about the combined effects of climate change, ocean acidification and an expanding fishery on krill and ultimately, their dependent predators—whales, seals and penguins3,4. However, little is known about the sensitivity of krill to ocean acidification. Juvenile and adult krill are already exposed to variable seawater carbonate chemistry because they occupy a range of habitats and migrate both vertically and horizontally on a daily and seasonal basis5. Moreover, krill eggs sink from the surface to hatch at 700–1,000 m (ref. 6), where the carbon dioxide partial pressure (pCO2) in sea water is already greater than it is in the atmosphere7. Krill eggs sink passively and so cannot avoid these conditions. Here we describe the sensitivity of krill egg hatch rates to increased CO2, and present a circumpolar risk map of krill hatching success under projected pCO2 levels. We find that important krill habitats of the Weddell Sea and the Haakon VII Sea to the east are likely to become high-risk areas for krill recruitment within a century. Furthermore, unless CO2 emissions are mitigated, the Southern Ocean krill population could collapse by 2300 with dire consequences for the entire ecosystem.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1.

    , , & Ocean acidification: The other CO2 problem. Ann. Rev. Mar. Sci. 1, 169–192 (2009).

  2. 2.

    , & The fishery for Antarctic krill– recent developments. Fish Fish. 13, 30–40 (2012).

  3. 3.

    Ecologists fear Antarctic krill crisis. Nature 467, 15 (2010).

  4. 4.

    et al. Impact of climate change on Antarctic krill. Mar. Ecol. Prog. Ser. 458, 1–19 (2012).

  5. 5.

    Krill, currents, and sea ice: Euphausia superba and its changing environment. BioScience 56, 111–120 (2006).

  6. 6.

    & Depth distribution of developing Euphausia superba embryos, predicted from sinking rates. Mar. Biol. 79, 47–53 (1984).

  7. 7.

    et al. Will krill fare well under Southern Ocean acidification? Biol. Lett. 7, 288–291 (2011).

  8. 8.

    Ontogenetic adaptation in growth and respiration of Euphausia superba in relation to temperature and pressure. J. Crustacean Biol. 4, 252–262 (1984).

  9. 9.

    & Comparative developmental physiology: An interdisciplinary convergence. Ann. Rev. Physiol. 67, 203–223 (2005).

  10. 10.

    Effects of CO2-driven ocean acidification on the early developmental stages of invertebrates. Mar. Ecol. Prog. Ser. 373, 275–284 (2008).

  11. 11.

    et al. The RCP greenhouse gas concentrations and their extensions from 1765 to 2300. Climatic Change 109, 213–241 (2011).

  12. 12.

    The natural history and geography of the Antarctic krill (Euphausia superba Dana). Discov. Rep. 32, 33–464 (1962).

  13. 13.

    , & Temperature-dependent growth of Antarctic krill: Predictions for a changing climate from a cohort model. Mar. Ecol. Prog. Ser. 358, 191–202 (2008).

  14. 14.

    Physiological and ecological responses of crustaceans to ocean acidification. Mar. Ecol. Prog. Ser. 430, 257–271 (2011).

  15. 15.

    , & The effect of CO2 acidified seawater and reduced salinity on aspects of the embryonic development of the amphipod Echinogammarus marinus (Leach). Mar. Poll. Bull. 58, 1187–1191 (2009).

  16. 16.

    The overwintering of Antarctic krill, Euphausia superba, from an ecophysiological perspective. Polar Biol. 35, 15–37 (2012).

  17. 17.

    , , , & Increased feeding and nutrient excretion of adult Antarctic krill, Euphausia superba, exposed to enhanced carbon dioxide (CO2). PLoS One 7, e52224 (2012).

  18. 18.

    & Cold resistance and metabolic responses to salinity variations in the amphipod Eusirus antarcticus and the krill Euphausia superba. Polar Biol. 9, 491–497 (1989).

  19. 19.

    , , , & Gone with the currents: Lack of genetic differentiation at the circum-continental scale in the Antarctic krill Euphausia superba. BMC Genetics 12, 32 (2011).

  20. 20.

    & Rapid climate change in the ocean west of the Antarctic Peninsula during the second half of the 20th century. Geophys. Res. Lett. 32, L19604 (2005).

  21. 21.

    , , & Long-term decline in krill stock and increase in salps within the Southern Ocean. Nature 432, 100–103 (2004).

  22. 22.

    , & Direct effects of climate change on the Antarctic krill fishery. Fish. Manage. Ecol. 16, 424–427 (2009).

  23. 23.

    et al. An experimental aquarium for observing the schooling behaviour of Antarctic krill (Euphausia superba). Deep-Sea Res. II 57, 683–692 (2010).

  24. 24.

    et al. Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. Nature 437, 681–686 (2005).

  25. 25.

    et al. The role of ocean transport in the uptake of anthropogenic CO2. Biogeosciences 6, 375–390 (2009).

  26. 26.

    & The role of the vertical fluxes of particulate organic matter and calcite in the oceanic carbon cycle: Studies using an ocean biogeochemical general circulation model. Glob. Biogeochem. Cycles 10, 361–382 (1996).

  27. 27.

    et al. A global ocean carbon climatology: Results from Global Data Analysis Project (GLODAP). Glob. Biogeochem. Cycles 18, GB4031 (2004).

  28. 28.

    et al. World Ocean Atlas 2001: Objective Analyses, Data Statistics, and Figures CD-ROM Documentation (National Oceanographic Data Center, 2002).

  29. 29.

    , , & WinBUGS– a Bayesian modelling framework: Concepts, structure, and extensibility. Stat. Comput. 10, 325–337 (2000).

  30. 30.

    et al. Oceanic circumpolar habitats of Antarctic krill. Mar. Ecol. Prog. Ser. 362, 1–23 (2008).

Download references

Acknowledgements

The authors thank S. Wotherspoon for advice on statistical analyses, B. Smith and Z. Jia for assisting with the experiments, J. Robinson for assistance in assembling the experimental system, and C. Wynn-Edwards for assisting with krill maintenance. The model projections were performed on the super computer at JAMSTEC. This study was supported by Australian Antarctic Science Program Project No. 4037.

Author information

Affiliations

  1. Australian Antarctic Division, Kingston Tasmania, 7050, Australia

    • S. Kawaguchi
    • , R. King
    • , B. Raymond
    • , N. Waller
    •  & A. Constable
  2. Antarctic Climate and Ecosystems Cooperative Research Centre, Hobart, Tasmania, 7001, Australia

    • S. Kawaguchi
    • , B. Raymond
    •  & A. Constable
  3. Department of Social Environment, Tokoha University, Fuji, Shizuoka, 417-0801, Japan

    • A. Ishida
  4. Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology, Yokohama, 236-0001, Japan

    • A. Ishida
    •  & M. Wakita
  5. Institute for Antarctic and Marine Studies, University of Tasmania, Sandy Bay, Tasmania, 7005, Australia

    • S. Nicol
  6. Mutsu Institute for Oceanography, Japan Agency for Marine-Earth Science and Technology, Mutsu, 035-0022, Japan

    • M. Wakita
  7. Institute for East China Sea Research, Nagasaki University, Nagasaki, 851-2213, Japan

    • A. Ishimatsu

Authors

  1. Search for S. Kawaguchi in:

  2. Search for A. Ishida in:

  3. Search for R. King in:

  4. Search for B. Raymond in:

  5. Search for N. Waller in:

  6. Search for A. Constable in:

  7. Search for S. Nicol in:

  8. Search for M. Wakita in:

  9. Search for A. Ishimatsu in:

Contributions

This study was initiated, designed, coordinated and analysed by S.K. Ocean carbon model projection was undertaken by A. Ishida. Experimental system was designed and assembled by R.K. Statistical modelling and analyses were undertaken by B.R. Experiments were undertaken by N.W. All authors made intellectual contribution. The manuscript was written by S.K. and edited by A. Ishida, R.K., B.R., A.C., S.N., M.W. and A. Ishimatsu.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to S. Kawaguchi.

Supplementary information

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/nclimate1937

Further reading