Outside of Australia, the continent of microalgae was born out of the smoke of “mega-fires” forests.

Between 2019 and 2020, Australia was caught in the most violent wildfire in its history. Three billion animals have been killed or displaced and 7 million hectares of forest have been cleared, which is one and a half times the area of ​​the EU. In addition, the smoke emitted more than 800 million tonnes of CO2, more than double the emissions generated by Australia over the course of a year.

In Sydney, this black cloud found on the Chilean coast across the Pacific Ocean also had an unexpected impact on marine life. The smoke has actually caused a microalgae called “phytoplankton” to bloom in the middle of the southern ocean, much larger than in Australia. It was revealed in a recent study published in the journal Science Nature. “There are small solid particles in the smoke of the fire, John Lord, one of the co-authors of this study, explains. “These are parts of unburned trees. They contain very little nitrate, substrate and especially iron. This water in the Pacific Ocean is very low. It causes a strong reaction on phytoplankton.”

This type of phenomenon has actually already been observed after fires but not in the middle of the ocean or on such a surface. Since then, these algae have disappeared because their lifespan is very short, but an event of such magnitude inevitably had consequences in this environment. In fact, researchers know that this phytoplankton, like all plants, absorbs carbon dioxide. They therefore consider that this algae formed by smoke from fire has absorbed the entire amount or part of the CO2 released into the atmosphere after the fire.

The question now is what became of this carbon dioxide after being absorbed by these plants. “There are two options, In advance John Lord. “LPhytoplankton may have been eaten by small animals. In this case CO2 was again converted into a gas, which was returned to the atmosphere, and had no buffer effect. ”

“Phytoplankton may have formed submerged deposits at the bottom of the ocean. In this case, carbon sequestration was an event that ended up at the bottom of the ocean and CO2 could stay there for hundreds or even billions of years.”

John Lord, researcher

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What happened in this particular case? It is unknown at this time what he will do after leaving the post. But this work will be deepened, especially by a team by boat to go and explore the bottom of this sea.