Brown algae slime is not a favourite dish. Algae take up carbon dioxide from the atmosphere and use the carbon to grow. They release up to a third of the carbon they absorb back into the seawater. Depending on the structure of these excretions, they are either quickly used by other organisms or sink towards the seafloor. The excretions of brown algae are very complex and therefore incredibly complicated to measure, With the method, the researchers scrutinised a large number of different substances. As a result, the carbon from the fucoidan does not return to the atmosphere quickly. This makes the brown algae particularly good helpers in removing carbon dioxide from the atmosphere in the long term -- for hundreds to thousands of years. Brown algae could bind almost all of Germany's carbon dioxide emissions. Brown algae are remarkably productive. It is estimated that they absorb about 1 gigaton (one billion tons) of carbon per year from the air.  And the growth of the brown algae is not affected by the carbon losses.