Skip to main content

Advertisement

SpringerLink
Log in

Overgrazing of Seagrass by Sea Urchins Diminishes Blue Carbon Stocks

  • Published:
Ecosystems Aims and scope Submit manuscript

Abstract

Seagrasses are among the Earth’s most efficient ecosystems for sequestering carbon, but are also in global decline, risking carbon they have accumulated over geological timescales. One contributor to this global decline is seagrass overgrazing by sea urchins; however, it is unknown how this may affect stocks of “blue carbon” by damaging the seagrass root systems that stabilise the carbon-rich sediments of seagrass meadows. To fill this knowledge gap, we used aerial and sonar mapping plus soil carbon measures to investigate a seagrass urchin overgrazing event in Southeast Australia and quantified the concomitant impacts on blue carbon stocks. We found that seagrass loss significantly diminished local organic carbon stocks. The decline was also rapid: areas grazed within the preceding 6 months showed a 35% loss of blue carbon, which continued even after urchins had left the area (46% loss after 3 years). High-resolution 3D sonar reconstructions revealed that urchin overgrazing of seagrass caused erosion of the top 30 ± 20 cm of sediment within the 26,892 m2 barren: the equivalent of 8100 ± 5400 m3 of sediment. To calculate the additional CO2 emissions from this erosion, we assumed between 50 and 90% of the seagrass carbon stock (11.7 ± 1.24 t Corg ha−1 in the top 10 cm) would be remineralised, resulting in the release of between 57.8 and 104 tonnes of CO2 equivalents due to sea urchin overgrazing-induced erosion. This study adds to a growing body of evidence that seagrass loss leads to erosion and concomitant loss of blue carbon stocks.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Figure 1
Figure 2
Figure 3
Figure 4

Similar content being viewed by others

Data Accessibility

Data are available on CloudStor (https://cloudstor.aarnet.edu.au/plus/s/Tt4yH8iQnNPjelP).

References

  • Abramoff MD, Magalhaes PJ. 2004. Image Processing with ImageJ. Biophotonics International 11:36–42.

    Google Scholar 

  • Atwood TB, Connolly RM, Ritchie EG, Lovelock CE, Heithaus MR, Hays GC, Fourqurean JW, Macreadie PI. 2015. Predators help protect carbon stocks in blue carbon ecosystems. Nature Climate Change 5:1038–45.

    Article  Google Scholar 

  • Baldock JA, Hawke B, Sanderman J, Macdonald LM. 2013. Predicting contents of carbon and its component fractions in Australian soils from diffuse reflectance mid-infrared spectra. Soil Research 51:577–95.

    Article  CAS  Google Scholar 

  • Barbier EB, Hacker SD, Kennedy C, Kock EW, Stier AC, Sillman BR. 2011. The value of estuarine and coastal ecosystem services. Ecological Monographs 81:169–93.

    Article  Google Scholar 

  • Bayraktarov E, Saunders MI, Abdullah S, Mills M, Beher J, Possingham HP, Mumby PJ, Lovelock CE. 2016. The cost and feasibility of marine coastal restoration. Ecological Applications. 264:1055–74.

    Article  Google Scholar 

  • Bellon-Maurel V, Fernandez-Ahumada E, Palagos B, Roger J-M, McBratney A. 2010. Critical review of chemometric indicators commonly used for assessing the quality of the prediction of soil attributes by NIR spectroscopy. Trends in Analytical Chemistry 29, 1073–81. https://doi.org/10.1016/j.trac.2010.05.006.

    Article  CAS  Google Scholar 

  • Bellon-Maurel V, McBratney A. 2011. Near-infrared (NIR) and midinfrared (MIR) spectroscopic techniques for assessing the amount of carbon stock in soils—Critical review and research perspectives. Soil Biology Biochemistry 43:1398–410. https://doi.org/10.1016/j.soilbio.2011.02.019.

    Article  CAS  Google Scholar 

  • Carnell PE, Keough MJ. 2016. The influence of herbivores on primary producers can vary spatially and interact with disturbance. Oikos 125:1273–83. https://doi.org/10.1111/oik.02502.

    Article  Google Scholar 

  • Carnell PE, Keough MJ. 2019. Reconstructing historical marine populations reveals major decline of a kelp forest ecosystem in Australia. Estuaries and Coasts 42:765–78.

    Article  Google Scholar 

  • Dahl M, Deyanova D, Lyimo LD, Näslund J, Samuelsson GS, Mtolera MSP, Björk M, Gullström M. 2016. Effects of shading and simulated grazing on carbon sequestration in a tropical seagrass meadow. Journal of Ecology 104:654–64.

    Article  CAS  Google Scholar 

  • de los Santos CB, Krause-Jensen D, Alcoverro T, Marbà N, Duarte CM, van Katwijk MM, Pérez M, Romero J, Sánchez-Lizaso JL, Roca G, Jankowska E, Pérez-Lloréns JL, Fournier J, Montefalcone M, Pergent G, Ruiz JM, Cabaço S, Cook K, Wilkes RJ, Moy FE, Trayter GMR, Arañó XS, de Jong DJ, Fernández-Torquemada Y, Auby I, Vergara JJ, Santos R. 2019. Recent trend reversal for declining European seagrass meadows. Nature Communications 10:3356.

    Article  Google Scholar 

  • Duarte CM, Losada IJ, Hendriks IE, Mazarrasa I, Marbà N. 2013. The role of coastal plant communities for climate change mitigation and adaptation. Nature Climate Change 3:961–8.

    Article  CAS  Google Scholar 

  • Eklof JS, de la Torre-Castro M, Gullstrom M, Uku J, Muthiga N, Lyimo T, Bandeira SO. 2008. Sea urchin overgrazing of seagrasses: a review of current knowledge on causes, consequences, and management. Estuarine and Coastal Shelf Science 79:569–80.

    Article  Google Scholar 

  • Estes JA et al. 2011. Trophic downgrading of planet Earth. Science 333:301–6.

    Article  CAS  Google Scholar 

  • Ewers Lewis CJ, Carnell PE, Sanderman J, Baldock JA, Macreadie PI. 2018. Variability and vulnerability of coastal ‘bluecarbon’ stocks: A case study from Southeast Australia. Ecosystems 21:263–79. https://doi.org/10.1007/s10021-017-0150-z.

    Article  CAS  Google Scholar 

  • Fourqurean JW, Duarte CM, Kennedy H, Marba N, Holmer M, Mateo MA, Serrano O. 2012. Seagrass ecosystems as a globally significant carbon stock. Nature Geoscience 5:505–9. https://doi.org/10.1038/ngeo1477.

    Article  CAS  Google Scholar 

  • Githaiga MN, Frouws AM, Kairo JG, Huxham M. 2019. Seagrass carbon is vulnerable to loss from bioturbating fauna following removal of vegetation. Frontiers in Ecology and Evolution 7:62. https://doi.org/10.3389/fevo.2019.00062.

    Article  Google Scholar 

  • Heck KL, Valentine JF. 2006. Plant–herbivore interactions in seagrass meadows. Journal of Experimental Marine Biology and Ecology 330:420–36.

    Article  Google Scholar 

  • Heithaus MR, Alcoverro T, Arthur R, Burkholder DA, Coates KA, Christianen MJ, Kelkar N, Manuel SA, Wirsing AJ, Kenworthy WJ, Fourqurean JW. 2014. Seagrasses in the age of sea turtle conservation and shark overfishing. Frontiers in Marine Science. 1:1–6. https://doi.org/10.3389/fmars.2014.00028.

    Article  Google Scholar 

  • Lovelock CE, Atwood T, Baldock J, Duarte CM, Hickey S, Lavery PS, Masque P, Macreadie PI, Ricart AM, Serrano O, Steven A. 2017. Assessing the risk of carbon dioxide emissions from blue carbon ecosystems. Frontiers in Ecology and the Environment 15:257–65.

    Article  Google Scholar 

  • Macreadie PI, Trevathan-Tackett SM, Skilbeck CG, Sanderman J, Curlevski N, Jacobsen G, Seymour JR. 2015. Losses and recovery of organic carbon from a seagrass ecosystem following disturbance. Proceedings of the Royal Society B-Biological Sciences 282:20151537. https://doi.org/10.1098/rspb.2015.1537.

    Article  CAS  PubMed Central  Google Scholar 

  • Macreadie PI, York PH, Sherman CD, Keough MJ, Ross DJ, Ricart AM, Smith TM. 2014a. No detectable impact of small-scale disturbances on ‘blue carbon’ within seagrass beds. Marine Biology, 16

  • Macreadie PI, Baird ME, Trevathan-Tackett SM, Larkum AWD, Ralph PJ. 2014b. Quantifying and modelling the carbon sequestration capacity of seagrass meadows – a critical assessment. Marine Pollution Bulletin 83:430–9.

    Article  CAS  Google Scholar 

  • Macreadie PI, Atwood TB, Seymour JR, Schmitz Fontes ML, Sanderman J, Nielsen DA, Connolly RM. 2019a. Vulnerability of seagrass blue carbon to microbial attack following exposure to warming and oxygen. Science of the Total Environment 686:264–75.

    Article  CAS  Google Scholar 

  • Macreadie PI, Anton A, Raven JA, Beaumont N, Connolly RM, Friess DA, Kelleway JJ, Kennedy H, Kuwae T, Lavery PS et al. 2019b. The future of Blue Carbon science. Nature Communications 10:3998. https://doi.org/10.1038/s41467-019-11693-w.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  • Mcleod E, Chmura GL, Bouillon S, Salm R, Björk M, Duarte CM, Lovelock CE, Schlesinger WH, Silliman BR. 2011. A blueprint for blue carbon: toward an improved understanding of the role of vegetated coastal habitats in sequestering CO2. Frontiers in Ecology and the Environment 9:552–60.

    Article  Google Scholar 

  • Marba N, Arias-Ortiz A, Masque P, Kendrick G, Mazarrasa I, Bastyan GR, Garcia-Orellana J, Duarte CM. 2015. Impact of seagrass loss and subsequent revegetation on carbon sequestration and stocks. Journal of Ecology 103:296–302.

    Article  CAS  Google Scholar 

  • Mateo MA, Cebrian J, Dunton K, Mutchler T. 2006. Carbon Flux in Seagrass Ecosystems. In: Larkum A, Orth R, Duarte C, Eds. Seagrasses: Biology, Ecology and Conservation. Netherlands: Springer-Verlag. p 159–92.

    Google Scholar 

  • Meehan AJ, West RJ. 2000. Recovery times for a damaged Posidonia australis bed in South Eastern Australia. Aquatic Botany 67:161–7.

    Article  Google Scholar 

  • Nellemann C, Corcoran E, Duarte CM, Valdés L, DeYoung C, Fonseca L, Grimsditch G(Eds.), 2009. Blue carbon—A rapid response assessment. United Nations Environment Programme. 544 Estuaries and Coasts (2012) 35:527–545 GRID-Arendal, Birkeland Trykkeri AS, Norway. ISBN 978-82-7701-060-1

  • Orth RJ, Carruthers TJB, Dennison WC, Duarte CM, Fourqurean JW, Heck KL, Randall Hughes A, Kendrick GA, Judson Kenworthy W, Olyarnik S, Short FT, Michelle W, Williams SL. 2006. A global crisis for seagrass ecosystems. Bioscience 56:987–96. https://doi.org/10.1641/0006-3568(2006)56[987:AGCFSE]2.0.CO;2.

    Article  Google Scholar 

  • Peterson BJ, Rose CD, Rutten LM, Fourqurean JW. 2012. Disturbance and recovery following catastrophic grazing : studies of a successional chronosequence in a seagrass bed. Oikos 3:361–70.

    Google Scholar 

  • Potouroglou M, Bull JC, Krauss KW, Kennedy HA, Fusi M, Daffonchio D, Mangora MM, Githaiga MN, Diele K, Huxham M. 2017. Measuring the role of seagrasses in regulating sediment surface elevation. Scientific Reports. 7:11917. https://doi.org/10.1038/s41598-017-12354-y.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  • Ricart AM, York PH, Rasheed MA, Pérez M, Romero J, Bryant CV, Macreadie PI. 2015. Variability of sedimentary organic carbon in patchy seagrass landscapes. Mar Pollut Bull 100:476–82.

    Article  CAS  Google Scholar 

  • Rose CD, Sharp WS, Kenworthy WJ, Hunt JH, Lyons WG, Prager EJ, Valentine JF, Hall MO, Whitfield P, Fourqurean JW. 1999. Overgrazing of a large seagrass bed by the sea urchin Lytechinus variegatus in outer Florida Bay. Marine Ecology Progress Series 190:211–22.

    Article  Google Scholar 

  • Serrano O, Ruhon R, Lavery PS, Kendrick GA, Hickey S, Masqué P, Arias-Ortiz A, Steven A, Duarte CM. 2016. Impact of mooring activities on carbon stocks in seagrass meadows. Scientific Reports 6:23193.

    Article  CAS  Google Scholar 

  • Tegner MJ, Dayton PK. 1991. Sea urchins, El Ninos, and the long term stability of southern California kelp forest communities. Marine Ecology Progress Series 77:49–63.

    Article  Google Scholar 

  • Thorhaug A, Poulos HM, López-Portillo J, Ku TC, Berlyn GP. 2017. Seagrass blue carbon dynamics in the Gulf of Mexico: Stocks, losses from anthropogenic disturbance, and gains through seagrass restoration. Science of The Total Environment. 605(626):2017.

    Google Scholar 

  • Trevathan-Tackett SM, Wessel C, Just Cebrián, Ralph PJ, Masqué P, Macreadie PI. 2018. Effects of small-scale, shading-induced seagrass loss on blue carbon storage: Implications for management of degraded seagrass ecosystems. Journal of Applied Ecology 55:1351–9. https://doi.org/10.1111/1365-2664.13081.

    Article  CAS  Google Scholar 

  • Valentine JP, Heck KL Jr. 1991. The role of sea urchin herbivory in regulating subtropical seagrass meadows: evidence from field manipulations in the northern Gulf of Mexico. Journal of Experimental Marine Biolgy and Ecolgy 154:215–30.

    Article  Google Scholar 

  • Wallner-Hahn S, De La Torre-Castro M, Eklöf JS, Gullström M, Muthiga NA, Uku J. 2015. Cascade effects and sea-urchin overgrazing: an analysis of drivers behind the exploitation of sea urchins predators for management improvement. Ocean & Coastal Management 107:16–27.

    Article  Google Scholar 

  • Waycott M, Duarte CM, Carruthers TJB, Orth RJ, Dennison WC, Olyarnik S, Calladine A, Fourqurean JW, Heck KL, Hughes AR, Kendrick GA, Kenworthy WJ, Short FT, Williams SL. 2009. Accelerating loss of seagrasses across the globe threatens coastal ecosystems. Proceedings of the National Acadamy of Sciences of the United States of America. 106:12377–81.

    Article  CAS  Google Scholar 

Download references

Acknowledgements

The authors thank Paul Tinkler, Mahala Ebery and Jordan Logan for field assistance; Jordan Logan for multibeam sonar data processing; Tim Kenner for help in processing soil samples; and Jonathon Stevenson from Parks Victoria. We thank the Australia Academy of Science Thomas Davies Research Grant for Marine, Soil and Plant Biology Grant (to PIM) for financially supporting this research.

Author information

Authors and Affiliations

  1. School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, 221 Burwood Highway, Burwood, Victoria, 3124, Australia

    Paul E. Carnell & Peter I. Macreadie

  2. School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Princes Highway, Warrnambool, Victoria, 3280, Australia

    Daniel Ierodiaconou

  3. Department of Watershed Sciences and Ecology Center, Utah State University, Logan, Utah, 84322, USA

    Trisha B. Atwood

Authors
  1. Paul E. Carnell
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Daniel Ierodiaconou
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Trisha B. Atwood
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Peter I. Macreadie
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Paul E. Carnell.

Additional information

Author’s Contributions: PC, DI and PM designed the study and performed the research; PC and DI analysed the data; PC, DI, TA and PM wrote the paper.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary material 1 (DOCX 22 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Carnell, P.E., Ierodiaconou, D., Atwood, T.B. et al. Overgrazing of Seagrass by Sea Urchins Diminishes Blue Carbon Stocks. Ecosystems 23, 1437–1448 (2020). https://doi.org/10.1007/s10021-020-00479-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10021-020-00479-7

Keywords

Search

Navigation