FACT SHEETS -
CORAL REEF IMPACTS
21 CLIMATE CHANGE
• Scientific experts agree that the earth’s climate is warming, primarily due to increases in carbon dioxide emissions resulting from human activities. Coral reefs are particularly vulnerable to climate change due to their sensitivity to environmental conditions, and in particular increasing sea temperatures.
• Rising sea temperatures have led to an increase in the frequency and severity of coral bleaching. Coral bleaching occurs when coral is put under stress (such as a sustained increase in sea temperature above normal levels), which leads it to expel its algae (zooxanthellae). Corals can recover from bleaching, however if the stressor is not removed the coral will eventually die.
• Reefs in Australia have so far not been as badly affected as other global reefs (such as those in the Pacific) by bleaching; however in the mass bleaching events of 1998 and 2002, around 55% of the Great Barrier Reef suffered bleaching. Overall around 5% of the reefs were severely damaged. As sea temperatures are predicted to rise with global climate change in the future, coral bleaching is seen as one of the most serious threats to the long term health of the Great Barrier Reef
• However, increasing temperature is just one of the many effects of climate change on reefs. Ocean acidification, the increasing acidity of oceans due to increased absorption of carbon dioxide, could have negative consequences for oceanic calcifying organisms such as coral. In addition, rising sea levels could lead to large redistributions of benthic (bottom-dwelling) habitats and the animals that depend on them.
• The Great Barrier Reef Marine Park Authority has set up a Climate Change Response Program to respond to the challenges of global climate change.
• GBRMPA: http://www.gbrmpa.gov.au/corp_site/info_services/science/climate_change
• AIMS: http://www.aims.gov.au/pages/about/communications/waypoint/004/index.html
• The Australian Bureau of Meteorology (Climate change): http://www.bom.gov.au/climate/change/
• Climate change chronicles: http://www.climatechange.com.au/