The Influence of p CO 2 -Driven Ocean Acidification on Open Ocean Bacterial Communities during A Short-Term Microcosm Experiment in the Eastern Tropical South Pacific (ETSP) off Northern Chile

• Published in: Microorganisms
• Main Authors: Paulina Aguayo, Víctor L. Campos, Carlos Henríquez, Francisca Olivares, Rodrigo De Ia Iglesia, Osvaldo Ulloa, Cristian A. Vargas
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2020
• Subjects: ocean acidification; bacterial composition; microcosm; bacterial diversity; metagenomics; Biology (General); QH301-705.5; Pacific; Ocean acidification
• Online Access: https://doi.org/10.3390/microorganisms8121924; https://doaj.org/article/794d075aac484ec5b0a573d439ad15c8

Due to the increasing anthropogenic CO 2 emissions, Ocean Acidification (OA) is progressing rapidly around the world. Despite the major role that microorganisms play on the marine biogeochemical cycling and ecosystem functioning, the response of bacterial communities upon OA scenarios is still not well understood. Here, we have conducted a detailed characterization of the composition and relative abundance of bacterial communities in the water column of an open-ocean station in the Eastern Tropical South Pacific (ETSP) off northern Chile and their interactions with environmental factors. In addition, through a short-term microcosm experiment, we have assessed the effect of low pH/high p CO 2 conditions over the abundance and genetic diversity of bacterial communities. Our results evidence a clear partitioning of community composition that could be attributed mostly to dissolved oxygen. However, our experimental approach demonstrated that low pH/high p CO 2 conditions might modify the structure of the bacterial community, evidencing that small changes in pH may impact significantly the abundance and diversity of key microorganisms. This study constitutes a first step aiming to provide insight about the influence of changing carbonate chemistry conditions on natural bacterial communities and to shed light on the potential impact of OA in biogeochemical cycles on the ETSP region.