Southern Ocean phytoplankton stimulated by wildfire emissions and sustained by iron recycling

Large ash plumes emitted by the 20192020 Australian wildfires were associated with a widespread phytoplankton bloom in the iron-limited Pacific sector of the Southern Ocean. In this study, we used satellite observations and aerosol reanalysis products to study the regional phytoplankton community re...

Full description

Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Weis, J, Schallenberg, C, Chase, Z, Bowie, AR, Wojtasiewicz, B, Perron, MMG, Mallet, MD, Strutton, PG
Format: Article in Journal/Newspaper
Language:English
Published: Amer Geophysical Union 2022
Subjects:
Earth Sciences
Oceanography
Chemical oceanography
Pacific
Southern Ocean
Online Access:https://doi.org/10.1029/2021GL097538
http://ecite.utas.edu.au/150790
Description
Summary:Large ash plumes emitted by the 20192020 Australian wildfires were associated with a widespread phytoplankton bloom in the iron-limited Pacific sector of the Southern Ocean. In this study, we used satellite observations and aerosol reanalysis products to study the regional phytoplankton community response to wildfire emissions. The bloom was stimulated by pyrogenic iron fertilization and coincided with elevated cellular pigment concentrations, increased photochemical efficiency, and apparent community structural shifts. Physiological anomalies were consistent with previously observed phytoplankton responses to iron stress relief and persisted for up to 9 months. Supported by a regional iron budget, we conclude that the bloom was sustained by iron recycling and episodic inputs of pyrogenic and dust-borne mineral iron. The continuous regeneration of iron was likely facilitated by the bloom's large size, mitigating edge dilution effects, as well as enhanced bioavailability of pyrogenic and mineral iron due to atmospheric and chemical processing during long-range transport.

Similar Items