Great Barrier Reef

Assembled from 25 blocks · 3 evidence · 16 related

1. Story
2. The largest coral reef system on Earth, running roughly 2,300 kilometres along the Queensland continental shelf and comprising on the order of three thousand individual reefs and several hundred islands. The Great Barrier Reef Marine Park, the management unit, covers about 344,400 square kilometres. It is not one reef but a shelf-edge system whose reefs sit at different distances from shore and behave differently: inshore reefs take the river runoff, mid-shelf reefs the crown-of-thorns outbreaks, outer reefs the open-ocean swell. Two features make it the most important reef in this Journey. It has been continuously surveyed since 1985 under a single monitoring programme, so its coral cover is one of the few long time series of reef condition anywhere. And it is the reef where recurrent mass bleaching was first documented at whole-system scale, in 2016 and again the following year, on a shelf where the previous assumption had been that the far northern reefs were remote enough to be safe.
3. Knowledge
4. Great Barrier Reef
5. Connections
6. Coral Triangle
7. Mesoamerican Barrier Reef System
8. Crown-of-thorns starfish (Acanthaster)
9. Australian Institute of Marine Science
10. Great Barrier Reef Marine Park Authority
11. Great Barrier Reef Marine Park Act creates a single managing authority
12. The Great Barrier Reef is inscribed on the World Heritage List
13. Mass synchronous spawning described on the Great Barrier Reef
14. The Long-Term Monitoring Program begins annual reef surveys
15. A measured decline in Great Barrier Reef coral calcification is published
16. Twenty-seven years of monitoring show coral cover roughly halved
17. Mass bleaching on the Great Barrier Reef
18. A second consecutive year of mass bleaching on the Great Barrier Reef
19. Mass bleaching on the Great Barrier Reef during a La Nina
20. The fifth mass bleaching on the Great Barrier Reef since 2016
21. The current state of the fourth global bleaching event is not established in this package
22. Evidence
23. The Great Barrier Reef was inscribed on the World Heritage List as a natural property in 1981. V55 verification basis: NOT retrieved; the inscription year and the property's status are stated from the producing model's knowledge of the World Heritage record. The property reference number is given as it is held and should be checked.
24. In the 2016 Great Barrier Reef bleaching event only a small minority of the more than eleven hundred reefs surveyed escaped bleaching, with the most severe bleaching in the northern third of the system, and water quality and past exposure did not protect reefs from it. V55 verification basis: not consulted; the survey design and headline result are stated from the producing model's knowledge, and the precise escaped-reef percentage is given as "around nine per cent" rather than to a decimal place.
25. Mean hard coral cover on surveyed Great Barrier Reef sites fell from 28.0 per cent in 1985 to 13.8 per cent in 2012, with roughly forty-eight per cent of the loss attributed to tropical cyclones, forty-two per cent to crown-of-thorns starfish and ten per cent to bleaching. V55 verification basis: not consulted; the cover figures and the three attribution percentages are stated from the producing model's knowledge of this widely cited result.