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Increasing CO2 changes community composition of pico- and nano-sized protists and prokaryotes at a coastal Antarctic site


Thomson, PG and Davidson, A and Maher, L, Increasing CO2 changes community composition of pico- and nano-sized protists and prokaryotes at a coastal Antarctic site, Marine Ecology Progress Series, 554 pp. 51-69. ISSN 0171-8630 (2016) [Refereed Article]


Copyright Statement

Copyright 2016 Inter-Research

DOI: doi:10.3354/meps11803


Ocean acidification is a globally recognised phenomenon, but little is known of its impacts on Antarctic marine microbes. Here we report on the community response of pico- and nanophytoplankton, heterotrophic nanoflagellates (HNF) and prokaryotes (Archaea and Bacteria) to elevated CO2 during 3 minicosm experiments over the 2008/2009 summer at Davis Station, Antarctica. Coastal seawater was incubated in 650 l minicosms (n = 6) for ≤ 12 d at CO2 concentrations ranging from preindustrial levels to those predicted for 2100 and beyond. The abundance of pico- and nano-sized protists and prokaryotes were determined by flow cytometry, using chlorophyll autofluorescence to discriminate the phytoplankton, SYBR-Green to stain the prokaryotes and LysoTracker Green stain to discriminate the HNF. While the effects on nanophytoplankton abundance were inconclusive, our results show that increasing CO2 can alter the composition of the microbial community in Antarctic coastal waters. Our 3 experiments consistently showed lower concentrations of HNF and higher abundances of picophytoplankton and prokaryotes in treatments exposed to elevated CO2. While the mechanism remains to be confirmed, our study suggests that CO2 may reduce the mortality of picoplankton by HNF grazing. Our results indicate that changes in the composition of Antarctic microbial communities may occur within the concentration range of 750 to 1118 ppm CO2, potentially impacting the Antarctic food web through reduced food availability.

Item Details

Item Type:Refereed Article
Keywords:ocean acidification, minicosms, CO2, flow cytometry, picophytoplankton, nanophytoplankton, heterotrophic nanoflagellates, bacteria, Archaea
Research Division:Earth Sciences
Research Group:Oceanography
Research Field:Biological oceanography
Objective Division:Environmental Management
Objective Group:Marine systems and management
Objective Field:Measurement and assessment of marine water quality and condition
UTAS Author:Davidson, A (Dr Andrew Davidson)
ID Code:114200
Year Published:2016
Web of Science® Times Cited:17
Deposited By:CRC-Antarctic Climate & Ecosystems
Deposited On:2017-02-08
Last Modified:2017-10-25
Downloads:4 View Download Statistics

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