In our efforts to mitigate the effects of climate change, we will need allies like brown algae. The natural world offers us options that can present themselves in unlikely ways…
Brown algae absorb large amounts of carbon dioxide from the air to grow before releasing some of that absorbed carbon into the environment in the form of a mucus called fucoidan.
Fucoidan remains difficult for sea creatures to break down, meaning that the CO2 absorbed in this way by the algae remains locked in for centuries and the algae act as effective carbon sinks.
German scientists at the Max Planck Institute for Marine Microbiology in Bremen have estimated how much CO2 brown algae absorb. They found that algae can remove up to 550 million tons of carbon dioxide from the air each year.
Brown algae outgrow forests
That’s almost all of Germany’s annual greenhouse gas emissions. In fact, say scientists, brown algae surpass forests in their carbon storage capacity and can therefore “play a decisive role for the atmosphere and our climate“.
Specifically, Buck-Wiese and his colleagues estimate that brown algae absorb 1 gigaton, billion tons of carbon a year from the air. This means that brown algae sequester up to 0.15 gigatons of carbon in the long term, equivalent to 0.55 gigatons of carbon dioxide, each year.
Meanwhile, Germany’s annual greenhouse gas emissions are around 0.74 gigatons of carbon dioxide, according to official 2020 figures.
the seaweed”they release up to a third of the carbon they absorb into seawater, for example, in the form of sugary excretions. Depending on the structure of these excretions, they are quickly used by other organisms or sink to the bottom of the sea.”, explain the scientists.
“Brown algae excretions are very complex and therefore incredibly difficult to measure.”, adds Hagen Buck-Wiese, the first author of a recently published study about the discoveries. “However, we managed to develop a method to analyze them in detail.”.
seaweed mucus
This method allowed the German scientists to examine substances such as fucoidan, responsible for about half of the excretion of the species of brown algae under study, commonly known as bacillus.
Bladderwrack is a type of seaweed with help-filled pods that allow it to float and grow on the North Atlantic and Pacific coasts of the United States and the North Atlantic and Baltic coasts of Europe. It has long been used for medicinal purposes.
“Fucoidan is so complex that it is very difficult for other organisms to use it. no one seems to likesays Buck-Wiese. “This makes brown algae particularly good helpers in removing carbon dioxide from the atmosphere in the long term, over hundreds or thousands of years.“.
ecoportal.ner