Elizabeth Katy Robertson

Elizabeth Katy Robertson
University of Gothenburg | GU · Department of Marine Sciences

Ph.D.

About

19
Publications
4,388
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272
Citations
Introduction
Elizabeth Katy Robertson currently works as Principal Research Engineer at the Department of Marine Science, Gothenburg University. Elizabeth does research in Biogeochemistry - specifically N and C cycling using isotope tracing methods. She's currently employed on several projects working with Prof. Helle Ploug (C and N cycling in phytoplankton field communities and cultures; anaerobic metabolisms in microalgal resting stages) and Prof. Per Hall (sediment biogeochemistry, especially N cycling)
Additional affiliations
January 2018 - present
University of Gothenburg
Position
  • Engineer
August 2017 - November 2017
University of Gothenburg
Position
  • Research Assistant
July 2016 - July 2017
University of Gothenburg
Position
  • Researcher
Education
January 2012 - March 2015
University of Southern Denmark
Field of study
  • Aquatic nutrient biogeochemistry
September 2009 - April 2011
Max Planck Institute for Marine Microbiology
Field of study
  • Marine Microbiology
September 2006 - May 2009
University of Plymouth
Field of study
  • Marine Biology

Publications

Publications (19)
Article
Full-text available
Growth of large phytoplankton is considered to be diffusion limited at low nutrient concentrations, yet their constraints and contributions to carbon (C) and nitrogen fluxes in field plankton communities are poorly quantified under this condition. Using secondary ion mass spectrometry (SIMS), we quantified cell-specific assimilation rates of C, nit...
Article
Full-text available
Determining accurate rates of benthic nitrogen (N) removal and retention pathways from diverse environments is critical to our understanding of process distribution and constructing reliable N budgets and models. The whole-core 15N isotope pairing technique (IPT) is one of the most widely used methods to determine rates of benthic nitrate-reducing...
Article
Full-text available
Coastal systems can act as filters for anthropogenic nutrient input into marine environments. Here, we assess the processes controlling the removal of phosphorus (P) and nitrogen (N) for four sites in the eutrophic Stockholm archipelago. Bottom water concentrations of oxygen (O2) and P are inversely correlated. This is attributed to the seasonal re...
Article
Full-text available
Coastal and shelf sediments are central in the global nitrogen (N) cycle as important sites for the removal of fixed N. However, this ecosystem service can be hampered by ongoing deoxygenation in many coastal areas. Natural reoxygenation could reinstate anoxic sediments as sites where fixed N is removed efficiently. To investigate this further, we...
Article
Full-text available
Estuarine sediments are critical for the remediation of large amounts of anthropogenic nitrogen (N) loading via production of N 2 from nitrate by denitrification. However, nitrate is also recycled within sediments by dissimilatory nitrate reduction to ammonium (DNRA). Understanding the factors that influence the balance between denitrification and...
Data
Robertson, Elizabeth (2021): Benthic nitrate reduction process rates from around the Baltic Sea (May 2016). PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.935305 (DOI registration in progress)
Article
Full-text available
In situ incubations of sediment with overlying water provide valuable and consistent information about benthic fluxes and processes at the sediment-water interface. In this paper, we describe our experiences and a variety of applications from the last 14 years and 308 deployments with the Gothenburg benthic chamber lander systems. We give examples...
Article
Full-text available
Understanding the biogeochemical controls on the partitioning between nitrogen (N) removal through denitrification and anaerobic ammonium oxidation (anammox), and N recycling via dissimilatory nitrate (NO 3 −) reduction to ammonium (DNRA) is crucial for constraining lacustrine N budgets. Besides organic carbon, inorganic compounds may serve as elec...
Article
Full-text available
Understanding the biogeochemical controls on the partitioning between nitrogen (N) removal through denitrification and anaerobic ammonium oxidation (anammox), and N recycling via dissimilatory nitrate (NO3-) reduction to ammonium (DNRA) is crucial for constraining lacustrine N budgets. Besides organic carbon, inorganic compounds may serve as electr...
Article
Full-text available
The planktonic marine diatom Skeletonema marinoi forms resting stages, which can survive for decades buried in aphotic, anoxic sediments and resume growth when re-exposed to light, oxygen, and nutrients. The mechanisms by which they maintain cell viability during dormancy are currently poorly known. Here, we investigated cell-specific nitrogen (N)...
Preprint
Full-text available
Coastal systems can act as filters for anthropogenic nutrient input into marine environments. Here, we assess the processes controlling the removal of phosphorus (P) and nitrogen (N) for four sites in the eutrophic Stockholm Archipelago. Bottom water concentrations of oxygen and P are inversely correlated. This is attributed to the seasonal release...
Article
Full-text available
The fate of nitrogen in natural environments is controlled by anaerobic nitrate-reducing processes by which nitrogen is removed as N2 or retained as NH4+. These processes can potentially be driven by oxidation of reduced inorganic compounds at oxic-anoxic interfaces. Several studies have investigated the use of Fe2+ as an electron donor in nitrate...
Conference Paper
Full-text available
Estuarine sediments are critical for the remediation of large amounts of anthropogenic N loading via production of N2 from nitrate by denitrification. However, nitrate can also be recycled within sediments by dissimilatory nitrate reduction to ammonium (DNRA), where bioavailable nitrogen is transported further to coastal zones, adding to eutrophica...
Conference Paper
Full-text available
In anoxic environments, iron reduction can function as a significant pathway for organic matter oxidation, resulting in the production of ferrous iron. This Fe 2+ can potentially be re-oxidised by nitrogen species formed in surface sediment (e.g. nitrate; NO 3-, nitrite; NO 2-). The fate of such oxidized nitrogen compounds is of particular importan...

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Projects

Projects (2)
Project
Primary production by diatoms based on nitrate in upwelling zones, and primary production by N2-fixing cyanobacteria comprise substantial sources of new production in the ocean. This new production reflects the export production out of the euphotic zone leading to net CO2 sequestration from the atmosphere by the ocean over longer time-scales. A significant fraction of these carbon and nitrogen fluxes are associated to suspended and sinking organic aggregates composed of diatoms, cyanobacteria, and/or detritus including zooplankton fecal pellets in the ocean. Hence, our mechanistic understanding and quantification of the processes controlling small-scale O2, carbon, and nitrogen fluxes associated with these aggregates, are important for our understanding of large-scale biogeochemical processes in the ocean. By combining digital holographic microscopy, microsensors (O2 and N2O), stable isotope tracers, novel secondary ion mass spectrometry (SIMS), and sensitive fluorometry with analytical and numerical modeling, we aim to: 1) quantify the physical/chemical/biological constraints for bacterial growth, and carbon and nitrogen transformation rates in suspended and sinking organic aggregates in the ocean 2) quantify the fluxes of C and N from diatoms to associated bacteria at a single cell level to reveal the identity, specificity, and activity of various bacteria colonizing aggregates 3) quantify O2 and inorganic nitrogen fluxes in suspended and sinking organic aggregate as a function of O2 concentration in the ambient water
Project
Chain-forming diatoms are key CO2-fixing organisms in the ocean. They play a significant role in the ocean’s biological carbon pump by forming fast-sinking aggregates, which are exported from the upper sunlit ocean to the mesopelagic and deep-ocean, or to shallow sediments. Using secondary ion mass spectrometry (SIMS) in combination with stable isotopic tracers we can now reveal assimilation of dissolved inorganic carbon (DIC) and nitrogen (DIN) at a single-cell level in mixed field populations. With this novel approach, we will investigate the correlation between CO2 sequestration and nutrient uptake in chain-forming diatoms from measurements of its physical, chemical and biological constraints in field populations, in laboratory cultures, and in diatom cells revived from up to 100 years old spores recently recovered from anoxic, laminated sediments.