Postdoctoral Scholars

[ Postdoctoral Scholars | Graduate Students | Alumni ]

	Benedetto Barone Post-doc in Church’s lab University of Hawai‘i at Manoa (UH Manoa) Research interest: Barone is focused on the interaction between light and the planktonic community. He tries to characterize station ALOHA based on its biooptical properties including the attenuation of light at different wavelengths, the photophysiological properties of the algal community and the particle size spectrum inferred from forward angle scattering. He is also interested in studying the influence of light on the cycling of nitrogen at station ALOHA and he is testing how to include the effect of photoheterotrophic processes in simple biogeochemical models. Keywords: bio-optics, photophysiology, particle size, photoheterotrophy, ecosystem modeling bbarone@hawaii.edu
	Paul Berube Post-doc in Chisholm’s lab Massachusetts Institute of Technology (MIT) Research interest: Berube studies the physiology and ecology of the cyanobacterium Prochlorococcus, the smallest and most abundant photosynthetic cell on the planet. Prochlorococcus offers several unique advantages for addressing questions in microbial ecology, including broad distribution in a well characterized environment, a collection of several physiologically distinct strains, and the availability of environmental and strain specific sequence data. Berube’s focus is on nitrogen acquisition strategies of Prochlorococcus and how these adaptations influence the ecology of this globally important microorganism. Keywords: microbial diversity, ecology, cyanobacteria, nitrogen cycle, Prochlorococcus, genomics pmberube@mit.edu
	Steven Biller Post-doc in Chisholm’s lab Massachusetts Institute of Technology (MIT) Research interest: Biller's research interests center on the ecology and evolution of the marine cyanobacterium Prochlorococcus. His work in the Chisholm lab at MIT involves a combination of genomic, transcriptomic and physiological studies to better understand how Prochlorococcus is able to both acclimate and adapt to different environmental niches in the oceans. Keywords: cyanobacteria, genomics, evolution, transcriptomics sbiller@mit.edu
	Deniz Bombar Post-doc in Zehr’s lab University of California, Santa Cruz (UCSC) Research interest: Bombar’s research focuses on the role of microbes in oceanic nitrogen cycling. He aims to understand how the distribution and activity of different nitrogen-fixing prokaryotes is regulated by environmental factors. The approach he uses combines flow-cytometric sorting of different populations of microbes, molecular methods for identification, and substrate uptake measurements using stable isotope tracers. Keywords: nitrogen fixation, isotopes, microbial diversity dbombar@ucsc.edu
	Daniela Böttjer Post-doc in Church’s lab University of Hawai‘i at Manoa (UH Manoa) Research interest: Böttjer is primary interested in studying the sensitivity of N2-fixation to perturbations in seawater carbon chemistry. Her work will investigate the responses and consequences of changes in seawater pCO2 on the growth and community structure of naturally-occurring assemblages of N2-fixers and place these experimental approaches into the context of monthly time-series estimates on N2-fixing bacterial dynamics at station ALOHA. Keywords: biogeochemical cycling, nitrogen fixation, ocean acidification dbottjer@hawaii.edu sites.google.com/site/cmorebottjer/
	Gonzalo Carrasco Post-doc in Boyle’s lab Massachusetts Institute of Technology (MIT) Research interest: Carrasco’s main interest is the study of trace metals of biogeochemical importance, focusing on their concentration, chemical speciation and isotopic fractionation in water, sediments and biological records. At ALOHA, he wants to corroborate preliminary studies that show specific water masses bring organic ligands from the West Pacific and hydrothermal vents, their reported presence in sub-surface waters related to a local maxima, their potential relationship to specific phytoplankton species, and possibly also to get some insight into their size and chemical nature. Keywords: trace metals, chemical speciation, organic ligands, gcarrasc@mit.edu
	Daniela del Valle Post-doc in Karl’s lab University of Hawai‘i at Manoa (UH Manoa) Research interest: Del Valle’s research focuses on the biogeochemistry of reduced gases in the surface ocean. She is particularly interested in the metabolic fate of dimethylsulfoniopropionate (DMSP) and the factors controlling dimethylsulfide (DMS) production. She is also interested in studying the dynamics of hydrogen gas at Station ALOHA and its relation to nitrogen fixation, as well as the production of methane from methylphosphonate in the surface ocean. Keywords: reduced gases in the surface ocean; DMSP-DMS production, nitrogen fixation dadv@hawaii.edu sites.google.com/site/cmoredelvalle/
	Julia Diaz Post-doc in Dyhrman’s lab Woods Hole Oceanographic Institution (WHOI) and Columbia University Research interest: Diaz explores the role of microorganisms (phytoplankton and heterotrophic bacteria) in globally-relevant biogeochemical processes, including the cycling of reactive oxygen species (ROS) and the vital nutrient phosphorus. With support from an NSF OCE postdoctoral research fellowship, she is currently examining microbial metabolism of exogenous and endogenous pools of polyphosphate, an environmentally ubiquitous biopolymer. Diaz is interested in using her research as a platform for broadening participation in ocean sciences, as well as advancing environmental literacy and natural conservation. Keywords: polyphosphate, phosphorus, ROS, phycology, geomicrobiology jdiaz@whoi.edu
	Kristina Fontanez Post-doc in DeLong's lab Massachusetts Institute of Technology (MIT) Research interest: Fontanez is interested in the composition and function of particle-associated microbial communities. She is using metagenomics and metatranscriptomics to examine the molecular basis of particulate organic carbon resource partitioning occurring during microbial blooms. Keywords: transcriptomics, marine particle degradation, metagenomics fontanez@mit.edu
	Stuart Goldberg Post-doc in Church's lab University of Hawai‘i at Manoa (UH Manoa) Research interest: Goldberg studies dissolved organic carbon (DOC) and nitrogen (DON) cycling by heterotrophic bacterioplankton in marine and freshwater ecosystems. His work investigates the biogeochemistry of DOC and DON at Station ALOHA. Keywords: DOC, DON, bacterioplankton, bioavailability stuartg@hawaii.edu
	Maria T. Kavanaugh Post-doc in Doney’s lab Woods Hole Oceanographic Institution (WHOI) Research interest: Modeling pelagic ecosystem responses and feedbacks to environmental perturbation, requires an objective framework to (1) track responses of unique, contiguous systems in time and (2) scale “snapshots” of data collected in a typical oceanographic research expedition to that which is resolved by satellites or global marine ecosystem models (MEMs). With this in mind, Kavanaugh's research takes a combined approach, integrating in situ observations into MEMs and satellite observations with an objective hierarchical seascape classification. The seascape framework allows Kavanaugh’s team to identify unique systems and conduct comparative analyses, but also to identify when the boundaries of these systems are shifting with seasonal or interannual forcing. With this combined approach, Kavanaugh and collaborators hope to not only improve model parameterization, but also address critical ecological questions related to the effects of climate on pelagic ecosystem complexity and diversity. Keywords: pelagic seascape ecology and biogeochemistry; phytoplankton diversity and biogeography mkavanaugh@whoi.edu
	Libusha Kelly Post-doc in Chisholm’s lab Massachusetts Institute of Technology (MIT) Research interest: A key challenge in biology is improving our understanding of the interactions between members of a heterogeneous population of organisms in a complex environment and determining the mechanisms that make this biological system stable to perturbation. In Kelly’s postdoctoral work in Sallie Chisholm’s lab, she is characterizing how genetic exchange between bacteria and viruses influences the ability of bacteria to adapt to different environments. Keywords: metagenomics, cyanophage, cyanobacteria, systems biology, ecology libusha@mit.edu
	Yawei Luo Post-doc in Doney’s lab Woods Hole Oceanographic Institution (WHOI) Research interest: Luo’s research focuses on microbial ecosystem modeling in the open ocean, particularly diazotrophic bacteria, heterotrophic bacteria and dissolved organic matter (DOM) dynamics. Luo uses data assimilation methods to combine observations and modeling through optimizing model parameters. Luo also models the decadal trends observed in the Hawaii Ocean Time-series (HOT). Keywords: ecosystem modeling, data assimulation, heterotrophic bacteria, dissolved organic matter, diazotroph yluo@whoi.edu
	Katherine Mackey Post-doc in Saito’s lab Woods Hole Oceanographic Institution (WHOI) Research interest: Mackey’s research focuses on phytoplankton photosynthesis, the role of phytoplankton in biogeochemical cycles, and the mechanisms they use to acclimate and adapt to environmental changes. She studies how photosynthetic adaptations allow different phytoplankton groups to dominate different areas of the ocean, particularly in dynamic environments subject to changing environmental conditions. As a postdoc in the Saito Lab at WHOI, Mackey uses proteomics to quantify iron-rich photosynthetic proteins in strains of Synechococcus from different ocean regions, and measures fluorescence to characterize photophysiology. Together these approaches link changes in protein abundance to changes in photosynthetic fitness and growth in laboratory cultures and natural populations of phytoplankton. Keywords: photosynthesis, picocyanobacteria, Synechococcus, proteomics, fluorescence kmackey@whoi.edu
	Sandra Martinez-Garcia Post-doc in Karl’s lab University of Hawai‘i at Manoa (UH Manoa) Research interest: Martinez-Garcia’s research focuses on the role of marine microbial communities on the biogeochemical fluxes through planktonic food webs. In particular, she is interested in understanding and predicting the effects that the anthropogenic changes in matter inputs into the ocean exert on the microbial heterotrophic and autotrophic metabolisms. She is also interested in studying carbon cycling at Station ALOHA, specifically through bacterial and community respiration rates. Keywords: biogeochemistry, nitrogen cycle, food-web structure, primary and secondary production, microbial respiration, metabolic balance sandramg@hawaii.edu
	Vanessa Michelou Post-doc in Rappé’s lab University of Hawai‘i at Manoa (UH Manoa) Research interest: Michelou’s research interests lie in understanding the forces that shape bacterial community structures and dynamics, microbial diversity, and the roles of microbes in biogeochemical fluxes. She wants to integrate genomic analysis with an understanding of the functional properties that connect microbial and abiotic ecosystem processes. Combining molecular biology with oceanographic tools and ecological concepts will refine our understanding of relationships between community diversity and ecosystem function. Michelou is currently a postdoctoral fellow in Mike Rappe’s lab. Her work at C-MORE will address specific hypotheses regarding the physiological characteristics of bacterial isolates derived from their whole genome sequences. Some of her projects will be to examine the growth of bacterial isolates possessing the genetic potential for phototrophy, in both light and dark incubations, in order to measure parameters that would be of primary interest to biological oceanographers. Keywords: microbial diversity, biogeochemical cycling, dissolved organic nutrients, photoheterotrophy, isolation, cultivation, microscopy, flow cytometry michelou@hawaii.edu sites.google.com/site/cmoremichelou/
	Olivia Nigro Post-doc in Steward’s lab University of Hawai‘i at Manoa (UH Manoa) Research interest: Nigro is interested in examining the environmental controls on the abundance and evolution of marine bacterioplankton. Specifically, Nigro is investigating vibrios and their relationship with the coastal environment, as well as interactions between vibrios and their viruses. Keywords: Vibrio, virus, bacterioplankton, population dynamics, evolution, phage-host interactions Email onigro@hawaii.edu
	Abigail Noble Post-doc in Boyle’s lab Massachusetts Institute of Technology (MIT) Research interest: Noble’s research revolves around the study of trace metals in seawater that act as metal micronutrients to phytoplankton (Co, Fe, Mn) and as anthropogenic tracers (Pb and Pb isotopes). Most of the Pb that exists in the ocean was originally derived from an anthropogenic source, with the most notable offender being the usage of alkyl leaded gasoline. High temperature industrial processes also contribute to the atmospheric source of anthropogenic Pb to the surface ocean. Sources of Pb can be traced by examining the stable isotope composition of environmental samples as different Pb ores have evolved over geologic time to have distinct compositions. Co, Fe, and Mn are hybrid-type metals that are incorporated into proteins and enzymes that participate in important biological functions such as carbon, nitrogen, and light acquisition. These metals are found in vanishingly low concentrations in the open ocean, and can limit or co-limit phytoplankton growth. Studying the distributions of these metals across strong biogeochemical gradients can help constrain the potential sources and sinks of these micronutrients in the global ocean and improve our understanding of the controls on global ocean productivity Keywords: biogeochemical cycling, trace metals, cobalt, lead anoble@mit.edu
	Julie Robidart Post-doc in Zehr’s lab University of California, Santa Cruz (UCSC) Research interest: Robidart’s research involves biogeochemical investigations of marine microbial cycles using in situ instrumentation. She is currently developing primer and probe sets for genes coding for key enzymes, to be deployed on the quantitative PCR module of the Environmental Sample Processor, in the Monterey Bay. Data collected by the ESP will give detailed information about how microbial communities respond to, and change, environmental conditions over time and space. Keywords: in situ instrumentation, biogeochemical cycling jrobidart@ucsc.edu
	Mónica Rouco-Molina Woods Hole Oceanographic Institution (WHOI) and Columbia University Research interest: Rouco-Molina is interested in studying the interaction of phytoplankton organisms with their geochemical environment. She examines the factors determining their growth and the strategies allowing them to adapt to different environmental conditions. She is also interested in understanding the factors driving phytoplankton niche differentiation in the ocean. Exploring the physiological ecology and biogeography of present phytoplankton communities is crucial to better understand the response of these communities to future global change scenarios. Her current perspective involves the combination of both physiological and molecular techniques to investigate phytoplankton nutrient physiology in field communities, with a special attention to phosphorus and nitrogen metabolism. She is also particularly interested in ocean acidification studies. Her research as a Postdoctoral Fellow with C-MORE focuses on investigating the physiological ecology of Trichodesmium sp. populations in the ocean. Keywords: Phytoplankton physiological ecology, molecular biology, environmental change mroucomolina@whoi.edu
	Ty Samo Post-doc in Karl’s lab University of Hawai‘i at Manoa (UH Manoa) Research interest: Samo is interested in detailing the spectrum of marine microbial growth, enzyme activity, and identity at the single cell level in coastal and open ocean habitats. Currently, he is developing microscopy and image analysis approaches to assess the contribution of individual free-living and particle-attached microbial cells to the availability and cycling of carbon and phosphorus. Keywords: bacterioplankton, phytoplankton, microscopy, physiology, biogeochemistry tsamo@hawaii.edu
	Mariona Segura-Noguera Post-doc in Karl’s lab University of Hawai‘i at Manoa (UH Manoa) Research interest: Segura Noguera is interested in plankton stoichiometry and its variations between and within key plankton groups and species. To determine plankton stoichiometry, she studies the elemental composition of plankton using single-cell methodologies (X-ray microanalysis). Because changes in plankton stoichiometry are related to environmental conditions, which determine the availability of nutrients and light, she is also interested in dissolved inorganic and organic nutrient distributions in the sea. Keywords: phytoplankton, stoichiometry, single-cell microanalysis, biogeochemical cycling, dissolved inorganic nutrients, dissolved organic nutrients mseguran@hawaii.edu sites.google.com/site/cmoresegura/
	Adrian Sharma Post-doc in DeLong’s lab Massachusetts Institute of Technology (MIT) Research interest: Sharma’s research uses experimental metatranscriptomics to examine the metabolic pathways, microbial community dynamics and chemical transformations associated with microbial utilization of dissolved organic matter in the sea. His project represents a multidisciplinary collaboration with the Repeta lab and monitors the microbial and biogeochemical changes over time in experimental microcosms treated with a high molecular weight dissolved organic matter amendment. Keywords: metatranscriptomics, microbial ecology, microbial metabolism, carbon cycling aksharma@mit.edu
	Irina Shilova Post-doc in Zehr’s lab University of California, Santa Cruz (UCSC) Research interest: Cyanobacteria: picocyanobacteria and diazotrophs. Gene expression in cyanobacteria under various environmental conditions and during a diel cycle. Application of high-density microarrays to study microbial community gene expression. Keywords: cyanobacteria, gene expression, stress responses, diel cycle, microarrays iirina@ucsc.edu
	Christine Shulse Post-doc in Rappé’s lab University of Hawai‘i at Manoa (UH Manoa) Research interest: Shulse is interested in understanding the factors that govern microbial community structure. At C-MORE, she is using next-generation, massively parallel tag sequencing to identify bacteria associated with corals from disparate geographic locations and across multiple stages of development. Keywords: microbial diversity, molecular ecology, coral, microbial metabolism, symbioses cshulse@hawaii.edu sites.google.com/site/cmoreshulse/
	Anne Thompson Post-doc in Zehr’s lab University of California, Santa Cruz (UCSC) Research interest: Thompson is interested in the ecology of the uncultured nitrogen fixer, UCYN-A. Specifically, she will be working on understanding patterns of whole-genome transcription in UCYN-A under different environmental conditions in the open ocean. Keywords: nitrogen fixation, transcriptomics, UCYN-A awthomps@ucsc.edu
	Sam Wilson Post-doc in Karl’s lab University of Hawai‘i at Manoa (UH Manoa) Research interest: Wilson’s research focuses on the cycling of trace gases in the upper ocean and examines why reduced gases such as methane, nitrous oxide, and hydrogen are supersaturated in surface seawater. To investigate this phenomenon, monthly measurements of dissolved gases are made at Stn ALOHA as part of the HOT program. Complimentary laboratory work with cultures of key cyanobacteria species including nitrogen-fixing micro-organisms provides species-specific production rates that are compared with the microbial community composition at Stn ALOHA. Current work focuses on the production of hydrogen and carbon monoxide by Trichodesmium and Crocosphaera cultures. Keywords: reduced gases, cyanobacteria stwilson@hawaii.edu
	Elisha M. Wood-Charlson University of Hawai‘i at Manoa (UH Manoa) Research interest: Wood-Charlson is interested in host-virus interactions. Her research focuses on two main areas: 1) tracking viral population dynamics in oligotrophic oceans over space and time, and 2) understanding the impact of viral infection on important marine symbioses. The work on viral population dynamics primarily looks at cyanobacterial viruses (cyanophages) using data collected at Station ALOHA, in collaboration with Dr. Matthew Church and the HOT program, but the project will soon be expanded to include upcoming cruises in the South Pacific. The research on symbiont viruses includes work on Symbiodinium dinoflagellates, which are mutualistic symbionts found in cnidarians such as corals and sea anemones, and will also include cyanobacteria, which can occur as symbionts in diatoms. Keywords: microbial diversity, viral ecology, symbioses, host-virus interactions elishawc@hawaii.edu