GREAT BARRIER REEF
// Outlook Report 2014
9.3.5 Trends in risks to the Region’s values
The assessed risk for a number of the threats to the Region’s ecosystem has changed since the assessment presented in the Outlook Report 2009. These variations are indicated in Figure 9.4. The risks to heritage values were not assessed in 2009. Increases in assessed risk Generally, increases in the risk grade have been the result of increased understanding of the threat, its distribution and the likely severity of its consequences. For example, in 2009 the risk associated with sediments in land-based run-off was assessed as high (likelihood: almost certain, consequence: moderate), but is now assessed as very high (likelihood: almost certain, consequence: major) based on improved understanding of both the distribution and effects of sediments in the marine system and the likely lag time between decreases in the loads entering the Region and improvements in the Region itself10 (see Section 3.2.4). Similarly, improved understanding of crown-of-thorns starfish outbreaks (see Section 3.6.2), their frequency, causes and effects, has increased the grading of this threat since the Outlook Report 2009. The resulting risk has increased from high to very high. Increases in the assessed risk of clearing and modifying coastal habitats (from high to very high) and artificial barriers to flow (from medium to high) are a reflection of improved understanding of the importance of healthy habitats and ecosystem processes in coastal areas adjacent to the Region (see Section 3.5). The risk presented by altered weather patterns has also increased since 2009: partly because the threat definition has been broadened from just cyclones to effects on weather more generally; and partly because of improved understanding (see Sections 3.2 and 6.3). Knowledge in this area has grown through both research associated with the extreme weather experienced since 200911 and longer term studies demonstrating the significance of extreme weather in shaping the ecosystem 9,12,13. The risks associated with an outbreak of disease or species other than crown-of-thorns starfish have increased, mostly due to a decline in the overall condition of the ecosystem, making such outbreaks more likely and of greater significance (see Section 3.6.1). Incidental catch of species of conservation concern has an increased level of risk in the current assessment compared to 2009. The move from high to very high reflects improved knowledge about which species are at risk and the implications for some species of even small numbers of deaths (see Chapter 2 and Section 5.4). Illegal fishing and collecting was assessed separately from illegal poaching in 2009, but these illegal extraction activities are now considered as a group. The risk of illegal poaching of species such as dugong and turtles is likely to have decreased since the Outlook Report 2009 because of its focus in management (see Sections 5.9.3 and 7.4.2 ). However, the risk associated with illegal fishing and collecting has increased (see Section 5.4.3). The risk grading of very high recognises the serious effects illegal extraction has on the resilience of the ecosystem and reducing the effectiveness of management actions implemented for biodiversity protection. Reductions in assessed risk Improved understanding of the distribution of pesticides in the Region 9 (see Section 6.5.1) and of the effects of pesticides on both inshore habitats and adjacent coastal habitats (with flow-on effects on the Region’s values) has decreased the assessed risk associated with pesticides in landbased run-off from very high to high.
Increased risk Altered weather patterns Illegal fishing and poaching Incidental catch of species of conservation concern Modifying coastal habitats Outbreak of crown-of-thorns starfish Sediment in land-based run-off Barriers to flow Outbreak of disease Outbreak of other species