Coastal Bacterial Community Response to Glacier Melting in the Western Antarctic Peninsula

• Published in: Microorganisms
• Main Authors: Alcamán-Arias, María Estrella, Fuentes-Alburquenque, Sebastián, Vergara-Barros, Pablo, Cifuentes-Anticevic, Jerónimo, Verdugo, Josefa, Polz, Martin, Farías, Laura, Pedrós-Alió, Carlos, Díez, Beatriz
• Other Authors: Agencia Nacional de Investigación y Desarrollo (Chile), Fondo Nacional de Desarrollo Científico y Tecnológico (Chile), Ministerio de Economía y Competitividad (España), Instituto Antártico Chileno
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Multidisciplinary Digital Publishing Institute 2021
• Subjects: Glacial melting; Bacterial microbial community; Coastal Antarctic zone; Antarctic; Antarctic Peninsula; Greenwich; Greenwich Island; Inach; The Antarctic; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/10261/227855; https://doi.org/10.3390/microorganisms9010088; https://doi.org/10.13039/501100002850; https://doi.org/10.13039/501100003329

© 2021 by the authors. Current warming in the Western Antarctic Peninsula (WAP) has multiple effects on the marine ecosystem, modifying the trophic web and the nutrient regime. In this study, the effect of decreased surface salinity on the marine microbial community as a consequence of freshening from nearby glaciers was investigated in Chile Bay, Greenwich Island, WAP. In the summer of 2016, samples were collected from glacier ice and transects along the bay for 16S rRNA gene sequencing, while in situ dilution experiments were conducted and analyzed using 16S rRNA gene sequencing and metatranscriptomic analysis. The results reveal that certain common seawater genera, such as Polaribacter, Pseudoalteromonas and HTCC2207, responded positively to decreased salinity in both the bay transect and experiments. The relative abundance of these bacteria slightly decreased, but their functional activity was maintained and increased the over time in the dilution experiments. However, while ice bacteria, such as Flavobacterium and Polaromonas, tolerated the increased salinity after mixing with seawater, their gene expression decreased considerably. We suggest that these bacterial taxa could be defined as sentinels of freshening events in the Antarctic coastal system. Furthermore, these results suggest that a significant portion of the microbial community is resilient and can adapt to disturbances, such as freshening due to the warming effect of climate change in Antarctica. This work was financially supported by the Agencia Nacional de Investigación y Desarrollo de Chile (ANID/FONDAP/15110009; DPI, grant number DPI20140044-ANID; ANID/INACH/ FONDECYT 3170807), Spanish Ministry of Economy and Competitivity grant CTM2016-80095-C2, and the Instituto Antártico Chileno (grant numbers INACH RT_15-10, INACH RG_09-17 and INACH RT_04-19). Peer reviewed