PhD position: NitrOnICE – Decipher Climate Change Impacts on the Arctic Ocean Nitrogen Microbiome – Deadline 31 May 2023

Nitrogen (N) is a fundamental element for living organisms and its biogeochemical cycle includes highly diverse microorganisms that make N compounds available for biological production. Previous studies from our research team suggested that prokaryotic communities involved in N-biogeochemistry strongly respond to environmental shifts across the Winter to Summer Arctic transition and that ammonia oxidizers assume a keystone function in promoting the recycling of N in the Arctic Ocean. In this PhD project we propose to extend previous observations in a complete study to understand the fixed-N sources and recycling pathways in the Arctic sea-ice changing scenario. We hypothesize that the fast retreat of sea ice will promote new N metabolic microbial functional regimes with transversal ecosystem implications. This PhD project will benefit from unique environmental observations, from 11 years of Arctic expeditions (2015 – 2026), experiments, and global data analysis in an international effort to produce reliable results and innovative science to understand the Arctic Ocean climate change perturbations on key microbial communities and their metabolism. This include i) novel knowledge to understand the sources of N (e.g. N-fixation, Nitrification) in the contemporary and future Arctic Ocean, which is still under debate without sufficient data that supports an effective answer ii) new and solid scientific understanding on the response of N microbiome and its functions on Arctic manifestations to climate changes, currently limited by the lack of biological long-term monitoring programs, and only achievable by undertaken the level of interdisciplinarity and completeness of our Arctic Ocean data set; iii) provide a comprehensive new picture on the environmental drivers of N cycle in diverse Arctic environments (fjord, shelf and oceanic domains). The results from this PhD project will represent an important breakthrough regarding Arctic ecosystem functioning, by filing critical gaps concerning the ecological role of N cycle in sustaining changes in Arctic productivity, diversity and their biological resources. This is crucial because there are dramatic changes happening in these areas, with retreating ice edge, thinning of the polar ice cap, potential disappearance of ice associated organisms, but the impact of these changing trends on microbial communities is currently unknown. In this context, the scientific outputs of this PhD project will also contribute to identify emerging risks and define actions prioritization by having the PhD student in close interaction and contributing to European Polar Board (EPB) activities.

This project is integrated in consolidated monitoring programs with already 8 years of microbiome genomics and functional data sets (2015-2022) and with monitoring missions planed for the next four years on behalf of ongoing financed projects from CIIMAR (Portugal), NPI (Norway) and DAL (Canada) (CONNECT2OCEANS-PTDC/CTA-AMB/4946/2020; and N-MICROARCTIC-2022.02983.PTDC), where the PhD student will participate and will be able to run field experiments, and where logistics are already guarantee.

Profile of applicants

Motivated and proactive young researcher with good academic performance and a genuine interest on Arctic science, specifically on microbial communities. Must hold a degree and master’s degree in Biology, Biogeochemistry or in other related field. We will prioritize candidates with experience on marine microbial communities sampling and laboratory techniques using molecular tools, with training on next generation sequencing platforms and bioinformatic pipelines (e.g metabarcoding, metagenomics).


Catarina Magalhães, CIIMAR (supervisor)
Julie LaRoche, DAL (co-supervisor)
Miguel Semedo, CIIMAR ( co-supervisor)

Host institutions

CIIMAR – Interdisciplinary Centre of Marine and Environmental Research, Portugal in collaboration with Dalhousie University, Canada

Doctoral programme

Climate change and sustainable Development Policies, LINK.


Scholarships are annual, renewable to a maximum of 4 years.


Applications and all supporting documents must be submitted online using the Application Form available on each scholarship page. Applications submitted by other means will not be accepted.

Application Process

Please note that you will need the items listed below. To ease the submission process, we suggest you gather them before you start your application:

  • Copy of your Identification Document (ID card, passport);
  • Certificate degree and grades transcript.
  • Your Curriculum Vitae and saved as PDF;
  • A Motivation Letter;
  • 2 Recommendation letters.

Notification of results

Evaluation results will be communicated to the email address provided by the candidates in the application form.


May 31 , 2023 |  23:59 Lisbon Time

Before applying, we STRONGLY RECOMMEND that you carefully read the Public Notice of the Call for detailed information on the application, evaluation and selection process.

Notice of the Call ( english version)

For  further information about this opportunity, click here.

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