Considerable work has been done in defining the thermal tolerance of coral reefs on the Great Barrier Reef, but until now there’s been little focus in this area on Australia’s other coral reef environments. This programme looks beyond the GBR to investigate other Commonwealth MPAs in the northeast and northwest of Australia.

Dr Ray Berkelmans from AIMS leads a team that established a large-scale temperature monitoring program (in conjunction with the Great Barrier Reef Marine Park Authority and CRC Reef) in the Commonwealth’s largest MPA, the Great Barrier Reef, using small low-cost data loggers. "Apart from building a library of long-term temperature trends, the information from the GBR logger programme has been used (in conjunction with bleaching surveys and satellite imagery) to explain patterns in bleaching. Combined with automatic reef weather station information we have been able predict present-day bleaching risk and seasonal bleaching forecasts," Dr Berkelmans said.

Dr Berkelmans said many of the Commonwealth MPAs are remote and very isolated and provide few opportunities to make direct observations over extended periods of time to monitor changes in the reef environment. "However, in recent times, temperature has become one of the easiest and cheapest environmental parameters to measure routinely and unattended."

The data loggers are capable of storing up to 21 months of data on sea temperatures at half-hourly intervals (or 42 months at hourly intervals). Retrieval and exchange of the loggers will take place every 1 to 3 years.

Funding from the Department of the Environment and Heritage has enabled the data logger network to be expanded to Coringa-Herald, Lihou Reef, Elizabeth and Middleton Reefs, Ashmore Reef and Cartier Island National Nature Reserves.

"The aim in the near future is to expand the programme to include all tropical Commonwealth MPAs, including Lord Howe Island Marine Park, Solitary Islands Marine Reserve in the east, and Mermaid Reef National Nature Reserve and Ningaloo Marine Park in the west. Further work will build on existing programmes where appropriate.

"Temperature is the most important environmental factor governing the distribution and abundance of organisms. Corals in particular have very narrow tolerance limits, and those limits vary with respect to location, species, depth (unconfirmed), micro-habitat and season.

"Small deviations outside their tolerable range cause corals to bleach (stress) and intense and/or sustained deviations can cause them to die."

Apart from climate change and bleaching studies temperature data are also useful for numerous other studies including fisheries productivity and movement, turtle nesting success, seabird population declines, seagrass productivity and dieback and ballast water risk assessment Dr Berkelmans said. "Data from the loggers on sub-surface sea temperatures can be used to supplement information on sea surface temperatures and habitat mapping from satellite images. It helps to provide a clearer understanding of what’s happening in remote locations without need for frequent trips to the sites".

"This improved understanding will contribute to evaluating effectiveness of management strategies and will support and strengthen management decisions for these MPAs in the future," Dr Berkelmans said.

The data from the GBR logger programme are available on the AIMS website, along with data from loggers in Queensland ports and the Solitary Islands. Currently the database houses 12.5 million records and is by far the most comprehensive temperature monitoring programme in Australia.