A new study conducted by the U.S. Geological Survey and published in the journal Scientific Reports has found that fish exposed to a specific synthetic hormone (known as 17a-ethinylestradiol) found in birth control have trouble fertilizing eggs. This is a major problem since birth control is being deposited into our water ways via toilets and sink drains.
"If those trends continued, the potential for declines in overall population numbers might be expected in future generations," said Ramji Bhandari, an assistant research professor at University of Missouri in an interview with the Washington Post. "These adverse outcomes, if shown in natural populations, could have negative impacts on fish inhabiting contaminated aquatic environments."
The Post's Darryl Fears reports:
The study, with Bhandari as lead author, also determined that the chemical BPA, used widely in plastics, had a similar effect on the small Japanese medaka fish used for the research. The medaka was chosen because it reproduces quickly so that scientists can see results of subsequent generations faster than slow reproducing species such as smallmouth bass.
BPA and EE2 are both endocrine disruptors that interfere with hormones and cause developmental disorders. Over the past 12 years, male smallmouth and largemouth bass throughout the country, including the Potomac River basin in the Chesapeake Bay region, have switched sex, developing ovaries where their testes should be, and the two disruptors are prime suspects.
"This study shows that even though endocrine disruptors may not affect the life of the exposed fish, it may negatively affect future generations," Bhandari said in a statement. "This is the first step in understanding how endocrine disruptors affect future generations, and more studies are needed to determine what happens in the natural environment."