Widespread phytoplankton blooms triggered by 2019–2020 Australian wildfires

Climate-change-driven warming is leading to more frequent and intense wildfires. The aerosol emitted by fires can relieve nutrient limitations and, consequently, enhance marine productivity, but direct observations are lacking. In this study recently published in Nature, the authors used remote and in-situ data to evaluate the effect of 2019–2020 Australian wildfires aerosols on marine life. We find anomalously widespread phytoplankton blooms in the Southern Ocean, thousands of kilometres downwind of Australia. Aerosol samples originating from the Australian wildfires contained a high content of soluble iron and atmospheric trajectories showed that aerosols were likely to be transported to the bloom regions, suggesting that the blooms were resulted from the fertilization of the iron-limited Southern Ocean waters.

Reference: Tang, W., LIort, J., Weis, J., et al. (2021). Widespread phytoplankton blooms triggered by 2019–2020 Australian wildfires. Nature, 597, 370–375.  https://doi.org/10.1038/s41586-021-03805-8.