Sex-changing chemicals found in Potomac River

The Potomac is fed by rivers and streams in Maryland, Virginia and West Virginia.

“We analyzed samples of 30 smallmouth bass from six sites, including male and female fish without intersex and male fish with intersex,” said Douglas Chambers, a USGS scientist who led the study.

“All samples contained detectable levels of at least one known endocrine-disrupting compound, including samples from fish without intersex.”