Dust particles from the Sahara have an unexpected impact on the oceans. These tiny grains carry essential nutrients for marine life. Their journey across the Atlantic could play a key role in global climate.
A recent study reveals that the iron transported by these dust particles changes depending on the distance traveled. The farther it gets, the more "bioreactive" it becomes, meaning more available to marine organisms. This phenomenon could have major implications for ecosystems.
Illustration image: Pixabay
Iron is a crucial micronutrient for the photosynthesis of phytoplankton. These organisms play a pivotal role in carbon capture, a key process for climate regulation. However, not all the iron carried by these dust particles is immediately available to marine organisms.
According to researchers, iron particles undergo chemical transformations during their transport in the atmosphere. These reactions make iron more accessible to marine organisms. The findings were obtained through the analysis of sediment cores collected in the Atlantic Ocean, at varying distances from the African coast.
These sediments, dating back 120,000 years, allowed scientists to observe variations in bioreactive iron concentration depending on the distance dust traveled. Isotopic analyses confirmed the Saharan origin of the iron and highlighted changes in its chemical form.
The results show that the proportion of bioreactive iron decreases the farther one moves from Africa, as the iron is absorbed by marine organisms. These chemical transformations, influenced by the atmosphere, allow the iron to be assimilated by phytoplankton before reaching the sea floor.
Thus, distant regions like the Amazon basin or the Bahamas receive iron that is more easily soluble, promoting marine life. This phenomenon, akin to natural fertilization, could significantly impact both terrestrial and marine ecosystems.
This discovery could help better understand how nutrients transported over long distances influence ecosystems and global climate cycles.