Fisheries Management & Legislative Report

When Colorado biologist John Woodling and a team of researchers pulled fish from the South Platte River and Boulder Creek two years ago, they found deformities they'd never seen before. Some had both male and female sex tissue.

The fish, white suckers native to Colorado, were swimming in the waters downstream of the Denver area's largest sewage plants. And the team found something else: Females far outnumbered males in these wastewater soups.

This is the first thing that I've seen as a scientist that really scared me, said Woodling, 58, a retired fisheries biologist with the Colorado Division of Wildlife now working with the University of Colorado.

The discovery of these freak fish just below Denver and Boulder has sent chills through the ranks of the Environmental Protection Agency. When they learned of Woodling's initial find, officials speedily approved a $100,000 grant so his team could expand its investigation.

Federal officials want to know whether the abnormalities - the first of their kind discovered in Colorado and perhaps the nation - are a result of the chemical brew now flushed by state sewage treatment plants. So far, the team can say only that they have consistently found these changes in fish collected near these two wastewater pipes.

After Denver, the towns of Brighton, Gilcrest, Platteville, the Morgan County Water Quality District and a host of small communities all the way to the Nebraska border pump their drinking water from shallow aquifers connected to the South Platte (see graphic). But it is not known whether the chemicals are present in their supplies.

What's more, little is known about how this pharmacological cocktail affects those who might consume it in drinking water.

One troubling group of these pollutants are called endocrine disrupters because they either mimic or upset hormones - in this case, estrogen - fooling the hormone system of male fish into producing the cells of female fish.

The CU team is now waist-deep in its quest to determine whether disrupters in those wastewater flows are turning boy fish into girl fish - or something in between.

Officials with the Metro Wastewater Reclamation District, the largest sewage treatment agency between Los Angeles and St. Louis, cautioned that it's too soon to tell what the fish deformities represent.

We're all concerned about it, said Barbara Biggs, Metro Wastewater's governmental officer, who added that the agency supports Woodling's research and other studies into the chemicals. We don't want to leap to any conclusions yet. There are a lot of estrogen sources in the environment, and this is going to take time.

CU professor David Norris, the research project leader, agrees. "We don't know the dose that produces effects in this species." But the concentrations of chemicals found in Boulder Creek are high enough to cause the feminizing effect in other fish, added Alan Vajda, a CU doctoral student on the research team.

The findings, which snagged the attention of the EPA's highest echelons, may have been the best kept secret in Colorado water science.

During the last five years, researchers with the U.S. Geological Survey have found a striking range of estrogen-related chemicals in Colorado waterways, including the South Platte River and Boulder Creek, where the team has found deformed fish.

Among the leading suspects in the gender-bending fish phenomenon: excreted birth-control hormones, natural female hormones, and commonly used detergents, which can also mimic the chemical structure of estrogen, one of nature's most potent and important hormones.

Hormones are one of life's great chemical messengers. Released by the body's glands, they travel through the blood until they link with a target molecule, like a key into a lock. They then transmit signals that instruct a cell, among other actions, to produce proteins or to multiply.

Hormones are involved in just about every biological process: reproduction, growth, immune function, even the development of a fetal brain.

They work in infinitesimal concentrations - as low as parts per trillion or even parts per quadrillion. And the hormones typically work in a tightly defined window in an organism's development.

Endocrine disrupters work by transmitting misinformation. A chemical that looks like estrogen, for example, can lock onto a receptor molecule and prevent a cell from receiving a necessary signal. Or it might transmit a stronger or weaker signal than the body's own hormone. And at the wrong time.

Norris, who was on Woodling's Ph.D. committee, said that over the last 10 years, scientists have documented the impact of endocrine disrupters on everything from British trout to Florida alligators and Arctic polar bears.

Little research has been done on the effects of chronic low- dose estrogen exposure in humans. But Norris pointed out that the estrogen-based pregnancy aid DES resulted in cancers and reproductive disorders in the children of mothers who took the drug in the 1950s and '60s.

Woodling's Colorado fish study began after he read about the discovery of intersex trout below sewage plants in Europe. Searching below Denver and Boulder sewage plants, the researchers found only one species that could survive in the effluent - the white sucker, a homely bottom-feeder.

Woodling's first sample on the South Platte below the Metro Wastewater plant produced 16 females and no males. But they also found four fish whose reproductive organs were so mixed with male and female tissues that they couldn't assign a gender.

Woodling quickly arranged a meeting with the EPA. "Their eyes got real big," he said. "They told us to put in the paperwork. It moved quickly." The team was given a grant to further their research with more collections and more blood and tissue analysis. Among their goals was to go upstream of the treatment plants to see whether they could detect the same deformities.

The fish sampling results on Boulder Creek were also disturbing. Just below the sewage plant outflow pipe, the team collected 101 females, 12 males and 10 intersex fish. Upstream of the sewage plant outflow, the team found 42 females, 37 males and zero intersex fish.

Although scientists have found these "environmental estrogens" in surface waters, federal and state regulatory agencies are not testing for them. Neither are the companies supplying drinking water.

Thornton, which diverts drinking water from the South Platte below the Bi-City Wastewater Treatment Plant in Englewood, recently installed an expensive reverse-osmosis water treatment system. It removes low concentrations of organic chemicals and endocrine disrupters, even though science has yet to prove they're harmful, said Vic Lucero, Thornton's water quality administrator.

As for other users of treated river water, Norris advises them not to wait for regulations to catch up with science. A 0.2-micron filter with an activated-charcoal system will remove most endocrine disrupters as well as other chemicals from tap water, Norris said.

Woodling and his team expect to have much of their own research done by next spring. But, he said, what he's found already is profoundly unsettling. "It's one thing to kill a river," said Woodling. "It's another thing to kill nature. If you're messing with the hormonal balance in your aquatic community, you're going deep down. You're twiddling with how life proceeds."

Post researcher Monnie Nilsson contributed to this report.

MOOREFIELD, W.Va. -- The South Branch of the Potomac River is as clear as bottled water here, where it rolls over a bed of smooth stones about 230 miles upstream from Washington. But there is a mystery beneath this glassy surface.

Many of the river's male bass are producing eggs. Scientists believe this inversion of nature is being caused by pollution in the water. But they say the exact culprit is still unknown: It might be chicken estrogen left over in poultry manure, or perhaps human hormones dumped in the river with processed sewage. Chances are, it is not something that federal and state inspectors regularly test for in local waters.

The discovery has made the South Branch the latest example of an emerging national problem: Hormones, drugs and other man-made pollutants appear to be interfering with the chemical signals that make fish grow and reproduce.

While researchers look for answers in West Virginia, other scientists are testing Rock Creek, and another group is seeking financial support to test the rest of the Potomac to see whether they can find the same troubling effects downstream.

Whatever's doing this to the fish may be the canary in the mineshaft, said Margaret Janes, a West Virginia activist with the Appalachian Center for the Economy and the Environment.

Scientists say it's still too early to tell what these findings will mean for the bass population in the South Branch; they aren't sure whether the affected males are still able to reproduce. And no one is aware of any effects on human health in the Potomac watershed. But scientists believe that fish might be the first to absorb any dangerous chemicals that might later affect humans. "They're likely to be hit first," said Mike Focazio, a researcher with the U.S. Geological Survey. "We look there, and it seems to be happening."

The situation in West Virginia was discovered by accident, when scientists from the state and the geological survey were called in to investigate reports that fish in the South Branch were developing lesions and dying en masse. They dissected dozens of bass caught last summer, mainly smallmouth bass. They found no obvious cause for the lesions or deaths, but did discover that 42 percent of the male bass had developed eggs inside their sex organs.

The study surprised scientists. Though the South Branch has been cited for problems with bacteria from poultry manure, state officials said it did well on most aspects of water-quality testing. "We always have, and still do, look at this as one of our highest-quality fisheries," said Patrick Campbell of the state Department of Environmental Protection. "It's counter-intuitive to think we would have this type of problem out there."

But the problem is there: A follow-up survey in the spring found even higher rates of "intersex" bass -- as the affected males are called. A study of 66 male smallmouths from the South Branch found that about 79 percent showed such symptoms, according to U.S. Geological Survey data.

The scientists are now analyzing water samples from the South Branch and the Cacapon River -- a nearby Potomac tributary where intersex bass were also found. The chemicals they're looking for now are not the well-known pollutants that the state already tests for, such as nitrogen and phosphorus from manure and metals from mine runoff. Instead, the culprit is probably in a class called "emerging contaminants," which includes everything from caffeine and prescription drugs to hormones excreted by livestock or humans.

Some of these pollutants have been linked to developmental problems in wildlife. Scientists believe that fish, especially, absorb hormones from other animals, as well as other chemicals that their bodies mistake for hormones.

One recent study near sewage plants in Colorado found male fish whose bodies were trying to produce eggs and some females whose reproductive systems were out of sync. Other studies have found similar effects from the hormones in cow manure and from chemicals from a wood-pulp plant. "It is certainly an alarming situation that we're seeing more and more gross effects," said David O. Norris, a professor who worked on the Colorado study.

These emerging contaminants were hard to detect without the finely tuned equipment developed recently. The first nationwide survey, conducted in 1999 and 2000, found hormones in about 37 percent of the streams surveyed and caffeine in more than half.

The only testing in the Potomac, done in Washington in 2002, found low levels of caffeine, plus the insecticide DEET and chemicals produced when a body breaks down nicotine. There were also a few suspected endocrine disruptors, including chemicals found in hand soap and household cleaners.

As of now, little is done to test for these chemicals -- either in river water or in drinking water. The U.S. Environmental Protection Agency has not set standards, saying more research is needed to determine which contaminants are harmful and what levels are unsafe.

West Virginia, Virginia, Maryland and the District do not test river water regularly for drugs or hormones. The same goes for drinking water after it is processed by the Washington Aqueduct, supplying the District, Arlington County and Falls Church, and the Washington Suburban Sanitary Commission.

Still, the West Virginia study has spurred scientists to look for more information. Researchers at the U.S. Fish and Wildlife Service are seeking money for a much larger study across the Potomac watershed. They want to look for intersex bass and potentially disruptive chemicals in sites including the Blue Plains sewage plant in Southwest Washington.

Another federal study is underway in Rock Creek, looking for intersex symptoms and other health problems in a species of fish called white suckers.

Scientists across the region stressed that their work is just beginning. "We really don't know what's going on," said Vicki S. Blazer, a researcher for the geological survey in West Virginia.