- Associated Press - Saturday, March 12, 2016

NEWPORT NEWS, Va. (AP) - In 2002, smallmouth bass began to sicken and die by the thousands in Chesapeake Bay tributaries.

Alarmed, federal scientists began retrieving fish for study from big rivers such as the Potomac, the Susquehanna, the Shenandoah, the upper James.

“They had bacterial infections, they had fungal infections, they had parasite infections,” recalled Vicki Blazer, a pathologist with the Fish Health Branch of the U.S. Geological Survey in Kearneysville, W.Va. “They just had a lot of different infectious diseases.”

But beneath those ugly surface lesions and ulcers lurked something even more bizarre: Male smallmouth bass were growing lady parts.

More specifically, Blazer said, males were growing immature eggs within their testes.



They had become “intersex” - exhibiting characteristics of both sexes, rather than one.

The reason? So far, there’s no smoking gun.

Blazer and her colleagues are still sampling, still studying. But they suspect that estrogenic chemicals polluting the water and sediment that these fish rely on for food and habitat are slowly sexually transforming them.

In fact, some waterways - such as the southern stretch of the Potomac, the Shenandoah, the Susquehanna near Hershey, Pa. - showed intersex fish in 100 percent of male smallmouth bass studied. Rates were nearly as high at sites in West Virginia.

A massive fish kill in the Susquehanna raised alarm bells back in 2005. A subsequent investigation found a link between weed-killing chemicals used on farmland and lawns as well as pharmaceuticals found in sewage treatment plant discharge, said John Arway, fish biologist with the Pennsylvania Fish & Boat Commission.

Diseased smallmouth bass still turn up in the Susquehanna, which supplies half the fresh water to the bay. In 2012, fishing for smallmouth was banned for more than a month in much of the river. In 2014, a huge tumor found on one bass turned out to be cancerous, which Arway said is “very rare.”

Pennsylvania lags far behind other bay states in meeting pollution-diet goals for the estuary, called Total Maximum Daily Loads. Those TMDLs were imposed by the U.S. Environmental Protection Agency in 2010 to reduce harmful amounts of nutrients and sediment that have impaired the bay for decades.

This month, Arway said the EPA is set to announce whether or not the Susquehanna is impaired, too. If it is, the state must move to a TMDL for the river.

“But until that happens,” Arway said, “we don’t really have a plan to make the river healthy again.”

Most recently, the USGS looked at smallmouth and largemouth bass in national wildlife refuges of the Northeast and Mid-Atlantic, including Virginia.

Among other things, it found that largemouths in the Rappahannock River Valley National Wildlife Refuge had intersex rates ranging from roughly 22 percent to more than 50 percent.

“That was some of our highest intersex,” Blazer said. “But I will say our sampling site was close to wastewater treatment plants.”

Four wastewater treatment facilities are strung along the Rappahannock, and the surrounding land use is largely agriculture and forest. Scientists consider agricultural runoff and, to a lesser degree, sewage effluent chief suspects in the intersex condition.

Disturbingly, they also found high rates of intersex at sites with no direct pollution sources. The freshwater ponds of the Back Bay National Wildlife Refuge near Virginia Beach, for instance - where there’s no known source of agriculture or wastewater contaminants - showed intersex in nearly a quarter of the largemouth bass tested, their report says.

In pristine waters, said Blazer, largemouth intersex rates typically run from zero to about 10 percent.

“I think that’s the point - that it isn’t pristine water,” Blazer said. “Because it’s a refuge doesn’t mean the water is pristine.”

Smallmouth bass are a popular sport fish in the fresh waters of the bay watershed. The Chesapeake Bay Foundation says the fish accounts for $630 million each year in sales in Virginia, Maryland, West Virginia and Pennsylvania. Of those states, Virginia sees the lion’s share, or $250 million.

But smallmouth are also considered one of the most sensitive fish species to chemical contaminants.

“In a lot of ways, they kind of serve as the canary in the coal mine in terms of what’s actually going on in our waterways,” said Chris Moore, CBF’s Virginia senior scientist.

And when the smallmouth suffer, the impact is both environmental and economic, he said.

A smallmouth fish kill in the Shenandoah River in 2005, for instance, disrupted fishing for 2,100 licensed anglers and caused about $700,000 in economic damage, according to CBF’s 2013 Smallmouth Bass Report.

And every day, synthetic and natural hormones and estrogenic chemicals are flushed down toilets, thrown out with personal care products, run off from confined feed lot operations and from farmland laced with herbicides.

“What I say to people is, many of these chemicals are getting into the waterways because of our lifestyles,” Blazer said.

Young smallmouth are particularly susceptible. When hatchlings and young of the year are exposed during spring runoff, she said, it disrupts their natural endocrine system - glands that secrete the hormones that regulate, among other things, sexual function.

While the intersex condition can cut both ways, scientists are finding far less of it in females. In only a couple of fish other than bass, out of thousands examined, said Blazer, did they find females with full-size immature testicular tissue in their ovaries. They’re not sure why the disparity.

Interestingly, while intersex males have somewhat fewer and less robust sperm, she said, they do seem to be reproducing normally, although time will tell for these long-lived fish.

“But, to me, the important thing is that it’s an indicator of these chemicals that are present and having an effect, and they may be having other effects,” Blazer said, such as suppressing fish immune systems, leaving them susceptible to disease and parasites.

It’s a growing problem not just in the Chesapeake tributaries, experts say, but worldwide.

But experts don’t believe intersex fish or the estrogenic chemicals suspected of causing the condition threaten human health the same way, in part because our exposure isn’t as direct, acute or prolonged.

The concentration of chemicals in rivers is considered too low to endanger swimmers or drinking water, said Greg Allen at the EPA.

“Fish are a different story,” Allen said, “because, of course, they’re exposed to it constantly and their systems are different than ours.”

Allen coordinates the Toxic Contaminants Workgroup at EPA’s Chesapeake Bay Program office in Annapolis, Md.

“Generally speaking,” he said, “the science community doesn’t see it as a risk to human beings.”

Consuming smallmouth bass isn’t a real risk, either, said Blazer.

“The good news is, most of the chemicals that would be inducing these effects in the fish are not accumulated in the muscle, which is obviously what we’re eating,” Blazer said.

“I think we as humans need to be concerned about it,” she added. “But we’re not getting exposed in the same way.”

Besides, said Moore, if an angler catches a smallmouth bass - or any fish - covered in lesions, skin ulcers, tumors or slime, the obvious response is not to eat it.

“Generally,” Moore said, “we think those fish that are healthy are fish for consumption, and people should enjoy that resource.”

All of those rivers and streams seeing fish kills and diseased bass eventually empty into the Chesapeake Bay.

But experts say endocrine-disrupting chemicals get diluted in the massive estuary, which also benefits from tidal flushing.

Nobody knows if the bay hosts sickly male fish growing female eggs, and there’s no scientific effort to find out.

“It’s a large world of fish out there, and we’re talking about tens if not hundreds of different species that live in these estuarine systems of the Chesapeake Bay that may potentially be impacted,” said Wolfgang Vogelbein, a pathologist at the Virginia Institute of Marine Science in Gloucester Point.

“It’s possible, certainly, that some of that is going on here in the bay,” Vogelbein added. “And maybe certain species that are sensitive like the smallmouth bass seems to be. But no one’s looking, as far as I’m aware.”

VIMS is affiliated with the College of William and Mary in Williamsburg and recognized for its groundbreaking work over the years on diseases of striped bass. But Vogelbein said the saltwater striped bass is an entirely different species than the freshwater smallmouth and largemouth.

Recently, a VIMS graduate student did look at how bacterial infections in the bay affect fertility in female striped bass, he said, but male striped bass weren’t examined in that research.

There might yet be an opportunity for sampling if they can expand on research being conducted at Old Dominion University in Norfolk, he said. VIMS has been assisting a scientist there in his study of leach infestations among largemouths in the Back Bay refuge.

“One of the things I’m going to suggest once he starts sampling fish again is that he collect the gonads and that we take a look,” Vogelbein said. “It’s certainly worth looking.”

The USGS hasn’t sampled fish in the bay, either, said Blazer, although it could be worthwhile one day to take samples at the mouths of rivers that feed into it.

The agency is honing a five-year plan for more intersex testing, she said, although it’s unlikely the bay will be included in that research since the focus is on freshwater habitats of smallmouths.

Both Blazer and Vogelbein say a dedicated study of intersex in the bay would be costly - and a hard sell at a time when government funding is in short supply.

“(Neither) the will nor the money is there,” Vogelbein said. “It’s just not there.”

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