Coral reefs are the global canaries, as they are already showing rapid responses to climate change at the global scale. Scientists, managers and policy makers can use reefs to examine the effectiveness of international attempts to understand and respond to the impact of global warming
Corals are a tropical species. Most of the species found on the Great Barrier Reef (GBR), for example, are also found in areas with much warmer water. (2) Corals have been around for over 200 million years. (Hotter and colder) (3) Coral tissue thickness increased with temperature. (4) In 1998 and 2002,most of the reef did not bleach and almost all that did bleach has almost fully recovered.
Based on limited research to date, clear impacts of enhanced runoff of sediments, nutrients and contaminants (as a result of landuse) on coral reefs of the GBR ecosystem have proven difficult to detect. (Reef CRC, 2001)
GBR Consensus Statement 2009 Analysis of the latest available evidence leads us to conclude: 1.Water discharged from rivers to the GBR continues to be of poor quality in many locations. 2. Land derived contaminants, including suspended sediments, nutrients and pesticides are present in the GBR at concentrations likely to cause environmental harm. 3. There is strengthened evidence of the causal relationship between water quality and coastal and marine ecosystem health. 4. The health of freshwater ecosystems is impaired by agricultural land use, hydrological change, riparian degradation and weed infestation 5. Current management interventions are not effectively solving the problem. 6. Climate change and major land use change will have confounding influences on GBR health. 7. Effective science coordination to collate, synthesise and integrate disparate knowledge across disciplines is urgently needed.
In other parts of the world, measuring that the coral reefs have been damaged is not “difficult to detect”