GREAT BARRIER REEF
// Outlook Report 2014
Engagement-related measures include: • Guidelines and codes of conduct, for example best practices for snorkelling, diving and anchoring • implementation of activities to improve water quality by reducing the run-off of nutrients, sediments and pesticides (including under the Reef Water Quality Protection Plan 2013 (Reef Plan)45 and the Australian Government Reef Programme) • implementation of a crown-of-thorns starfish control program • development of industry-led guidelines for aquarium supply collection practices46. Knowledge, innovation and integration measures include: • research and monitoring to assess impacts and monitor ecosystem condition33,47,48,49 • social and economic long-term monitoring program50 • development of new incident response plans for coral disease, bleaching and tropical cyclones51,52,53 • significant expansion and integration of the Eye on the Reef program components and data management platform • assessment and improved understanding of terrestrial ecosystem function and processes important to the long-term health of the Great Barrier Reef38. The biodiversity conservation strategy, the starfish control program, the stewardship guidelines, social and economic monitoring, incident response plans, expansion and integration of the Eye on the Reef program and improved understanding of coastal ecosystems have all been introduced since the Outlook Report 2009. Evidence for recovery Recent analysis has shown significant declines in hard coral cover on the Great Barrier Reef (see Figure 2.5 and Figure 8.2).39 However, there is evidence that healthy reefs can recover after disturbances at local scales.54 Reefs that are dominated by fast-growing coral species, such as the Acropora-dominated reef flats around the Keppel Islands, showed remarkably rapid initial recovery following substantial mortality induced by coral bleaching in 2006.54 However, continued recovery has since been suppressed by a combination of exposure to flooding, minor storms and ongoing incidents of coral disease.55,56 In 2012, the reefs in Keppel Bay were in poor condition, with little evidence of recovery, including little or no signs of recruitment (settlement of coral larvae and abundance of juvenile corals).55 This recent trend of declining recovery potential is evident along the inshore area from reefs in the Keppel Bay area to those adjacent to the Wet Tropics (Figure 8.2).36 Despite evidence that inshore reefs had remained healthy over many hundreds of years prior to European settlement57, these reefs are now being gradually but seriously damaged by disturbances occurring at a frequency that allows little or no time for recovery.55 The decline in coral cover and lack of recovery coincides with degraded water quality as a result of land clearing, land use changes and agricultural use of the catchment.57 The overall condition of inshore reefs in the Wet Tropics region has continued to decline from 2010 to 2013 (Figure 8.2).36 The causes of this decline vary spatially. Some Wet Tropics sub-regions experienced high levels of coral disease in 2010 and 2011 which resulted in slow rates of coral cover increase that, in combination with crown-of-thorns starfish outbreaks, has reduced overall coral cover.36 The density of juvenile corals has also declined to low levels.
A wide range of measures address coral reef protection.
Average hard coral cover has declined; there is some evidence of recovery at a local scale.
Outbreaks of crown-of-thorns starfish are a major cause of reduced coral cover
© Chris Jones