Julie Huber
Assistant Scientist
e: jhuber@mbl.edu
p: 508 289 7291
f: 508 457 4727
Huber_CV

Dr. Julie Huber is a microbial oceanographer by training and is broadly interested in microbial ecology and understanding how microbial communities establish, function, and evolve in diverse ecosystems. Her main research programs investigate deep-sea microbial ecosystems with an emphasis on using crustal fluids to interrogate the rocky subseafloor habitat. The functional consequences of an extensive population of microbes living in the subseafloor remains unknown, as does our understanding of how these organisms interact with one another and influence the biogeochemistry of the oceans. Dr. Huber is a sea-going scientist and has participated in over 15 deep-sea cruises using cutting-edge submersible technology to sample these novel and hard to access environment. Due to the inherently risky nature of her field investigations, she often has limited access to samples and must leverage the best available technology and experimental strategies in order to maximize return of information from those precious few samples. This includes using next-generation sequencing, high temperature cultivation, stable isotope experimentation, geochemical measurements, and novel sampling and seafloor instrumentation for her subseafloor studies. Dr. Huber played a critical role in the Sloan Foundation’s International Census of Marine Microbes (ICoMM). Together with scientists in the JBPC, she helped lead the effort to apply new cost-effective 454 pyrotag sequencing strategies to generate assessments of microbial diversity, evenness, and community structure at a 100- to 1000-fold finer scale than traditional techniques. This general strategy, and the many iterations of it since (different hypervariable regions, next-generation sequencing platforms), have impacted all microbial ecology studies ranging from her own deep-sea work to the human gut to planetary protection.

Marine Microbiology
For more than three billion years, microbes have served as the primary engines of Earth’s biosphere, mediating essential biogeochemical cycles that shape planetary habitability. In particular, the world’s oceans are teeming with microscopic life forms, and it is predicted that the oceans harbor 3.6 x 1029 microbial cells, encompassing a staggering amount of metabolic and genetic diversity. Although they are largely invisible to the naked eye, microbial communities of untold diversity continue to dominate nearly every corner of our oceans, from the deepest marine sediments to the sun-drenched coral reefs. Despite their crucial role in elemental cycling, carbon sequestration, and earth’s evolution, the marine microbial world remains vastly undersampled, and our understanding of these microbial communities severely limited.

The Subseafloor Biosphere
One particular realm of the marine world that remains poorly studied is also one of the largest and least accessible, the subseafloor crustal environment. Circulation of seawater occurs within the porous upper 500 m of basaltic extrusives, and there is constant interaction and exchange between the crustal aquifer, marine sediments, and seawater. The emerging picture of the deep-sea includes the subseafloor as not necessarily an isolated environment, but instead as an important component of oceanic circulation and chemical cycling, and for that reason alone, it deserves more attention. However, it is the subseafloor microbial community living within oceanic crust that offers opportunities to study many exciting and cutting-edge aspects of marine microbial ecology, including limits of life, molecular evolution, microbial diversity and biogeography, functional genomics of complex communities, origins of life, and biofilm formation. Yet the crustal biosphere remains under-sampled, and our knowledge of what microbes are present and how they are distributed in this dynamic geochemical environment over time and space is fragmentary. My lab focuses on determining the phylogenetic and physiological diversity, distribution, and genomic content of subseafloor microbial communities in the deep-sea. Microbial data is integrated with geochemical and geophysical measurements at to develop models for subseafloor contributions to biogeochemical cycling, global carbon budgets, and marine food webs.

Schematic of oceanic crust, showing generalized porosity, heat sources, and fluid circulation patterns in the subseafloor. Image Credit: Julie Huber

Pacific Study Sites
Axial Seamount, Juan de Fuca Ridge in the northeast Pacific (45.92° N, 130° W)
Seamounts along the Mariana Arc (14-22° N, 143-146° E) in the western Pacific
Loihi Seamount (18.92° N 155.27° W), the newest Hawaiian Island
My main three study sites represent geographically and geographically distinct deep-sea seamounts across the Pacific Ocean. All three locations host recently eruptive seamounts located above 2000 m with diffusely venting fluids that contain high concentrations of carbon dioxide. However, their geological and chemical setting differs greatly; Axial is a mid-ocean ridge seamount with fluids dominated by high concentrations of hydrogen sulfide, Loihi is a mid-plate hotspot seamount with extremely high concentrations of dissolved iron (FeII), and the Mariana seamounts are at a convergent plate boundary and host a variety of fluids, including those with very low pH and high concentrations of particulate sulfur. These sites were chosen for a number of reasons, including 1) access to actively venting low-temperature hydrothermal fluids and the subseafloor microbial community, 2) experience and collaborations with an interdisciplinary research team at all sites providing a wealth of geological, chemical, and biological studies to set the context for subseafloor microbiological analyses, and 3) the emerging importance of seamounts as biological hotspots in the ocean (Seamount Biogeosciences Network).

Julie and Dr. David Butterfield collecting samples from “The Beast” during an expedition to the Mariana Arc. Image Credit: NOAA Ocean Explorer

Diffuse vent Marker 52 from Axial Seamount on the Juan de Fuca Ridge taken by the ROV ROPOS. Image Credit: NOAA/PMEL Vents Program

Atlantic Study Sites
With support from the Integrated Ocean Drilling Program and the Moore Foundation, a transect of borehole “CORKed” microbial observatories will be established on 7–8 Ma seafloor on the western flank of the Mid-Atlantic Ridge at 22°N. This observatory transect is being designed to allow long-term (decadal), manipulative, community-based experiments, observations, and sampling as part of the overarching MARME (Mid-Atlantic Ridge Microbiological Experiments) program. Goals of this work are to determine the origin and nature of microbial communities within basaltic basement below an isolated sediment “pond.” We hope to begin drilling at North Pond in 2010.

Personnel

Julie (Smith) Meyer
Postdoctoral Scientist
e: jmeyer@mbl.edu
p: 508 289 7196
f: 508 457 4727
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Nuria Fernandez
Postdoctoral Scientist
e: nfernandez@mbl.edu
p: 508 289 7659
f: 508 457 4727
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Angus Angermeyer
MBL/Brown Graduate Student
e: aangermeyer@mbl.edu
p: 508 289 7659
f: 508 457 4727

Julie Reveillaud
Research Assistant III
e: jreveillaud@mbl.edu
p: 508 289 7294
f: 508 457 4727

Emily Reddington
Research Assistant II
e: ereddington@mbl.edu
p: 508 289 7659
f: 508 457 4727

Chris Algar
Postdoctoral Scientist
e: calgar@mbl.edu
p: 508 289 7713
f: 508 457 4727

Caroline Fortunato
Postdoctoral Scientist
e: cfortunato@mbl.edu
p: 508 289 7713
f: 508 457 4727
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