BPA Exposure Allegedly Leads to Inter-Species Mating in Shiner Fish

A recent study has reportedly claimed that two species of shiner fish
exposed to bisphenol A (BPA) were more likely to mate in mixed-species
pairings. Jessica Ward and Michael Blum, “Exposure to an environmental
estrogen breaks down sexual isolation between native and invasive species,”
Evolutionary Applications, July 2012. After collecting specimens from rivers
throughout Georgia, scientists evidently used a controlled environment
to study the effects of short term BPA exposure on both the red shiner fish
(Cyprinella lutrensis), an invasive species, and the native blacktail shiner fish
(Cyprinella venustra). Their results allegedly showed that males exposed to
BPA lost some of their distinctive coloring, leading females to more frequently
choose mates not of their own species.

“Until now studies have primarily focused on the impact to individual fish, but
our study demonstrates the impact of BPA on a population level,” explained
one of the study’s authors in a July 11, 2012, University of Minnesota press
release. “Our research shows how the presence of these manmade chemicals
leads to a greater likelihood of hybridization between species. This can have
severe ecological and evolutionary consequences, including the potential for
the decline of our native species.”