Nestled between the United States and Canada, Lake Erie serves as a beacon of nature’s beauty and a challenge of environmental stewardship. This vital water body, a source of sustenance, recreation, and rich biodiversity, is engaged in a silent yet intensifying struggle against eutrophication—the rampant growth of algae nourished by an excess of nutrients, especially that of phosphorus. While concerted efforts have been made to diminish the flow of nutrients from agricultural lands and urban environments, a surprising development has shifted the narrative of Lake Erie’s ecological health. It has been discovered that a considerable fraction of the phosphorus fueling the lake’s algal blooms originates not just from the surrounding landscape but from within the lake itself. This insight compels us to rethink our strategies for maintaining Lake Erie’s pristine waters, prompting a deeper exploration into the unseen internal mechanisms that influence its nutrient balance.

Recently highlighted in the Ecological Informatics journal, groundbreaking work by Dr. Serghei Bocaniov, with significant insights from Professor Philippe Van Cappellen and Professor Donald Scavia, all from University of Waterloo, sheds light on the persistent eutrophication issues facing Lake Erie. Despite concerted efforts to reduce phosphorus contributions from external sources, their research uncovers that a notable amount of phosphorus pollution in Lake Erie originates from within the lake itself. This revelation about internal phosphorus loading, contributing a considerable portion to the lake’s overall phosphorus levels, challenges previously held views and highlights the complexity of the lake’s nutrient dynamics.

Dr. Bocaniov and the team initiated a meticulous journey to understand the full extent of phosphorus sources impacting Lake Erie. “To constrain the magnitude of the net phosphorus input associated with in-lake processes, we generated a comprehensive phosphorus budget for the Lake St. Clair–Lake Erie system, considering data over several years,” shared Dr. Bocaniov. Their comprehensive approach involved weaving together extensive datasets to create a complete picture of phosphorus dynamics in the lake.

In simpler terms, the team compiled and analyzed data on water movement and phosphorus concentrations from various sources around and within Lake Erie. They meticulously accounted for phosphorus coming into the lake from rivers, rain, dry atmospheric deposition, and groundwater, as well as that leaving the lake through outflows and sedimentation. This holistic analysis was pivotal in revealing the substantial role played by the lake’s internal processes in its phosphorus budget.

“The analysis shows that the phosphorus output from the system significantly exceeds the external phosphorus inputs,” Dr. Bocaniov explained, underscoring a pivotal finding of their work. This insight pointed to the fact that Lake Erie itself was a significant contributor to its phosphorus problem, an aspect that had not been fully appreciated before.

The variability in how phosphorus inputs distributed around and within the lake was also a key discovery. “The internal phosphorus contribution is not uniformly distributed across the lake’s basins, with different regions receiving varying shares of the total internal phosphorus loading” Dr. Bocaniov added. This nuanced understanding emphasizes that solutions to eutrophication must be as adaptive and recognize the complexity of the problem itself, and tailored to the unique conditions of each part of the lake.

“Our findings represent a significant advancement in our understanding of Lake Erie’s eutrophication challenges and offer a blueprint for the holistic management of eutrophication in large lakes worldwide,” Dr. Bocaniov stated. The implications of their work stretch far beyond Lake Erie, offering insights and methodologies that could help manage freshwater ecosystems across the globe. This research by Dr. Bocaniov, Professor Van Cappellen, and Professor Scavia marks a significant contribution to the field of ecological informatics, offering new insights into the complex interactions driving eutrophication in Lake Erie and beyond. It underscores the necessity for ongoing research and adaptive management strategies to preserve the health of freshwater ecosystems globally, highlighting the importance of looking beneath the surface to truly understand and tackle the challenges faced.


Serghei Bocaniov, Philippe Van Cappellen, Donald Scavia, “Long-term phosphorus mass-balance of Lake Erie (Canada-USA) reveals a major contribution of in-lake phosphorus loading,” Ecological Informatics, 2023.



Serghei Bocaniov

Dr. Serghei Bocaniov is a Research Associate at the University of Waterloo. His primary research interest is to study the interaction between physical and biogeochemical processes in lakes using a combination of numerical modelling and field studies to investigate specific processes of interest, such as harmful algal blooms, aquatic hypoxia (low dissolved oxygen concentrations), physical and biological disturbances in aquatic ecosystems caused by climate change. His broader research interest includes coupling watershed and lake models to evaluate the short- and long-term impacts of changing climate and land-use on water quality in lakes to assess possible mitigation and adaptation strategies. Links to his research and publications can be found at

Van Cappellen

Philippe Van Cappellen is the Canada Excellence Research Chair laureate in Ecohydrology. Previously, he was the Eminent Scholar in Global Environmental Studies at the Georgia Institute of Technology, and a Professor of Geochemistry at Utrecht University. Van Cappellen’s research combines laboratory studies with field observations and theoretical developments to understand and model the processes that regulate water chemistry, carbon and nutrient cycling, microbial activity, and mineral transformations – in agricultural and urban landscapes, river, groundwater and lake systems, groundwater, and coastal marine environments. To see more about the ecohydrology research group:

Donald Scavia is Professor Emeritus of Environment and Sustainability at the University of Michigan.  Along with his students and postdocs, he combines numerical models and environmental assessments to improve the understanding of interactions between human activities on land and their impacts on coastal marine and freshwater ecosystems. Most of his recent work has focused on impacts on the iconic Gulf of Mexico, Chesapeake Bay, and Great Lakes. His research also supports development and application of Integrated Assessment, a tool that brings together natural systems science, social science, engineering, and environmental policy making. Links to his research, students, postdocs, and publications can be found at