Microzooplankton grazing along the Western Antarctic Peninsula Journal Article


Authors: Garzio, Lori M.; Steinberg, Deborah K.; Erickson, Matthew; Ducklow, Hugh W.
Article Title: Microzooplankton grazing along the Western Antarctic Peninsula
Abstract: The significance of microzooplankton as grazers in pelagic ecosystems has been established, yet relatively few studies of microzooplankton grazing, compared to that of macrozooplankton, have been conducted in the Southern Ocean. We report phytoplankton and bacterial growth and grazing mortality rates along the Western Antarctic Peninsula (WAP), a region of rapid climate change. Growth and grazing rates were determined by dilution experiments at select stations along the WAP in January of 2009 to 2011 and in the nearshore waters near Palmer Station in February and March 2011. Microzooplankton exerted higher grazing pressure on bacteria compared to phytoplankton along the WAP and also selectively grazed on smaller phytoplankton (picoautotrophs and nanophytoplankton) and on the more actively growing (high nucleic acid) bacterial cells. Among all phytoplankton size classes, growth rates ranged from undetectable (i.e. not significant; NS) to 0.99 d(-1), grazing mortality rates were NS to 0.56 d(-1), and microzooplankton removed 100% of daily bacterial production. There was a significant (albeit weak) exponential relationship between temperature and phytoplankton mortality, although the range of experimental temperatures was small. The present study provides a reference point of microzooplankton grazing impact along the WAP in the summer and contributes valuable information to studies modeling the flow of carbon through the WAP food web, improving our ability to predict climate-induced changes in the WAP ecosystem.
Keywords: PROTOZOA; Southern Ocean; COASTAL; bacterial production; WATERS; CLIMATE; GRAZING; SOUTHERN-OCEAN; AUSTRAL SUMMER; PHYTOPLANKTON GROWTH; MICROBIAL FOOD-WEB; Microzooplankton; ATLANTIC SECTOR; HETEROTROPHIC PROTISTS; western Antarctic Peninsula; PROTOZOOPLANKTON COMMUNITY STRUCTURE; CILIATE MICROZOOPLANKTON
Journal Title: Aquatic Microbial Ecology
Volume: 70
Issue: 3
ISSN: 0948-3055
Publisher: Inter Research  
Publication Place: OLDENDORF LUHE; NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY
Date Published: 2013
Start Page: 215
End Page: 232
DOI/URL:
Notes: PT: J; TC: 0; UT: WOS:000325896800004
Woods Hole Authors
  1. Hugh W Ducklow
    157 Ducklow
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