Related Experiment Video
Updated: May 21, 2026
10:49
Laboratory-determined Phosphorus Flux from Lake Sediments as a Measure of Internal Phosphorus Loading
Published on: March 6, 2014
Continuous Bayesian network for studying the causal links between phosphorus loading and plankton patterns in Lake
Alexey Gudimov1, Eavan O'Connor, Maria Dittrich
1Ecological Modeling Laboratory, Department of Physical and Environmental Sciences, University of Toronto, Toronto, Ontario, Canada M1C 1A4.
Environmental Science & Technology
|June 9, 2012
Summary
Restoring Areas of Concern requires ecosystem thinking. Reducing phosphorus loading by 15% in Lake Simcoe may not meet water quality targets, especially in embayments.
Area of Science:
- Ecological modeling
- Environmental management
- Aquatic ecosystem restoration
Background:
- Ecosystem restoration necessitates a shift towards multicausal thinking to manage complexity.
- Holistic management paradigms are increasingly adopted in ecological modeling.
- Sophisticated ecosystem modeling tools are crucial for effective restoration.
Purpose of the Study:
- Develop a Bayesian hierarchical network for Lake Simcoe to model nutrient and plankton dynamics.
- Represent causal links between nutrient loading, nutrient conditions, and plankton.
- Assess phosphorus loading reduction scenarios for water quality improvements.
Main Methods:
- Spatially explicit mass-balance model for predicting total phosphorus (TP).
- Structural equation modeling to analyze nutrient-phytoplankton-zooplankton interactions.
- Bayesian network to evaluate exceedance frequencies of TP and chlorophyll a (chla) thresholds.
Main Results:
- Strong causal links exist between TP, water clarity, and phytoplankton.
- Zooplankton grazing significantly modulates phytoplankton biomass.
- A 15% TP loading reduction may still lead to >25% exceedance of the 4 μg/L chla threshold in Cook's Bay and Kempenfelt Bay.
Conclusions:
- Ecosystem modeling aids in understanding complex causal relationships for restoration.
- Phosphorus loading reductions improve TP levels, primarily in northcentral Lake Simcoe.
- Targeted management strategies are needed to meet water quality goals in Lake Simcoe embayments.
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