Illuminating Biodiversity of the Ningaloo Canyons

Biodiversity hotspots
The remote Western Australian coast (Eastern Indian Ocean) is known for its extensive karst system (sharp limestone ridges and towers in the landscape that are formed by erosion) and network of subterranean water bodies, supporting an incredible diversity of evolutionarily significant fauna. In stark contrast, the deep sea environment adjacent to this celebrated area remains almost unexplored. Major patterns of marine biodiversity appear to be strongly related to temperature, so exploring marine areas near known terrestrial hotspots offers an effective strategy for identifying undiscovered biodiversity. To counter the information deficit found in Western Australian coast, the interdisciplinary team on this expedition plans to actively survey a significant and biologically unexplored submarine canyon, Cape Range Canyon.

To get a true understanding of the area's diversity, the science team will complement ROV SuBastian video surveys and collections with eDNA. This inventory will be helped by the use of eDNA (Environmental DNA), which refers to all the genetic material that can be recovered from an environmental sample. This cutting-edge technique can detect traces of animals left behind that may not be encountered during surveys and will serve as a comparison to more traditional techniques.

Mapping to Lead the Way
The ROV sampling will be guided by experts, as opposed to ‘blind’ grabs or trawls. This allows significant improvements in collection success, as well as re-collection on subsequent dives, and less environmental impacts. The team will also expand on the baseline seafloor mapping in the Gascoyne Marine Park to develop the regional context of canyon habitats in which to interpret the faunal inventory.

When the ROV is not in the water, R/V Falkor’s EM302 deepwater multibeam system will be used to map the seafloor. The resulting continuous high-resolution bathymetry and backscatter of the entire Cape Range Canyon (from head to abyssal fan) will help characterize habitats from which fauna are sampled.

The resulting faunal inventory is fundamental to a better understanding from which more robust ecological approaches can be developed. These areas are usually overlooked when policies are made. North-western Australian deep sea environments are broadly impacted by extraction by oil and natural gas industries. These industrial impacts are ‘out of sight, out of mind’, and an overall lack of understanding of these environments inhibits conservation actions. Understanding what biodiversity occurs in these zones is paramount to activating effective management processes.