Scholarships
Opportunities

contact

Département de Biologie /
Pavillon Alexandre-Vachon
1045, av. de la Médecine, local 2078
Université Laval
Québec (Québec) G1V 0A6
Canada
Phone : +1 418 656 5193

00

SCHOLARSHIP OPPORTUNITIES

Many scholarships are available to conduct graduate studies under the supervision of the professors associated with the program. The research projects currently available for funding are listed below. For more information, please contact Debra Christiansen-Stowe.

Ocean ecosystems/geosystems

Major changes are taking place in the Arctic Ocean. The summer sea-ice cover has decreased by more than 30% over the last three decades, which allows much more sunlight to penetrate into the ocean surface layer. Combined with an increase in seawater temperature two times larger than that global scale, an increase in freshwater runoff from major Arctic rivers, and an increase in UV radiation, this should deeply modify marine biotopes. Phytoplankton, which form the basis of the marine food chain, is at the forefront of living organisms that are impacted by these changes.

STUDY OF THE OPTICAL PROPERTIES OF THE ARCTIC OCEAN AND APPLICATION TO REMOTE SENSING OF OCEAN COLOUR

SUPERVISOR

Marcel Babin, Canada Excellence Research Chair on Remote sensing of Canada's new Arctic frontier, Université Laval

co-SUPERVISOR

Simon Bélanger, Université du Québec à Rimouski

Primary production in the Arctic Ocean may increase significantly in the near future as a result of sea-ice receding. Strengthened vertical stratification resulting from increased freshwater input may, however, limit nutrient supply in the surface lit layer and thereby limit primary production. Some key southern phytoplankton species are already migrating toward the Arctic Ocean. The structure of the food web is being modified. More observations in this remote and harsh environment are required to better quantify and understand these changes. Ocean color remote sensing from satellite is the most appropriate tool to monitor primary production in the Arctic Ocean and determine the spatial distribution of some key phytoplankton species or groups. Its use in this environment is however impeded by a number of difficulties, notably the optical complexity of seawater, which makes standard ocean colour algorithms inadequate. The goal of this Ph.D. work will be to further document the optical properties of Arctic seawater, and to develop and validate ocean colour algorithms that will allow monitoring primary production and some key phytoplankton species and/or groups. Special emphasis will be put on the use of sun-induced chlorophyll fluorescence, a signal measured by current ocean color sensors but largely underused in optically complex waters. The research activity will include field work, radiative transfer numerical experiments, and processing of ocean colour data.

MONITORING OF ICE-EDGE BLOOMS IN THE ARCTIC OCEAN FROM REMOTE SENSING OF OCEAN COLOUR

SUPERVISOR

Marcel Babin, Canada Excellence Research Chair on Remote sensing of Canada's new Arctic frontier, Université Laval

co-SUPERVISOR

Simon Bélanger, Université du Québec à Rimouski

A large fraction of primary production by phytoplankton occurs in so-called ice-edge blooms (IEBs). IEBs form at (and follow) the ice-edge during spring when sea-ice progressively recedes. Vertical stratification, nutrient availability and light are then optimal to support a bloom for about 3 weeks. IEBs are found over the seasonal ice zone (SIZ), which covers the area between the maximum and minimum yearly sea-ice extent. It is expected that the SIZ will cover the whole Arctic Ocean in one or two decades when multiyear ice will completely disappear. Therefore, IEBs will become an even more important phenomenon in the Arctic Ocean. To better quantify and understand the dynamics of IEBs, it is necessary to augment our observing capacity. Ocean color remote sensing from satellite is the most appropriate tool to monitor primary production in the Arctic Ocean, and has recently proved to be a promising tool for monitoring IEBs. The complexity of the spatial distribution of IEBs and the fact that IEBs are always adjacent to or intermingled with sea ice make, however, the use of ocean colour remote sensing difficult. The goal of this Ph.D. work will be to develop improved approaches for using ocean colour remote sensing to monitor IEBs in the Arctic Ocean, based on state-of-the-art image analysis methods. The research activity will include field work, radiative transfer numerical experiments, and processing of ocean colour data.

STUDY OF THE IMPACT CLIMATE CHANGE ON THE PHYSIOLOGY OF PHYTOPLANKTONIC SPECIES IN THE ARCTIC OCEAN

SUPERVISOR

Marcel Babin, Canada Excellence Research Chair on Remote sensing of Canada's new Arctic frontier, Université Laval

Primary production increases as the sea-ice covers decreases, despite strengthened stratification that may limit nutrient supply in the surface waters. Some key southern phytoplankton species are already migrating toward the Arctic Ocean. The structure of the food web is being modified. To anticipate the extent of these changes in the near future, it is necessary to better understand the physiology of Arctic phytoplankton species, and more specifically their photosynthesis and growth properties. Several key Arctic phytoplankton species (mainly diatoms and prasinophytes) have recently been isolated and can be grown in the laboratory. The objective of this Ph.D. project is to characterize and parameterize the growth and photosynthetic properties of those strains using state-of-the-art bioreactors. Experiments will be conducted in which different light intensities, temperatures and nutrient availabilities (or any combination of these factors) will be applied. The results from these experiments will be used to design models for predicting the impact of climate change on Arctic marine ecosystems.

THE REGULATION OF ARCTIC ICE EDGE BLOOMS BY ZOOPLANKTON AND IMPLICATIONS FOR THE BIOLOGICAL PUMP IN A PERIOD OF DECLINING ICE COVER

SUPERVISOR

Louis Fortier, Université Laval

co-SUPERVISOR

Marcel Babin, Canada Excellence Research Chair on Remote sensing of Canada's new Arctic frontier, Université Laval

Ice edge blooms are recurrent and near-ubiquitous structures that form following the melting of seasonal ice across the Arctic Ocean in spring. They account for a rapid but substantial proportion (>50%) of primary production over the annual cycle and provide a pivotal fodder for Arctic food webs. Climate-related changes in the timing and intensity of ice edge blooms might have profound implications for both the transfer of energy to higher trophic levels and for the vertical export of carbon and nutrients to depth. Understanding the consequences of match-mismatch scenarios between ice edge blooms and zooplankton populations are thus key to our comprehension of the nature and magnitude of the biological pump in the rapidly changing Arctic Ocean.

The proposed Ph.D. project aims at investigating the role of Arctic zooplankton in regulating the development and fate of an ice edge bloom. The major goal will be to quantify the transfer pathways and to characterize the sources and sinks of major biogeochemical elements (C, N, P, Si) between the ice edge bloom, the community of zooplankton and the sinking particle flux. The candidate will be able to use a multi-methodological approach combining traditional samplers (rosette, sediment traps, zooplankton nets), in situ ocean profilers (automated underwater vehicle, particle cameras), biochemical assays (CHN, IP25, delta13C, delta15N) and microscopic observations. The project will be developed in the multidisciplinary framework of the Takuvik CNRS-Université Laval Joint Laboratory located in Québec City (Canada).

SPATIOTEMPORAL VARIABILITY IN THE MESOZOOPLANKTON – PRIMARY PRODUCTION COUPLING USING OPTICAL IMAGING SYSTEMS.

SUPERVISOR

Louis Fortier, Université Laval

co-SUPERVISOR

Marcel Babin, Canada Excellence Research Chair on Remote sensing of Canada's new Arctic frontier, Université Laval

Arctic mesozooplankton organisms (0.2 – 2 cm), largely dominated by copepods, transfer the bulk of energy and carbon from primary producers to the vertebrate fauna of the Arctic Ocean (fish, marine mammals, seabirds). Traditional net sampling, which integrates or roughly stratifies the water column, does not provide the necessary resolution for studying the fine-scale vertical distribution of key zooplankton components. In particular, zooplankton often form thin layers over only a few centimeters of the water column, which are critically important for the dynamics and fate of primary production, as well as for prey supply of upper trophic levels. The lack of resolution from traditional zooplankton samplers is resolved with recent in situ optical imaging systems for zooplankton identification. These devices allow determining the exact vertical distribution of organisms in the water column, as well as corresponding environment data (e.g. T, S, Chl a). The central objective of this study is to assess spatiotemporal variability in the coupling between primary and secondary production in the Canadian Arctic Ocean.

Zooplankton will be sampled onboard the CCGS Amundsen with in situ imaging systems such as the "Underwater Vision Profiler" (UVP) and the Lightframe On-sight Key species Investigation System" (LOKI) throughout the Canadian Arctic archipelago. The candidate will first develop a database for the automatic taxonomic classification of zooplankton using images of single organisms identified to the species level. Once the automatic identification process is validated, vertical abundance and biomass profiles of key zooplankton taxa will be determined to quantify their respective role on the dynamics and fate of primary production.

COMPARATIVE TRANSCRIPTOMICS OF POLAR PHYTOPLANKTONIC SPECIES

SUPERVISOR

Connie Lovejoy, Université Laval

co-SUPERVISOR

Marcel Babin, Canada Excellence Research Chair on Remote sensing of Canada's new Arctic frontier, Université Laval

Doctoral Project on comparative transcriptomics of microbial eukaryotes in the changing Arctic Ocean. The successful candidate will research the basis of adaption to cold, nutrient stress and changing light regimes on small protists isolated from the Arctic Ocean. The protists are part of a larger genome sequencing project, which will provide opportunities for international collaboration and training. The successful candidate will become part of a dynamic microbial oceanography laboratory with access to algal culture facilities, next generation high throughput sequencing and bioinformatics support.

TAXONOMIC AND FUNCTIONAL DIVERSITY OF ARCTIC CHROMIST FLAGELLATES

SUPERVISOR

Connie Lovejoy, Université Laval

co-SUPERVISOR

Marcel Babin, Canada Excellence Research Chair on Remote sensing of Canada's new Arctic frontier, Université Laval

Doctoral Project on the taxonomic and functional diversity of Arctic chromist flagellates (single celled photosynthetic eukaryotes or protists) in the Arctic Ocean and surrounding seas. Specifically the student will use high throughput tag sequencing to investigate the partitioning of space within the upper euphotic zone of the salinity stratified Arctic Ocean. The project will entail participation in oceanographic missions to the Arctic. The student will use microcosms to test community responses to changes in light, nutrients and salinity. The successful candidate will become part of a dynamic microbial oceanography laboratory.

FINE-SCALE VERTICAL RESOLUTION OF NITROGEN CYCLING IN SUBSURFACE CHLOROPHYLL LAYERS OF THE HIGH ARCTIC OCEAN

SUPERVISOR

Jean-Eric Tremblay, Université Laval

co-SUPERVISOR

Marcel Babin, Canada Excellence Research Chair on Remote sensing of Canada's new Arctic frontier, Université Laval

Recent work in our research group has shown that subsurface chlorophyll maxima (SCM) are dominant, widespread features in the highly stratified Arctic Ocean. However their contribution to total, new and regenerated primary production and how this contribution is likely to be altered by climate change is poorly known. This PhD project will investigate the photosynthetic and nutritive ecology of diffuse and sharp subsurface chlorophyll layers in contrasted environments (shelf, offshore, marginal ice zone) of the High Canadian Arctic. The work will include direct estimations of autotrophic (photosynthesis, nitrification, N assimilation) and regenerative (ammonification) processes at high vertical resolution. This work will be coupled to targeted gene surveys and eukaryotic diversity estimates.

UTILIZATION OF ORGANIC NITROGEN BY PROKARYOTIC AND EUKARYOTIC PLANKTON IN THE COASTAL ARCTIC OCEAN.

SUPERVISOR

Jean-Eric Tremblay, Université Laval

co-SUPERVISOR

Marcel Babin, Canada Excellence Research Chair on Remote sensing of Canada's new Arctic frontier, Université Laval

Nitrogen is considered to be the limiting element for primary production in coastal waters of the High Arctic. Changes in the supply of nutrients by rivers (discharge, permafrost thawing), adjacent oceans, the atmosphere and the deep ocean are likely to exert a strong influence on future primary production. Yet the extent to which Arctic primary producers use different sources of nitrogen, especially organic ones, and the importance of prokaryotes and photochemical processes in making this nitrogen available (or labile) is poorly known. This PhD project will combine gene surveys with direct estimations of the uptake/transformation of different nitrogen substrates in contrasted shelf environments of the Canadian Arctic. This investigation will be complemented by controlled laboratory work on the ability of ecologically-relevant species to grow with organic nitrogen substrates under different regimes of light and temperature.

REMOTE SENSING OF OCEAN COLOUR IN POLAR REGIONS: THE PROBLEMS OF LOW SUN ELEVATION AND SEA ICE CONTAMINATION

SUPERVISOR

Simon Bélanger, Université du Québec à Rimouski

co-SUPERVISOR

Marcel Babin, Canada Excellence Research Chair on Remote sensing of Canada's new Arctic frontier, Université Laval

Satellite ocean colour remote sensing (OCRS) is a powerful tool to monitor the remote arctic marine ecosystems. Meaningful bio-optical and biogeochemical properties of the upper ocean - phytoplankton chlorophyll-a, particulate and dissolved organic carbon concentrations - can be estimated from the spectral water-leaving radiance (Lwn), which is derived from OCRS data after the removal of the atmospheric signal, the so called atmospheric correction (AC). The quality of AC over polar regions, however, may be significantly affected in presence of 1) prevailing low solar elevations and 2) sea ice. On one hand, at high latitudes, the Sun zenith angle is generally larger than 55°, and often larger than the maximum (70°) for which atmospheric correction algorithms have been developed based on plane-parallel radiative transfer calculations. Consequently, at high latitudes, a large fraction of the ocean surface is undocumented for a large part of the year even though primary production may be significant. Whether or not this is a major problem must be determined, and the quality of standard atmospheric corrections for high Sun zenith angle must be assessed. On the other hand, Bélanger et al. (2007) and Wang and Shi (2009) have examined, based on radiative transfer simulations, the effects of the sea ice adjacency and of sub-pixel ice contamination on retrieved Lwn and level-2 ocean products. They found significant impacts over the first several kilometers from the ice-edge and for concentrations of sub-pixel ice floes beyond a few percent. The extent of the problem (i.e. whether it compromises the use of ocean color) in typical polar conditions is unknown. The research proposal involves radiative transfer modelling, AC algorithms development and remote sensing data processing. Thus, the PhD candidate will preferably have a solid background in atmospheric physics and possibly in radiative transfer modeling, and skills in computer programming (C or Fortran). The project will be conducted in Rimouski under the supervision of Dr. Simon Bélanger and co-supervised by Dr. Marcel Babin, the chairholder of the Canada Excellence Research Chair in Remote Sensing of Canada's New Arctic Frontier, Université Laval.

Land ecosystems/geosystems

The thawing of permafrost in response to global warming will lead to important changes of the polar and subpolar ecogeosystems. Anthropogenic activities, at large, impact and will be impacted by such changes. One of the negative feedbacks is the fate of soil metals in the context of thawing permafrost. Indeed, a changing environment may significantly change metal cycles by altering soil-water balance, vegetation types, aquatic productivity and land-use. Research projects at Takuvik aim to study different aspects of the behavoiur of metals in arctic and sub-arctic regions, including their sources and distribution in the various compartments of eco- and geosystems, as well as the exposition of northern populations to metallic contaminants.

SNOW-CLIMATE-PERMAFROST-VEGETATION INTERACTION - PhD thesis.

SUPERVISOR

Florent Domine, Takuvik-CEN, Département de Chimie, Université Laval

Snow impacts climate because of its strong albedo and because its insulating properties limit ground-atmosphere heat exchanges. But since climatic conditions determine snow physical properties, there aresnow-climate feedbacks that need to be quantified. Snow physical properties, and in particular its thermal conductivity, are also affected by the type of vegetation. Shrubs and trees protect snow from wind action, reducing its density and its thermal conductivity, so that snow in regions with high vegetation strongly insulates the ground. This limits winter ground cooling and accelerates permafrost thawing, resulting in complex feedbacks between snow, climate, vegetation and permafrost that have so far not been quantified. This project will plan and perform field work to study snow physical properties in the Canadian subarctic, arctic and high arctic and will attempt to elucidate the detailed mechanisms of these feedbacks. Data will be used in collaboration with several modeling groups to improve predictions of permafrost thawing and arctic warming

SPECIATION AND ISOTOPIC COMPOSITION OF SELENIUM, SULFURE AND RELATED METALS IN THEMOKARST LAKE SYSTEMS - PhD thesis.

SUPERVISOR

Jean Carignan, Takuvik-CEN, Département de Chimie, Université Laval

co-SUPERVISOR

David Amouroux, CNRS-IPREM, Pau (France)

The Arctic Metals project aims at developing tools (speciation, isotopes) to assess metal sources, mobility and reactivity in "remote" areas of the Arctic and sub-Arctic and to determine their bio-availability for northern biota and populations. Accelerated air warming in Northern areas results in the thawing of permafrost and the subseuently development of thaw ponds or thermokarst lakes. Metals deposited are in lake sediments through atmospheric deposition or the remobilization of thawing soils.
We will be recruiting a PhD candidate in isotope chemistry. The student will specialize and focus his/her work on the geochemistry of selenium and sulfur. Dissolved S-Se species in aquatic environments are +4 and/or +6 ions that can be reduced by bacteria or plankton to S2-- Se2- and eventually volatile organic molecules DMS, DMSe and even DMSSe. The chemical speciation of S and Se is a critical prerequisite in assessing environmental reactivity as the bioavailability and toxicity of S and Se are greatly affected by their chemical forms. The student will be in charge of Se isotopic analyses related to experimental work on Se reduction and production of organic Se molecules as well as the collection and analysis of water and sediment samples from the Hudson Bay area. The student may have to develop techniques to improve the sensitivity of the analysis, particularly for DMSe. Internships at French laboratories (Pau, Nancy) will be necessary.

ISOTOPE TRACING OF SOURCES AND PHYTO-AVAILABILITY OF METALS IN THERMOKARST LAKE SYSTEMS - MSc. thesis.

SUPERVISOR

Jean Carignan, Takuvik-CEN, Département de Chimie, Université Laval

co-SUPERVISOR

Reinhard Pienitz, Takuvik-CEN, Département de Géographie, Université Laval

The Arctic Metals project aims at developing tools (speciation, isotopes) to assess metal sources, mobility and reactivity in "remote" areas of the Arctic and sub-Arctic and to determine their bio-availability for northern biota and populations. Accelerated air warming in Northern areas results in the thawing of permafrost and the subsequent development of thaw ponds or thermokarst lakes. Metals deposited are in lake sediments through atmospheric deposition or the remobilization of thawing soils.
We will be recruiting a MSc. candidate in isotope chemistry. The student will be using the stable isotope spike equilibration technique to access the phyto-availability of metals (Ni, Zn, Hg, Se, Pb) in soils (surface active zone) surrounding the lakes of interest (Hudson Bay area). Metal concentrations will be determined in lake water and sediments (cores) and in vegetation (grass, small trees, berries, etc) surrounding the thaw lakes in order to estimate the flux of metals transferring to vegetation and to aquatic systems in comparison to the available stock in soils. Pb isotope source tracing will be used.