Androgyny and the Potomac Bass

I ran across an interesting study over the weekend called Intersex (Testicular Oocytes) in Smallmouth Bass from the Potomac River and Selected Nearby Drainages published  by the American Fisheries Society and as reported by the US Geological Service.  This topic got quite a flurry of press coverage last year, from my recollection.

Technically the sampled populations were from the Shenandoah and the North Branch of the Potomac in West Virginia, but I wonder if something similar is occurring in the Monocacy or the Potomac proper as it boarders Southern Frederick County?  The study concluded that:

“a high incidence of intersex occurs in the Potomac watershed at sites where farming is most intense and where human population density is highest. The study also shows the greatest prevalence of this form of intersex, known as testicular oocytes (TO), occurs in the spring, just before and during the spawning season.”

with an assignable cause being an association:

“with known or suspected endocrine disrupting compounds in wastewater effluent, which are not removed during standard sewage treatment, and in runoff from farming operations. These compounds can include estrogen from birth control pills and hormone replacements, pesticides and fertilizers used on crops, and hormones from livestock operations.”

Interesting.  They report rates of immature oocytes in male gonads as high as 75%.  This is very good research that goes largely unnoticed aside from sensationalize headlines in the news.