Field Notes
U.S. Fish & Wildlife Service
Field Notes Entry   
Confusion Among Sturgeon Continues in the Mighty Missouri River
Midwest Region, March 27, 2012
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Jennifer Gorman (FWS), Mandy Annis (USGS-CERC) and Hilary Meyer (FWS) examine the intersex gonads of a shovelnose sturgeon.
Jennifer Gorman (FWS), Mandy Annis (USGS-CERC) and Hilary Meyer (FWS) examine the intersex gonads of a shovelnose sturgeon. - Photo Credit: Heather Calkins- Columbia FWCO

In March, the Columbia Fish and Wildlife Conservation Office continued to assist with research on intersex (male and female reproductive tissues) in shovelnose sturgeon from the Missouri River. Dr. Diana Papoulias of the USGS Columbia Environmental Research Center (CERC) has been working to find the cause of intersex in sturgeon for over 10 years. This current 2-year study focuses on what effect hormonally active agents (HAAs; endocrine disruptors that interfere with important hormonal processes) and thermal influences have on the incidence of reproductive abnormalities within the native shovelnose sturgeon populations in the Missouri River. Shovelnose sturgeon are often used as surrogates for the endangered pallid sturgeon because of overlapping ranges, similar morphologic features and similar life histories. Fish collection sites were selected in proximity to facilities and outfalls that may contribute HAAs or have thermal effects on the system (waste water treatment plant effluent, wastewater treatment wetland, combined sewer system outfalls and facilities that discharge “cooling waters”). HAAs can accumulate in river and lake sediments, where bottom feeding fish (i.e. shovelnose and pallid sturgeon) may consume them directly or indirectly.

Assisting the USGS CERC, Columbia FWCO’s biological technicians Heather Calkins, Anna Clark, Hilary Meyer, Jordan Fox, Lloyd Dugan and Jennifer Gorman performed necropsies on male and female shovelnose sturgeon. Performing each necropsy was a detailed and dexterous process. Blood was drawn from each fish and processed, then placed on ice to be examined later. Scientists at the USGS CERC lab will examine the plasma (the clear fluid portion of the blood) from blood samples for traces of hormones. Each sturgeon was then externally and internally visually examined for abnormalities and sex determination. Tissue samples were taken from the reproductive organs and liver for later cellular and molecular examination. When an intersex fish was found, the brain tissue was snap frozen. During each step, photographs were taken to record abnormalities and confirm visual examination.

To date, we have visually identified two intersex shovelnose sturgeon that were captured at the study’s Eagle Bluffs Conservation Area collection site. There are 3 sample collection sites in Missouri; the Jackass Bend Unit of the Big Muddy National Wildlife Refuge (just downstream of Kansas City, MO), Eagle Bluffs conservation area (downstream of Columbia, MO), and the confluence of the Missouri and Gasconade rivers (downstream of Jefferson City, MO). No other visually intersex fish were collected from the two remaining sites. The Eagle Bluffs collection site is located downstream from Columbia's Constructed Wetlands Wastewater Treatment Project. The 130 acre constructed wetlands project began in 1991 and was completed in 2001 as the final stage of treatment for all of Columbia, Missouri’s wastewater treatment. We appreciate and enjoy the opportunity to collaborate with other agencies for the good of natural resources. Stay tuned for the results from the cellular and molecular examinations.

Contact Info: Heather Calkins, 573-445-5001 ext 29, heather_calkins@fws.gov
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