scholarly journals Submerged banks in the Great Barrier Reef, Australia, greatly increase available coral reef habitat

2012 ◽  
Vol 70 (2) ◽  
pp. 284-293 ◽  
Author(s):  
Peter T. Harris ◽  
Thomas C.L. Bridge ◽  
Robin J. Beaman ◽  
Jody M. Webster ◽  
Scott L. Nichol ◽  
...  

Abstract Harris, P. T., Bridge, T. C. L., Beaman, R. J., Webster, J. M., Nichol, S. L., and Brooke, B. P. 2013. Submerged banks in the Great Barrier Reef, Australia, greatly increase available coral reef habitat. – ICES Journal of Marine Science, 70: 284–293. Anthropogenic global ocean warming is predicted to cause bleaching of many near-sea-surface (NSS) coral reefs, placing increased importance on deeper reef habitats to maintain coral reef biodiversity and ecosystem function. However, the location and spatial extent of many deep reef habitats is poorly known. The question arises: how common are deep reef habitats in comparison with NSS reefs? We used a dataset from the Great Barrier Reef (GBR) to show that only about 39% of available seabed on submerged banks is capped by NSS coral reefs (16 110 km2); the other 61% of bank area (25 600 km2) is submerged at a mean depth of around 27 m and represents potential deep reef habitat that is spatially distributed along the GBR continental shelf in the same latitudinal distribution as NSS reefs. Out of 25 600 km2 of submerged bank area, predictive habitat modelling indicates that more than half (around 14 000 km2) is suitable habitat for coral communities.

2013 ◽  
Vol 10 (10) ◽  
pp. 6747-6758 ◽  
Author(s):  
R. Albright ◽  
C. Langdon ◽  
K. R. N. Anthony

Abstract. Ocean acidification is projected to shift coral reefs from a state of net accretion to one of net dissolution this century. Presently, our ability to predict global-scale changes to coral reef calcification is limited by insufficient data relating seawater carbonate chemistry parameters to in situ rates of reef calcification. Here, we investigate diel and seasonal trends in carbonate chemistry of the Davies Reef flat in the central Great Barrier Reef and relate these trends to benthic carbon fluxes by quantifying net ecosystem calcification (nec) and net community production (ncp). Results show that seawater carbonate chemistry of the Davies Reef flat is highly variable over both diel and seasonal cycles. pH (total scale) ranged from 7.92 to 8.17, pCO2 ranged from 272 to 542 μatm, and aragonite saturation state (Ωarag) ranged from 2.9 to 4.1. Diel cycles in carbonate chemistry were primarily driven by ncp, and warming explained 35% and 47% of the seasonal shifts in pCO2 and pH, respectively. Daytime ncp averaged 37 ± 19 mmol C m−2 h−1 in summer and 33 ± 13 mmol C m−2 h−1 in winter; nighttime ncp averaged −30 ± 25 and −7 ± 6 mmol C m−2 h−1 in summer and winter, respectively. Daytime nec averaged 11 ± 4 mmol CaCO3 m−2 h−1 in summer and 8 ± 3 mmol CaCO3 m−2 h−1 in winter, whereas nighttime nec averaged 2 ± 4 mmol and −1 ± 3 mmol CaCO3 m−2 h−1 in summer and winter, respectively. Net ecosystem calcification was highly sensitive to changes in Ωarag for both seasons, indicating that relatively small shifts in Ωarag may drive measurable shifts in calcification rates, and hence carbon budgets, of coral reefs throughout the year.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Maoz Fine ◽  
Ove Hoegh-Guldberg ◽  
Efrat Meroz-Fine ◽  
Sophie Dove

Abstract Coral reefs are under increasing stress from local and global factors. Long-term perspectives are becoming increasingly important for understanding ecosystem responses. Here, we provide insights from a 91-year study of the Low Isles on the northern Great Barrier Reef (GBR) that begins with the pioneering Great Barrier Reef Expedition (1928-29). We show that intertidal communities have experienced major phase-shifts since 1928, with few signs of a return to the initial state. Coral communities demolished by cyclones 50 years ago and exposed to multiple stressors have yet to recover. Richness and diversity of these communities systematically declined for corals and other invertebrates. Specifically, massive corals have replaced branching corals, and soft corals have become much more numerous. The long-term perspective of this study illustrates the importance of considering multiple factors in reef decline, and potential recovery, of coral reefs, and the importance of tracking changes in community structure as well as coral abundance over long periods.


2016 ◽  
Author(s):  
Hilton B. Swan ◽  
Graham B. Jones ◽  
Elisabeth S. M. Deschaseaux ◽  
Bradley D. Eyre

Abstract. Atmospheric dimethylsulfide (DMSa), continually derived from the world’s oceans, is a feed gas for the tropospheric production of new sulfate particles, leading to cloud condensation nuclei that influence the formation and properties of marine clouds, and ultimately the Earth’s radiation budget. Previous studies on the Great Barrier Reef (GBR), Australia, have indicated coral reefs are significant sessile sources of DMSa capable of enhancing the tropospheric DMSa burden mainly derived from phytoplankton in the surface ocean; however, specific evidence of coral reef DMS emissions and their characteristics is lacking. By using on-site automated continuous analysis of DMSa and meteorological parameters at Heron Island in the southern GBR, we show that the coral reef was the source of occasional spikes of DMSa identified above the oceanic DMSa background signal. In most instances, these DMSa spikes were detected at low tide under low wind speeds, indicating they originated from the lagoonal platform reef surrounding the island, although evidence of longer range transport of DMSa from a 70 km stretch of coral reefs in the southern GBR was also observed. The most intense DMSa spike occurred in the winter dry season at low tide when convective precipitation fell onto the aerially exposed platform reef. This co-occurrence of events appeared to biologically shock the coral resulting in a seasonally aberrant extreme DMSa spike concentration of 45.9 nmol m−3 (1122 ppt). Seasonal DMS emission fluxes for the 2012 wet season and 2013 dry season campaigns at Heron Island were 5.0 and 1.4 µmol m−2 d−1, respectively, of which the coral reef was estimated to contribute 4 % during the wet season and 14 % during the dry season to the dominant oceanic flux.


2017 ◽  
Vol 14 (1) ◽  
pp. 229-239 ◽  
Author(s):  
Hilton B. Swan ◽  
Graham B. Jones ◽  
Elisabeth S. M. Deschaseaux ◽  
Bradley D. Eyre

Abstract. Atmospheric dimethylsulfide (DMSa), continually derived from the world's oceans, is a feed gas for the tropospheric production of new sulfate particles, leading to cloud condensation nuclei that influence the formation and properties of marine clouds and ultimately the Earth's radiation budget. Previous studies on the Great Barrier Reef (GBR), Australia, have indicated coral reefs are significant sessile sources of DMSa capable of enhancing the tropospheric DMSa burden mainly derived from phytoplankton in the surface ocean; however, specific environmental evidence of coral reef DMS emissions and their characteristics is lacking. By using on-site automated continuous analysis of DMSa and meteorological parameters at Heron Island in the southern GBR, we show that the coral reef was the source of occasional spikes of DMSa identified above the oceanic DMSa background signal. In most instances, these DMSa spikes were detected at low tide under low wind speeds, indicating they originated from the lagoonal platform reef surrounding the island, although evidence of longer-range transport of DMSa from a 70 km stretch of coral reefs in the southern GBR was also observed. The most intense DMSa spike occurred in the winter dry season at low tide when convective precipitation fell onto the aerially exposed platform reef. This co-occurrence of events appeared to biologically shock the coral resulting in a seasonally aberrant extreme DMSa spike concentration of 45.9 nmol m−3 (1122 ppt). Seasonal DMS emission fluxes for the 2012 wet season and 2013 dry season campaigns at Heron Island were 5.0 and 1.4 µmol m−2 day−1, respectively, of which the coral reef was estimated to contribute 4 % during the wet season and 14 % during the dry season to the dominant oceanic flux.


Author(s):  
Rosaria Ria Damai

Beralas Pasir is part of the Regional Marine Conservation Area (KKLD), which was established by the Bintan Regency Government with Bintan Regent Decree No. 261 / VIII / 2007. Water tourism activities undertaken by tourists on the island have had an impact on the condition of the coral reefs, as have other factors, such as bauxite, granite and land sand mining activities around the island. This research aims to determine changes in the coral reef habitat cover and the condition of the coral reefs around Beralas Pasir Island with a remote sensing function, using SPOT 4 imagery acquired on June 1, 2011 and SPOT 7 imagery from April 5, 2020. Data collection of environmental parameters related to the coral reefs was also made. The image processing used the Lyzenga algorithm to simplify the image classification process. The percentage of coral live cover around the island ranges from 26% -53%; this has experienced a significant change, from 67,560 hectares in 2011 to 38,338 hectares in 2018, a total decrease in the area of 29,222 hectares. Some of the natural factors found in the research which have caused damage to the reefs were Drupella snails, the abundance of Caulerpa racemosaalgae, and sea urchins. The majority of the coral reef types consist of Non-Acropora: Coral Massive, Coral, Coral Foliose, Coral Encrusting, Acropora: Acropora Tabulate, Acropora Encrusting, and Acropora Digitate


2021 ◽  
Vol 8 ◽  
Author(s):  
Gal Eyal ◽  
Jack H. Laverick ◽  
Pim Bongaerts ◽  
Oren Levy ◽  
John M. Pandolfi

Mesophotic coral ecosystems (MCEs) are characterized by the presence of photosynthetically active organisms such as corals and algae, and associated communities at depths ranging from 30 to 150 m in tropical and subtropical regions. Due to the increased awareness of the potential importance of these reefs as an integral part of coral reef ecosystems (i.e., deep reef refuge, specialized biodiversity, transition zone between shallow and deep-sea environments, and recreational and intrinsic values), interest from the scientific community has grown around the world over the last two decades. Several nations have already made management declarations and started to extend marine protected areas and fishery management to MCEs. The estimated area of Australian MCEs is likely equivalent to that of shallow reef ecosystems down to 30 m; however, Australian MCEs attract limited research effort compared to other major coral reef regions around the world. In this perspective, we briefly explore the reasons for this scarcity of research on mesophotic ecosystems of the Great Barrier Reef (GBR) of Australia (e.g., strict diving regulations, new researchers’ involvement, and logistics and cost). At present, research efforts on the mesophotic ecosystems of the GBR are in decline and if this trajectory is maintained, the global disparity in knowledge between MCEs near Australia and those from the other main coral reef regions worldwide will sharpen deeply. We call for action from the research community, grant agencies, and decision-makers toward a wider understanding of these important ecosystems in Australia.


1989 ◽  
Vol 21 (2) ◽  
pp. 31-38 ◽  
Author(s):  
Simon Woodley

The Great Barrier Reef is the largest coral reef system in the world. It is recognised and appreciated worldwide as a unique environment and for this reason has been inscribed on the World Heritage List. The Reef is economically-important to Queensland and Australia, supporting substantial tourism and fishing industries. Management of the Great Barrier Reef to ensure conservation of its natural qualities in perpetuity is achieved through the establishment of the Great Barrier Reef Marine Park. The maintenance of water quality to protect the reef and the industries which depend on it is becoming an increasingly important management issue requiring better knowledge and possibly new standards of treatment and discharge.


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