The Great Australian Deep-Sea Coral and Canyon Adventure

Rising water temperatures and increasing carbon dioxide concentrations remain among the greatest threats to ocean ecosystems globally. This warming trend and associated ocean acidification poses a unique threat to species that use calcium carbonate to build their shells or skeletons, such as corals. While significant research has been dedicated to examining the effects of changing ocean dynamics on coastal reefs – this January Dr. Julie Trotter, University of Western Australia, and her team, will join Falkor to look deeper.

This expedition will be of great significance, as SOI and the science team undertakes the first ROV-based deep sea exploration of submarine canyons that have formed offshore southwestern Australia. For the first time, these unique deep-sea canyons will be documented, imaged, and strategically sampled by ROV SuBastian. Sampling will not only be for identifying yet to be discovered species, but also to undertake comprehensive, high-resolution geochemical analyses of, for example, coral skeletons post-cruise. Deep-sea ROV technology is unavailable to Australian researchers, making this expedition a true voyage of discovery.

Maps of some main study sites: Bremer Canyon and nearby canyons of the Albany Group. Transect indicated by arrows, and nominal ROV dive sites and Rosette casts shown in red and blue. Maps from Exon et al., 20152 (top), Geoscience Australia (bottom).Exon et al. and Geoscience Australia

An Expedition of Epic Proportions
The area along the shelf-edge of southwestern Australia holds a number of unexplored submarine canyons that face the Southern Ocean region. The waters above the Bremer Canyon are known to be a hotspot of biodiversity that includes large marine mammals and seabirds, which has led to its establishment as a Commonwealth Marine Reserve. It is renowned for attracting congregations of the largest seasonal populations of killer whales in the Southern Hemisphere, which has become a significant tourist attraction.

Characterized by its steep-sided, interconnected system, this unexplored canyon offers great prospects for the discovery and exploration of new life within its deep-water habitats. In addition to genuine frontier exploration, key species, such as deep-water hard corals, are highly prized environmental archives that can provide invaluable ‘windows’ into the recent and geological past for understanding both long-term natural climate variations and how anthropogenic-driven climate change is impacting the deep oceans. Corals from the southwest Australian submarine canyons are especially significant given their proximity to the all-important Southern Ocean. The waters formed in the Southern Ocean feed all major ocean basins so play a central role in driving the global ocean-climate system.

The team is advancing the findings of their successful 2015 expedition to Perth Canyon, which offered significant optimism for finding prospective habitats, new species, and particular coral types suitable for proxy applications. In all, the team plans on visiting three submarine canyon systems: Bremer, Leeuwin, and Perth Canyons.

Extensive fossil coral graveyards – coral deposit remnants from the Last Glacial Maximum – were found at two locations in the Perth Canyon discovered during the 2015 Perth Canyon cruise.

Protecting Corals and Telling a Story
A primary focus will be to sample anticipated living and fossil deep-water corals from this region. The skeletons of these organisms will be used to reconstruct recent and long-term ocean environmental records as there are large gaps in “climate proxy” records, and instrumental ship-based data is very limited covering only the past few decades. The coral skeletons can provide continuous records of important environmental variables, including fluctuations in the temperature of these deeper oceans, pH, nutrients, and dissolved calcium carbonate concentrations. These records can span decades, centuries and even millennia, and help to elucidate not only changes in the ocean-climate system but also the inherent vulnerability of corals and other calcifiers to extreme conditions.

In addition to characterizing a genuine frontier, the data collected from these deep-water corals and their surrounding environments will allow scientists to develop an understanding of the physical and temporal changes occurring in the Southern Ocean. Only recently has it been realized that the formation of the deeper water masses of the Southern Ocean hold the key to unlocking the response of the global ocean-climate system to both climate and environmental change. The acquisition of baseline data obtained from these deeper water masses of the canyons thus provides a unique window into both the recent and geological past. The answers found can have major implications both regionally and worldwide, such as helping to predict the effects on deep-sea calcifiers and their ecosystems, and for modeling future climate change scenarios and their potential impacts on society.

Cruise Log

February 29, 2020

Data & Publications

Annotated imagery is available in Squidle+. [You may have to create a username and password to access full capabilities]. To view images from this cruise, click SELECT DEPLOYMENTS, and choose FK200126.

ADCP data has been processed and archived by UHDAS.

Environmental sensor data is archived at Rolling Deck to Repository.

ROV data, Falkor navigation, Google Earth visualizations, and processed multibeam is archived at MGDS.

Preliminary physico-chemical water column data collected from CTD casts, can be found in this spreadsheet.

Processed multibeam data is archived at MGDS.

Water Column Chemistry Data has been archived at Australian Ocean Data Network.

30 day Preliminary Post Cruise Report: The Great Australian Deep-sea Coral and Canyon Adventure
Final Cruise Report: ROV Exploration of Deep-water Coral Habitats of Southwest Australian Submarine Canyons
Beaman, R., Picard, K., and Miller, A. (2022). RV Falkor Surveys in Australia 2020-2021. Oral Presentation and Conference Paper, Hydrospatial 2021 Conference, Australasian Hydrographic Society, Cairns, Australia. [Abstract and presentation are OPEN ACCESS].
Trotter, J., McCulloch, M., D'Olivo, J., Tisnérat-Laborde, N., Taviani, M., and Montagna, P. (2022). Deep-water Coral Records of Glacial and Recent Ocean-atmosphere Dynamics from the Perth Canyon in the Southeast Indian Ocean. Quaternary Science Advances, 6, doi: 10.1016/j.qsa.2022.100052. [This articel has been published OPEN ACCESS].
Trotter, J., Taviani, M., Foglini, F., Sadekov, A., Skrzypek, G., Mazzoli, C., et al. (2022). Unveiling Deep-sea Habitats of the Southern Ocean-facing Submarine Canyons of Southwestern Australia. Progress in Oceanography, 209, doi: 10.1016/j.pocean.2022.102904. [This article has been published as OPEN ACCESS with support from SOI].
Taviani, M., Foglini, F., Castellan, G., Montagna, P., McCulloch, M., and Trotter, J. (2023). First assessment of anthropogenic impacts in submarine canyon systems off southwestern Australia. Science of the Total Environment, 857 (1), doi: 10.1016/j.scitotenv.2022.159243. [This article has been published as OPEN ACCESS with support from SOI].
Stewart, A., Pietsch, T., Moore, J., Peng, X. (2023). Upside-down swimming: in situ observations of inverted orientation of Gigantiactis, with a new depth record for the Ceratioidei. Journal of Fish Biology, doi: 10.1111/jfb.15609.

Live ROV Footage

ROV SuBastian live footage from Bremer, Leeuwin, and Perth Canyons

30 day Preliminary Post Cruise Report: The Great Australian Deep-sea Coral and Canyon Adventure
Final Cruise Report: ROV Exploration of Deep-water Coral Habitats of Southwest Australian Submarine Canyons
Beaman, R., Picard, K., and Miller, A. (2022). RV Falkor Surveys in Australia 2020-2021. Oral Presentation and Conference Paper, Hydrospatial 2021 Conference, Australasian Hydrographic Society, Cairns, Australia. [Abstract and presentation are OPEN ACCESS].
Trotter, J., McCulloch, M., D'Olivo, J., Tisnérat-Laborde, N., Taviani, M., and Montagna, P. (2022). Deep-water Coral Records of Glacial and Recent Ocean-atmosphere Dynamics from the Perth Canyon in the Southeast Indian Ocean. Quaternary Science Advances, 6, doi: 10.1016/j.qsa.2022.100052. [This articel has been published OPEN ACCESS].
Trotter, J., Taviani, M., Foglini, F., Sadekov, A., Skrzypek, G., Mazzoli, C., et al. (2022). Unveiling Deep-sea Habitats of the Southern Ocean-facing Submarine Canyons of Southwestern Australia. Progress in Oceanography, 209, doi: 10.1016/j.pocean.2022.102904. [This article has been published as OPEN ACCESS with support from SOI].
Taviani, M., Foglini, F., Castellan, G., Montagna, P., McCulloch, M., and Trotter, J. (2023). First assessment of anthropogenic impacts in submarine canyon systems off southwestern Australia. Science of the Total Environment, 857 (1), doi: 10.1016/j.scitotenv.2022.159243. [This article has been published as OPEN ACCESS with support from SOI].
Stewart, A., Pietsch, T., Moore, J., Peng, X. (2023). Upside-down swimming: in situ observations of inverted orientation of Gigantiactis, with a new depth record for the Ceratioidei. Journal of Fish Biology, doi: 10.1111/jfb.15609.

Breakfast with Josh Szeps (starts at 2:56:15)

ABC Radio Sydney • January 8, 2020