Surface alkaline phosphatase activities of macroalgae on coral reefs of the central Great Barrier Reef, Australia

Coral Reefs ◽  
2001 ◽  
Vol 19 (4) ◽  
pp. 310-317 ◽  
Author(s):  
B. Schaffelke
Keyword(s):  
Alkaline Phosphatase ◽  
Coral Reefs ◽  
Great Barrier Reef ◽  
Barrier Reef ◽  
Phosphatase Activities

Benthic community composition influences within-habitat variation in macroalgal browsing on the Great Barrier Reef

2010 ◽  
Vol 61 (9) ◽  
pp. 999 ◽  
Author(s):  
C. Cvitanovic ◽  
A. S. Hoey
Keyword(s):  
Coral Reefs ◽  
Great Barrier Reef ◽  
Benthic Community ◽  
Spatial Scales ◽  
Structural Complexity ◽  
Barrier Reef ◽  
Removal Rates ◽  
Ecological Processes ◽  
Habitat Variation ◽  
Benthic Composition

The removal of macroalgae by herbivores is fundamental to the long-term persistence of coral reefs. Variation in macroalgal browsing has been documented across a range of spatial scales on coral reefs; however, few studies have examined the factors that influence within-habitat rates of herbivory. The aim of the present study was to quantify herbivory on two species of Sargassum across three bays on an inshore island in the central Great Barrier Reef (GBR), and to determine whether these removal rates were related to the benthic composition or herbivorous fish communities. Removal rates of Sargassum differed significantly among bays, with removal rates in the southern bay (66.9–83.0% per 3 h) being approximately double that of the two other bays (29.2–38.5% per 3 h). The removal rates displayed a direct relationship with the benthic community structure, in particular the cover of macroalgae and live plate corals. Although it is difficult to determine whether these relationships are related to the availability of food resources or the structural complexity of the substratum, they highlight the potential influence of benthic composition on ecological processes. Quantifying and understanding the drivers of herbivory across a range of spatial scales is essential to the future management of coral reefs.

scholarly journals Progressive seawater acidification on the Great Barrier Reef continental shelf

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Katharina E. Fabricius ◽  
Craig Neill ◽  
Erik Van Ooijen ◽  
Joy N. Smith ◽  
Bronte Tilbrook
Keyword(s):  
Coral Reefs ◽  
Continental Shelf ◽  
Great Barrier Reef ◽  
Ocean Acidification ◽  
Seawater Temperature ◽  
Barrier Reef ◽  
Saturation State ◽  
Seawater Acidification ◽  
Seawater Ph ◽  
Seawater Samples

Abstract Coral reefs are highly sensitive to ocean acidification due to rising atmospheric CO2 concentrations. We present 10 years of data (2009–2019) on the long-term trends and sources of variation in the carbon chemistry from two fixed stations in the Australian Great Barrier Reef. Data from the subtropical mid-shelf GBRWIS comprised 3-h instrument records, and those from the tropical coastal NRSYON were monthly seawater samples. Both stations recorded significant variation in seawater CO2 fugacity (fCO2), attributable to seasonal, daytime, temperature and salinity fluctuations. Superimposed over this variation, fCO2 progressively increased by > 2.0 ± 0.3 µatm year−1 at both stations. Seawater temperature and salinity also increased throughout the decade, whereas seawater pH and the saturation state of aragonite declined. The decadal upward fCO2 trend remained significant in temperature- and salinity-normalised data. Indeed, annual fCO2 minima are now higher than estimated fCO2 maxima in the early 1960s, with mean fCO2 now ~ 28% higher than 60 years ago. Our data indicate that carbonate dissolution from the seafloor is currently unable to buffer the Great Barrier Reef against ocean acidification. This is of great concern for the thousands of coral reefs and other diverse marine ecosystems located in this vast continental shelf system.

scholarly journals Socio-Ecological Controversies in the News as Trigger of a Model-Based Inquiry Instructional Sequence about the Effect of Global Warming on the Great Barrier Reef

2020 ◽  
Vol 12 (11) ◽  
pp. 4676
Author(s):  
M. Rut Jiménez-Liso ◽  
Manuela González-Herrera ◽  
Isabel Banos-González
Keyword(s):  
Global Warming ◽  
Secondary School ◽  
Coral Reefs ◽  
Great Barrier Reef ◽  
Ecological System ◽  
Alternative Conceptions ◽  
Instructional Sequence ◽  
Barrier Reef ◽  
School Students ◽  
Model Based

The use of socio-ecological controversies, such as global warming, in classrooms has been suggested to increase students’ awareness about complex issues, although detailed analysis of their implementation in classrooms are still scarce. This research shows a model-based inquiry approach (MBI) instructional sequence, using scientific news as a trigger, aimed at addressing a global problem on a real socio-ecological system: the effect of global warming on the Great Barrier Reef. Its implementation in a lower secondary school classroom allowed the assessment of the effectiveness of the instructional sequence designed, based on students’ perception of what secondary school students have learned and felt. Results show that the MBI instructional sequence seems to have favored the mobilization of students’ alternative conceptions about global warming, coral reefs, and symbiotic relationships. In addition, it contributed to increasing the students’ awareness of the problem of global warming and its effects on an essential socio-ecological system, such as coral reefs.

scholarly journals Optimising cool-water injections to reduce thermal stress on coral reefs of the Great Barrier Reef

PLoS ONE ◽  
2020 ◽  
Vol 15 (10) ◽  
pp. e0239978
Author(s):  
Mark Edward Baird ◽  
Rebecca Green ◽  
Ryan Lowe ◽  
Mathieu Mongin ◽  
Elodie Bougeot
Keyword(s):  
Thermal Stress ◽  
Coral Reefs ◽  
Great Barrier Reef ◽  
Barrier Reef ◽  
Cool Water

scholarly journals The Great Bacterial Reef: Communication and development in human oral bacterial biofilms

2005 ◽  
Vol 26 (3) ◽  
pp. 130
Author(s):  
Paul E Kolenbrander ◽  
Patricia I Diaz ◽  
Nicholas S Jakubovics ◽  
Alexander H Rickard ◽  
Natalia I Chalmers ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Great Barrier Reef ◽  
Oral Hygiene ◽  
Bacterial Communities ◽  
Dental Plaque ◽  
Oral Bacteria ◽  
Bacterial Biofilms ◽  
Time Interval ◽  
Barrier Reef

Consider that The Great Barrier Reef is home to thousands of species of plants and animals with spatiotemporally predictable fish communities on coral reefs, and compare this with the fact that human oral bacteria develop spatiotemporally predictable dental plaque communities on enamel after each oral hygiene procedure. This reassembling of oral bacterial communities over a time interval of only a few hours offers an opportunity to investigate the role of communication in community architecture and composition.

Factors affecting the cycling of dimethylsulfide and dimethylsulfoniopropionate in coral reef waters of the Great Barrier Reef

2007 ◽  
Vol 4 (5) ◽  
pp. 310 ◽  
Author(s):  
Graham Jones ◽  
Mark Curran ◽  
Andrew Broadbent ◽  
Stacey King ◽  
Esther Fischer ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Great Barrier Reef ◽  
Coral Bleaching ◽  
Time Of Day ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Barrier Reef ◽  
Magnetic Island ◽  
Surface Temperatures ◽  
Acropora Formosa

Environmental context. Levels of atmospheric dimethylsulfide (DMS) and its oxidation products are reputed to affect the microphysics of clouds and the amount of incoming solar radiation to the ocean. Studies of DMS and its precursor compound dimethylsulfoniopropionate (DMSP) at two inshore fringing coral reefs in the Great Barrier Reef highlight pronounced seasonal, diurnal and tidal variation of these compounds, with dissolved DMS and DMSP significantly correlated with sea surface temperatures (SSTs) up to 30°C. During a coral bleaching episode at one of the reef sites, dissolved DMS concentrations decreased when SSTs exceeded 30°C, a result replicated in chamber experiments with staghorn coral. The results raise interesting questions on the role of these organosulfur substances in corals and whether DMS emissions from coral reefs could have an effect on regional climate in the Great Barrier Reef. Abstract. A study of dissolved dimethylsulfide (DMSw), dissolved and particulate dimethylsulfoniopropionate (DMSPd, DMSPp), and atmospheric dimethylsulfide (DMSa) was carried out at two inshore fringing coral reefs (Orpheus Island and Magnetic Island) in the Great Barrier Reef (GBR) to investigate the variation of these organosulfur substances with season, sea surface temperature, tides, and time of day. Highest concentrations of these organosulfur substances occurred in the summer months at both reefs, with lowest concentrations occurring during winter, suggesting a biological source of these compounds from the reef flats. At the Orpheus Island reef, where more measurements were made, DMSw and DMSPd were significantly correlated with tidal height during the flooding tide over the reef (r = 0.37, P < 0.05; r = 0.58, P < 0.01 respectively), and elevated DMSw and DMSa concentrations generally occurred in the daylight hours, possibly reflecting photosynthetic production of DMSw from the reef flats. Chamber experiments with the staghorn coral Acropora formosa confirmed that corals produce DMSw in the day. DMSw (r = 0.43, P < 0.001) and DMSPd (r = 0.59, P < 0.001) were significantly positively correlated with sea surface temperatures (SST) at the Orpheus Island reef. During severe coral bleaching at the eutrophic Magnetic Island reef in the summer, DMSw concentrations decreased at SSTs greater than 30°C, suggesting that reef production of DMSw decreases during elevated SSTs. This was later confirmed in chamber experiments with Acropora formosa, which showed that when this coral was exposed to temperatures at its bleaching threshold (31°C), decreased production of DMSw occurred. These results suggest that DMS and DMSP in coral zooxanthellae may be functioning as antioxidants, but further experiments are needed to substantiate this.

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