Desert and anthropogenic mixing dust deposition influences microbial communities in surface waters of the western Pacific Ocean

• Published in: The Science of the total environment 2021-10, Vol.791, p.148026-148026, Article 148026
• Main Authors: Maki, Teruya, Lee, Kevin C., Pointing, Stephen B., Watanabe, Koichi, Aoki, Kazuma, Archer, Stephen D.J., Lacap-Bugler, Donnabella C., Ishikawa, Akira
• Format: Article
• Language: English
• Subjects: Aerosol deposition; Asian dust; Bacteria; Oligotrophic ocean; Phytoplankton
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2021.148026

The western Pacific Ocean is particularly affected by dust aerosols due to the transport of desert-natural sand and industrially derived particulate matter with aerodynamic diameter < 2.5 μm (PM2.5) from continental Asia. Both oligotrophic and nutrient-sufficient surface water occurs in this region and these are speculated to support different microbial community dynamics. Here, we report evidence from four shipboard experiments in the western Pacific Ocean supplying oligotrophic and nutrient-sufficient surface waters with aerosol particles obtained from the nearby coastal mountains, to simulate dust and anthropogenic aerosol inputs in the ocean region. A sharp increase in nitrate for surface waters after addition of dust aerosols resulted in large increases in diatom abundance in oligotrophic waters, whilst in nutrient-sufficient waters the response of diatom population was reduced. The increase in organic matter provided by aerosol inputs and/or increase in phytoplankton biomass induced the growth of heterotrophic prokaryotes, such as Rhodobacteraceae and Alteromonadaceae populations, in both oligotrophic and nutrient-sufficient seawater. Anthropogenic and desert-natural dust is an important source of nitrate and organics to oceanic waters and such inputs can directly affect primary production and heterotrophic prokaryotic abundance in the ocean, implying consequences for the carbon cycle in these aerosol-affected waters. [Display omitted] •Shipboard assessments for the aerosol-deposition influencing oceanic microorganisms.•Snow solution containing anthropogenic and desert dust particles was added to seawater.•Nitrate by aerosol deposition enhanced the diatom growth under oligotrophic condition.•Organics associated with aerosol deposition changed the oceanic bacterial compositions.