Toggle Main Menu Toggle Search

Open Access padlockePrints

Functional group-specific traits drive phytoplankton dynamics in the oligotrophic ocean

Lookup NU author(s): Professor Sam Wilson

Downloads

Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


Abstract

A diverse microbial assemblage in the ocean is responsible for nearly half of global primary production. It has been hypothesized and experimentally demonstrated that nutrient loading can stimulate blooms of large eukaryotic phytoplankton in oligotrophic systems. Although central to balancing biogeochemical models, knowledge of themetabolic traits that govern the dynamics of these bloom-forming phytoplankton is limited. We used eukaryotic metatranscriptomic techniques to identify the metabolic basis of functional group-specific traits that may drive the shift between net heterotrophy and autotrophy in the oligotrophic ocean. Replicated blooms were simulated by deep seawater (DSW) addition to mimic nutrient loading in the North Pacific Subtropical Gyre, and the transcriptional responses of phytoplankton functional groups were assayed. Responses of the diatom, haptophyte, and dinoflagellate functional groups in simulated blooms were unique, with diatoms and haptophytes significantly (95% confidence) shifting their quantitative metabolic fingerprint from the in situ condition, whereas dinoflagellates showed little response. Significantly differentially abundant genes identified the importance of colimitation by nutrients, metals, and vitamins in eukaryotic phytoplankton metabolism and bloom formation in this system. The variable transcript allocation ratio, used to quantify transcript reallocation following DSW amendment, differed for diatoms and haptophytes, reflecting the longstanding paradigm of phytoplankton r- And K-type growth strategies. Although the underlying metabolic potential of the large eukaryotic phytoplankton was consistently present, the lack of a bloom during the study period suggests a crucial dependence on physical and biogeochemical forcing, which are susceptible to alteration with changing climate.


Publication metadata

Author(s): Alexander H, Rouco M, Haley ST, Wilson ST, Karl DM, Dyhrman ST

Publication type: Article

Publication status: Published

Journal: Proceedings of the National Academy of Sciences of the United States of America

Year: 2015

Volume: 112

Issue: 44

Pages: E5972-E5979

Print publication date: 03/11/2015

Online publication date: 12/10/2015

Acceptance date: 15/09/2015

ISSN (print): 0027-8424

ISSN (electronic): 1091-6490

Publisher: National Academy of Sciences

URL: https://doi.org/10.1073/pnas.1518165112

DOI: 10.1073/pnas.1518165112

PubMed id: 26460011


Altmetrics

Altmetrics provided by Altmetric


Share