An organic Geochemical analysis of Terrestrial biomarkers in a transect of the Great Barrier Reef Lagoon

1989 ◽  
Vol 40 (3) ◽  
pp. 275 ◽  
Author(s):  
BR Currie ◽  
RB Johns
Keyword(s):  
Great Barrier Reef ◽  
Barrier Reef ◽  
Terrestrial Organic Matter ◽  
Higher Plant ◽  
Pentacyclic Triterpenoid ◽  
Lipid Biomarker ◽  
Additional Input ◽  
Near Shore ◽  
Benthic Sediments ◽  
Geochemical Analyses

Organic geochemical analyses of benthic sediments from a Northern Queensland coastal transect indicate that most terrestrial organic material is confined to near-shore sediments (<10 km offshore). Traces of higher plant material reach the inner fringes of the Great Barrier Reef, as indicated by the presence of pentacyclic triterpenoid alcohols (PTA) in near-reef sediments. A likely source of these alcohols is mangroves. PTA and long-chain normal alkanes appear to be the most reliable of the lipid biomarker classes analysed in assessing the distribution of terrestrial organic matter along the transect. Other terrestrial biomarker classes (sterols, normal fatty acids and fatty alcohols) present in the sediment do not show good correlation with distance from the land. This is believed to be due to the additional input of these biomarkers from planktonic sources.

Influence of asexual reproduction on the structure and dynamics of Holothuria (Halodeima) atra and Stichopus chloronotus populations of the Great Barrier Reef

2001 ◽  
Vol 52 (2) ◽  
pp. 205 ◽  
Author(s):  
S. Uthicke
Keyword(s):  
Great Barrier Reef ◽  
Asexual Reproduction ◽  
Fission Products ◽  
Barrier Reef ◽  
Frequency Distributions ◽  
Near Shore ◽  
Wet Weight ◽  
Stichopus Chloronotus ◽  
Holothuria Atra ◽  
Individual Size

To determine the effect of asexual reproduction by transverse fission on the population structure of holothurians, ensities and individual weights of Holothuria atra (JÄÄger,1833)and Stichopus chloronotus (Brandt, 1835)were measured over a 26-month period on near-shore reefs of the Great Barrier Reef. Densities of H.atra (0.01—0.69 individuals m –2 )and S. chloronotus (0.11—1.67) did not increase during periods of intense asexual reproduction, and the density on each reef remained relatively stable.The effect of fission was clearly visible in the weight —frequency distributions of both species. The average individual wet weight in each population declined (H. atra from 105/134 g to 64/94 g in two respective populations;S. chloronotus from 128/302 g to 82/190 g in two respective populations) with the onset of fission in early winter, and more individuals in the weight range of fission products were found. The biomass followed the seasonal trend of the average weights for both species, with minimum values in winter. A conceptual model based on these and previous findings identified five possible factors (mortality, habitat stability, optimum individual size, food availability, larval supply) involved in promoting or repressing transverse fission, and the model indicated the consequences for the population.

Intra-annual variation in turbidity in response to terrestrial runoff on near-shore coral reefs of the Great Barrier Reef

2013 ◽  
Vol 116 ◽  
pp. 57-65 ◽  
Author(s):  
Katharina E. Fabricius ◽  
Glenn De’ath ◽  
Craig Humphrey ◽  
Irena Zagorskis ◽  
Britta Schaffelke
Keyword(s):  
Coral Reefs ◽  
Great Barrier Reef ◽  
Annual Variation ◽  
Barrier Reef ◽  
Terrestrial Runoff ◽  
Near Shore

scholarly journals Influence of marine biochemical cycles on seasonal variation of Ba/Ca in the near-shore coral Cyphastrea, Rat Island, southern Great Barrier Reef

2018 ◽  
Vol 499 ◽  
pp. 71-83 ◽  
Author(s):  
Narottam Saha ◽  
Gregory E. Webb ◽  
Jian-Xin Zhao ◽  
Nicole D. Leonard ◽  
Ai Duc Nguyen
Keyword(s):  
Seasonal Variation ◽  
Great Barrier Reef ◽  
Barrier Reef ◽  
Near Shore

scholarly journals pH homeostasis during coral calcification in a free ocean CO2 enrichment (FOCE) experiment, Heron Island reef flat, Great Barrier Reef

2015 ◽  
Vol 112 (43) ◽  
pp. 13219-13224 ◽  
Author(s):  
Lucy Georgiou ◽  
James Falter ◽  
Julie Trotter ◽  
David I. Kline ◽  
Michael Holcomb ◽  
...  
Keyword(s):  
Great Barrier Reef ◽  
Reef Flat ◽  
Co2 Enrichment ◽  
Barrier Reef ◽  
Ph Homeostasis ◽  
Skeletal Density ◽  
Constant Ph ◽  
In Situ Conditions ◽  
Ocean Carbon ◽  
Geochemical Analyses

Geochemical analyses (δ11B and Sr/Ca) are reported for the coral Porites cylindrica grown within a free ocean carbon enrichment (FOCE) experiment, conducted on the Heron Island reef flat (Great Barrier Reef) for a 6-mo period from June to early December 2010. The FOCE experiment was designed to simulate the effects of CO2-driven acidification predicted to occur by the end of this century (scenario RCP4.5) while simultaneously maintaining the exposure of corals to natural variations in their environment under in situ conditions. Analyses of skeletal growth (measured from extension rates and skeletal density) showed no systematic differences between low-pH FOCE treatments (ΔpH = ∼−0.05 to −0.25 units below ambient) and present day controls (ΔpH = 0) for calcification rates or the pH of the calcifying fluid (pHcf); the latter was derived from boron isotopic compositions (δ11B) of the coral skeleton. Furthermore, individual nubbins exhibited near constant δ11B compositions along their primary apical growth axes (±0.02 pHcf units) regardless of the season or treatment. Thus, under the highly dynamic conditions of the Heron Island reef flat, P. cylindrica up-regulated the pH of its calcifying fluid (pHcf ∼8.4–8.6), with each nubbin having near-constant pHcf values independent of the large natural seasonal fluctuations of the reef flat waters (pH ∼7.7 to ∼8.3) or the superimposed FOCE treatments. This newly discovered phenomenon of pH homeostasis during calcification indicates that coral living in highly dynamic environments exert strong physiological controls on the carbonate chemistry of their calcifying fluid, implying a high degree of resilience to ocean acidification within the investigated ranges.

scholarly journals Spatial and Temporal Variation in Fecundity of Acropora spp. in the Northern Great Barrier Reef

Diversity ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 60 ◽  
Author(s):  
Morgan S. Pratchett ◽  
Andrew S. Hoey ◽  
Chun-Hong Tan ◽  
Chao-Yang Kuo ◽  
Andrew G. Bauman ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Great Barrier Reef ◽  
Environmental Conditions ◽  
Coral Species ◽  
Outer Shelf ◽  
Life History Strategies ◽  
Spatial And Temporal Variation ◽  
Barrier Reef ◽  
Inner Shelf ◽  
Near Shore

The amount of energy invested in sexual reproduction by scleractinian corals depends on their life history strategies (i.e., allocation of energy between growth, reproduction, and maintenance). However, energy allocated to reproduction will also be affected by the amount of energy acquired and prevailing environmental conditions. Coral fecundity is therefore likely to vary spatially, especially along marked gradients in environmental conditions. One of the foremost gradients in reef structure and environmental conditions occurs with distance from the coast, whereby inner-shelf or near shore reefs are generally subject to higher levels of nutrients, sediments and pollutants, which often adversely affect reef-building corals. This study quantified fecundity (oocytes per polyp) for three species, Acropora nasuta, A. spathulata, and A. hyacinthus, at six locations in the northern Great Barrier Reef (GBR), encompassing inner-, mid- and outer-shelf reefs. Replicate colonies were sampled at each location prior to the predicted date of spawning in 2013 and 2014. Both shelf position and year were important factors explaining variation in fecundity for each of the three coral species. Most notably, there were clear and consistent declines in the number of oocytes between 2013 and 2014, coinciding with the incidence of category 4 Cylone Ita in early 2014. Contrary to expectations, polyp-level fecundity was no lower (and in some cases substantially higher) on inner-shelf reefs, compared to conspecifics growing on mid-shelf or outer-shelf reefs. The observed patterns are much more complicated than anticipated, necessitating further research to understand differential population dynamics of corals on inner-shelf versus mid- and outer-shelf reefs.

scholarly journals The Gogo Formation Lagerstätte: A view of Australia's first Great Barrier Reef

2021 ◽  
pp. jgs2021-105
Author(s):  
Kate Trinajstic ◽  
Derek E.G. Briggs ◽  
John A. Long
Keyword(s):  
Soft Tissue ◽  
Great Barrier Reef ◽  
Late Devonian ◽  
Tissue Preservation ◽  
Barrier Reef ◽  
Origin And Evolution ◽  
Canning Basin ◽  
Exceptional Preservation ◽  
Geochemical Analyses ◽  
And Cartilage

Discoveries from the Late Devonian Gogo Formation, in the Canning Basin, Western Australia have provided insights into the origin and evolution of many unique gnathostome features such as the origins of teeth, internal fertilisation, air-breathing, transitional tissues between bone and cartilage, and insights into the fin to limb transition. Although vertebrate studies have dominated evolutionary work, invertebrate studies have added important insights into the palaeoecology of the site and demonstrated close faunal affinities along the margins of northern Gondwana and China. Geochemical analyses have broadened the understanding of the pathways involved in the exceptional preservation of this Devonian Konservat-Lagerstätte. Fossils from the Gogo Formation show extensive soft tissue preservation through phosphatization recording anatomical details not normally obtained from fossil sites.

Sign in / Sign up

Export Citation Format

Share Document