Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Complex causes of amphibian population declines

Nature volume 410, pages 681–684 (2001)Cite this article

Abstract

Amphibian populations have suffered widespread declines and extinctions in recent decades. Although climatic changes, increased exposure to ultraviolet-B (UV-B) radiation and increased prevalence of disease have all been implicated at particular localities1,2,3,4,5,6, the importance of global environmental change remains unclear. Here we report that pathogen outbreaks in amphibian populations in the western USA are linked to climate-induced changes in UV-B exposure. Using long-term observational data and a field experiment, we examine patterns among interannual variability in precipitation, UV-B exposure and infection by a pathogenic oomycete, Saprolegnia ferax. Our findings indicate that climate-induced reductions in water depth at oviposition sites have caused high mortality of embryos by increasing their exposure to UV-B radiation and, consequently, their vulnerability to infection1. Precipitation, and thus water depth/UV-B exposure, is strongly linked to El Niño/Southern Oscillation cycles, underscoring the role of large-scale climatic patterns involving the tropical Pacific7. Elevated sea-surface temperatures in this region since the mid-1970s, which have affected the climate over much of the world8, could be the precursor for pathogen-mediated amphibian declines in many regions1,3,4,9.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Trends in Southern Oscillation Index (SOI), precipitation, water depth and embryo mortality.
Figure 2: Field experiment results.

Similar content being viewed by others

References

  1. Kiesecker, J. M. & Blaustein, A. R. Synergism between UV-B radiation and a pathogen magnifies amphibian embryo mortality in nature. Proc. Natl Acad. Sci. USA 92, 11049–11052 (1995).

    Article  ADS  CAS  Google Scholar 

  2. Blaustein, A. R. et al. UV repair and resistance to solar UV-B in amphibian eggs: a link to population declines? Proc. Natl Acad. Sci. USA 91, 1791–1795 (1994).

    Article  ADS  CAS  Google Scholar 

  3. Berger, L. et al. Chytridiomycosis causes amphibian mortality associated with population declines in the rainforests of Australia and Central America. Proc. Natl Acad. Sci. USA 95, 9031–9036 (1998).

    Article  ADS  CAS  Google Scholar 

  4. Pounds, J. A., Fogden, M. P. L. & Campbell, J. H. Biological response to climate change on a tropical mountain. Nature 398, 611–615 (1999).

    Article  ADS  CAS  Google Scholar 

  5. Beebee, T. J. C. Amphibian breeding and climate. Nature 374, 219–220 (1995).

    Article  ADS  CAS  Google Scholar 

  6. Houlahan, J. E., Findlay, C. S., Schmidt, B. R., Meyer, A. H. & Kuzmin, S. L. Quantitative evidence for global amphibian population declines. Nature 404, 752–755 (2000).

    Article  ADS  CAS  Google Scholar 

  7. Guilderson, T. P. & Schrag, D. P. Abrupt shift in subsurface temperatures in the Tropical Pacific associated with changes in El Niño. Science 281, 240–243 (1998).

    Article  ADS  CAS  Google Scholar 

  8. Graham, N. E. Simulation of recent global temperature trends. Science 267, 661–671 (1995).

    Article  ADS  Google Scholar 

  9. Pounds, J. A. & Crump, M. L. Amphibian declines and climate disturbance: the case of the golden toad and the harlequin frog. Conserv. Biol. 8, 72–85 (1994).

    Article  Google Scholar 

  10. Blumthaler, M. & Ambach, W. Indication of increasing solar ultraviolet-b radiation flux in alpine regions. Science 248, 206–208 (1990).

    Article  ADS  CAS  Google Scholar 

  11. Kerr, J. B. & McElroy, C. J. Evidence for large upward trends of ultraviolet-b radiation linked to ozone depletion. Science 262, 1032–1034 (1993).

    Article  ADS  CAS  Google Scholar 

  12. Stolarski, R. et al. Measured trends in stratospheric ozone. Science 256, 342–349 (1992).

    Article  ADS  CAS  Google Scholar 

  13. Häder, D. P. Impact of UVB on aquatic organisms. Photochem. Photobiol. 69, S23–S32 (1999).

    Google Scholar 

  14. Schindler, D. W., Curtis, P. J., Parker, B. R. & Stainton, M. P. Consequences of climate warming and lake acidification for UV-B penetration in North American boreal lakes. Nature 379, 705–708 (1996).

    Article  ADS  CAS  Google Scholar 

  15. Yan, N. D., Keller, W., Scully, N. M., Lean, D. R. S. & Dillon, P. J. Increased UV-B penetration in a lake owing to drought-induced acidification. Nature 381, 141–143 (1996).

    Article  ADS  CAS  Google Scholar 

  16. Nussbaum, R. A., Brodie, E. D. & Storm, R. M. Amphibian and Reptiles of the Pacific Northwest (Idaho Univ. Press, Moscow, Idaho, 1983).

    Google Scholar 

  17. Stebbins, R. C. & Cohen, N. W. A Natural History of Amphibians (Princeton Univ. Press, New Jersey, 1995).

    Google Scholar 

  18. Kiesecker, J. M. & Blaustein, A. R. Influences of egg laying behavior on pathogenic infection of amphibian eggs. Conserv. Biol. 12, 214–220 (1997).

    Article  Google Scholar 

  19. Blaustein, A. R., Hokit, D. G., O'Hara, R. K. & Holt, R. A. Pathogenic fungus contributes to amphibian losses in the Pacific Northwest. Biol. Conserv. 67, 251–254 (1994).

    Article  Google Scholar 

  20. Kiesecker, J. M. & Blaustein, A. R. Pathogen reverses competition between larval amphibians. Ecology 80, 2442–2448 (1999).

    Article  Google Scholar 

  21. Blaustein, A. R. & Kiesecker, J. M. in The Effects of Ozone Depletion on Aquatic Ecosystems (ed. Hädar, D. P.) 175–188 (R.G. Landes, Austin, Texas, 1997).

    Google Scholar 

  22. Redmond, K. T. & Koch, R. W. Surface climate and streamflow variability in the western United States and their relationship to large-scale circulation indexes. Water Resourc. Res. 27, 2381–2399 (1991).

    Article  ADS  Google Scholar 

  23. Meehl, G. A. & Washington, W. M. El Niño-like climate change in a model with increased atmospheric CO2 concentrations. Nature 382, 56–60 (1996).

    Article  ADS  CAS  Google Scholar 

  24. Timmermann, A. et al. Increased El Niño frequency in a climate model forced by future greenhouse warming. Nature 398, 694–697 (1999).

    Article  ADS  CAS  Google Scholar 

  25. Lips, K. R. Decline of a tropical montane amphibian fauna. Conserv. Biol. 12, 106–117 (1996).

    Article  Google Scholar 

  26. Laurance, W. F., McDonald, K. R. & Speare, R. Epidemic disease and the catastrophic declines of Australian rain forest frogs. Conserv. Biol. 10, 406–413 (1996).

    Article  Google Scholar 

  27. Epstein, P. R. Perspectives: Medicine, climate and health. Science 285, 347–348 (1999).

    Article  CAS  Google Scholar 

  28. Hughes, L. Biological consequences of global warming: is the signal already apparent? Trends Ecol. Evol. 15, 56–61 (2000).

    Article  CAS  Google Scholar 

  29. Post, E., Peterson, R. O., Stenseth, N. C. & McKaren, B. E. Ecosystem consequences of wolf behavioural response to climate. Nature 401, 905–907 (1999).

    Article  ADS  CAS  Google Scholar 

  30. Lima, M., Keymer, J. E. & Jaksic, F. M. El Niño-Southern oscillation-driven rainfall variability and delayed density dependence cause rodent outbreaks in western South America: linking demography and population dynamics. Am. Nat. 153, 476–491 (1999).

    PubMed  Google Scholar 

Download references

Acknowledgements

We thank the U.S. Forest Service, Pacific Northwest Research Station and D. H. Olson for the use of vehicles and temperature data loggers, and D. G. Hokit and S. Walls for discussions regarding experimental design. We also thank G. Taylor from the Oregon State Climate Center for help with obtaining the climate data. J. A. Pounds, E. Post, M. Vronsky and N. Chevoteravich provided helpful suggestions on this manuscript. Funding was provided by the Declining Amphibian Population Task Force Seed Grant (to J.M.K.); NIH/NSF Ecology of Infectious Diseases grant (to J.M.K.); and the Department of Biology, Pennsylvania State University.

Author information

Authors and Affiliations

  1. Department of Biology, The Pennsylvania State University, 208 Mueller Laboratory, University Park, 16802-5301, Pennsylvania, USA

    Joseph M. Kiesecker

  2. Department of Zoology, Oregon State University, Corvallis, 97331, Oregon, USA

    Andrew R. Blaustein & Lisa K. Belden

Authors
  1. Joseph M. Kiesecker
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Andrew R. Blaustein
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Lisa K. Belden
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Joseph M. Kiesecker.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Kiesecker, J., Blaustein, A. & Belden, L. Complex causes of amphibian population declines. Nature 410, 681–684 (2001). https://doi.org/10.1038/35070552

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/35070552

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing