Letter | Published:

Dolomite-rich coralline algae in reefs resist dissolution in acidified conditions

Nature Climate Change volume 3, pages 268272 (2013) | Download Citation

Abstract

Coral reef ecosystems develop best in high-flow environments but their fragile frameworks are also vulnerable to high wave energy. Wave-resistant algal rims, predominantly made up of the crustose coralline algae (CCA) Porolithon onkodes and P. pachydermum1,2, are therefore critical structural elements for the survival of many shallow coral reefs. Concerns are growing about the susceptibility of CCA to ocean acidification because CCA Mg-calcite skeletons are more susceptible to dissolution under low pH conditions than coral aragonite skeletons3. However, the recent discovery4 of dolomite (Mg0.5Ca0.5(CO3)), a stable carbonate5, in P. onkodes cells necessitates a reappraisal of the impacts of ocean acidification on these CCA. Here we show, using a dissolution experiment, that dried dolomite-rich CCA have 6–10 times lower rates of dissolution than predominantly Mg-calcite CCA in both high-CO2 ( 700 ppm) and control ( 380 ppm) environments, respectively. We reveal this stabilizing mechanism to be a combination of reduced porosity due to dolomite infilling and selective dissolution of other carbonate minerals. Physical break-up proceeds by dissolution of Mg-calcite walls until the dolomitized cell eventually drops out intact. Dolomite-rich CCA frameworks are common in shallow coral reefs globally and our results suggest that it is likely that they will continue to provide protection and stability for coral reef frameworks as CO2 rises.

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.

    & Ecological components structuring seaward edges of Tropical Pacific reefs: Distribution, communities and productivity of Porolithon. J. Ecol. 63, 117–129 (1975).

  2. 2.

    & Crustose coralline algae: A re-evaluation in the geological sciences. Geol. Soc. Am. Bull. 84, 883–904 (1973).

  3. 3.

    , & Biogenically produced magnesian calcite: In homogeneities in chemical and physical properties; comparison with synthetic phases. Am. Mineral. 68, 1183 (1983).

  4. 4.

    et al. First discovery of dolomite and magnesite in living coralline algae and its geobiological implications. Biogeosciences 8, 3331–3340 (2011).

  5. 5.

    & Secular variation in abiotic marine carbonates: Constraints on phanerozoic atmospheric carbon dioxide contents and oceanic Mg/Ca ratios. J. Geol. 94, 321–333 (1986).

  6. 6.

    , , & Coral reef sedimentation on Rodrigues and the Western Indian Ocean and its impact on the carbon cycle. Phil. Tran. R. Soc. A 363, 101–120 (2005).

  7. 7.

    Review: Coral reefs: Algal structured and mediated ecosystems in shallow, turbulent, alkaline waters. J. Phycol. 34, 393–406 (1998).

  8. 8.

    Aspects of the biogeochemistry of magnesium 1. Calcareous marine organisms. J. Geol. 62, 266–283 (1954).

  9. 9.

    , & Utilization of magnesium in coralline algae. Geol. Soc. Am. Bull. 82, 573–580 (1971).

  10. 10.

    & Predicting mineral solubility from rate data: Application to the dissolution of magnesian calcites. Am. J. Sci. 274, 61–83 (1974).

  11. 11.

    , & Stabilities of synthetic magnesian calcites in aqueous solution: Comparison with biogenic materials. Geochim. Cosmochim. Acta 51, 1413–1423 (1987).

  12. 12.

    , & Calcium Carbonate formation and dissolution. Chem. Rev. 107, 342–381 (2007).

  13. 13.

    , , & Diel coral reef acidification driven by pore water advection in permeable carbonate sands, Heron Island, Great Barrier Reef. Geophys. Res. Lett. 38, L03604 (2011).

  14. 14.

    , , , & Interactions between ocean acidification and warming on the mortality and dissolution of coralline algae. J. Phycol. 48, 32–39 (2012).

  15. 15.

    , , , & et al. A short-term in situ CO2 enrichment experiment on Heron Island (GBR). Sci. Rep. 2, 413 (2012).

  16. 16.

    & Kinetics and mechanism of dolomite dissolution in neutral to alkaline solutions revisited. Am. J. Sci. 301, 597–626 (2001).

  17. 17.

    Dissolution Rate Constant of Carbonates under Natural Environments. Tikrit J. Pure Sci. 15 (3), 84–90 (2010).

  18. 18.

    & Dissolution of biogenic carbonates: Effects of skeletal structure. Mar. Geol. 71, 341–362 (1986).

  19. 19.

    , & Mass transfer from smooth alabaster surfaces in turbulent flows. Geophys. Res. Lett. 14, 1131–1134 (1987).

  20. 20.

    & The Inorganic Constituents of Marine Invertebrates (USGS, 1922).

  21. 21.

    , , , & Decreased abundance of crustose coralline algae due to ocean acidification. Nature Geosci. 1, 114–117 (2008).

  22. 22.

    , , , & Ocean acidification causes bleaching and productivity loss in coral reef builders. Proc. Natl Acad. Sci. USA 105, 17442–17446 (2008).

  23. 23.

    , & Marine calcifiers exhibit mixed responses to CO2-induced ocean acidification. Geology 37, 1131–1134 (2009).

  24. 24.

    , , , & Polysaccharide-catalyzed nucleation and growth of disordered dolomite: A potential precursor of sedimentary dolomite. Am. Mineral. 97, 556–567 (2012).

  25. 25.

    et al. Microbial nucleation of Mg-rich dolomite in exopolymeric substances under anoxic modern seawater salinity: New insight into an old enigma. Geology 40, 587–590 (2012).

  26. 26.

    & Polysaccharides of calcareous algae and their effect on the calcification process. Russ. J. Bioorg. Chem. 27, 2–16 (2001).

  27. 27.

    The production of extracellular polysaccharide by the unicellular red algae Porphyridium aerugineum. J. Phycol. 8, 97–111 (1972).

  28. 28.

    , , , & Ocean acidification reduces coral recruitment by disrupting intimate larval-algal settlement interactions. Ecol. Lett. 15, 338–346 (2012).

Download references

Acknowledgements

Thanks to F. Brink and the team at the ANU Centre for Advanced Microscopy for assistance with SEM work, A. Harvey for CCA samples from Victoria, L. Teneva for differential interference contrast analyses, J. Caves for field work assistance, the FOCE team and staff at Heron Island Research Centre, J. W. Lai and D. Nash for sample preparation. S. Connell for assistance with Heron experiments and J. Roberts for assistance with SEM.

Author information

Affiliations

  1. Research School of Physics, The Australian National University, Acton, Australian Capital Territory 0200, Australia

    • M. C. Nash
  2. Research School of Earth Sciences, The Australian National University, Acton, Australian Capital Territory 0200, Australia

    • B. N. Opdyke
    • , U. Troitzsch
    • , C. Brent
    • , M. Gardner
    •  & J. Prichard
  3. Southern Seas Ecology Laboratories, School of Earth and Environmental Sciences, University of Adelaide, Adelaide, South Australia 5005, Australia

    • B. D. Russell
  4. National Museum of Natural History, Smithsonian Institution, Washington DC 20013, USA

    • W. H. Adey
  5. Takehara Fisheries Research Station, Center for Education and Research of Field Science, Hiroshima University, Minato-machi, Takehara, Hiroshima 725-0024, Japan

    • A. Kato
  6. Griffith School of Environment and Australian Rivers Institute—Coast and Estuaries, Griffith University, Brisbane, Nathan, Queensland 4111, Australia

    • G. Diaz-Pulido
  7. Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093, USA

    • D. I. Kline
  8. Coral Reef Ecosystems Laboratory, School of Biological Sciences, University of Queensland, Brisbane, Queensland 4072, Australia

    • D. I. Kline

Authors

  1. Search for M. C. Nash in:

  2. Search for B. N. Opdyke in:

  3. Search for U. Troitzsch in:

  4. Search for B. D. Russell in:

  5. Search for W. H. Adey in:

  6. Search for A. Kato in:

  7. Search for G. Diaz-Pulido in:

  8. Search for C. Brent in:

  9. Search for M. Gardner in:

  10. Search for J. Prichard in:

  11. Search for D. I. Kline in:

Contributions

M.C.N. and B.N.O. designed initial project; M.C.N., B.D.R. and D.I.K. carried out Heron Island experimental work and water chemistry measurements; U.T. assisted with subsequent analyses and project design. G.D-P., sample identification and design of experimental tank facilities; A.K. and W.H.A., sample collection and identification. M.C.N., U.T. and W.H.A., SEM. M.C.N. and U.T., XRD analysis. C.B., M.G. and J.P., sample collection, survey, XRD and data analyses. M.C.N. and U.T. wrote and edited the manuscript and all authors contributed.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to M. C. Nash.

Supplementary information

PDF files

  1. 1.

    Supplementary Information

    Supplementary Information

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/nclimate1760

Further reading