Big Bank Shoals of the Timor Sea


Mapping the Big Bank Shoals has helped AIMS build a comprehensive picture of these remote seabed ecosystems, providing an important baseline for monitoring the impacts of the oil and gas industry, as well as environmental conditions.

BHP Petroleum supported the project, which began with the interpretation of images and data from industry surveys, and created the Big Bank Shoals of the Timor Sea: an environmental atlas.

This resource atlas was the foundation for a long-term research program that has seen AIMS gradually build knowledge of the shoals—and successful industry partnerships.

Big Bank Shoals are submerged carbonate banks in the Timor Sea, which rise up from depths of 200 to 300 metres to within 20 to 30 metres below sea level. They are found where the Australian Continental Shelf deepens steeply towards the Timor Trough, off the north-west coast of Australia.

Prior to AIMS’s research, many Big Bank Shoals had not been studied because the region was too remote.

AIMS’s initial research revealed that life on the Big Bank Shoals differed greatly from that found on the seabed of the surrounding continental shelf waters.

Greater light penetration and more nutrients supported a range of biological communities on the Big Bank Shoals. The study highlighted three distinct ecosystem types on the shoal plateaus:

  • the Halimeda algae–dominated ecosystem, which is the dominant type for the area
  • the coral-dominated ecosystems, which are restricted to the shallower bank regions
  • the filter-feeding ecosystems, which consist of sponge types and soft corals such as gorgonians, and which dominate the deeper banks due to light restrictions.

In 2011 AIMS worked with PTTEP Australasian Ltd to map nine Big Bank Shoals and assess the long-term impact of the 2009 Montara Well Head Platform uncontrolled oil release.

This Montara study built substantially on the pioneering work of the Big Bank Shoals project, providing confirmation that the submerged banks and shoals of Australia’s north-west are important ecological features, often supporting very high levels of diversity.