Impacts of aeolian dust deposition on phytoplankton dynamics in Queensland coastal waters

Abstract

Aeolian dust deposition has been shown to stimulate phytoplankton growth in various oligotrophic oceanic regions of the northern hemisphere. The present study investigated the relationship between the change in phytoplankton biomass in Queensland coastal waters and aeolian dust deposition during the severe October 2002 dust storm, using satellite-derived chlorophyll concentrations. A response in phytoplankton standing stock immediately following dust deposition from this event was found in the area of maximal dust deposition, as defined by a previous dust transport modelling analysis. Standing stock levels increased to 1.5-2 times the long-term mean. This is the first documented episode of a dust fertilisation event in Australian coastal waters and, given the high frequency of dust storms in northern Australia, demonstrates that aeolian delivery of nutrients may be an important factor in future regional nutrient budget analyses.