Skip to Content
Big Muddy Speaker Series logo

Big Muddy Speaker Series presents:

Intersex Sturgeon on the Missouri River?

Illustrated river waves in white
Presented by Diana Papoulias, PhD
Sturgeon in net

Presentation by – Diana Papoulias, PhD, Research Fish Biologist –  US Geological Survey Columbia Environmental Research Center

Original Presentations:

In 2000, research fish biologist Diana Papoulias began documenting an uptick in previously rare cases of intersex shovelnose sturgeon. These Missouri River fish were developing both male and female reproductive organs.

Those fish were shovelnose sturgeon, which are considered a valid experimental surrogate for the federally endangered pallid sturgeon. Diana's discovery began more than a decade of research into this phenomena, focusing on finding the chemical and environmental causes that are present in Missouri River water that might be effecting the reproduction of the pallid.

This research has been ongoing during a period when a lot of research into "emerging contaminants" in our water supply has shown disturbing effects of phyto-estrogen compounds and other endocrine disrupting chemicals.

dissection of an intersex sturgeon

This dissection of an intersex sturgeon shows both male and female reproductive tissue. photo courtesy of Diana Papoulias, USGS.

Diana described the reproductive effects they've documented in fish, what is known about the chemical contaminants in the Missouri River, and the pathways for how these chemicals are causing such dramatic changes in fish.

Meet Your Presenter

Big Muddy Speaker Series

Diana Papoulias, PhD

, Research Fish Biologist, US Geological Survey Columbia Environmental Research Center

Diana Papoulias, PhD, is a Research Fish Biologist at the USGS Columbia Environmental Research Center. The primary focus of her study is to investigate factors that disrupt normal developmental and reproductive processes in fishes.

learn more

Related Presentations

Resources & Links

Upcoming Presentations

Missouri River Relief: 25 Years on the Big Muddy

November 10, 2026
Columbia, MO

Join us for a journey through time celebrating 25 years of Missouri River Relief's work on the Big Muddy.

See Event

Plastic Pollution, Gulf Hypoxia, and Water Quality

November 11, 2026
St Charles, MO

Jennifer Wendt from MidAmerica Clean Future guides us through understanding regional water quality challenges.

See Event

Disclaimer

The views and opinions expressed by our presenters do not necessarily reflect the view or policies of Missouri River Relief, the Big Muddy Speaker Series or any of the partners that support this public forum. The Big Muddy Speaker Series believes that hearing diverse perspectives is a crucial building block for an informed public.
© 2026 Missouri River Relief. Website design and development by Pixel Jam Digital