Katie Marshall

Associate Professor

Research Classification

Research Interests

Environmental Change
Marine biodiversity
Population Ecology
invertebrates and temperature adaptation

Relevant Thesis-Based Degree Programs

Affiliations to Research Centres, Institutes & Clusters

Research Options

I am available and interested in collaborations (e.g. clusters, grants).
I am interested in and conduct interdisciplinary research.
I am interested in working with undergraduate students on research projects.

Research Methodology

machine learning


Doctoral students

Population variation in enzyme activity, metabolic rate

I support public scholarship, e.g. through the Public Scholars Initiative, and am available to supervise students and Postdocs interested in collaborating with external partners as part of their research.
I support experiential learning experiences, such as internships and work placements, for my graduate students and Postdocs.
I am open to hosting Visiting International Research Students (non-degree, up to 12 months).
I am interested in supervising students to conduct interdisciplinary research.

Complete these steps before you reach out to a faculty member!

Check requirements
  • Familiarize yourself with program requirements. You want to learn as much as possible from the information available to you before you reach out to a faculty member. Be sure to visit the graduate degree program listing and program-specific websites.
  • Check whether the program requires you to seek commitment from a supervisor prior to submitting an application. For some programs this is an essential step while others match successful applicants with faculty members within the first year of study. This is either indicated in the program profile under "Admission Information & Requirements" - "Prepare Application" - "Supervision" or on the program website.
Focus your search
  • Identify specific faculty members who are conducting research in your specific area of interest.
  • Establish that your research interests align with the faculty member’s research interests.
    • Read up on the faculty members in the program and the research being conducted in the department.
    • Familiarize yourself with their work, read their recent publications and past theses/dissertations that they supervised. Be certain that their research is indeed what you are hoping to study.
Make a good impression
  • Compose an error-free and grammatically correct email addressed to your specifically targeted faculty member, and remember to use their correct titles.
    • Do not send non-specific, mass emails to everyone in the department hoping for a match.
    • Address the faculty members by name. Your contact should be genuine rather than generic.
  • Include a brief outline of your academic background, why you are interested in working with the faculty member, and what experience you could bring to the department. The supervision enquiry form guides you with targeted questions. Ensure to craft compelling answers to these questions.
  • Highlight your achievements and why you are a top student. Faculty members receive dozens of requests from prospective students and you may have less than 30 seconds to pique someone’s interest.
  • Demonstrate that you are familiar with their research:
    • Convey the specific ways you are a good fit for the program.
    • Convey the specific ways the program/lab/faculty member is a good fit for the research you are interested in/already conducting.
  • Be enthusiastic, but don’t overdo it.
Attend an information session

G+PS regularly provides virtual sessions that focus on admission requirements and procedures and tips how to improve your application.



These videos contain some general advice from faculty across UBC on finding and reaching out to a potential thesis supervisor.

Graduate Student Supervision

Master's Student Supervision

Theses completed in 2010 or later are listed below. Please note that there is a 6-12 month delay to add the latest theses.

Ice-binding proteins and invertebrate freeze tolerance in the intertidal zone (2022)

The mechanisms behind freeze tolerance in intertidal invertebrates is poorly understood. Due to differences in habitat and physiology, many biochemical processes utilized by terrestrial freeze tolerant organisms are not possible for intertidal invertebrates. Here I investigate the potential role of ice-binding proteins (IBPs) in the freeze tolerance of intertidal invertebrates. I first used bioinformatics to determine if there is molecular evidence for IBPs in intertidal invertebrates. I found a significant overrepresentation of putative IBPs in intertidal invertebrates relative to invertebrates from other habitat types, with no taxonomic patterns. These putative IBPs had high sequential similarity to type II antifreeze proteins from fish and antifreeze glycoproteins from both fish and ticks. Using some basic gene mapping I was also able to investigate the potential evolutionary origin of one of these putative IBPs from a mussel species (Mytilus coruscus), finding that a duplication and neofunctionalization event likely occurred. Knowing this I investigated the role of IBPs in the freeze tolerance of the local mussel species M. trossulus, a species that is more freeze tolerant in individuals from high shore positions during the winter months. I predicted that IBP activity would be measured in the protein extract of the species and that said activity would be greatest in winter individuals from high shore heights. Using a series of freezing assays and chemical treatments, I was able to find ice nucleation activity in M. trossulus and show strong evidence the activity was mediated by a protein, which I interpreted as IBPs. IBP activity did not vary by season or by shore height. This means IBPs may play a role in the year-long freeze tolerance of the species, but other mechanisms must explain the seasonal and tidal patterns in their freeze tolerance. In all, this thesis expands on our knowledge of intertidal freeze tolerance and provides the groundwork for future research into IBPs in multiple intertidal species.

View record

Mechanisms and consequences of surviving freezing in the bay mussel, Mytilus trossulus (2022)

Many intertidal invertebrates are freeze tolerant, meaning that they can survive ice formation within their bodies when exposed to freezing air temperatures during low tides. In my thesis I addressed two key questions regarding intertidal invertebrate freeze tolerance using the intertidal mussel Mytilus trossulus. First: What biochemical mechanisms enable freeze tolerance in intertidal invertebrates? Second: How do sublethal single and repeated freeze exposures negatively impact intertidal invertebrates? To address the first question, I investigated the role of osmolytes in mussel freeze tolerance, which may be cryoprotective by mitigating osmotic stress caused by freezing. I sought to determine if different osmolytes are interchangeable cryoprotectants (acting as colligative cryoprotectants), or if each osmolyte has unique a cryoprotective role, beyond just contributing to increased intracellular osmolarity (and thus act as non-colligative cryoprotectants). I did this by manipulating the composition of mussels’ intracellular osmolyte pools, and then testing how mussel freeze tolerance changed. I found that mussel freeze tolerance did not change after taurine and betaine increased in concentration, significantly decreased after alanine and glycine increased in concentration, and increased with increasing TMAO concentrations, indicating that TMAO may be cryoprotective. Overall, my findings indicate that osmolytes are non-colligative cryoprotectants. Next, I explored how mussels are impacted by sublethal freezing. I found that mussels do not filter feed for the first four hours post-freeze, but resume filter feeding 24 hours after freezing, which corresponds to my microscopic examinations of mussel gill tissues after freezing which reveal freeze-related damage. I also found that freezing decreased mussel posterior adductor strength, although this effect did not lead to an increase in mussel susceptibility to sea star predation. Finally, I found that mussels survived shorter, repeated freezes (where mussels received 1 day for recovery between freezes) better than prolonged freezes, when total time frozen is held constant. Thus, mussels are well-adapted to survive the short freezing events which they regularly encounter in their habitat, and one mechanism behind this survival could be TMAO accumulation. Further, the effects of sublethal freezing on mussel performance are limited, although how these effects scale up to entire mussel beds remains unknown.

View record

Plasticity of cold-hardiness in the eastern spruce budworm, Choristoneura fumiferana (2020)

Of all abiotic factors that drive range boundaries, temperature is the best studied because of its pervasive influence on biological processes. For populations at high-latitudes, extreme cold and the populations’ cold-hardiness set the range boundary. Phenotypic plasticity, where a single genotype results in differentiated phenotypes under differential environmental conditions, can assist populations in managing changing temperatures. Local adaptation in phenotypic plasticity, which results in different responses in different populations, can assist with the variability in temperature a species can experience across its range, especially at range boundaries. I used the eastern spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae) as a model system for exploring local adaptation and phenotypic plasticity of insect cold-hardiness. The species is one of the most destructive forest pests in North America, therefore accurately predicting its range and population growth is essential for management. In this thesis, I show that there is no transgenerational plasticity in cold-hardiness. However, I found a fitness cost associated with repeated cold exposures. Additionally, across the species’ range, I found both local adaptation of seasonal cold-hardiness and short-term plasticity of this trait. Therefore, the findings of this thesis provide evidence for including phenotypic plasticity and local adaptation when modelling species distributions under climate change.

View record


Current Students & Alumni

This is a small sample of students and/or alumni that have been supervised by this researcher. It is not meant as a comprehensive list.

If this is your researcher profile you can log in to the Faculty & Staff portal to update your details and provide recruitment preferences.


Discover the amazing research that is being conducted at UBC!