USGS Integrates Findings about Endocrine-Disrupting Compounds in the Chesapeake Watershed

Science Center Objects

Issue: Studies in the Chesapeake Bay Watershed have documented the exposure of fish to toxic contaminants including endocrine-disrupting compounds (EDCs) - compounds which can alter normal hormonal function in organisms. Given the importance of fisheries to the economic and environmental health of the Watershed, observed endocrine disruption and fish kills in the Watershed have raised public and management concerns. The Chesapeake Bay Program recognized concerns over potential toxic exposures and effects, and developed a goal for the Chesapeake Bay Watershed Agreement: Ensure that the Bay and its rivers are free of effects of toxic contaminants on living resources and human health.

USGS Studies and Summary

The USGS and its partners conducted a 5-year study on the endocrine-disrupting compounds in the Chesapeake Bay Watershed (hereafter EDC study), which was concluded in 2021. The study built from previous USGS work on the factors affecting fish health.

The USGS just released a summary of findings from the EDC study and historical investigations throughout the Chesapeake Bay Watershed which include:

  • Spatiotemporal variation in occurrence of organic contaminants
  • Groundwater discharges as a source of contaminants
  • Environmental and anthropogenic drivers of contaminants
  • Estrogenic endocrine disruption in fish and land-use influences
  • Probability of estrogenic activity in surface waters
  • Contaminant reduction via Best Management Practices (BMPs)

The summary uses maps, diagrams, and pictures to highlight the findings and can be found at: Endocrine Disrupting Compounds in the Chesapeake. The authors are Stephanie Gordon, Kelly Smalling, Vicki Blazer and Scott Phillips.


Application of Findings

The EDC study has contributed to the Chesapeake Bay Program Toxic Contaminants Research Outcome to increase understanding of the impacts and mitigation options for toxic contaminants, including EDCs, in the Chesapeake Bay Watershed.


For more information

For more information on the summary, please contact Stephanie Gordon (, Kelly Smalling (, or Vicki Blazer (

For more information on USGS Chesapeake Bay studies, please contact Scott Phillips (

Links to individual research papers are in the map-based summary.

Posted September 1, 2021


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