The Great Barrier Reef: Threats and Management

1. The Great Barrier Reef: Threats and Management Rhys Murray, Anthea Shedley, Lucya Roncevich, Colin Hedderwick, Luke Sullivan and Adam Bartle

2. Introduction • Threats and Prioritisation • Issues Explained • Management • Recommendations

3. Threats and Prioritisation Note: Consequence classified using scale of 15; Where 1= complete extinction, 3= local irreversible damage, 5= Minor Damage.

4. Water Quality • The Burdekin catchment is a major source of Water Quality pollutants and is ranked as the most significant risk are in the total GBR catchment. • Contributes ~ 6 x 106 tonnes of sediment per annum (approximately 40% of total GBR catchment input) • Contributes ~ 40,000 tonnes on Nitrogen and 15,000 tonnes of Phosphorus per annum

5. Causes….

6. Sediment Impacts on the Great Barrier Reef • Smothering by settlement • Turbidity inhibiting photosynthesis and growth • However a natural turbidity gradient exists – some corals are more resilient than others

7. Nutrient Impacts on the Great Barrier Reef • Increased phytoplankton growth (leads to an increase in filter feeders and bivalves, which compete for space) • Macro-algae blooms (overgrow coral and shade them out) • Faster Coral Growth (less dense and weaker skeletons are more prone to storm damage) • Inhibition of Fertility rates

8. Fishing • The GBR sustains a $250 million fishing industry • Trawling (8,200 tonnes) • Reef-line (Commercial 3000 – 4000 tonnes, Recreational estimated at 2000 tonnes)

9. Shipping • The GBRMP facilitates Australia’s major commercial trading routes, and contains five out of six of Queensland’s major ports • Approximately 6000 ships greater than 50m length pass through the reef per year • Damage is done to the reef through fire, grounding, sinking and spills • Oil spills pose the greatest risk for point-source pollution from boating

10. Coral Bleaching

11. Coral Bleaching Causes: - Elevated Sea Temperatures - High Light Intensity - Low Salinity - Pollutants In recent years high sea temperatures have been the major cause of coral bleaching

12. Crown of Thorns

13. Crown of Thorns Is it a problem????

14. Current Management • Many regulatory bodies involved in the management of the GBR i.e. Commonwealth Government, GBR Marine Park Authority, Australian Fisheries Management Authority etc. • Consequently, management policies often overlap or leave out important threats to the GBR in the current statutes.

15. Current Management • Current management fails to adequately address the issue of water quality. • Zoning aims to balance reasonable human use with the maintenance of natural and cultural integrity • Mandatory pilotage of vessels through navigationally hazardous areas and reducing traffic through high risk areas

16. Current Management • No current polices to prevent coral bleaching • To hard to manage due to the fact that global management is required to prevent rising sea temperatures. • Crown of thorns is hard to manage and its effect on the reef is unsure in the longterm

17. Recommendations • Agriculture in the GBR catchment should be managed as a source of diffuse pollutants, particularly in relation to controlling agricultural practice in the sugarcane and beef grazing industry. • Trash blanketing • Ground cover • Certain areas should have certain practices made mandatory, not voluntary, with cost incentives for encouragement as 90% of pollutants come from 30% of the GBR catchment area.

18. Recommendations • Fishing is currently regulated fairly effectively. • Improvements to the system could be made: • Detailed stock analysis in different areas • Valid logbook catch recording system • Analysis of mortality rates from trawling • Spatial partitioning to reduce over fishing certain areas

19. Recommendations • Shipping is already highly monitored. • Improvements to the system could be made: • Reducing total boating hours within the reef • Upgrading navigational charts • Restricting the size of boats using high risk areas • Improve education of recreational boat users about, ballast water, sewerage, and litter

20. Recommendations • Improve public awareness on the impacts of global warming with respect to coral bleaching on the GBR “every little bit helps” • Continue crown of thorns starfish research and monitoring

21. Application to Ningaloo

22. Application to Ningaloo • Ningaloo is a completely different system to the GBR • Existing threats are different • Leads to different management policies

23. Application to Ningaloo • Water Quality pollution is limited to point sources, such as effluent waste, as there is no significant river system leading to the diffuse leaching of sediment and nutrients into the reef environment. • Over fishing and shipping are believed to have greater effect on the reef as the reef is restricted to small localised patches. Over fishing and localised boating pollution can hence play a significant role in reducing reef biodiversity.

24. Application to Ningaloo • Bleaching is potentially more disastrous, as reefs are isolated limiting regrowth after bleaching events. • Crown of Thorns is present in small patches but is effect is once again unknown.

25. Conclusion “Thanks for Listening”