Skip to main content

Advertisement

Log in

Shifting base-lines, declining coral cover, and the erosion of reef resilience: comment on Sweatman et al. (2011)

  • Comment
  • Published:
Coral Reefs Aims and scope Submit manuscript

Abstract

Formal monitoring of the Great Barrier Reef was initiated in 1986 in response to the clear scientific evidence (and growing public concern) over the loss of corals caused by two protracted outbreaks of crown-of thorns starfish, which began in 1962 and 1979. Using monitoring data from manta tows along and across the Great Barrier Reef, Sweatman et al. (Coral Reefs 30:521–531, 2011) show that coral cover after these outbreaks declined further from 28 to 22% between 1986 and 2004. Pointing to the current levels of protection of the Great Barrier Reef, they state that earlier estimates of losses of coral cover since the early 1960s have been exaggerated. However, the loss of close to one-quarter of the coral cover over the past two decades represents an average loss of 0.34% cover per year across the whole GBR after 1986, which is very similar to previously reported rates of annual loss measured over a longer timeframe. The heaviest recent losses have occurred on inshore and mid-shelf reefs, which Sweatman et al. (Coral Reefs 30:521–531, 2011) attribute to a natural cycle of disturbance and recovery. But there has been very limited recovery. While coral cover has increased for short periods on some individual reefs, it has declined sharply on many more to produce the observed system-wide trend of declining cover. Close to 40% of coral cover on inner reefs has been lost since 1986. Of particular significance is the new evidence that coral cover has remained unchanged or declined further from a low 1986 baseline in 28 out of 29 sub-regions of the Great Barrier Reef, indicating a gradual erosion of resilience that is impeding the capacity of this huge reef system to return towards its earlier condition. This result, and other clear evidence of widespread incremental degradation from overfishing, pollution, and climate change, calls for action rather than complacency or denial.

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

Access this article

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

Instant access to the full article PDF.

Fig. 1

References

  • Bell PRF, Elmetri I (1995) Ecological indicators of large-scale eutrophication in the Great-Barrier-Reef lagoon. Ambio 24:208–215

    Google Scholar 

  • Bellwood DR, Hughes TP, Folke C, Nyström M (2004) Confronting the coral reef crisis. Nature 429:827–833

    Article  CAS  PubMed  Google Scholar 

  • Berkelmans R, Oliver JK (1999) Large-scale bleaching of corals on the Great Barrier Reef. Coral Reefs 18:55–60

    Article  Google Scholar 

  • Berkelmans R, De’ath G, Kinimonth S, Skirving W (2004) A comparison of the 1998 and 2002 coral bleaching events on the Great Barrier Reef: spatial correlation, patterns and predictions. Coral Reefs 23:74–83

    Article  Google Scholar 

  • Birrell CL, McCook LJ, Willis BL, Diaz-Pulido GA (2008) Effects of benthic algae on the replenishment of corals and the implications for the resilience of coral reefs. Oceanogr Mar Biol 46:25–65

    Google Scholar 

  • Brodie J, Fabricius K, De’ath G, Okaji K (2005) Are increasing nutrient inputs responsible for more outbreaks of crown-of-thorns starfish? An appraisal of the evidence. Mar Pollut Bull 51:266–278

    Article  CAS  PubMed  Google Scholar 

  • Brodie J, Binney J, Fabricius K, Gordon I, Hoegh-Guldberg O, Hunter H, O’Reagain P, Pearson R, Quirk M, Thorburn P, Waterhouse J, Webster I, Wilkinson S (2008) Synthesis of evidence to support the scientific consensus statement on water quality in the Great Barrier Reef. The State of Queensland (Department of Premier and Cabinet), Brisbane, http://www.reefplan.qld.gov.au/library/pdf/publications/Synthesis%20of%20evidence%20to%20support%20the%20Scientific%20Consensus%20Statement%20on%20Water%20Quality%20in%20the%20GBR.pdf

  • Brodie J, Schroeder T, Rohde K, Faithful J, Masters B, Dekker A, Brando V, Maughan M (2010) Dispersal of suspended sediments and nutrients in the Great Barrier Reef lagoon during river-discharge events: conclusions from satellite remote sensing and concurrent flood-plume sampling. Mar Freshw Res 61:651–664

    Article  CAS  Google Scholar 

  • Brodie JE, Devlin MJ, Haynes D, Waterhouse J (2011) Assessment of the eutrophication status of the Great Barrier Reef lagoon (Australia). Biogeochemistry. doi:10.1007/s10533-010-9542-2

  • Bruno JF, Selig ER (2007) Regional decline of coral cover in the Indo-Pacific: timing, extent, and subregional comparisons. PLoS ONE 2:e711

    Article  PubMed  PubMed Central  Google Scholar 

  • Bruno JF, Peters LE, Harvell CD, Hettinger A (2003) Nutrient enrichment can increase the severity of coral diseases. Ecol Lett 6:1056–1061

    Article  Google Scholar 

  • Cheal AJ, McNeil MA, Cripps E, Emslie MJ (2010) Coral-macroalgal phase-shifts or reef resilience: links with diversity and functional role of herbivorous fishes on the Great Barrier Reef. Coral Reefs 29:1005–1015

    Article  Google Scholar 

  • Connell JH (1973) Population biology of reef-building corals. In: Jones OA, Endean R (eds) Biology and geology of coral reefs, vol 2. Academic Press, New York, pp 205–245

    Chapter  Google Scholar 

  • Connell JH, Hughes TP, Wallace CC (1997) A 30-year study of coral community dynamics: influence of disturbance and recruitment on abundance, at several scales in space and time. Ecol Monogr 67:461–488

    Article  Google Scholar 

  • De’ath G, Fabricius K (2010) Water quality as a regional driver of coral biodiversity and macroalgae on the Great Barrier Reef. Ecol Appl 20:840–850

    Article  PubMed  Google Scholar 

  • De’ath G, Lough JM, Fabricius KE (2009) Declining coral calcification on the Great Barrier Reef. Science 323:116–119

    Article  PubMed  Google Scholar 

  • DeVantier LM, De’ath G, Turak E, Done TJ, Fabricius KE (2006) Species richness and community structure of reef-building corals on the nearshore Great Barrier Reef. Coral Reefs 25:329–340

    Article  Google Scholar 

  • Devlin M, Brodie J (2005) Terrestrial discharge into the Great Barrier Reef lagoon: nutrient behaviour in coastal waters. Mar Pollut Bull 51:9–22

    Article  CAS  PubMed  Google Scholar 

  • Devlin M, Schaffelke B (2009) Spatial extent of riverine flood plumes and exposure of marine ecosystems in the Tully coastal region, Great Barrier Reef. Mar Freshw Res 60:1109–1122

    Article  CAS  Google Scholar 

  • Done TJ (1982) Patterns in the distribution of coral communities across the central Great Barrier Reef. Coral Reefs 1:95–107

    Article  Google Scholar 

  • Done TJ (1985) Effects of two Acanthaster outbreaks on coral community structure: the meaning of devastation. Proc 5th Int Coral Reef Congr: 315–320

  • Done TJ (1992) Phase shifts in coral reef communities and their ecological significance. Hydrobiologia 247:121–132

    Article  Google Scholar 

  • Done TJ, Turak E, Wakeford M, DeVantier L, McDonald A, Fisk D (2007) Decadal change in turbid-water coral communities at Pandora Reef: loss of resilience or too soon to tell? Coral Reefs 26:789–805

    Article  Google Scholar 

  • Done TJ, DeVantier LM, Turak E, Fisk DA, Wakeford M, van Woesik R (2010) Coral growth on three reefs: development of recovery benchmarks using a space for time approach. Coral Reefs 29:815–833

    Article  Google Scholar 

  • Endean R, Stablum W (1973) A study of some aspects of the crown-of-thorns starfish (Acanthaster planci) infestations of reefs of Australia’s Great Barrier Reef. Atoll Res Bull 167:1–62

    Article  Google Scholar 

  • Endean R, Stablum W (1975) Population explosions of Acanthaster planci and associated destruction of the hard coral cover of reefs of the Great Barrier Reef, Australia. Environ Conserv 2:247–256

    Article  Google Scholar 

  • Fabricius KE (2005) Effects of terrestrial runoff on the ecology of corals and coral reefs: review and synthesis. Mar Pollut Bull 50:125–146

    Article  CAS  PubMed  Google Scholar 

  • Fabricius KE (2011) Factors determining the resilience of coral reefs to eutrophication: a review and conceptual model. In: Dubinsky Z, Stambler N (eds) Coral reefs: an ecosystem in transition. Springer Press, pp 493–506

  • Fabricius K, De’ath G, McCook L, Turak E, Williams D (2005) Changes in algal, coral and fish assemblages along water quality gradients on the inshore Great Barrier Reef. Mar Pollut Bull 51:384–398

    Article  CAS  PubMed  Google Scholar 

  • Fabricius KE, Okaji K, De’ath G (2010) Three lines of evidence to link outbreaks of the crown of thorns seastar Acanthaster planci to the release of larval food limitation. Coral Reefs 29:593–605

    Article  Google Scholar 

  • Fisk DA, Done TJ (1985) Taxonomic and bathymetric patterns of bleaching in corals, Myrmidon reef (Queensland). Proc Fifth Int Coral Reef Congress, Tahiti 6:149–154

    Google Scholar 

  • Gardener TA, Côté IM, Gill JA, Grant A, Watkinson AR (2003) Long-term region-wide declines in Caribbean corals. Science 301:958–960

    Article  Google Scholar 

  • Haapkyla J, Unsworth RKF, Flavell M, Bourne DG, Schaffelke B, Willis BL (2011) Seasonal rainfall and runoff promote coral disease on an inshore reef. PLoS One 6:e16893

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  • Hughes TP, Connell JH (1999) Multiple stressors on coral reefs: a long-term perspective. Limnol Oceanogr 44:932–940

    Article  Google Scholar 

  • Hughes TP, Tanner JH (2000) Recruitment failure, life histories, and long-term decline of Caribbean corals. Ecology 81:2250–2263

    Article  Google Scholar 

  • Hughes TP, Baird AH, Dinsdale EA, Moltschaniwskyj NA, Pratchett M, Tanner JE, Willis BL (2002) Supply-side ecology works both ways: the link between benthic adults, fecundity and larval recruits. Ecology 81:2241–2249

    Article  Google Scholar 

  • Hughes TP, Gunderson LH, Folke C, Baird AH, Bellwood D, Berkes F, Crona B, Helfgott A, Leslie H, Norberg J, Nyström M, Olsson P, Österblom H, Scheffer M, Schuttenberg H, Stenect RS, Tengö M, Troell M, Walker B, Wilson J, Worm B (2007) Adaptive management of the Great Barrier Reef and the Grand Canyon World Heritage Area. Ambio 36:586–592

    Article  PubMed  Google Scholar 

  • Hughes TP, Graham NAJ, Jackson JBC, Mumby PJ, Steneck RS (2010) Rising to the challenge of sustaining coral reef resilience. Trends Ecol Evol 25:633–642

    Article  PubMed  Google Scholar 

  • Jackson JBC, Kirby MX, Berger WH, Bjorndal KA, Botsford LW, Bourque BJ, Bradbury RH, Cooke R, Erlandson J, Estes JA, Hughes TP, Kidwell S, Lange CB, Lenihan HS, Pandolfi JM, Peterson CH, Steneck RS, Tegner MJ, Warner RR (2001) Historical overfishing and the recent collapse of coastal ecosystems. Science 293:629–638

    Article  CAS  PubMed  Google Scholar 

  • Kenchington RA, Morton B (1976) Two surveys of the crown of thorns starfish over a section of the Great Barrier Reef. Report of the steering committee for the crown of thorns survey. Australian Government Publishing Service, Canberra

  • Le Grand HM, Fabricius KE (2011) Relationship of internal macrobioeroder densities in living massive Porites to turbidity and chlorophyll on the Australian Great Barrier Reef. Coral Reefs 30:97–107

    Article  Google Scholar 

  • Lewis S, Shields G, Kamber B, Lough J (2007) A multi-trace element coral record of land-use changes in the Burdekin River catchment, NE Australia. Palaeogeogr Palaeoclimatol Palaeoecol 246:471–487

    Article  Google Scholar 

  • Lewis SE, Brodie JE, Bainbridge ZT, Rohde KW, Davis AM, Masters BL, Maughan M, Devlin MJ, Mueller JF, Schaffelke B (2009) Herbicides: a new threat to the Great Barrier Reef. Environ Pollut 157:2470–2484

    Article  CAS  PubMed  Google Scholar 

  • Lourey MJ, Ryan DAJ, Miller IR (2000) Rates of decline and recovery of coral cover on reefs impacted by, recovering from and unaffected by crown-of-thorns starfish, Acanthaster planci: a regional perspective of the Great Barrier Reef. Mar Ecol Prog Ser 196:179–186

    Article  Google Scholar 

  • McCook LJ, Ayling T, Cappo M, Choat JH, Evans RD, De Freitas DM, Heupel M, Hughes TP, Jones GP, Mapstone B, Marsh H, Mills M, Molloy FJ, Pitcher CR, Pressey RL, Russ GR, Sutton S, Sweatman H, Tobin R, Wachenfeld DR, Williamson DH (2010) Adaptive management of the Great Barrier Reef: a globally significant demonstration of the benefits of networks of marine reserves. Proc Natl Acad Sci USA 107:18278–18285

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  • McCulloch M, Fallon S, Wyndham T, Hendy E, Lough J, Barnes D (2003) Coral record of increased sediment flux to the inner Great Barrier Reef since European settlement. Nature 421:727–730

    Article  CAS  PubMed  Google Scholar 

  • McKergow LA, Prosser IP, Hughes AO, Brodie J (2005a) Sources of sediment to the Great Barrier Reef World Heritage Area. Mar Pollut Bull 51:200–211

    Article  CAS  PubMed  Google Scholar 

  • McKergow LA, Prosser IP, Hughes AO, Brodie J (2005b) Regional scale nutrient modelling: exports to the Great Barrier Reef World Heritage Area. Mar Pollut Bull 51:186–189

    Article  CAS  PubMed  Google Scholar 

  • Moran PJ (1986) The Acanthaster phenomenon. Oceanogr Mar Biol Annu Rev 24:379–480

    Google Scholar 

  • Olsson P, Folke C, Hughes TP (2008) Navigating the transition to ecosystem-based management of the Great Barrier Reef, Australia. Proc Natl Acad Sci USA 105:9489–9494

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  • Osborne K, Dolman AM, Burgess SC, Kerryn JA (2011) Disturbance and dynamics of coral cover on the Great Barrier Reef (1995–2009). PLoS One 6:e17516

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  • Pandolfi JM, Bradbury RH, Sala E, Hughes TP, Bjorndal KA, Cooke RG, McArdle D, McClenachan L, Newman MJ, Paredes G, Warner RR, Jackson JBC (2003) Global trajectories of the long-term decline of coral reef ecosystems. Science 301:955–958

    Article  CAS  PubMed  Google Scholar 

  • Pearson RG (1974) Recolonization by hermatypic corals of reefs damaged by Acanthaster. Proc 2nd Int Coral Reef Symp 2: 207–215

  • Pearson RG (1981) Recovery and recolonization of coral reefs. Mar Ecol Prog Ser 4:105–122

    Article  Google Scholar 

  • Richmond RH (1997) Reproduction and recruitment in corals: critical links in the persistence of reefs. In: Birkeland C (ed) Life and death of coral reefs. Chapman and Hall, New York, pp 175–197

    Chapter  Google Scholar 

  • Sweatman, H, Cheal A, Coleman G, Delean S, Fitzpatrick B, Miller AI, Ninio R, Osborne K, Page C, Thompson A (2001) Long-term monitoring of the Great Barrier Reef: status report number 5. Australian Institute of Marine Science, Townsville

  • Sweatman H, Abdo D, Burgess S, Cheal A, Coleman G, Delean S, Emslie M, Miller I, Osborne K, Oxley W, Page C, Thompson A (2003) Long-term monitoring of the Great Barrier Reef: status report number 6. Australian Institute of Marine Science, Townsville

  • Sweatman H, Delean S, Syms C (2011) Assessing loss of coral cover on Australia’s Great Barrier Reef over two decades, with implications for longer term-trends. Coral Reefs 30:521–531

    Article  Google Scholar 

  • Veron JEN (1978) Deltaic and dissected reefs of the far northern region. Philos Trans R Soc Lond Ser B: Biol Sci 284:23–37

    Article  Google Scholar 

  • Veron JEN, Hudson RCL (1978) Ribbon reefs of the northern region. Philos Trans R Soc Lond Ser B: Biol Sci 284:3–21

    Article  Google Scholar 

  • Wachenfeld D (1997) Long-term trends in the status of coral reef-flat benthos: the use of historical photographs. Proceedings of the State of the Great Barrier Reef World Heritage Area Workshop. Great Barrier Reef Marine Park Authority, Townsville, pp 134–148

  • Walsh RJ, Harris CL, Harvey JM, Maxwell WGH, Thomson JM, Tranter DJ (1971) Report of the committee on the problem of the crown-of-thorns starfish (Acanthaster planci). CSIRO, Melbourne, 45 pp

  • Wilkinson CR (2008) Status of coral reefs of the world 2008. Global Coral Reef Monitoring Network and Australian Institute of Marine Sciences, Townsville

    Google Scholar 

  • Wismer S, Hoey AS, Bellwood DR (2009) Cross-shelf benthic community structure on the Great Barrier Reef: relationships between macroalgal cover and herbivore biomass. Mar Ecol Prog Ser 376:45–54

    Article  Google Scholar 

  • Wolanski E, Spagnol S (2000) Pollution by mud of Great Barrier Reef coastal waters. J Coast Res 16:1151–1156

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to T. P. Hughes.

Additional information

Communicated by Environment Editor Prof. Rob van Woesik

Rights and permissions

Reprints and permissions

About this article

Cite this article

Hughes, T.P., Bellwood, D.R., Baird, A.H. et al. Shifting base-lines, declining coral cover, and the erosion of reef resilience: comment on Sweatman et al. (2011). Coral Reefs 30, 653–660 (2011). https://doi.org/10.1007/s00338-011-0787-6

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00338-011-0787-6

Keywords

Navigation