People

Dr. Maggie Xenopoulos

I am a full Professor in the Department of Biology. I held a University Faculty Award position from Canada's Natural Sciences and Engineering Research Council (NSERC) and am the recipient of the Early Researcher Award from the Ontario Ministry of Research and Innovation. I was born in Montréal where I completed a B.Sc. (1995) at the Université du Québec à Montréal (UQAM). I completed an MSc (1997) under the supervision of Dr. David Bird at UQAM followed by a PhD (2001) with Dr. David W. Schindler from the University of Alberta. Before arriving at Trent University, I was an NSERC postdoctoral fellow (2001-2004) in the lab of Dr. David Lodge at the University of Notre Dame, USA.



Current Lab Members

more_vertSarah D'Amario

Lab Manager

closeSarah D'Amario

Lab Manager

Sarah joined the Xenopoulos lab in 2013 as a NSERC USRA student, completing a research project on linking dissolved organic matter quality to greenhouse gases in streams of varying land use. She completed her Master’s Thesis with the lab looking at the effects of flooding on nutrients in catchments across Ontario. Now, she assists students with their projects and keeps lab operations running smoothly.

more_vertChristina Fasching

Postdoctoral Fellow

closeChristina Fasching

Postdoctoral Fellow

My research focuses on the understanding of the biogeochemical processes which govern carbon and nutrient fluxes at the stream ecosystem level, particularly in the light of global climatic and environmental changes. My research is part of a long-term ecological project aimed at assessing and further advancing the understanding of the impact of long-term hydrological changes and extreme events on carbon dynamics in streams. Furthermore, I will be investigating the impact of browning on carbon and nutrient cycling in inland waters and consequently CO2 emissions from therein.

more_vertStephen Oni

Postdoctoral Fellow

closeStephen Oni

Postdoctoral Fellow

Changing land use and climate are exerting great pressure on our limited water resources. Therefore, my research goal is to better understand the influence of existing or anticipated human activities/climate on the aquatic ecosystems. I adopt a strong integrated approach that includes monitoring and suites of analytical/modelling techniques to assess changing watershed/ecosystem processes. Using mass balance approach, I am currently working on carbon balance of Lake Erie to determine whether the lake is a net sink or source of carbon.

more_vertKern Lee

Postdoctoral Fellow

closeKern Lee

Postdoctoral Fellow

more_vertMarisha Lamond

Doctoral Candidate

closeMarisha Lamond

Doctoral Candidate

Marisha's research interests include the protection of drinking water sources, wastewater treatment, and sustainable stormwater management practices. Her PhD research focuses on the hydrochemical functioning of several urban stormwater ponds in Ontario.

more_vertSandra Klemet-N’Guessa

Doctoral Candidate

closeSandra Klemet-N’Guessa

Master’s Student

I study the role that aquatic animals (fish and invertebrates) play in the cycling of nutrients in both streams and lake ecosystems, and how this role may vary by trophic position and be modulated by abiotic factors such as dissolved organic matter quality and quantity. I use two approaches to address this question: a meta-analysis approach using a large database on aquatic animal-mediated cycling of nutrients across various habitats (varying in DOM quantity) and taxa, and an empirical approach through the sampling of fish and invertebrates across Great Lakes catchments.

more_vertJamie Wasielewski

Master's Student

closeJamie Wasielewski

Master's Student

My research interests include ecosystem level responses to environmental changes such as landscape use, geomorphic alterations, and climate change. I am interested in how these changes influence nutrient distribution and movement through watersheds and subsequent nutrient cycling and food web dynamics in the Great Lakes.

more_vertJessica Dyczko

Master's Student

closeJessica Dyczko

Master's Student

After completing my HBSc in Water Resource Science at Lakehead University, the Xenopoulos lab is the perfect place to continue developing my understanding of aquatic ecosystems. My research interests revolve around how to reduce anthropogenic impacts on freshwater ecosystems and how to maximize the benefits these ecosystems provide. For my MSc thesis I will investigate how different types of land-use alter carbon cycling in streams. More specifically, I will look at how the quality and quantity of dissolved organic matter changes such that microbial metabolism and therefore greenhouse gas emissions are affected.

more_vertSarah King

Master's Student

closeSarah King

Master's Student

Sarah is studying dissolved organic phosphorus and carbon in Lake Erie’s tributaries. In particular, she’s looking at how hydrology and catchment land cover are related to phosphomonoester and phosphodiester concentrations, and how the forms of dissolved organic phosphorus and dissolved organic matter change moving from stream to lake.

more_vertMeredith Kadjeski

Master's Student

closeMeredith Kadjeski

Master's Student

I am studying dissolved organic carbon in streams flowing through watersheds with contrasting land uses: agriculture vs. forested. In particular, I am looking at how land use and seasonality interact to alter the quantity and quality of carbon being exported downstream from the two streams.

more_vertAndrew Brown

Honour's Student

closeAndrew Brown

Doctoral Candidate

Andrew is currently completing a dual honours degree in Biology and Environmental and Resource Science at Trent. His honours thesis involves examining the effects of DOC on aquatic nutrient cycling and fish behaviour.

more_vertMarina Taskovic

NSERC-USRA

closeMarina Taskovic

NSERC-USRA

I study Biology and Sustainable Agriculture at Trent and am currently an NSERC-USRA student working as a lab assistant for the summer of 2019. For my honours thesis project I will be focusing on the effects of land use on nutrient excretion and cycling by animals.

Past Lab Members

more_vertPeter Silk

NSERC-USRA

closePeter Silk

NSERC-USRA

Peter started by volunteering in the Fall of 2016, and is currently working as a lab assistant with Master's and Honours students. He will begin research as a NSERC student over the summer, and will focus on monitoring streams across Southern Ontario and understanding the effects of urbanization on aquatic ecosystems.

more_vertSabateeshan Mathavarajah

NSERC-USRA

closeSabateeshan Mathavarajah

NSERC-USRA

Sabateeshan is interested in the microbial communities of aquatic ecosystems, their metabolism, and it's relation to ecological characteristics and biogeochemical cycling. His research focuses on the characterization of winter microbial communities in Lake Erie through functional and taxonomic analysis through the novel approach of Metagenomics.

more_vertChristian Akotoye

NSERC-USRA

closeChristian Akotoye

NSERC-USRA

Chris's research is examining the effects of agricultural land use on stream microbes through metagenomics.

more_vertPaige Cuthbert

Honour's Student

closePaige Cuthbert

Honour's Student

Paige is currently completing a dual honours degree in Biology and Environmental & Resource Science. Her undergraduate thesis project involves examining the impacts of a local hydroelectric dam on the water quality of the Otonabee River.

more_vertCeara Talbot

Master's Student

closeCeara Talbot

Master’s Student

Ceara studies changes in nutrients caused by flooding and the effects of these changes on ecosystem services.

more_vertKatarina Cetinic

Doctoral Candidate

closeKatarina Cetinic

Doctoral Candidate

I received my M.Sc. in Ecology and Nature Preservation (with a special focus on freshwater ecology) at the University of Zagreb, Croatia in 2011. My Ph.D. research, under the supervision of Dr. Marguerite Xenopoulos, will attempt to evaluate the ability of silver nanoparticles to move through lake food webs and effect upper trophic levels. There will be a particular focus placed on primary consumers, zooplankton and benthic invertebrates, where biological effects are most likely to be observed, due to their unique capacity to reflect the overall condition of an aquatic environment. With the increased use of silver nanoparticles in consumer goods, industry, and medicine, and their inevitable release into the environment, it is critical that we assess the potential environmental impacts these nanomaterials could have on aquatic ecosystems.

My research interests include freshwater and marine ecology, environmental science and conservation biology. I still actively collaborate with my colleagues at the University of Zagreb, and am involved in several projects, including research on the emergence of aquatic insects from the Plitvice Lakes National Park, and the effects of various stressors on coral biodiversity in the Adriatic Sea.

more_vertDan Rearick

Doctoral Candidate

closeDan Rearick

Doctoral Candidate

Dan is part of the Lake Ecosystem Nanosilver project conducted at the Experimental Lakes Area. He studies the biological consequences and the fate of silver in the lake and within the food web.

more_vertAndrew Darcy

Honour's Student

closeAndrew Darcy

Honour's Student

Andrew is a graduate of the Ecosystem Management Technology program at Fleming College, and is currently completing a dual honours degree in Biology and Environmental and Natural Resource science at Trent. His undergraduate thesis work involves the effects of contaminants on the olfactory-mediated behaviours of fish, specifically Fathead Minnows.

more_vertJoseph Tonin

Honour's Student

closeJoseph Tonin

Honour's Student

Joey was as a part of the final year of the Lake Ecosystem Nanosilver project at the Experimental Lakes Area. His undergraduate thesis involves examining the effects of nanosilver on aquatic microbial decomposition and fungal biomass.

more_vertKatie Musial

NSERC-USRA

closeKatie Musial

NSERC-USRA

Katie joined the Xenopolous Lab during the Summer 2015 as an NSERC student. She was involved in gathering samples from the Lake Erie tributaries and running tests on some of these samples. She is currently doing a reading course to investigate the relationship between lipid phosphorus content within algae samples from various waters around Ontario.

more_vertAndrew Scott

Lab Manager

closeAndrew Scott

Lab Manager

Andrew has been working in the Xenopoulos Lab since 2007. He support projects to complete field and lab work. I have spent time at ELA, on the Limnos and in tributaries from Peterborough to Lake Simcoe.

more_vertChristina Fridgen

Doctoral Candidate

closeChristina Fridgen

Doctoral Candidate

I'm currently working on my Ph.D. thesis with Dr. Chris Metcalfe and Dr. Maggie Xenopoulos. Our lab is currently working with titanium dioxide and silver nanomaterials. I am interested in questions concerning the bioavailability, bioaccumulation, elimination, acute and chronic physiological effects in aquatic organisms, as well as the ability of nanomaterials to act as vectors for common pollutants. Since my past full time work (2001-2005) and MSc thesis (2005-2008) here at Trent, my research has focused on the chronic effects of pesticides on amphibian development, and thus my specialties lie in chronic toxicology, developmental biology, histology, genetics, and amphibians. Through this current project, I hope to build upon my current experience to include food web studies (fish and daphnia), immunohistochemistry, gene expression, and SEM; while broadening my knowledge in the field of geochemistry of natural waters. When I am not in the lab you can find me continuing my search for answers while teaching, debating in the pub, relaxing at home with friends and family, or spinning on skinny tires….

more_vertDr. Richard Vogt

Post Doctoral Researcher

closeDr. Richard Vogt

Post Doctoral Researcher

Through my research I try to provide a conceptual basis for understanding and quantifying the unique and interactive effects of climate and human activities on aquatic ecosystems. Here at Trent, my primary project focused on exploring the processes that influence Lake Erie's carbon balance, including regulation of CO2 fluxes between surface water and the atmosphere.

more_vertDr. Beth Norman

Post Doctoral Researcher

closeDr. Beth Norman

Post Doctoral Researcher

My research at Trent is a part of the LENS project, which is addressing the ecological consequences of the discharge of silver nanoparticles (AgNP) for lentic ecosystems at the Experimental Lakes Area in northern Ontario. AgNP are used in many commercial products and have the potential to impair ecosystem functions due to their antimicrobial properties. I am investigating the recovery of various ecosystem functions following chronic and acute exposure to AgNP. Functions performed by a broad array of microorganisms, such as nitrogen uptake or carbon mineralization, may recover more quickly compared to functions performed by specialized taxa, such as nitrification.

more_vertDr. Emily Porter-Goff

Post Doctoral Researcher

closeDr. Emily Porter-Goff

Post Doctoral Researcher

Emily worked on an outreach program for the Kawartha Lakes cottagers to foster a better understanding of the algae in the lakes and how to keep a healthy and natural algal community. She also studied the Lake Simcoe watershed and the effects of salt and sand de-icers on stream and lake communities. Salinization of inland waters is becoming an increasing threat to our freshwater resources. Emily is currently working for the Vermont State Agency of Natural Resources in their inland lakes division doing lake assessments.

more_vertDr. Clayton Williams

Post Doctoral Researcher

closeDr. Clayton Williams

Post Doctoral Researcher

As a post-doc in the Xenopoulos lab, Clayton determined how landscape modification and disturbance affect organic matter quality and quantity in aquatic ecosystems. At a regional scale, Clayton helped demonstrate that streams impacted by human land use support more productive bacterial communities, a more labile organic matter pool, and higher rates of nutrient uptake than wetland and forest dominated streams. Clayton is currently a Research Associate in John Downing's Lab at Iowa State University where he is focusing on lake management and restoration.

more_vertDr. Dan Spooner

Post Doctoral Researcher

closeDr. Dan Spooner

Post Doctoral Researcher

As a post-doc in the Xenopoulos lab, Dan worked on incorporating novel ecological markers (stable isotopes, fatty acid analysis, and algal pigment analysis) to evaluate how local nutrient contexts, associated with varying land-use, influence the movement of energy, nutrients and contaminants (heavy metals) through benthic food webs. This research integrated ecological stoichiometry and biodiversity ecosystem function theory into contemporary food-web models. Dan is currently at the Leetown Science Center with the United States Geological Survey.

more_vertDr. Daelyn Woolnough

Post Doctoral Researcher

closeDr. Daelyn Woolnough

Post Doctoral Researcher

Daelyn worked in the Xenopoulos Lab as a post-doctoral fellow from 2006 to 2008 on assessing the effects of urbanization on aquatic systems. She is currently an Assistant Professor at Central Michigan University in the Biology Department.

more_vertDr. Matt Roberts

Post Doctoral Researcher

closeDr. Matt Roberts

Post Doctoral Researcher

Matt was a post-doc in the Xenopoulos lab working on how biotic and abiotic components of aquatic ecosystems respond to disturbances, including river and watershed regulation, which modify hydrological regimes. Specific kinds of disturbances that Matt has studied include those that are anthropogenic (effects of dams, effects of channelization, watershed use and management, introduced species) or natural (effects of floods and drought). Matt is currently a fisheries biologist at the Mississippi Natural History Museum.

more_vertDr. Victor Evrard

Post Doctoral Researcher

closeDr. Victor Evrard

Post Doctoral Researcher

Victor was a postdoctoral fellow in 2007-08. During this time he worked on transformation and processing of carbon in river sediment food webs using stable isotopes. Victor is currently a Research Fellow and Stable Isotope Lab Manager at Monash University (Australia)

more_vertPranab Das

PhD Student

closePranab Das

PhD Student

Pranab completed his PhD at Trent on the effects of nanomaterials, mainly silver nanoparticles and titanium dioxide, on bacterial, algal  and zooplankton communities. Pranab is currently a PDF at Queen's University.

more_vertHenry Wilson

PhD Student

closeHenry Wilson

PhD Student

Henry's work generally focused on stream ecology issues across broader spatial scales, especially on dissolved organic matter dynamics. Henry is currently a Research Scientist for Agriculture and Agri-Food Canada in Brandon, Manitoba.

more_vertMike White

PhD Student

closeMike White

PhD Student

Mike's Ph.D. research focused on water level fluctuations  in lentic boreal shield environments and their effects on the benthos. Mike is currently working for Minnow Enivronmental Inc.

more_vertJennifer Vincent

Master Student

closeJennifer Vincent

Master Student

Jenn completed her Masters degree as part of the LENS project.

more_vertMallory Nadon

Master Student

closeMallory Nadon

Master Student

Mallory's M.Sc thesis investigated the alteration of flow regimes that are related to the construction of dams and waterpower facilities in Northern Ontario, and how these alterations effect the ecological condition of river systems.

more_vertLisa Graham

Master Student

closeLisa Graham

Master Student

Lisa's MSc. research project involved assessing fish communities over a gradient of productivity to evaluate nitrogen enrichment in fish and their associated trophic levels.

more_vertAisha Chiandet

Master Student

closeAisha Chiandet

Master Student

Aisha's MSc research focused on the relatively new field of urban limnology. She characterized the aquatic habitats of urban stormwater ponds in Southern Ontario in terms of algae, zooplankton, fish and macrophytes, and determined the effects of urban runoff on the flora and fauna that inhabit these ponds. Aisha is currently a Water Scientist at Severn Sound Environmental Association.

more_vertRathika Balthasar

Master Student

closeRathika Balthasar

Master Student

Rathika completed her Masters degree on tracing concentrations and isotope ratios of zinc in stream mussels across and agricultural gradient. Rathika is currently completing her PhD at Trent University.

more_vertLaura Tessier

Undergratuate Student

closeLaura Tessier

Undergratuate Student

Laura Tessier investigated the effects of agriculture on fish respiration, nutrient excretion, and stable isotopes. Laura is now an MSc student at Wilfrid Laurier University.

more_vertPaul Finigan

Undergratuate Student

closePaul Finigan

Undergratuate Student

Paul was a member of Lake Ecosystem NanoSilver project. His research focused on the effects of silver nanoparticles on benthic invertebrate communities. Paul is currently doing his Masters at Queens University

more_vertMyra Jukers

Undergratuate Student

closeMyra Jukers

Undergratuate Student

Myra worked in the lab as an NSERC-USRA student. She completed work on the impacts of land use on stream sediment nutrient and gas fluxes. Myra is currently travelling.

more_vertKatelyn Doughty

Honour Student

closeKatelyn Doughty

Honour Student

Kate completed an honours thesis on the impacts of land use on nutrient cycling and metabolism of stream biofilms. Kate recently returned from the US where she was a lab technician in an aquatic lab and is looking to start an MSc thesis soon.

more_vertElysabeth Theberge

Undergratuate Student

closeElysabeth Theberge

Undergratuate Student

Elysabeth was an NSERC USRA student and concentrated her work on exploring the effects of agricultural land use on stream benthic macroinvertebrate community assemblages. Elyzabeth continues to work in aquatic ecology as an MSc student at the University of Ottawa with Dr. Antoine Morin.

more_vertJennifer Van Eindhoven

Honour Student

closeJennifer Van Eindhoven

Honour Student

Jenn completed her Honour's thesis on the effect of golf courses on fungal and bacterial communities in southern Ontario streams. Jenn is currently completing her Bachelor of Education at Trent University.

more_vertGraham Irvine

Honour Student

closeGraham Irvine

Honour Student

Graham completed an honours thesis on the amount of the greenhouse gas nitrous oxide that is being produced by urban stormwater ponds. Graham recently completed his Masters at the University of Ottawa.

more_vertOlivia Puckrin

Honour Student

closeOlivia Puckrin

Honour Student

Olivia completed an honours thesis on land use effects on mussel communities and nutrient excretions. Olivia recently completed an MSc on the cod fisheries at Memorial University in St. Johns Newfoundland.

more_vertJacob Brownscombe

Honour Student

closeJacob Brownscombe

Honour Student

Jake completed an Honours thesis on the microbial degradation of DOC along a land use gradient. Jake later completed an MSc at Trent looking at the invasive Round Goby population in Ontario. He is currently completing his PhD Carleton University.

more_vertRobert Buchkowski

Undergratuate Student

closeRobert Buchkowski

Undergratuate Student

Rob was an NSERC USRA student examining a possible connection between zero-valent iron(ZVI) nanoparticles and the rates of denitrification in benthic water columns and in waste water. Rob is currently completing a graduate degree at Yale University.

more_vertJasmine Hamilton

Undergratuate Student

closeJasmine Hamilton

Undergratuate Student

Jasmine is currently pursuing a degree in Biochemistry and Molecular Biology. While in the Xenopoulos Lab her focus will be on the Milton Project. During the previous semester she worked in the Frost lab on testing the effect of elemental nutrition on the vulnerability of Daphnia infection by bacteria.

more_vertHeather Foy

Honour Student

closeHeather Foy

Honour Student

Heather's honour's project examined how land use affects leaf litter decomposition in streams. Heather recently completed an MSc at Trent University.

more_vertLindsey McAlister

Honour Student

closeLindsey McAlister

Honour Student

For her honours thesis Lindsey looked at the assemblage of fish communities within urban stormwater ponds. Prior to attending Trent University for biology she completed a diploma at Fleming College in fish and wildlife technology.

more_vertRyan Kelly

Undergraduate Student

closeRyan Kelly

Undergraduate Student

Ryan began working in the lab in May 2006 and has been involved in analyzing water samples for phosphorus and ammonia, assisting graduate students with their research and helping Paul Frost with Daphnia research.

more_vertStephen McCarthy

Undergraduate Student

closeStephen McCarthy

Undergraduate Student

Stephen worked in the lab as a summer student. He completed his Thesis with Dr. Paul Frost at Trent. He is currently working on his PhD at the University of Toronto
Awards: NSERC summer research award

more_vertOla Zalewskiy

Undergraduate Student

closeOla Zalewski

Undergraduate Student

Ola worked in the Xenopoulos/ Frost lab as a research assistant part time in January 2007.

more_vertNaheed Mirebrahimi

Honour Student

closeNaheed Mirebrahimi

Honour Student

Naheed completed a Joint Major Honours in Biology and Mathematics. She was part of an environmental monitoring team in the lab which seeks to understand how urbanization in Milton, Ontario is affecting the aquatic ecosystems.

more_vertCassandra Borm

Honour Student

closeCassandra Borm

Honour Student

Cassandra graduated in 2006 from Trent with an Honours Bachelor of Science in Biology and Geography and was part of the Milton Project. Currently, she is working towards her Bachelor of Education at Queen's University in Kingston, Ontario.

more_vertKyla Warren

Honour Student

closeKyla Warren

Honour Student

Kyla completed an honours thesis on the effects of cannibalism on mosquito larva.

more_vertLaura Hansen

Honour Student

closeLaura Hansen

Honour Student

After working for Maggie as a lab assistant, Laura completed her honours thesis with Paul Frost and Chris Metcalfe. It focused on the ecotoxicology of human pharmaceutical products in the environment. More specifically, she used Daphnia magna to show whether the toxicity of fluoxetine (a.k.a. Prozac) is mediated by varying elemental food quality.

more_vertLeah James

Honour Student

closeLeah James

Honour Student

Leah completed an honours thesis on the effects of land use on the excretion of nitrogen and phosphorus from Mayflies. Leah currently works at Golder Associates in Calgary.

more_vertNicole Novodvorsky

Reasearch Technician

closeNicole Novodvorsky

Reasearch Technician

Nicole was a Science Horizon's Intern on the Lake Ecosystem NanoSilver project. Nicole is currently an MSc student at Laurentian University.

more_vertSarah Nienhuis

Reasearch Technician

closeSarah Nienhuis

Reasearch Technician

Sarah was a Science Horizon's Intern working on DOM degradation in urban ponds. Sarah currently works for the Ontario Ministry of Natural Resources.

more_vertMelanie Kingsbury

Reasearch Technician

closeMelanie Kingsbury

Reasearch Technician

Melanie was lab manager in the Xenopoulos lab until 2008. She has since completed an MSc at Queen's University and is currently completing her PhD in the UK.

more_vertDarren Doherty

Reasearch Technician

closeDarren Doherty

Reasearch Technician

Darren was a Science Horizon's Intern working on the effects of land use on stream ecosystem function.

more_vertMichelle Marcus

Reasearch Technician

closeMichelle Marcus

Reasearch Technician

Michelle was a Science Horizon's Intern working on the Environmental Monitoring of streams in Milton as the town underwent rapid urbanization.