1. Is the Great Barrier Reef facing a significant environmental threat? Peter Ridd School of Engineering and Physical Sciences James Cook University, Townsville, 4811. [email_address]

3. Image from Tim

5. Threat 1: Sediment Input

6. Newspaper Headline

9. Inshore corals are well adapted to high sediment loads

11. Paluma Shoals Very high turbidity during strong wind events

12. Image from Tim

16. Sydeny harbour has a flushing time of 250 days. It is highly susceptible to pollution

17. The GBR lagoon is relatively open to the coral sea and has a short residence time A couple of weeks for the main reef matrix A couple of months for inshore regions

19. Photo: Paul Marshall. Threat 3: Global Warming The influence of coral bleaching We must provide “resilience” for GW. Links all other supposed stressors to GW.

24. Corals: Canary or

25. 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)

26. 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.

27. In other parts of the world, measuring that the coral reefs have been damaged is not “difficult to detect”

29. Salinity IS destroying major ecosystems. These systems are collapsing

30. Noxious weeds ARE choking our water ways and displacing native ecosystems. These systems ARE collapsing

31. Introduced species are changing marine and terrestrial ecosystems

32. Urban sprawl and growing population is destroying prime land near cities