Hard branching coral on consolidated substrate in shallow to deep water

Long description

Subtidal branching hard coral on consolidated substrate in shallow water to deep water on fringing reefs, reef slopes, patch reefs or platform reefs. Typically dominated by Acropora spp. or Pocillopora damicornis, noting that Acropora spp. can also exist in other forms (e.g. tabular). Branching hard corals are also known as staghorn corals.

Branching corals often experience some wave action and if pieces are broken off by a storm they can disperse vegetatively. Branching corals can be very fast-growing and are capable of recovery after events such as flooding.

Species diversity of the Acropora genus is highest in north Queensland and on the offshore reefs of the Great Barrier Reef, and also on coral rocky communities influenced by the East Australian Current further south. Inner shelf and fringing reefs have a lower species diversity, especially towards their range limits where high latitude specialists such as Acropora bushyensis occur[6][10]. Some shallow water Acropora spp. are depth generalists, also found in mesophotic coral ecosystems (MCEs. i.e. low-light coral ecosystems).

Special values

The values of Queensland’s coral reefs are internationally recognised in the World Heritage and Ramsar conventions. The Outstanding Universal Value of the Great Barrier Reef World Heritage area is based on four criteria (vii), (viii), (ix), (x). The Ramsar convention also includes coral reefs as one of its wetland types which make up part of a site’s ecological character (a combination of the ecosystem components, processes and services of the wetland). The Great Sandy Strait Ramsar wetland includes coral reefs (e.g. Woody and Round Island reefs, coral communities at Little Woody Island, and soft corals on coffee rock reefs). Shoalwater and Corio Bays Ramsar wetland and the Moreton Bay Ramsar Wetland also include fringing coral reefs.

Branching corals are significant reef-building species that create structural substrates and are highly valued for their recreational (snorkelling, spear-fishing, angling) tourism and aesthetic values. They form important fish habitats for a variety of coral-dwelling fish species and support major line fin fisheries (e.g. coral trout, red throat emperor, slatey bream Diagramma picta, tuskfish and wrasses such as parrotfish) and sharks[20].

Coral reefs and communities also stabilise the shoreline preventing erosion and protect the coastline by moderating the impacts of waves[16].

Diagnostic attributes

Inundation 'Subtidal'

Benthic depth 'Shallow (0–10m)', 'Deep (10-30m)' however mapped coral mostly occurs in shallow water to 8 metres

Structural macrobiota 'Hard coral - branching'

Consolidation 'Consolidated'

Qualifiers

Period and Trend qualifiers are relevant to subtidal branching hard coral ecosystems that fluctuate in their extent and composition subject to storm, cyclone and flood events[12][3][4]. Physical breakages can disperse the coral pieces to form new colonies with rapid growth[4] (Zann pers. obs.). The Cover qualifier is relevant as percentage cover of branching corals is of relevance to coral ecosystem monitoring.

Distribution

Branching corals in shallow to deep water constitute the major reef-building corals of the outer Great Barrier Reef platform reefs and coral cays, and are also found on inshore fringing reefs such as the far north Queensland coastline, on continental islands such as the Whitsundays, Magnetic Island and the Keppels[8], and in creeks and bays such as Pancake Creek and Hervey Bay in Central Queensland. Further south the warm East Australian Current influences offshore branching coral-dominated communities of rocky reefs of the Sunshine Coast (e.g. Inner and Outer Gneerings[1]) and Moreton Bay (Flinders Reef[9], Flat Rock and Shag Rock), off the New South Wales coastline at Byron Bay and the Solitary Islands, and further offshore at Middleton Reef and Lord Howe Island[18]. Branching corals are present in Moreton Bay but do not form significant stands (e.g. at Myora on North Stradbroke Island[7]).

The following relates to distribution of this ecosystem type within the Central Queensland mapping area:

• Generally branching corals are indicative of slightly clearer waters and this is supported by coral cores in Hervey Bay, where branching corals were indicative of a long El Nino period with little flooding whereas non-branching was associated with high turbidity and flooding, based on coral cores (1,500 year cycle with 30 to 40 year cycle within[4]).
• In Central Queensland, branching corals (dominated by Acropora millepora) are a major feature of the Keppel Islands. Branching corals are found on Rundle Island[5] and near Rat Island[17] inside Facing Island. Notable examples towards their southern range limit include:
  • Pancake Creek Acropora fringing reef
  • a small Acropora patch on the Woongarra coast[2]
  • Pocillopora damicornis dominated Four Mile Reef south-east of Elliott Heads[3][4]
  • Acropora stands larger than 300 square metres on mainland fringing reefs of Hervey Bay at Gatakers Bay and Point Vernon[19]
  • areas along continuous reef crests at Woody Island and on Round Island in the Great Sandy Strait[19][6].

Comments

Other relevant attributes include Energy magnitude (wave) as branching corals frequently grow where there is some wave action[15], at levels imperceptible by the very coarse wave energy attribute dataset. Water clarity and Freshwater volume are relevant water column attributes as nearshore branching coral reefs in the path of river flood plumes are shaped by these plumes, as is Sediment texture of suspended sediment/sediment deposited by floods. Water clarity is a strong determinant of the commonly-occurring branching genus Acropora in term of occurrence and depth[13]. Acropora is also very sensitive to human-related impacts.

Water temperature is critical to all corals as they are sensitive to extremes of heat and cold, resulting in bleaching due to the loss of endosymbiotic dinoflagellates (e.g. zooxanthellae) and therefore the ability to photosynthesise[11].

Benthic rugosity of coral reefs, particularly branching corals, is important for creating three-dimensional living space for biota including fish. This also allows more shading which can protect corals during bleaching events[14].

Additional Information

Protecting the Great Barrier Reef - Queensland Government

Coral - Department of the Environment, Tourism, Science and Innovation

Coral reefs - Queensland Museum

The Reef - Great Barrier Reef Marine Park Authority

Corals of the World

Great Barrier Reef - UNESCO

Nationally (DIWA) and internationally important (Ramsar) wetlands - WetlandInfo

Coral Indicators for the 2017 Gladstone Harbour Report Card - Australian Institute of Marine Science

Reef Report Card 2016 - Queensland Government

Great Barrier Reef Outlook Report - Great Barrier Reef Marine Park Authority

Monitoring inshore reefs - Australian Institute of Marine Science

Reef Check Methods - Reef Check Australia

Coral reefs - Museum of Tropical Queensland

Remote Sensing Research Centre - The University of Queensland

References

1. ^ Banks, S & Harriott, V (1995), 'Coral communities of the Gneering Shoals and Mudjimba Island, south-eastern Queensland', Marine and Freshwater Research. [online], vol. 46, no. 8, p. 1137. Available at: http://www.publish.csiro.au/?paper=MF9951137 [Accessed 10 June 2019].
2. ^ Bushell, HL (2008), Assessment of the status of the benthic reef communities within the Woongarra region. Unpublished third year undergraduate report, , School of Environmental Science and Management, Southern Cross University, Lismore, NSW 2480.
3. ^ a b Butler, IR, Sommer, B, Zann, M, Zhao, J & Pandolfi, JM (2013), 'The impacts of flooding on the high-latitude, terrigenoclastic influenced coral reefs of Hervey Bay, Queensland, Australia', Coral Reefs, vol. 32, no. 4, pp. 1149-1163, Springer.
4. ^ a b c d Butler, IR (2015), Flood response and palaeoecology of the high-latitude, terrigenoclastic influenced coral reefs of Hervey Bay, Queensland, Australia. PhD thesis, School of Biological Sciences The University of Queensland.
5. ^ Ceccarelli, DM, Ayling, AM & Ayling, AL (2013), Changes in Benthic Communities on Fringing Coral Reefs around Facing Island: August 2013.
6. ^ a b Devantier, LD (2010), Reef-building corals of Hervey Bay, South-East Queensland. [online] Available at: https://www.researchgate.net/publication/285100297_DeVantier_2010_Reef-building_Corals_of_Hervey_Bay_South-east_Queensland.
7. ^ Fellegara, I & Harrison, PL (2008), 'Status of the subtropical scleractinian coral communities in the turbid environment of Moreton Bay, southeast Queensland', Proceedings of the Thirteenth International Marine Biological Workshop: The Marine Fauna and Flora of Moreton Bay, Queensland, pp. 277-291.
8. ^ Great Barrier Reef Marine Park Authority (2007), Biophysical assessment of the reefs of Keppel Bay: a baseline study April 2007. [online], Climate Change Group. Available at: http://elibrary.gbrmpa.gov.au/jspui/bitstream/11017/203/1/Biophysical-assessment-of-reefs-in-Keppel-Bay-a-baseline-study-April-2007.pdf.
9. ^ Hall, NJ, Tibbetts, IR, Dennison, W, University of Queensland & School of Marine Science (1999), Moreton Bay and catchment, School of Marine Science, University of Queensland, Brisbane.
10. ^ Harriott, V & Banks, S (April 2002), 'Latitudinal variation in coral communities in eastern Australia: a qualitative biophysical model of factors regulating coral reefs', Coral Reefs. [online], vol. 21, no. 1, pp. 83-94. Available at: http://link.springer.com/10.1007/s00338-001-0201-x [Accessed 10 June 2019].
11. ^ Hoegh-Guldberg, O (1999), 'Climate change, coral bleaching and the future of the world's coral reefs', Marine and Freshwater Research. [online], vol. 50, no. 8, p. 839. Available at: http://www.publish.csiro.au/?paper=MF99078 [Accessed 11 June 2019].
12. ^ Jones, AM & Berkelmans, R (2014), 'Flood impacts in Keppel Bay, Southern Great Barrier Reef in the aftermath of cyclonic rainfall', PLoS ONE. [online], vol. 9, no. 1. Available at: Scopus.
13. ^ Muir, P, Wallace, C, Bridge, TCL & Bongaerts, P (25 February 2015), 'Diverse Staghorn Coral Fauna on the Mesophotic Reefs of North-East Australia', PLOS ONE. [online], vol. 10, no. 2, p. e0117933, ed. S C A Ferse. Available at: http://dx.plos.org/10.1371/journal.pone.0117933 [Accessed 19 March 2019].
14. ^ Muir, PR, Wallace, CC, Pichon, M & Bongaerts, P (19 December 2018), 'High species richness and lineage diversity of reef corals in the mesophotic zone', Proceedings of the Royal Society B: Biological Sciences. [online], vol. 285, no. 1893, p. 20181987. Available at: http://www.royalsocietypublishing.org/doi/10.1098/rspb.2018.1987 [Accessed 19 March 2019].
15. ^ Roelfsema, C, Kovacsa, E, Ortizb, J, Wolff, NH, Callaghan, D, Wettled, M, Ronan, M, Hamylton, SH, Mumby, PJ & Phinn, S (2018), 'Coral reef habitat mapping: A combination of object-based image analysis and ecological modelling', Remote Sensing of Environment, vol. 208, pp. 27-41.
16. ^ Siebentritt, M (2016), Understanding sea-level rise and climate change, and associated impacts on the coastal zone. CoastAdapt Information Manual 2.
17. ^ Thompson, A, Davidson, J & Costello, P (2016), Coral Indicators for the 2016 Gladstone Harbour Report Card 2106: ISP014. Report prepared for Gladstone Healthy Harbour Partnership. (33 pp), Australian Institute of Marine Science, Townsville.
18. ^ Veron, J & Done, T (1979), 'Corals and coral Communities of Lord Howe Island.', Marine and Freshwater Research. [online], vol. 30, no. 2, p. 203. Available at: http://www.publish.csiro.au/?paper=MF9790203 [Accessed 10 June 2019].
19. ^ a b Zann, M (2012), The use of remote sensing and field validation for mapping coral communities of Hervey Bay and the Great Sandy Strait and implications for coastal planning policy, The University of Queensland.
20. ^ Zeller, B (1998), Queensland's fisheries habitats: current condition and recent trends, vol. DPI Information Series Q198025, The State of Queensland Department of Primary Industries, Brisbane.

Last updated: 18 July 2019