Authors: Beaman, R.J.
Publication: Poiner, I., and Kitazawa, K., eds., Second Australia-Japan Marine Science Forum, 27-30 October 2008, Australian Institute of Marine Science, Townsville, Australia.
A future Australian-Japan marine expedition could build directly on the already funded ‘Deep Australia’ ARC Discovery project, as well as the completed RV Southern Surveyor cruise (Sep-Oct 2007) to the GBR margin and Coral Sea. These projects investigate the succession of drowned fossil coral reefs and terraces located on the deep outer shelf and fore-reef slopes (40-300 m) of Ribbon Reef 5 and Osprey Reef. Located on a stable tectonic margin and platform, the GBR and Coral Sea drowned reefs are ideally situated to address fundamental questions about the nature and mechanisms responsible for abrupt sea-level, climate and ecological changes in the GBR region over the last 20 kyr.
Note the Ribbon Reef 5 site is now the focus of an IODP coring program scheduled in late 2009. The fossil reefs likely grew and died repeatedly in response to periods of extreme environmental stress, and an investigation of these features is an opportunity to establish a framework with which to better predict and manage the response of the modern GBR to future global climate changes. Further, the fossil reefs provide a stable and hard substrate for the attachment of dense assemblages of sessile benthos.
Therefore, an Australian-Japan marine expedition utilising high-resolution geophysical data and groundtruth underwater video and rock samples would help define the age, composition and origin of the fossil reefs and terraces, and assess their importance as growth substrates and habitats for modern biological communities. The key aims of a future project would be to:
- Define the distribution, composition and origins of the fossil reefs and terraces to understand the relationship of these features to past sea-level and climate variability.
- Establish the composition, extent and processes that control the modern biological communities associated with the fossil reefs and terraces.