Diversity and distribution of microbial eukaryotes in the deep tropical and subtropical North Atlantic Ocean

Author(s)
Danielle Morgan-Smith, Melissa A. Clouse, Gerhard J. Herndl, Alexander B. Bochdansky
Abstract

Employing a combination of 4',6-diamidino-2-phenylindole and fluorescein isothiocyanate (DAPI-FITC) staining and catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH), we distinguished a variety of taxonomic and morphological types of eukaryotic microbes in the central and deep water masses of the tropical and subtropical North Atlantic Ocean. Samples were taken along a transect across the tropical Atlantic, along the equatorial upwelling and into the West-African upwelling region. Samples were collected as deep as 7000. m in the Romanche Fracture Zone within the Mid-Atlantic Ridge. Approximately 50-70% of FISH-identified eukaryotes in deep water masses belong to one of seven groups: kinetoplastids, labyrinthulomycetes, fungi, diplonemids, group II alveolates, MAST 4 (stramenopiles), and an unidentified organism with a peculiar nuclear morphology. A smaller percentage of total eukaryotes was identified in the Central Water, especially in the oxygen minimum zone, than in deep water masses. CARD-FISH probes designed to identify broad taxonomic groups revealed kinetoplastids and fungi were more abundant than noted in previous studies employing 18S rRNA gene clone libraries. Group II alveolates, in contrast, were much less prevalent than previously reported. On a second survey, eukaryotic microbes were enumerated in the deep-sea basins below the North Atlantic subtropical gyre including the Vema Fracture Zone, which is another prominent trench in the Mid-Atlantic Ridge. The abundance of eukaryotes and chlorophyll concentrations were significantly different between the two cruises, which covered very different hydrographic regimes with associated high and low levels of primary production, respectively.

Organisation(s)
Functional and Evolutionary Ecology
External organisation(s)
Old Dominion University
Journal
Deep-Sea Research. Part 1: Oceanographic Research Papers
Volume
78
Pages
58-69
No. of pages
12
ISSN
0967-0637
DOI
https://doi.org/10.1016/j.dsr.2013.04.010
Publication date
08-2013
Peer reviewed
Yes
Austrian Fields of Science 2012
106021 Marine biology
Keywords
ASJC Scopus subject areas
Aquatic Science, Oceanography
Portal url
https://ucris.univie.ac.at/portal/en/publications/diversity-and-distribution-of-microbial-eukaryotes-in-the-deep-tropical-and-subtropical-north-atlantic-ocean(9fb84ccb-9ad7-414a-adcc-fda98abbccfb).html