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Tabulate Acropora corals from John Brewer Reef, a midshelf reef in the Central GBR, at the beginning of in water bleaching survey transects following the peak of heat stress in April 1 2017. Moderate levels of bleaching with no visible mortality at this reef. Photo credit: Neal Cantin, AIMS.

News

Oceanographic drivers of bleaching in the Great Barrier Reef: from observations to prediction

A new project is looking to understand how local or reef scale, regional and global oceanographic and meteorological processes influence the severity and spatial variability of thermally driven coral bleaching.

Mass coral bleaching has occurred on the Great Barrier Reef (GBR) and Torres Strait in 2016 and 2017 as part of a continuous global bleaching event that started in late 2014 (NOAA). The combined effect has meant that the majority of the reef has been severely affected.

A new project using IMOS data is looking to understand how local or reef scale, regional and global oceanographic and meteorological processes influence the severity and spatial variability of thermally driven coral bleaching. By doing this a better appreciation of which parts of the reef are more tolerant (or fortunate) and therefore more likely to retain their health into the future can be used to better manage the GBR. 

The three-year project is funded under the National Environmental Science Programme (NESP) Tropical Water Quality Hub and is being undertaken by researchers from Australian Institute of Marine Science (AIMS) and CSIRO in partnership with the Bureau of Meteorology (BoM) and National Oceanic and Atmospheric Administration (NOAA).

The project is structured in three main components:

1 Summary of oceanographic conditions during the 2015-17 bleaching years

All available relevant environmental observations of the recent bleaching events will be gathered to be more easily discoverable to researchers and managers via a gateway/summary webpage. These include hundreds of temperature loggers deployed along the GBR by AIMS, weather stations and the use of IMOS remote sensing, moorings and glider deployments. This publicly available and quality-controlled data set will allow the most comprehensive understanding yet of how individual coral reefs faired.

2 Hydrodynamics of bleaching and improved understanding The data will be used to improve the current understanding of the relationship between heat stress and bleaching response from repeated in situ observations of coral health and also assess how well the eReefs models perform and analyse the hydrodynamic reasons behind the variations of response. 3D versions of remotely sensed bleaching products by NOAA’s Coral Reef Watch and BoM ReefTemp will be produced.

3 Improved seasonal predictions of marine heatwaves in the GBR

A seasonal prediction capability for marine heatwaves will be developed in partnership with BoM. This is being developed as a tailored research product to assist GBR management of developing marine heat waves and will utilise BoM’s next generation seasonal prediction model ACCESS-S.

This news item was written by Craig Steinberg (AIMS)

Categories:  news, Facility, Satellite Remote Sensing, Ocean Gliders, National Mooring Network, Node, Q-IMOS, Home Slider

Water column profiles of temperature from Palm Passage mooring for the period October 2016 to April 2017. Cool water bottom intrusions are evident through the summer period (left) and Glider temperature transects across the continental shelf between Cooktown and Cairns between 22 March and 12 April 2016 (right). Click on image to enlarge.

IMOS OceanCurrent images of the Coral Sea and GBR on 15 March 2017. Satellite altimetry 30 day sea level anomaly product (left) and the Monthly average SST anomaly with derived geostrophic velocity from altimetry overlain (right). Click on image to enlarge.