Investigating the IOT

Voyage Number

IN2022_V08

Voyage Dates

30 Sep, 2022 to 03 Nov, 2022

Voyage Location

Darwin to Fremantle

Chief Scientist

Dr Tim O'Hara

Institution

Museums Victoria Research Institute

View the full voyage

Voyage summary

Research voyage from Darwin to Fremantle, traveling via Christmas Island and Cocos (Keeling) Islands to complete a marine biodiversity survey of the Indian Ocean Territories (IOT) that belong to Australia. This voyage is the second voyage in a world-first biodiversity survey that started in 2021 on voyage IN2021_V04.

These voyages will provide vital data to support the management of the new marine parks that were established around these islands in March 2022.

Almost nothing is known about the biodiversity values of Australia’s IOT around the remote Christmas Island and Cocos (Keeling) Islands. This project will complete a world-first investigation of the marine biodiversity of the massive underwater mountains (seamounts) that make up these islands. These seamounts are mostly of late Cretaceous age (65-80 million years ago) and may harbour ancient endemic communities. Marine habitats on seamounts are also easily damaged by human activities and this voyage will gather important data for their conservation and management. An experienced team of scientists will describe the marine life from these remote seamounts, use advanced DNA techniques to study their origin, and evaluate the conservation significance of these unexplored habitats.

The voyage will be led by Dr Tim O'Hara from Museums Victoria Research Institute and is being conducted in partnership with Parks Australia, as well as leading Australian museums and research collections including the Australian National Fish Collection.

There are 2 other projects on this voyage:

• Bush Blitz outreach program (Kate Cranney, Department of Climate Change, Energy, the Environment and Water)
• Argo float deployments (Mr Craig Hanstein, CSIRO): Deployment of 4 standard Argo floats.

The science team on this voyage includes 32 participants from 7 institutions, including 3 Australian museums and 2 international research institutes.

Voyage outcomes

The waters of Australia’s Indian Ocean Territories (IOT) are little studied and differ from all other Australian maritime environments in that they are remote localities in the central-eastern Indian Ocean. This voyage, along with the associated voyage IN2021_V04 delivered in 2021, have now substantially increased understanding of the composition and distribution of seafloor ecosystems and fauna in the new Christmas Island and Cocos (Keeling) Island Marine Parks, which were announced by the Australian Government in 2021.

As a result of these two voyages, significant areas of seafloor in the region have now been mapped and more than 100 biodiversity surveys have provided a greater understanding of marine life in the region. Prior to these voyages, and except for inshore waters around the islands, very little was known about marine life in this region. The new knowledge and understanding will be vital for marine park manager, Parks Australia, which is responsible for development and delivery of management plans for the new marine parks.

Across the two IOT voyages, sixty-seven seafloor macrofaunal samples were obtained from 22 seamounts, the two island groups and the surrounding abyssal plain, collected at depths ranging from 94 to 5431 metres. Researchers identified 1059 taxonomic groups from the collected materials. Of these, only 47% could be identified to a described species (495 known species), 14% were identified as species new to science (149 new species), and the remainder require additional taxonomic work to determine whether they are new or known species. Decapods and fishes provided the most species collected, with ophiuroids (brittle stars) being the most abundant group overall.

Undoubtedly, numerous new invertebrate species will be described by taxonomists from this remote and under-sampled region.