Risks to the Region’s values
Unchanged risk levels Notably, the risks associated with some threats have remained the same despite an increase in the causes of the threats. For example, because of improvements in the management of shipping in the Region (both implemented and pending as outlined in the draft NorthEast Shipping Management Plan), the likelihood of a serious shipping incident such as a large vessel grounding or a large oil and chemical spill has remained unchanged, despite the significant increase in shipping traffic (see Sections 5.8 and 7.3.7).
For some threats, management changes have kept the risk stable.
The continued strong management of direct uses such as commercial marine tourism has resulted in associated threats, such as small vessel grounding and damage to reef structure from anchoring, snorkelling and diving activities, remaining unchanged (see Section 7.3.1). The risks associated with the legal extraction of the Region’s resources (for example herbivores and predators) have remained stable overall. For the threat of extraction of predators, the assessed risk is stable; the threat is a combination of two previous threats — extraction of top-order predators and extraction of lower order predators. There is a worldwide increase in marine debris and increased understanding of domestic contributions and dispersal (see Section 6.6.2). The risk to the Region’s values from marine debris continues to be high and is unlikely to decrease in the immediate future.
The overall risk to the Reef from small vessel groundings remains low
Undetermined changes in risk Dredging and disposal threats were considered together in 2009. These risks were separated for this assessment given the different management approaches and understanding of the effects of each activity. Historically, capital dredging activities did not occur every year. While the permitted amount of dredging has increased since the Outlook Report 2009 and is projected to continue to increase in the coming decade, its consequences to the Region’s ecosystem are constrained to the area around the dredged footprint. The frequency of disposal and resuspension of dredge material (from both capital and maintenance dredging) is likely to increase with continued development and expansion of ports in the coming decade. The risk level of ‘high’ for disposal and resuspension reflects increases in the likely future trends in volume of material requiring disposal, uncertainty of its potential effects on the ecosystem, and the need for strengthened monitoring of the effects of this threat (see Sections 5.5, 6.6, 7.3.4).
9.3.6 Effectiveness at managing threats
As was the case in the Outlook Report 2009, the origins of many of the highest risk threats are outside the Region (either global or within the Great Barrier Reef catchment). The effectiveness of their management (Figure 9.5) was independently assessed as some of the weakest, especially in terms of outcomes (see Chapter 7). Overall risk associated with climate change and land-based run-off has remained very high and high, respectively, since 2009. The effectiveness of management in relation to climate change has weakened in relation to context, planning, inputs, processes and outcomes (see Section 7.3.9), while positive gains have been made in planning, processes and outputs for management around land-based run-off (see Section 7.3.11).