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:

Coral mucus functions as an energy carrier and particle trap in the reef ecosystem

Abstract

Zooxanthellae, endosymbiotic algae of reef-building corals, substantially contribute to the high gross primary production of coral reefs1, but corals exude up to half of the carbon assimilated by their zooxanthellae as mucus2,3. Here we show that released coral mucus efficiently traps organic matter from the water column and rapidly carries energy and nutrients to the reef lagoon sediment, which acts as a biocatalytic mineralizing filter. In the Great Barrier Reef, the dominant genus of hard corals, Acropora, exudes up to 4.8 litres of mucus per square metre of reef area per day. Between 56% and 80% of this mucus dissolves in the reef water, which is filtered through the lagoon sands. Here, coral mucus is degraded at a turnover rate of at least 7% per hour. Detached undissolved mucus traps suspended particles, increasing its initial organic carbon and nitrogen content by three orders of magnitude within 2 h. Tidal currents concentrate these mucus aggregates into the lagoon, where they rapidly settle. Coral mucus provides light energy harvested by the zooxanthellae and trapped particles to the heterotrophic reef community, thereby establishing a recycling loop that supports benthic life, while reducing loss of energy and nutrients from the reef ecosystem.

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

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

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

Figure 1: Changes in coral mucus during its ageing process.
Figure 2: Transect studies at Heron Island.
Figure 3: Proposed cycle of coral mucus for the Heron Island reef ecosystem.

Similar content being viewed by others

References

  1. Goreau, T. F., Goreau, N. I. & Goreau, T. J. Corals and coral reefs. Sci. Am. 241, 124–135 (1979)

    Article  Google Scholar 

  2. Crossland, C., Barnes, D. & Borowitzka, M. Diurnal lipid and mucus production in the staghorn coral Acropora acuminata. Mar. Biol. 60, 81–90 (1980)

    Article  CAS  Google Scholar 

  3. Davies, P. S. The role of zooxanthellae in the nutritional energy requirements of Pocillopora eydouxi. Coral Reefs 2, 181–186 (1984)

    ADS  Google Scholar 

  4. Muscatine, L., McCloskey, L. R. & Marian, R. E. Estimating the daily contribution of carbon from zooxanthellae to coral animal respiration. Limnol. Oceanogr. 26, 601–611 (1981)

    Article  ADS  CAS  Google Scholar 

  5. Meikle, P., Richards, G. & Yellowlees, D. Structural investigations on the mucus from 6 species of coral. Mar. Biol. 99, 187–193 (1988)

    Article  CAS  Google Scholar 

  6. Ducklow, H. & Mitchell, R. Bacterial populations and adaptations in the mucus layers on living corals. Limnol. Oceanogr. 24, 715–725 (1979)

    Article  ADS  Google Scholar 

  7. Krupp, D. A. Mucus production by corals exposed during an extreme low tide. Pacif. Sci. 38, 1–11 (1984)

    Google Scholar 

  8. Schuhmacher, H. Proc. 3rd Int. Coral Reef Symp. Miami, Florida 503–509 (University of Miami, Florida, 1977)

    Google Scholar 

  9. Coles, S. & Strathman, R. Observations on coral mucus flocs and their potential trophic significance. Limnol. Oceanogr. 18, 673–678 (1973)

    Article  ADS  Google Scholar 

  10. Marshall, M. Observations on organic aggregates in the vicinity of coral reefs. Mar. Biol. 2, 50–55 (1968)

    Article  Google Scholar 

  11. Johannes, R. Ecology of organic aggregates in the vicinity of a coral reef. Limnol. Oceanogr. 12, 189–195 (1967)

    Article  ADS  Google Scholar 

  12. Romaine, S., Tambutte, E., Allemand, D. & Gattuso, J. P. Photosynthesis, respiration and calcification of a zooxanthellate scleractinian coral under submerged and exposed conditions. Mar. Biol. 129, 175–182 (1997)

    Article  Google Scholar 

  13. Moriarty, D. J. W., Pollard, P. C. & Hunt, W. G. Temporal and spatial variation in bacterial production in the water column over a coral reef. Mar. Biol. 85, 285–292 (1985)

    Article  Google Scholar 

  14. Ferrier-Pages, C., Leclercq, N., Jaubert, J. & Pelegri, S. P. Enhancement of pico- and nanoplankton growth by coral exudates. Aquat. Microb. Ecol. 21, 203–209 (2000)

    Article  Google Scholar 

  15. Vacelet, E. & Thomassin, B. Microbial utilization of coral mucus in long term in situ incubation over a coral reef. Hydrobiologia 211, 19–32 (1991)

    Article  Google Scholar 

  16. Shanks, A. L. & Edmondson, E. W. Laboratory-made artificial marine snow—a biological model of the real thing. Mar. Biol. 101, 463–470 (1989)

    Article  Google Scholar 

  17. Riedl, R. J., Huang, N. & Machan, R. The subtidal pump: a mechanism of interstitial water exchange by wave action. Mar. Biol. 13, 210–221 (1972)

    Article  Google Scholar 

  18. Parnell, K. E. Water movement within a fringing reef flat, Orpheus Island, North Queensland, Australia. Coral Reefs 5, 1–6 (1986)

    Article  ADS  Google Scholar 

  19. Oberdorfer, J. A. & Buddemeier, R. W. Coral-reef hydrology: field studies of water movement within a barrier reef. Coral Reefs 5, 7–12 (1986)

    Article  ADS  Google Scholar 

  20. Wild, C. et al. Degradation and mineralization of coral mucus in reef environments. Mar. Ecol. Prog. Ser. 267, 159–171 (2004)

    Article  ADS  Google Scholar 

  21. Marsden, J. & Meeuwig, J. Preferences of planktotrophic larvae of the tropical serpulid Spirobranchus giganteus (Pallas) for exudates of corals from a Barbados reef. J. Exp. Mar. Biol. Ecol. 137, 97–104 (1990)

    Article  Google Scholar 

  22. Benson, A. & Muscatine, L. Wax in coral mucus—energy transfer from corals to reef fishes. Limnol. Oceanogr. 19, 810–814 (1974)

    Article  ADS  Google Scholar 

  23. Richman, S., Loya, Y. & Slobodkin, L. Rate of mucus production by corals and its assimilation by the coral reef copepod Acartia negligens. Limnol. Oceanogr. 20, 918–923 (1975)

    Article  ADS  Google Scholar 

  24. Wilkinson, C. R. Microbial ecology on a coral reef. Search 18, 31–33 (1987)

    Google Scholar 

  25. Richter, C., Wunsch, M., Rasheed, M., Kotter, I. & Badran, M. I. Endoscopic exploration of Red Sea coral reefs reveals dense populations of cavity-dwelling sponges. Nature 413, 726–730 (2001)

    Article  ADS  CAS  Google Scholar 

  26. Herndl, G. J. & Velimirov, B. Microheterotrophic utilization of mucus released by the Mediterranean coral Cladocora cespitosa. Mar. Biol. 90, 363–369 (1986)

    Article  Google Scholar 

  27. Stimson, J. & Kinzie, R. A. The temporal pattern and rate of release of zooxanthellae from the reef coral Pocillopora damicornis (Linnaeus) under nitrogen-enrichment and control conditions. J. Exp. Mar. Biol. Ecol. 153, 63–74 (1991)

    Article  Google Scholar 

  28. Huettel, M. & Gust, G. Solute release mechanisms from confined sediment cores in stirred benthic chambers and flume flows. Mar. Ecol. Prog. Ser. 82, 187–197 (1992)

    Article  ADS  Google Scholar 

Download references

Acknowledgements

We thank M. Alisch, S. Menger, H. Woyt, S. Gonelli and L. Hönemann for experimental assistance and for help with chemical analyses; O. Hoegh-Guldberg, R. Johnstone, T. Upton, R. Forbes and other staff members of Heron Island Research Station for logistical assistance; and P. Cook, C. Richter, R. Tollrian and H. Zech for improving the manuscript. All sample collections and in situ experiments were carried out under permits issued by the Great Barrier Reef Marine Park Authority. The Max Planck Society, Germany, funded this research.Authors' contributions M.H. and C.W. conceptually designed and coordinated all experimental work, made most of the measurements, and wrote the manuscript. A.K. quantified coral distribution on Heron Island. S.K. and M.R. helped with chamber experiments and water analyses. B.B.J. contributed with ideas and advice to the significant improvement of the manuscript.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Christian Wild.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Supplementary information

Supplementary Information

This includes a detailed explanation of the in-situ chamber experiments described in the manuscript. (DOC 20 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Wild, C., Huettel, M., Klueter, A. et al. Coral mucus functions as an energy carrier and particle trap in the reef ecosystem. Nature 428, 66–70 (2004). https://doi.org/10.1038/nature02344

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature02344

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

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