Sea temperatures

Building a comprehensive database of sea temperatures from around tropical Australia

Seawater temperature is the most important environmental variable governing the abundance and distribution of life in our coastal seas.

Reef corals, in particular, have a very narrow range of temperature tolerance, and this tolerance can vary according to geography, temperature levels and duration of exposure.

For example, corals at Magnetic Island in the central Great Barrier Reef can happily stand 30.5 °C for 20 days, but just 90 kilometres away at Davies Reef the same species of corals will bleach within a day, and at Great Keppel Island in the southern Great Barrier Reef they would be dead within a day.

The world is changing and understanding how conditions change is critical to understanding the future of our reefs. We need reliable baseline data from a range of locations to predict the impact of future climate scenarios.

Our research

AIMS’s Sea Temperatures program uses a range of technologies, from temperature loggers to satellite images, to build a comprehensive database of baseline water temperatures. It also brings together data from a range of projects, including the Integrated Marine Observing System.

AIMS has been recording sea temperature data since 1987, and our resulting research has linked an increase in the frequency of mass coral bleaching events, coral disease outbreaks, and plagues of crown-of-thorns starfish to prolonged exposure to warm sea temperatures.

We are also using the data to develop ocean temperature climatologies for specific locations. These climate studies show the historical water temperatures as averages and minimum–maximum ranges, allowing us to identify long-term water temperature trends. This helps us to understand how temperature varies from year to year, as well as from decade to decade.

For example, in the Torres Strait we use climatologies to understand current conditions in an historical context.

Modelling programs such as eReefs also use this data to identify times and places of unusual water temperatures, and the University of Queensland uses our data to report conditions for the Great Barrier Reef.

Lastly, we use the sea surface temperature data to calibrate temperature reconstructions from coral cores and satellite imagery, and also to better understand other biological processes, such as coral growth and reproduction, on coral reefs.

Sea temperature data is recorded from locations at:

  • 80 Great Barrier Reef sites
  • 16 Coral Sea sites
  • 7 north-west Australia sites
  • 8 Queensland regional ports
  • 13 Solitary Islands sites
  • 4 Papua New Guinea sites
  • 10 Cocos (Keeling) Islands sites.