Scientists have found new evidence that desertification, potentially linked to global warming, leads to large amounts of nutrient-rich dust landing in the sea, causing ocean algae to grow rapidly. Biological oceanographer John A. Gittings and an international group of researchers have found an example of this phenomenon in the Indian Ocean south-east of Madagascar.
They analysed satellite images that showed how the colour of the sea in that area had changed over the years. Phytoplankton (microscopic algae found in the oceans) affect the colour of the water when they grow rapidly in response to higher levels of nutrients – including iron that’s found in dust. The researchers found that drought in southern Africa’s drylands had caused the strongest phytoplankton bloom in about 27 years, south-east of Madagascar.
