A hormone-mimicking chemical often found in rivers can affect
the mating choices of fish, leading to changes in their
appearance and behavior and to more interspecies breeding, a new
study led by a University of Minnesota scientist has found. The
study, published in Evolutionary Applications, reveals the
threat to biodiversity when boundaries between species are
blurred, according to Jessica Ward, an adjunct assistant
professor in the Department of Fisheries, Wildlife and
Conservation Biology. While at Tulane University two years ago,
Ward and her team examined the impact of Bisphenol A on two
species of fish, blacktail shiner and red shiner. BPA is an
endocrine-disrupting compound used to harden plastics that, like
other manmade chemicals and pharmaceuticals, has often found its
way into the nation's rivers. Three years ago, Minnesota became
the first of 11 states to ban its use in baby bottles and
children's cups. Ward's team collected fish from two streams in
Georgia and separated them for two weeks in tan