Nicholas E. Mandrak

Nicholas E. Mandrak is an Associate Professor in Biological Sciences at the University of Toronto Scarborough (UTSC) in Toronto, Ontario. He is Director of the Conservation and Biodiversity stream of the professional M.Env.Sci. program at UTSC. Nick is a Research Associate of the Royal Ontario Museum and South Africa Institute of Aquatic Biodiversity. He is the Co-Chair of the Freshwater Fishes Species Specialist Subcommittee of COSEWIC. Nick is an Associate Editor of Biological Invasions and on the Editorial Board of the Journal of Aquatic Ecosystem Health and Management. He is President of the Canadian Aquatic Resources Section of the American Fisheries Society. His research interests are the biodiversity, biogeography, and conservation of Canadian freshwater fishes, with emphasis on endangered and invasive fishes. Nick has co-authored over 100 primary publications, over 100 government reports, 40 COSEWIC reports, and three books, including the ROM Field Guide to Ontario Fishes.

Post-Doctoral Fellows:

Dr. Nathan Lujan

I obtained my PhD from Auburn University in 2009, followed by post-doctoral research at Texas A&M University, the University of Toronto, the Academy of Natural Sciences, and the Royal Ontario Museum. I have published over 25 papers in a wide range of journals and have organized, led, or participated in 18 ichthyofaunal surveys of rivers in seven countries. Broad questions that drive my research include: How many fish species are there? What rules govern the community assembly of riverine primary consumers? How do disjunct habitats within stream and river networks affect the gene flow and evolutionary specialization of freshwater fishes? I enjoy backpacking, camping, traveling and exploring with my wife Bernadette and dog Percy. To find out more, visit my website at:

PhD Lab Members (UTSC):

Sara Campbell: I am currently a PhD Candidate examining spatio-temporal community assembly using multiple dimensions of biodiversity.  I graduated from the University of Vermont (2013) with a BSc. in Biological Sciences, where I contributed to various projects including a longterm study on the minimum viable population of fiddlehead ferns, how biodiversity impacts cattle health and well-being, and immune responses to Influenza.  Following undergrad, I spent a year volunteering in the Cadotte lab, where I expanded my interests in examining different facets of biodiversity.  My broad interests are in community ecology, specifically, species coexistence, how ecological communities are formed, and using novel tools to predict invasion success using ecological theory.  My interests outside of science include competitive running, scent detection with my dog River, and being outdoors.


Rowshyra Castañeda, MSc

I am currently a PhD Candidate with Nick Mandrak and Olaf Weyl (SAIAB) studying the detection and quantification of rare freshwater fishes. I am assessing the use of underwater cameras as a non-invasive novel method. I am combining mathematical models, experiments, and field work to develop this method. I completed my undergrad and MSc at McGill University, where I worked a variety of projects, ranging from behavioural neurobiology, to evolutionary ecology, invasion biology, and conservation biology. These research projects have allowed me to explore biodiversity at home and around the world, fulfilling my need to travel and explore new places and cultures. When I’m not doing thesis research or traveling, I spend my time doing science outreach for youth, especially for young girls interested in Science, Technology, Engineering, and Mathematics (STEM). I’ve also dabbled in microplastic research and actively help with public outreach projects. To find out more visit my website.


Tej Heer, MSc

I am a PhD candidate in the Department of Physical and Environmental Sciences. I received my BSc in Physics from Mcgill University in 2013, followed by a MSc in Climate Change from the University of College London in 2015. My current project attempts to predict where Asian carps  would potentially spawn in the Canadian Great Lakes Basin. Specifically, I am attempting to use 3-D hydrodynamic modelling to simulate the movement of carp eggs in potential spawning tributaries. In general, I enjoy applied physics research, both in the atmosphere and in waterways, especially those that involve climate change or conservation.




Fielding Montgomery

I am a PhD candidate in the Ecology and Evolutionary Biology program, co-supervised by Nick Mandrak and Scott Reid from the OMNRF. I completed my BSc in Biology at Dalhousie University, with a certificate in Environmental Impact Assessment. I am interested in applied ecology and conservation of freshwater fishes. My research focuses mainly on the impacts of habitat loss and fragmentation on local and regional fish extinction, using wetlands as a model system. I spend my summers camping by the water, and my winters in the rink! Find out more at my website.


Thaïs Bernos: PhD Student


Paul Bzonek, MSc

I am a PhD Student with Nick Mandrak at UTSC. My current research interests are centred around the behaviours and movement patterns of fish, and how this can impact movement and dispersal across geographic bottlenecks. For my MSc, I evaluated how Common Carp respond to non-physical behavioural barriers such as acoustic and visual stimuli. This work pertains to invasive Asian Carps and their potential dispersal into Great Lakes ecosystems. I completed a BSc. at the University of Guelph with a major in Ecology and minor in Zoology.  My non-academic interests include travel, Scuba diving, reading and water-skiing.



Emily Chenery, MEnvSc

I am a PhD student in the Department of Physical and Environmental Sciences, co-supervised by Péter Molnár and Nicholas Mandrak. Originally from the UK, I graduated in 2016 from the University of Toronto with a Masters of Environmental Science, specializing in Conservation & Biodiversity. My main interests lie in predicting species’ survival under changing environmental conditions, particularly invasive species, parasites and diseases of wildlife health concern. My Masters research used a novel combination of expert opinion surveys and mechanistic modelling to investigate the transmission potential of aquatic invasive species in the Laurentian Great Lakes. My doctoral research focuses on understanding the ongoing range expansion into Yukon of the winter tick, a parasite of cervids but particularly moose, the pathology of which ranges from mild to severe. Using a combination of fieldwork, modelling and citizen science, I aim to develop new approaches to understanding population dynamics of species with little data but potentially large implications for conservation policy and practice.

Erik Dean, MEnvSc: PhD student

Kyla Greenham, MSc: I am PhD student in the Department of Physical and Environmental Sciences. I graduated from Dalhousie University with a Bachelor of Science with Honours in Marine Biology. My research interests centered on the combined impact of environmental pollutants and human cleaning surfactants on the microscopic trophic level. I then completed my Masters degree at the University of Guelph in Aquaculture studying fish health management as a result of stressors in husbandry practices. I am currently the Curator of Conservation & Environment and Acting Curator of Fishes & Marine Invertebrates for the Toronto Zoo. I specialize in the impact of climate change on native wildlife and engaging the public in taking action to mitigate climate change. I also oversee the Zoo’s Sustainability platform to reduce its ecological footprint. I am currently interested in assessing the resiliency of native fish species to invasive species and climate change. I hope to expand the Toronto Zoo’s conservation programs for saving local freshwater fishes with hands on programs to stop the introduction of invasive species and create fish recovery programs to improve the resiliency of fish populations and aquatic habitat against climate change. With what time I have left in my day, I enjoy camping with my husband and son, running the Ontario BioBlitz program and scuba diving.


Meagan Kindree, MSc

I am a PhD student in the Department of Ecology and Evolutionary Biology, co-supervised by Nick Mandrak and Nick Jones from the OMNRF. I completed by undergraduate degree at Dalhousie University, with a certificate in Environmental Impact Assessment and Geographic Information Systems. For my MSc, studying the effect of gear type on the Index of Biotic Integrity (IBI) in the Huron-Erie Corridor Areas of Concern. I am interested in freshwater fish distribution patterns in the Great Lakes basin. My research aims to develop landscape-based distribution models of fish species and assess their change over time due to the influence of multiple stressors. This work will fill knowledge gaps in Canadian fish distribution patterns, particularly fish species at risk. I also will assess how the physical and anthropogenic connectivity between waterbodies influences the predicted future distributions of fish species. Outside of the office I spend my time fishing, hiking, scuba diving, and reading.


Noelle Stratton, M.Env.

I am a PhD student in the Department of Physical and Environmental Science, co-supervised by Nick Mandrak and Nicole Klenk. I completed my undergraduate Biology degree at Algoma University, conducting aquatic invasive species research. I then completed my Master of Environmental Sciences at University of Guelph. I am currently interested in exploring the linkages that exist between policy makers, public perception and scientific researchers, particularly as they relate to the implementation of early detection and rapid response (EDRR) for aquatic invasive species in the Great Lakes. My hope is to discover some of the factors contributing to the favouring of some species as targets for action at the expense of others, and hopefully produce recommendations regarding how the barriers to effective EDRR might be overcome. Outside of academia, my interests include gaming (video and table-top), traveling, and reading.

PhD Lab Members (McGill University):

Suncica Avlijas, MSc: PhD Candidate co-supervised with Tony Ricciardi.

Dustin Raab, MSc: PhD Candidate co-supervised with Tony Ricciardi.

MSc Lab Members:

Kavishka Gallage: MSc student


Alexandra Leclair
Alexandra Leclair

I am an MSc student in the Department of Ecology and Evolutionary Biology at UTSC co-supervised by Nicholas Mandrak and Andrew Drake from Fisheries and Oceans Canada. I completed my BSc at the University of Toronto, with a double major in Ecology and Evolutionary Biology and Philosophy. My Masters’ thesis aims to evaluate the potential thermal impacts facing an endangered Canadian fish species, Redside Dace (Clinostomus elongatus), by assessing its capacity to persist in warmer waters. We hope to better understand the physiological limits of Redside Dace and assess the species’ viability in the face of current climate-change projections. When I am not in the lab or sampling in the field, you can find me camping across Ontario, enjoying the outdoors or attending concerts.


Courtney Leermakers

I am currently a MSc student with Nick Mandrak and Marc Cadotte evaluating PIT tag placement for freshwater turtles to increase detection probability and determining road mortality hotspot variables. This research is important for turtle conservation by understanding variables that cause hotspots and improving detection of PIT tags to study turtle movement and the use of ecopassages. I am combining statistical analysis, experiments and field work to develop this method. I completed my undergrad at Trent University and Fleming College as an Ecological Restoration Honours B.Sc. joint program. Combining my passion for turtle conservation and restoration studies I wish to fill knowledge gaps to improve the connection of landscapes for turtle movement.

Yiminxue Zheng: I’m a Master Student studying Ecology and Evolutionary Biology at the University of Toronto Scarborough Campus, supervised by Nick Mandrak. I completed my BSc at UTSC as well, with a specialization in Biodiversity, Ecology, and Evolution. I have a broad interest in ecology in the context of conservation. In a warming world driven by anthropogenic stressors, my research looks at the thermal stress response of freshwater fishes to increasing water temperatures, using Brook Trout as my study organism.  I am a writer at heart, spending most of my doing so both academically and as a hobby.

MSc Lab Member (McGill University):

Lindsay Potts: MSc Candidate co-supervised with Lauren Chapman.

Lab Alumni:

Brett Allen, MSc 2017

Shannon Ritchie, MSc 2017

Dr. Pasan Samarasin, Post-doc 2015-2017

Dr. Andrew Drake, Post-doc 2013-2016

Natalie Rook, MSc 2016

Gabrielle Malcolm, MSc 2015