(La Seyne-sur-Mer) The crane gently lowers the small white and yellow “rover” mounted on caterpillars to the bottom of a test basin at the Ifremer center in La Seyne-sur-Mer.
On their screens, engineers and scientists check the operation of the cameras of BathyBot, which will soon be the first underwater mobile device in the world permanently installed at a depth of 2,500 meters, to unravel the mysteries of the abyss.
“We know less about the deep ocean than the Moon”, explains Christian Tamburini of the CNRS, researcher at the Mediterranean Institute of Oceanology. “We don’t know what’s going on there or what organisms live there.”
It must be said that the environment is hostile. The average depth of the oceans, which cover 70% of the earth’s surface, is 3800 meters. From 180 meters, darkness sets in. And at 1000 meters, it’s total darkness, “the dark ocean”.
As a result, most scientific research is done in the layers near the surface, where life is concentrated.
But at a time of climate crisis, it is vital to understand the changes that warming is causing to the oceans and how it will affect these natural carbon sinks, which sequester almost a third of the CO2 emitted by humans.
Thanks in particular to BathyBot, “we will be able to study what is produced on the surface and what happens to the bottom”, enthuses Christian Tamburini.
Another primary objective is to understand the biodiversity of the abyss, a poorly known reservoir of life, even as scientists believe that the “sixth mass extinction” has begun.
see in the dark
The CNRS, as part of a European project, and in collaboration with the public institution Ifremer, will therefore deploy, 40 kilometers off the coast of Toulon, the deepest permanent observation platform in the world. There is only one other, Canadian, less than 800 meters “only”.
The French project took advantage of the existence in the area of an “underwater telescope” that hunts cosmic particles. And already served by a permanent cable for electricity and data, on which they will be grafted.
This new observatory will be deployed from January 31 to February 14 by the Why not, flagship of the French oceanographic fleet, with the Nautile submarine.
And he will therefore have as an emblematic figure, equipped with a Twitter account @bathybot to popularize his finds, the little “rover”. One meter twenty long by one wide and 90 centimeters high.
It bears only a distant resemblance to its space exploration cousins: instead of solar panels it is powered by a cable, a “leash” which also collects its data, but limits its range to 50 meters , which it travels very slowly.
A distance that can later be increased, with the hope that one day he can even be autonomous. Provided that you solve your orientation difficulties, because no GPS at less than 2500 meters! One possibility would be to plant stakes with QR codes telling him where he is.
It will be accompanied by static equipment lowered at the same time: a radiometer (radioactivity), a biocamera to capture in particular bioluminescence phenomena, a seismograph and the BathyReef, a “bio-inspired” artificial reef.
This concrete structure, just over 4 meters long and 2.5 wide, rises gently up to 1.5 meters in height. It will offer BathyBot a point to climb to widen its field of vision.
Its semi-open structure, with numerous crevices, will allow life forms to settle there, and to study the reactions of others to this obstacle.
Another essential part of the device, the “scientific junction box”. A sort of (large) intelligent power strip that supplies electricity, connects at high speed and monitors all the instruments of the station.
“We will be able to connect equipment to the bottom of the water, remove it, all controllable from land”, explains Jan Opderbecke, head of the Undersea Systems unit for the Ifremer fleet.
BathyBot will be reassembled every two years and will then be able to receive new tools, for example to allow “micro-coring” in the sediment soil on which it will evolve.
The expected service life is at least five to ten years. Something to shed some light on the “dark ocean”.