Coral reefs can cope with natural disturbances like floods and cyclones, however extreme intensity weather is rare and often causes severe and widespread damage that takes decades to recover.
Floodwaters running off the land and into the Great Barrier Reef lagoon can form reduced-salinity plumes laden with nutrients, sediments and agricultural chemicals such as fertilisers and pesticides.
Many animals and plants that inhabit coral reef ecosystems can be stressed or killed through reduced salinity, increased turbidity and elevated concentrations of nutrients and agricultural chemicals.
Some species can benefit from the increased input of materials like nutrients, leading to excessive productivity in certain groups, such as algae, which can create imbalances in the system.
Tropical cyclones are major structuring forces on coral reefs, causing extensive damage to individual corals and to the structure of the Reef.
Between 1995 and 2009, approximately 34 per cent of all coral mortality recorded in the Great Barrier Reef Long-term Monitoring Program (by the Australian Institute of Marine Science) was caused by storm damage.
Extreme intensity systems such as cyclone Yasi are particularly important influences on coral reefs, as they can have impacts that affect large areas and last for decades, if not centuries.
Impacts on communities
Communities and industries can be impacted by Reef damage after extreme weather events through:
- reduced catch rates for some commercial fishing sectors
- damage to reef and island sites important for fishing and tourism activities
- reduced vessel access to some locations due to debris
- decreased destination appeal due to media coverage of extreme weather impacts.
We have collaborated with the CSIRO and James Cook University on research to better understand the social and economic impacts of extreme weather on industries.
This information helps Reef-based industries understand the risks associated with extreme weather, and to support efforts to build their resilience to the predicted impacts of climate change.
Great Barrier Reef Extreme Weather Program
We implemented the Great Barrier Reef Extreme Weather Program after the 2010–11 summer. The program was funded through the Australian Government and involved a range of partners, including the Queensland Government, reef industry groups and research agencies.
The program assisted us to understand what extreme cyclones and floods mean for the Reef and the people who depend on it. It also helped target efforts to support recovery of damaged areas and build the resilience of the Reef over the longer term.
The Extreme Weather and the Great Barrier Reef Report presents key findings from the program and profiles management and stewardship efforts put in place to help the Reef cope with the after-effects of extreme weather.
The report also provides an overview of extreme weather in the context of climate change and the long-term outlook for the Reef and its management.