in 2011. Of the habitats that support marine turtles, the condition of seagrass meadows and coral reefs have declined significantly. While nesting habitats are generally in good condition, projected changes to environmental conditions such as sea level rise82 and increasing air temperature83 are predicted to affect them in the future.84 While the nesting habitats for seabirds remain in generally good condition, declines have been recorded for some seabird populations, in part related to declines in vegetation in nesting areas (for example on Gannet Cay) and food supplies to support reproduction (see Section 2.4.13). Two inshore dolphin species are known to be at risk, including through deterioration of their habitats. The humpback whale population is recovering strongly after being decimated by commercial whaling.85 Within the Region, their calving habitats are well protected. Plant diversity is generally well protected, with about one-third of the islands contained within national parks.
Integrity is an important prerequisite of outstanding universal value. At the time of inscription it was considered that to include virtually the entire Great Barrier Reef ecosystem within the property was a way of ensuring the integrity of the coral reefs in all their diversity.
Major impacts on the world heritage values arise from external pressures.
The property is of sufficient size to ensure the complete representation of the features and processes which convey its significance. It is vast, covering 14 degrees of latitude and extending 80 to 250 kilometres from the coast. Except for some small exclusions and about 600 of the 1050 islands, almost all of the World Heritage Area is within marine or national parks, and is therefore afforded a high level of protection and management. While some habitats, populations and processes are under pressure, the attributes of outstanding universal value remain largely intact overall. Factors external to the property — climate change, coastal development and land-based run-off — are affecting the ecosystem as are some impacts of direct use. Activities within the property are comprehensively managed and direct use is generally sustainable; the remoteness of some of the property poses challenges for managing agencies.
4.5.6 Benchmarking outstanding universal value
The Reef continues to include all attributes necessary to express its outstanding universal value.
Many of the attributes identified in the official statement of outstanding universal value of the world heritage property (Appendix 3) remain in good or very good condition. Those related to coral reef and seagrass meadow habitats, marine turtles, seabirds and dugongs are assessed as being in poor condition overall, but areas of good condition are still present in the Region (Chapters 2 and 3). Attributes relevant to Traditional Owner’s interaction with the environment are also assessed as being in generally poor condition (Section 4.2). The condition of about two-thirds of the 38 attributes identified as contributing to outstanding universal value has been assessed as having deteriorated since 1981.53 Examples include: • superlative natural beauty above and below the water • spectacular and globally important breeding colonies of seabirds and marine turtles • ongoing ecological processes such as upwellings, larval dispersal and migration • vegetation on cays and continental islands, exemplifying the important role of birds in seed dispersal and plant colonisation
The condition of many attributes has deteriorated since 1981.