Wind-blown dust from the Sahara, a desert spanning across North Africa, is crucial for ocean life, a new study revealed on September 20. The secret is in the iron carried by Saharan dust which helps tiny ocean plants, known as phytoplankton, grow. In their study, titled «Long-range transport of dust enhances oceanic iron bioavailability», and published by Swiss peer-reviewed, open-access, scientific journals publisher Frontiers, scientists explain that the growth of phytoplankton influences how much carbon dioxide (CO2) is removed from the atmosphere and stored in the ocean. «Iron, a limiting micronutrient for phytoplankton growth, is fundamental in regulating ocean primary productivity and in turn the global carbon cycle», reads the study. Although it is still unknown how the iron from Saharan dust becomes usable in the ocean, scientists studied sediments from four locations and tracked the distance from where Sahara dust is blown. Findings show that the farther the dust travels, the more usable the iron becomes, but much of it is lost once it settles in the ocean. «Spatial trends do, however, suggest increasing Fe bioavailability with increasing distance of atmospheric transport, and our sediments also indicate the loss of this Fe and thus potential bioavailability utilization once deposited in the ocean», the study concluded. This study highlights how important iron is for ocean ecosystems, especially in places like the Southern Ocean, where it could play a key role during different climate periods.
