Program and Agenda

Abstract

THE ROLE OF B1 AND OTHER B-VITAMINS AT THE OLIGOTROPHIC STATION ALOHA DURING NATURAL AND INDUCED BLOOM CONDITIONS

In some oceanic regions, vitamin bioavailability might limit primary production and control phytoplanktonic community composition. At Station ALOHA, summer-time concentrations of measured B-vitamins (B1, thiamine; B2, riboflavin; B6, pyrodixine, B7, biotin; B9, folic acid; B12, cobalamin) do not exceed 30pM and follow a similar depth pattern, with higher concentrations in the top 100m, decreasing to <1pM at depths >200m. In the mixed layer, B1 uptake was carried out mostly by the <0.6µm size-fraction (76%), indicating that B1 uptake is mainly controlled by small prokaryotes. Phytoplankton blooms were induced in 20L microcosms by addition of filtered 300m seawater to 25m seawater followed by light-incubation. The growth of large phytoplankton (>10µm) was highly correlated with the uptake of B1, in agreement with the lack of B1 biosynthetic pathways in many diatoms. The >10µm fraction was responsible for 40% of B1 uptake at the peak of the bloom. Results indicate that B-vitamins are available, albeit at very low concentrations, in surface waters of Station ALOHA under non-bloom conditions; with prokaryotes normally dominating B1 uptake, and large phytoplankton competing for B1 under bloom conditions.

ePoster:

Authors

del Valle, D. A., University of Hawaii - Center for Microbial Oceanography: Research and Education, USA, dadv@hawaii.edu

Martínez-García, S., University of Hawaii - Center for Microbial Oceanography: Research and Education, USA

Suffridge, C., University of Southern California, USA

Cutter, L., University of Southern California

Sañudo-Wilhelmy, S. A., University of Southern California, USA

Details

Poster presentation

Session #:151
Date: 2/24/2014
Time: 16:00 - 18:00
Location: Poster/Exhibit Hall

Presentation is given by student: No

PosterID: 551