ATHENS, Ga. -- Is something in the water turning fish in the Oconee River into sexual freaks - making male fish a little girly and impeding the ability of female fish to reproduce?
Robert Bringolf, a professor of fish biology and ecotoxicology in the University of Georgia's Warnell School of Forestry and Natural Resources, suspects so. This summer he has launched a research project to find out for sure.
"It's fairly predictable, if you look in any area that receives wastewater effluent," he said.
In other American urban rivers, researchers have repeatedly detected measurable quantities of the chemicals, called environmental estrogens. Some are natural sex hormones produced in female ovaries. But scientists also find synthetic estrogens, used in birth control pills and for hormone replacement therapy, and so-called estrogen mimickers that affect humans and other animals in the same way estrogens do.
Until now, no one has tried to measure the chemicals' impact in Georgia rivers.
"To our knowledge, nothing along these lines has been done in the state of Georgia," Bringolf said.
The researchers suspect that even fish exposed for a short time - especially at critical stages of development - might suffer effects that may not show up until the fish are adults and try to reproduce.
Ultimately, Bringolf wants to find out how these chemicals are affecting river ecology - whether the estrogens' harmful effects are limited to relatively few fish, or spread in the whole web of stream life.
Male fish exposed to even small levels of environmental estrogens in other researchers' studies - 5 or 6 parts per trillion - begin producing female egg proteins, and females begin producing fewer viable eggs.
Scientists also believe that some pesticides like the herbicide atrazine also interfere with the endocrine system and could be linked to widespread developmental problems they're seeing in frogs.