The expedition Under The Pole left Concarneau in 2017 and a book is coming out this week to retrace these four years of exploration of the seabed.
After a first mission dedicated to the study of biofluorescence and bioluminescence, the expedition continued in French Polynesia with a scientific program called Deep hope. For nearly 18 months, divers observed mesophotic corals, those found between 30 meters and 150 meters deep. The objective was to understand and find a solution to the destruction of surface corals.
During the mission, the team dived more than 800 times and collected more than 4,000 samples. At 172 meters deep, in the Gambiers archipelago, divers have successfully collected the deepest photosynthetic scéractiniaire coral ever found.
“Contrary to popular belief, the greatest coral diversity is not found on the surface, but beyond 30/40 meters depth, explains Ghislain Bardout. When we observe coral bleaching, we realize that the phenomenon is much more important near the surface than in great depths “, he continues.
These mesophotic corals, which live in complete darkness, are just as varied as those found on the surface but much more resilient in the face of climate change. In fact, we realize that in the darkness of the depths, the coral adapts and transforms to capture the maximum amount of light. An important discovery because the study and understanding of this mesophotic zone suggests that it can be a kind of climatic refuge for biodiversity.
“Coral reefs are home to 25% of the ocean’s diversity.”
Explorer and diver Ghislain Bardoutto franceinfo
For the explorer, it is urgent for man to release the pressure he exerts on the planet to preserve biodiversity. “All the children in the world have had a teddy bear or a stuffed seal, but today they are highly endangered”, he said.
The Under The Pole team designed and tested an underwater capsule that allows you to stay underwater for three days, without having to come back to the surface, which allows you to observe the flora and fauna up close. .
Today, explorers are considering building a new boat to replace the schooner “Why”. A larger boat capable of accommodating a recompression chamber on the deck for divers.
