Publications by authors named "E V Armbrust"
The proportions of carbon (C), nitrogen (N), and phosphorus (P) in surface ocean particulate matter deviate greatly from the canonical Redfield Ratio (C:N:P = 106:16:1) in space and time with significant implications for global carbon storage as this matter reaches the deep ocean. Recent work has revealed clear latitudinal patterns in C:N:P, yet the relative importance of ecological, physiological, or biochemical processes in creating these patterns is unclear. We present high-resolution, concurrent measurements of particulate C:N:P, macromolecular composition, environmental conditions, and plankton community composition from a transect spanning a subtropical-subpolar boundary, the North Pacific Transition Zone.
View Article and Find Full Text PDFArticle Synopsis
- Marine microbial eukaryotes, or protists, are crucial for ocean ecosystems, but their functions and diversity are not well understood due to limited lab isolation efforts.
- The North Pacific Eukaryotic Gene Catalog compiles data from 261 metatranscriptomes collected across various locations in the North Pacific Ocean, including surface transects and diel-resolved field studies.
- These metatranscriptome sequences were assembled into 175 datasets, annotated, and are now available for research on platforms like Zenodo and GitHub, providing insights into protist diversity and genetic functions.
Article Synopsis
- Marine microbial ecologists aim to measure organismal abundance and diversity in ecosystems at a high taxonomic resolution, using various methods to capture accurate data.
- Traditional flow cytometry estimates the number of microbial cells but lacks the ability to differentiate among many species, while amplicon sequencing offers detailed taxonomic data but often only provides relative abundances.
- This study introduces a technique that combines genomic internal standards with amplicon sequencing, allowing for accurate absolute cell counts of marine picocyanobacteria, which aligns closely with flow cytometry results, indicating a reliable method for analyzing microbial populations in complex marine environments.
Photosynthesis fuels primary production at the base of marine food webs. Yet, in many surface ocean ecosystems, diel-driven primary production is tightly coupled to daily loss. This tight coupling raises the question: which top-down drivers predominate in maintaining persistently stable picocyanobacterial populations over longer time scales? Motivated by high-frequency surface water measurements taken in the North Pacific Subtropical Gyre (NPSG), we developed multitrophic models to investigate bottom-up and top-down mechanisms underlying the balanced control of Prochlorococcus populations.
View Article and Find Full Text PDF