COLUMBIA — About 13 years ago, scientists studying fish on the Missouri River noticed something strange: They were pulling pallid and shovelnose sturgeon out of the river that had both male and female reproductive organs.
Sturgeon are an ancient family of bony fish that cruise along river bottoms. The pallid sturgeon is one of three endangered species in the Missouri River, and scientists from various branches of government are working to learn more about what threatens them.
Diana Papoulias, supervisory research fish biologist with the U.S. Geological Survey’s Columbia Environmental Research Center, will give a talk on her work with pallid and shovelnose sturgeon at 7 p.m. Tuesday at Les Bourgeois Vineyards in Rocheport.
Papoulias’ talk, sponsored by Missouri River Relief, will focus on the extent and distribution of intersex sturgeon on the river. She will also explain some of how chemicals similar to estrogen could affect the fish’s development.
Papoulias has been studying intersex sturgeon in the Missouri and Mississippi rivers since 2000, when she found some at a site on the river south of Columbia. Since then, she and other researchers at the center have been searching for answers in the laboratory and in the field.
Papoulias said they are 18 months into a two-year study on whether tiny amounts of a chemical found in birth control medication will cause sturgeon to develop both male and female reproductive organs.
“These chemicals that we’re talking about, they aren’t easy to pick up in a fish or even easy to pick up in the water,” Papoulias said.
The chemicals are hard to detect because they show up in weak concentrations and are quickly broken down into smaller molecules.
Since January 2012, researchers at the center have been exposing pallid sturgeon to 5 nanograms per liter of ethinyl estradiol, a form of estrogen found in various hormone-altering medications, to see if they can induce intersex development in a controlled environment.
Next spring, they will cut the sturgeon open to see if they can find abnormal sex organs. They will also try to get the fish to reproduce to study any effects on spawning.
The results could be valuable in determining whether this chemical or related chemicals affect sturgeon in the wild. It will provide some laboratory evidence to back up what Papoulias has observed in the field.
In 2008, the USGS worked with the Missouri Department of Conservation to collect wild sturgeon from points in the Missouri and Mississippi rivers, including sites near St. Joseph, Kansas City, Columbia, St. Louis and Crystal City. In portions of the river immediately downstream from urban areas, they found higher distributions of intersex sturgeon.
“We see these peaks right below the major cities,” Papoulias said. “It seemed odd that we would see that kind of a distribution because the fish move so much.”
The survey’s studies of sturgeon ecology have provided greater understanding of the fish’s behavior and travel habits. Using telemetry to track the fish throughout the river, they learned that sturgeon do migrate to different parts of the river to spawn, but then they return to familiar territory where a long exposure to contaminants could plausibly occur.
While Papoulias said she cannot provide definitive answers yet on exactly what is happening to the sturgeon and why, she will present the evidence she and other researchers have gathered so far.
Papoulias’ talk is part of a series that has been going on for three years. Once a month, three speakers — one in Kansas City, the second in Rocheport and the third in St. Charles — give free public talks about Missouri River issues.
Steve Schnarr, program manager with Missouri River Relief, helps organize the Big Muddy Speakers Series. Schnarr said the last time one of the speakers talked about chemical contaminants, the subject got a lot of attention online. He said the pages on Missouri River Relief’s website that deal with chemical contaminants consistently get the most page views.
“People are looking for information on what’s going on on this huge river,” Schnarr said. “But there’s not really good information on water quality, especially emerging contaminants.”
Schnarr said endocrine-disrupting chemicals, the effects of which Papoulias focuses on in her sturgeon work, are not easily removed in wastewater treatment or drinking water treatment.
He said he hopes local residents will attend Papoulias’ talk to learn more about where these chemicals are coming from and what they can do to prevent them from making their way to the river. One easy way people can help is to avoid flushing medications or other chemicals down the toilet, he said.
The Big Muddy Speaker Series is hosted by Missouri River Relief, Friends of Big Muddy and the U.S. Fish and Wildlife Service. More information about the series can be found at BigMuddySpeakers.org.
Supervising editor is John Schneller.