scholarly journals Spatial patterns of microbial communities across surface waters of the Great Barrier Reef

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Pedro R. Frade ◽  
Bettina Glasl ◽  
Samuel A. Matthews ◽  
Camille Mellin ◽  
Ester A. Serrão ◽  
...  
Keyword(s):  
Great Barrier Reef ◽  
Surface Waters ◽  
Nutrient Dynamics ◽  
Community Dynamics ◽  
Environmental Gradients ◽  
Meta Analysis ◽  
Environmental Data ◽  
Nutrient Loads ◽  
Barrier Reef ◽  
Reef Health

AbstractMicroorganisms are fundamental drivers of biogeochemical cycling, though their contribution to coral reef ecosystem functioning is poorly understood. Here, we infer predictors of bacterioplankton community dynamics across surface-waters of the Great Barrier Reef (GBR) through a meta-analysis, combining microbial with environmental data from the eReefs platform. Nutrient dynamics and temperature explained 41.4% of inter-seasonal and cross-shelf variation in bacterial assemblages. Bacterial families OCS155, Cryomorphaceae, Flavobacteriaceae, Synechococcaceae and Rhodobacteraceae dominated inshore reefs and their relative abundances positively correlated with nutrient loads. In contrast, Prochlorococcaceae negatively correlated with nutrients and became increasingly dominant towards outershelf reefs. Cyanobacteria in Prochlorococcaceae and Synechococcaceae families occupy complementary cross-shelf biogeochemical niches; their abundance ratios representing a potential indicator of GBR nutrient levels. One Flavobacteriaceae-affiliated taxa was putatively identified as diagnostic for ecosystem degradation. Establishing microbial observatories along GBR environmental gradients will facilitate robust assessments of microbial contributions to reef health and inform tipping-points in reef condition.

scholarly journals Cumulative impacts across Australia’s Great Barrier Reef: A mechanistic evaluation

2020 ◽  
Author(s):  
Yves-Marie Bozec ◽  
Karlo Hock ◽  
Robert A. B. Mason ◽  
Mark E. Baird ◽  
Carolina Castro-Sanguino ◽  
...  
Keyword(s):  
Water Quality ◽  
Life History ◽  
Great Barrier Reef ◽  
Community Dynamics ◽  
Multiple Stressors ◽  
Coral Cover ◽  
Environmental Data ◽  
Environmental Drivers ◽  
Barrier Reef ◽  
Cumulative Impacts

ABSTRACTCumulative impacts assessments on marine ecosystems have been hindered by the difficulty of collecting environmental data and identifying drivers of community dynamics beyond local scales. On coral reefs, an additional challenge is to disentangle the relative influence of multiple drivers that operate at different stages of coral ontogeny. We integrated coral life history, population dynamics and spatially-explicit environmental drivers to assess the relative and cumulative impacts of multiple stressors across 2,300 km of the world’s largest coral reef ecosystem, Australia’s Great Barrier Reef (GBR). Using literature data, we characterized relationships between coral life history processes (reproduction, larval dispersal, recruitment, growth and mortality) and environmental variables. We then simulated coral demographics and stressor impacts at the organism (coral colony) level on >3,800 individual reefs linked by larval connectivity, and exposed to temporally- and spatially-realistic regimes of acute (crown-of-thorns starfish outbreaks, cyclones and mass coral bleaching) and chronic (water quality) stressors. Model simulations produced a credible reconstruction of recent (2008–2020) coral trajectories consistent with monitoring observations, while estimating the impacts of each stressor at reef and regional scales. Overall, corals declined by one third across the GBR, from an average ∼29% to ∼19% hard coral cover. By 2020, less than 20% of the GBR had coral cover higher than 30%. Global annual rates of coral mortality were driven by bleaching (48%) ahead of cyclones (41%) and starfish predation (11%). Beyond the reconstructed status and trends, the model enabled the emergence of complex interactions that compound the effects of multiple stressors while promoting a mechanistic understanding of coral cover dynamics. Drivers of coral cover growth were identified; notably, water quality (suspended sediments) was estimated to delay recovery for at least 25% of inshore reefs. Standardized rates of coral loss and recovery allowed the integration of all cumulative impacts to determine the equilibrium cover for each reef. This metric, combined with maps of impacts, recovery potential, water quality thresholds and reef state metrics, facilitates strategic spatial planning and resilience-based management across the GBR.

Estimates of sediment and nutrient loads in 10 major catchments draining to the Great Barrier Reef during 2006–2009

2012 ◽  
Vol 65 (4-9) ◽  
pp. 150-166 ◽  
Author(s):  
Marianna Joo ◽  
Myriam A.A. Raymond ◽  
Vivienne H. McNeil ◽  
Raethea Huggins ◽  
Ryan D.R. Turner ◽  
...  
Keyword(s):  
Great Barrier Reef ◽  
Nutrient Loads ◽  
Barrier Reef

Spatio-temporal variability in surface Chlorophyll distribution in the Central Great Barrier Reef as derived from CZCS imagery

1990 ◽  
Vol 41 (3) ◽  
pp. 313 ◽  
Author(s):  
AJ Gabric ◽  
P Hoffenberg ◽  
W Boughton
Keyword(s):  
Great Barrier Reef ◽  
Temporal Variability ◽  
Large Scale ◽  
Nutrient Loads ◽  
Barrier Reef ◽  
Phytoplankton Abundance ◽  
Wet Season ◽  
Chlorophyll Distribution ◽  
Consistent Feature ◽  
Spatio Temporal

A series of Coastal Zone Colour Scanner (CZCS) images has been used to compare the surface phytoplankton variation in the central Great Barrier Reef waters over the period 1979-81. Near- concurrent field data have been obtained for all the scenes so that approximate chlorophyll concentrations have been applied in the image classification. A consistent feature in the dry-season chlorophyll distribution is a cross shelf gradient with high chlorophyll levels inshore and lower levels in the mid-lagoonal waters increasing to higher concentrations in the reef matrix. The effects of higher nutrient loads in the wet season are also evident, although correlation between riverine discharge and phytoplankton abundance in the lagoon is problematic. In fact, a large scale 'bloom' event occurs before the start of the 1980-81 wet season and may be related to wind resuspension of sedimentary nutrients.

scholarly journals A spatial analysis of seagrass habitat and community diversity in the Great Barrier Reef World Heritage Area

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alex B. Carter ◽  
Catherine Collier ◽  
Emma Lawrence ◽  
Michael A. Rasheed ◽  
Barbara J. Robson ◽  
...  
Keyword(s):  
Great Barrier Reef ◽  
World Heritage ◽  
Environmental Data ◽  
Seagrass Habitat ◽  
Water Type ◽  
Barrier Reef ◽  
Seagrass Community ◽  
Eastern Australia ◽  
World Heritage Area ◽  
Heritage Area

AbstractThe Great Barrier Reef World Heritage Area (GBRWHA) in north eastern Australia spans 2500 km of coastline and covers an area of ~ 350,000 km2. It includes one of the world’s largest seagrass resources. To provide a foundation to monitor, establish trends and manage the protection of seagrass meadows in the GBRWHA we quantified potential seagrass community extent using six random forest models that include environmental data and seagrass sampling history. We identified 88,331 km2 of potential seagrass habitat in intertidal and subtidal areas: 1111 km2 in estuaries, 16,276 km2 in coastal areas, and 70,934 km2 in reef areas. Thirty-six seagrass community types were defined by species assemblages within these habitat types using multivariate regression tree models. We show that the structure, location and distribution of the seagrass communities is the result of complex environmental interactions. These environmental conditions include depth, tidal exposure, latitude, current speed, benthic light, proportion of mud in the sediment, water type, water temperature, salinity, and wind speed. Our analysis will underpin spatial planning, can be used in the design of monitoring programs to represent the diversity of seagrass communities and will facilitate our understanding of environmental risk to these habitats.

scholarly journals Diversity and Activity of Diazotrophs in Great Barrier Reef Surface Waters

2017 ◽  
Vol 8 ◽  
Author(s):  
Lauren F. Messer ◽  
Mark V. Brown ◽  
Miles J. Furnas ◽  
Richard L. Carney ◽  
A. D. McKinnon ◽  
...  
Keyword(s):  
Great Barrier Reef ◽  
Surface Waters ◽  
Barrier Reef

scholarly journals Diuron tolerance and potential degradation by pelagic microbiomes in the Great Barrier Reef lagoon

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1758 ◽  
Author(s):  
Florent E. Angly ◽  
Olga Pantos ◽  
Thomas C. Morgan ◽  
Virginia Rich ◽  
Hemerson Tonin ◽  
...  
Keyword(s):  
Great Barrier Reef ◽  
Relative Abundance ◽  
Rrna Gene ◽  
Barrier Reef ◽  
Marine Food Web ◽  
Herbicide Degradation ◽  
Long Term Effect ◽  
Reef Health ◽  
Agricultural Areas ◽  
The Impact

Diuron is a herbicide commonly used in agricultural areas where excess application causes it to leach into rivers, reach sensitive marine environments like the Great Barrier Reef (GBR) lagoon and pose risks to marine life. To investigate the impact of diuron on whole prokaryotic communities that underpin the marine food web and are integral to coral reef health, GBR lagoon water was incubated with diuron at environmentally-relevant concentration (8 µg/L), and sequenced at specific time points over the following year. 16S rRNA gene amplicon profiling revealed no significant short- or long-term effect of diuron on microbiome structure. The relative abundance of prokaryotic phototrophs was not significantly altered by diuron, which suggests that they were largely tolerant at this concentration. Assembly of a metagenome derived from waters sampled at a similar location in the GBR lagoon did not reveal the presence of mutations in the cyanobacterial photosystem that could explain diuron tolerance. However, resident phages displayed several variants of this gene and could potentially play a role in tolerance acquisition. Slow biodegradation of diuron was reported in the incubation flasks, but no correlation with the relative abundance of heterotrophs was evident. Analysis of metagenomic reads supports the hypothesis that previously uncharacterized hydrolases carried by low-abundance species may mediate herbicide degradation in the GBR lagoon. Overall, this study offers evidence that pelagic phototrophs of the GBR lagoon may be more tolerant of diuron than other tropical organisms, and that heterotrophs in the microbial seed bank may have the potential to degrade diuron and alleviate local anthropogenic stresses to inshore GBR ecosystems.

Targeting resource investments to achieve sediment reduction and improved Great Barrier Reef health

2013 ◽  
Vol 180 ◽  
pp. 148-156 ◽  
Author(s):  
M. Star ◽  
J. Rolfe ◽  
P. Donaghy ◽  
T. Beutel ◽  
G. Whish ◽  
...  
Keyword(s):  
Great Barrier Reef ◽  
Barrier Reef ◽  
Reef Health ◽  
Sediment Reduction
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