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.

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.

Postdoctoral Fellow

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.

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.

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.

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.

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.

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.

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.

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)

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.

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.

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.

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….

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.

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.

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.

Lab Manager/Master's Student

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.

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.

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.

Master’s Student

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

Master's Student

Jenn completed her Master's degree as part of the LENS project.

Master's 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.

Master's 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.

Master's 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.

Master's 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.

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.