Project 1.3 'Characterising the cumulative impacts of global, regional and local stressors on the present and past biodiversity of the Great Barrier Reef'

Project 1.3 'Characterising the cumulative impacts of global, regional and local stressors on the present and past biodiversity of the Great Barrier Reef'

Coral reefs are showing evidence of decline on local, regional and global scales. Historical overfishing, nutrient loading and terrestrial discharge, combined with more recent threats of global warming, coral bleaching, ocean acidification and disease have resulted in long-term losses of abundance, diversity and habitat structure. Since European settlement of the Queensland coastline in the mid-19th century, extensive land use changes in the GBR catchment region have occurred resulting from grazing, agriculture and land clearance. However, it has been difficult to ascertain the link between terrestrial discharge, water quality, global warming, ocean acidification and coral decline on a regional scale, and the contribution of anthropogenic influence to the disturbance regimes of inshore reefs remains highly controversial. Up until now, there has been no direct evidence of changes in coral community structure following European settlement. This is largely due to, (1) lack of a reliable chronological tool that can be used to correlate episodes of ecological change and degradation with potential stressors and to reconstruct long-term (millennial timescale) same-site records of coral community change that can provide baselines against which to compare recent coral community changes, and (2) the lack of clear understanding of various stressors and their past variability and cyclicity, as well as their future trends, including sea-level; El Niño-Southern Oscillation (ENSO) variability and related flood/drought cycles; cyclones; sea-surface temperature (SST), salinity (SSS) and alkalinity (or acidity); sediment/nutrient discharge; and pollution from coastal development.

Project objectives at a glance

Building on the success of several MTSRF projects, this project aims to:

  • Determine decadal death rates of inshore reef corals over the last 150 years (since European settlement).
  • Reconstruct reef accretion rates and coral mortality rates over the past 1-2 millennia.
  • Reconstruct the history of coral calcification.
  • Determine the variation in coral reef community structure prior to and after European settlement.
  • Quantify past sea-surface temperatures, salinity and El-Niño – Southern Oscillation (ENSO) variability and cyclicity prior to and after European settlement.
  • Reconstruct past sea-level variability based on high-precision dating and elevation survey of well-preserved fossil microatolls.
  • Reconstruct cyclone history and frequency over the past 1-2 millennia through precise dating of transported reef blocks, cyclone ridges and lagoon sediment cores.
  • Assess water quality change since European settlement based on geochemical proxy analyses of coral cores in close spatial association with palaeoecological data retrieved during the project.
  • Reconstruct past seawater alkalinity variation and recent acidification based on high-precision boron isotope analyses of selected coral cores.
  • Correlate palaeoecological changes with major natural climatic and anthropogenic disturbance events.
  • Assess the impacts on coral reef biodiversity and identify drivers of ecological change.

Specific objectives and intended outputs of this Project are detailed in the NERP TE Hub Multi-Year Research Plan.


Project Factsheet


 

Link to the Project 1.3 homepage on e-Atlas


 

Project Duration: 
1 Jul 2011 to 31 Dec 2014

 

Project Outputs