Scientists are delighted with the diversity of species observed in deep in the Indian Ocean off the coast of Western Australia.
A paper from the Minderoo-University of WA Deep-Sea Research Centre reveals what was found during a survey of the Wallaby-Cuvier Escarpment in 2021.
Researchers used a small submarine to explore the escarpment, a 700-kilometre-long rise connecting the Perth Abyssal Plain – an area 5,500-metres deep – to the 3,000m-deep Cuvier Plateau.
The area, about 500km west of Carnarvon, was surveyed so that researchers could observe whether there were changes in the bottom-dwelling creatures as the landscape transitioned from plain to plateau.
Todd Bond from the research centre said there were three main types of habitat encountered.
"You've got the flat muddy sea floor, you've got the debris field at the bottom of the slopes, and then you've got the slope or the cliff itself," he said.
"We get different organisms living in those different environments.
"There's sea cucumbers, there's anemones, there's corals.
"It may not look as colourful as a coral reef but certainly the diversity of organisms and the diversity of function of those organisms is very, very high."
'Quite incredible'
There were 52 different organisms – morphotaxa – spotted in the three hours of surveying the researchers did at the escarpment.
Dr Bond said despite the level of diversity there were fewer different creatures than in other parts of the ocean.
"[But] to be able to go on a dive for a couple of hours and see 52 different species of organisms across about a three hour survey is quite incredible," he said.
"Some of them are also probably not described … and this is from eight phyla.
"We're talking the difference between a worm versus a fish versus a sponge."
The research is part of broader work undertaken by the research centre to learn more about the depths of the world's oceans.
The information gathered will help to determine areas for future conservation and marine parks.
The under-explored south-east of the Indian Ocean is a point of focus.
Researchers from the centre will also be taking trips to Tonga and other parts of the Pacific this year, as well as more visits off the Perth and Gascoyne coasts.
