'Intersex' fish in Pennsylvania spur search for chemical contaminants

(NaturalNews) Pennsylvania officials are conducting extensive sampling of chemical contaminants throughout the state following the discovery of intersex fish in three of the state's major waterways.

According to reports, male fish carrying eggs have been discovered in the Susquehanna, Delaware and Ohio River basins, which indicates that the water could be tainted with chemicals, according to new research released recently by the U.S. Geological Survey.

Amanda Witman, a Department of Environmental Protection spokeswoman, said the agency is testing two tributaries of the Susquehanna River: Juniata River and Swatara Creek, according to India's Business Standard online

The U.S. agency said that two fish species -- smallmouth bass and white sucker -- have exhibited intersex characteristics because of exposure to endocrine-disrupting chemicals -- especially hormones and hormone-mimicking chemicals that have caused the male fish to produce eggs like females.

'We weren't expecting this to be so widespread'

"The sources of estrogenic chemicals are most likely complex mixtures from both agricultural sources, such as animal wastes, pesticides and herbicides, and human sources from wastewater treatment plant effluent and other sewage discharges," Vicki Blazer, a fish biologist and lead author of the USGS study, was quoted as saying by the Los Angeles Times.

Estrogenic chemicals can disrupt the endocrine system, which regulates the release of hormones like estrogen and testosterone. That, in turn, interferes with the fish's ability to reproduce.

Witman said that some of the contaminants and compounds discovered were new, and that researchers were forced to develop new lab tests and procedures to measure them.

"The results will provide a much better understanding of the kinds, distribution and concentrations of these compounds," she said.

The Pennsylvania discovery is not the first time intersex fish have been found in U.S. rivers, the Times said. Since 2006, the USGS has found similar characteristics after conducting several surveys of bass in the Potomac River, according to the agency's report.

In the Pennsylvania testing, Blazer and colleagues gathered fish from 16 sites in the three river basins; intersex males were discovered at every site where smallmouth bass were collected. Their conditions were generally worse in areas located just downstream from wastewater treatment plants, according to the researchers' findings.

The Times further reported:

Bass seem especially prone to becoming intersex when exposed to estrogenic compounds, the study found. The researchers also sampled white suckers and redhorse suckers. Redhorse suckers didn't have any intersex characteristics, but the team found an egg cell precursor, or stem cells that could potentially develop into eggs, in the blood of some white suckers.

Estrone was the most common hormone found in the water and soil samples taken in the basins, reports said. Estrone is a potent endocrine-disrupting chemical that is often found in sewage from wastewater plants, as well as the manure of animals such as cattle, pigs and chickens, the researchers said.

Sample collection is ongoing

"We weren't expecting the issue to be as widespread as it was," Blazer said. "The number of fish affected and the severity was surprising."

Blazer also said that any of the chemicals could affect human beings, especially chemicals that were able to enter through the water from pharmaceuticals and personal care products like fragrances. The fish sampled showed effects of pollutants, she said, because spending all their time in water means they are saturated with the substances constantly.

She said that upgrading wastewater plant technology and fencing rivers so that animals can't excrete directly into the water would help curb the sex changing.

The state's environmental agency says it began a multiyear analysis of the Susquehanna River in 2012, but samples collected by researchers are still under analysis. Samples will continue to be collected through the summer of 2014; those results, says Witman, won't be available until sometime next year.

"DEP's plan is to continue the sampling until it has an understanding of how these compounds may or may not impact the aquatic life in all streams and rivers, not just the Susquehanna," she said.

Sources:

http://www.business-standard.com

http://www.latimes.com

http://www.fws.gov [PDF]