Program and Agenda



We sought to investigate environmental controls of two phylogenetically distinct Marine Group I (MGI) ammonia-oxidizing Thaumarchaea at Station ALOHA, the field site for the Hawaii Ocean Time-series (HOT) program. Samples were collected throughout the water column (0-4000 m) on near-monthly cruises between 2006 and 2012. We utilized quantitative PCR amplification of ammonia monooxygenase subunit A (amoA) genes and gene transcripts to evaluate temporal variability in the abundances, transcriptional activities, and vertical distributions of ammonia-oxidizing MGI at Station ALOHA. Our results revealed amoA gene abundances underwent moderate increases in the epipelagic waters (0-100 m) during periods of deeper winter mixing. MGI amoA genes near the base of the euphotic zone (100-200 m) were elevated in the fall and winter, suggesting seasonal decreases in irradiance in this region of the water column could partly regulate abundances. Maximum amoA gene abundances occurred between 125 and 300 m. Examination of MGI amoA mRNA revealed peak transcriptional activity near the base of the euphotic zone (125-175 m). Our results provide new information on processes influencing the distributions and physiological activities of microorganisms mediating nitrification.



Wai, B. R., University of Hawaii / Department of Oceanography, USA,

Church, M. J., University of Hawaii / Department of Oceanography, USA,

Karl, D. M., University of Hawaii / Department of Oceanography, USA,

DeLong, E. F., Massachusetts Institute of Technology / Civil and Environmental Engineering, USA,


Poster presentation

Session #:049
Date: 2/27/2014
Time: 16:00 - 18:00
Location: Poster/Exhibit Hall

Presentation is given by student: Yes

PosterID: 2457