By: Dr Laetitia Gunton, Category: AMRI, Date: 13 Aug 2018
New worm species have been discovered thousands of metres below the ocean surface in the Australian eastern abyss
Over four hundred marine worms living on the deep-sea floor in the Australian abyss have been identified to species level at the Australian Museum. New species were discovered and information on how these species are distributed in the deep sea has been gathered. This is the first investigation on deep-sea marine worms from the Australian eastern abyss.
The abyss is the least understood and sampled of any Australian environment. The abyssal environment is defined as the area between 3501 to 6500 m water depth, in total it makes up around 30% of Australia’s marine territory (42.8 million km2). The Australian eastern abyss starts relatively close to the shore, on average only 15 km, despite this before 2017 only three biological samples had been collected from Australia’s eastern abyss, these were collected by Russian and New Zealand vessels in 1976 and 1982 respectively.
In 2017 the national research vessel Investigator with forty scientists on board including three scientists from the Australian Museum (Frank Kohler, Lauren Hughes, and Elena Kupriyanova) took part in the pioneering expedition, ‘Sampling the Abyss’. The ship voyaged from Tasmania to Southern Queensland, the total distance covered was 3,489 nautical miles (6461 km or 1163 nautical leagues). The expedition attracted a lot of international media attention; you may remember the faceless cusk fish (Typhlonus nasus) and the peanut worm!
Using trawling nets towed off the side of the ship marine organisms were sampled from the deep-sea floor at two different depths, 2500 m and 4000 m. A large number of different organisms were recovered including crustaceans, fish, starfish, molluscs and many more. The marine worms collected, in particular the polychaetes or bristle worms, from the expedition were sent to the Australian Museum. My colleagues at the Australian Museum (Elena Kupriyanova, Pat Hutchings, Anna Murray, Hannelore Paxton), a visiting research scientist from China (Jinghuai Zhang), a colleague from Museums Victoria (Robin Wilson) and I have all been collaborating together to identify the worms to species level. This is not an easy task considering the worms have been dredged up from thousands of metres below the ocean surface and then preserved in chemicals such as ethanol or formalin. However, we were able to capture some fascinating images of these worms.
To date we have discovered around 90 species, many of them new to science, the next task is to formally describe the deep-sea critters, this involves comparing their physical characteristics with other similar species and performing molecular analyses to understand their genetic diversity. Another interesting finding was that these marine worms (polychaetes) appear to have very large species ranges, two species Ampharetidea sp. C and Laetmonice yarramba were both found from Fraser Island, Southern Queensland all the way along to Tasmania.
I presented these findings during a talk in the Deep Seas session at the Australian Marine Science Association (AMSA) conference in Adelaide last month. This was a great opportunity to highlight to scientists from all over Australia, the great work that is being done by scientists and volunteers at the Australian Museum. Furthermore in September this year, my colleague, Elena Kupriyanova, will present the results to leading scientists from all over the world, at the international Deep-sea Biology conference in California.
The abyssal environment makes up a third of Australia’s marine territory, yet it has been extremely poorly studied. The cruise ‘Sampling the Abyss’ has given us a brief glance into the environment off the east coast of Australia. New species of worm have been discovered, many of which have large distributions along the eastern Australian shelf. What else lies in the Australian abyss, who knows perhaps a roaming Nautilus?!
Dr Laetitia Gunton, Volunteer, Australian Museum Research Institute