Heavy Metals, Chemical Pollution, and Hidden Clues: Decoding Lake Maurepas

Area of Science:

• Environmental Chemistry
• Ecotoxicology
• Water Quality Assessment

Background:

• Lake Maurepas faces contamination from toxic chemicals and heavy metals.
• Understanding pollutant sources and their drivers is crucial for effective management.

Purpose of the Study:

• To conduct a comprehensive assessment of toxic chemicals and heavy metals in Lake Maurepas.
• To introduce and apply an innovative framework integrating Bayesian spatiotemporal multivariate receptor model (BSMRM) with event response and causality analysis (ERCA).
• To quantitatively evaluate pollutant sources, drivers, and identify high-risk zones.

Main Methods:

• Integration of BSMRM with ERCA for pollutant source apportionment and causality analysis.
• Utilized temporal clustering for source behavior analysis and anomaly detection.
• Performed sensitivity analysis to determine the influence of environmental and anthropogenic factors.

Main Results:

• Identified four distinct pollutant source behaviors linked to events near river mouths and Pass Manchac.
• Transportation-recreational-accidental release (TRAR) emerged as the most sensitive source, while death and decay of biological species (DDBS) was the most tolerable.
• Salinity, atmospheric pressure, and wind speed significantly influenced pollutant variability; seismic-drilling had mixed effects on contaminant transport and mobilization.
• Causality analysis pinpointed local waterways and Pass Manchac as primary pollutant origins.

Conclusions:

• The study provides critical insights into pollutant resilience and thresholds in Lake Maurepas.
• The developed framework offers a robust approach for targeted mitigation strategies in lakes and similar aquatic environments.
• Identified key environmental factors and anthropogenic activities influencing contaminant distribution.