African Dust Deposition Triggers Unprecedented Phytoplankton Bloom Near Madagascar

Rising temperatures are intensifying droughts in drylands, increasing dust emissions from arid regions. These dust aerosols, often rich in nutrients, travel vast distances and settle on the ocean's surface, enhancing ocean productivity. This study highlights how dust from drought-stricken Southern Africa was wet-deposited in nutrient-poor waters southeast of Madagascar, triggering an unusually strong phytoplankton bloom. The event occurred at an unexpected time of year, but with climate change potentially driving higher dust emissions, such blooms may become more frequent. These events may have broader implications for marine ecosystems and global carbon cycles. If we are to forecast the evolving functional role of oceans in a warmer Earth, it is necessary to improve our understanding of the interlinked feedback loop between land, atmosphere, and ocean processes.
Reference: Gittings J.A., Dall'Olmo G., Tang W., et al. (2024). An exceptional phytoplankton bloom in the southeast Madagascar Sea driven by African dust deposition. PNAS Nexus, 3(10): 386. https://doi.org/10.1093/pnasnexus/pgae386