Field Samples: Fish Earbones Tell Story of Kingston Coal Ash Spill

In this addition of our weekly Q&A asking researchers what they’ve been up to and what they’ve learned, Brenda Pracheil, a former CFL post doc and current research at the Oak Ridge National Laboratory, talks fish earbones, coal ash, and environmental monitoring.

Who are you, where are you from, and how did you get to where you are now?

Pracheil once wrangled big fish on big rivers. Now she studies smaller structures in a big lab.
Pracheil once wrangled big fish on big rivers. Now she studies smaller structures in a big lab.

My name is Brenda Pracheil and I am a research staff member at Oak Ridge National Laboratory in Oak Ridge, Tennessee. I am originally from South Sioux City, Nebraska—a town of about 10,000 people in the northeast corner of the state where Nebraska, Iowa and South Dakota meet. I have done a lot of research on fish and large rivers which is an interest that probably stems from growing up on the banks of the Missouri River and spending a lot of time fishing with my grandpa when I was a kid.
My path to where I am now has been circuitous one. All told, I have received training from five colleges/ universities including three undergraduate institutions (University of Nebraska-Kearney, Western Iowa Tech Community College, University of Nebraska-Lincoln) before finally graduating with a BS in Biological Sciences and BA in Philosophy. I also attended two universities for grad school (MS: Michigan State University, Zoology, PhD: University of Nebraska-Lincoln, Natural Resources), and held postdoctoral positions at two universities (University of Wisconsin-Madison, University of Nebraska-Lincoln). I joined the staff at ORNL in January 2014.
Pretend we just boarded an elevator and you only have a one-minute ride to tell me about your work. (in this case, otolith related stuff). Can you capture it a few sentences?
Much like trees, the rings of an otolith can help researchers determine the age and growth rate of a fish.
Much like trees, the rings of an otolith can help researchers determine the age and growth rate of a fish.

Fish earbones, or otoliths, are one of the most incredible structures in the animal kingdom because they not only form rings on them every year (like rings on a tree) that can tell us how old a fish is and how much it grew in a year, but they can also tell us where a fish has been. Fish otoliths incorporate the water chemistry signature of their habitat that allows us to see the chemical fingerprint of the environments where they lived. These techniques have frequently been used to determine migratory history of fishes; something that we have done with my past work in Wisconsin.
My ongoing work with otoliths at Oak Ridge National Laboratory uses otolith microchemistry to understand the impact of an environmental disaster (Tennessee Valley Authority Kingston Coal Ash Spill) on a riverine ecosystem. For this study, we will use otolith material that was formed prior to and after the disaster, allowing for a comparison of pre-spill and post-spill environmental contamination. Practically speaking, the pre-spill/ post-spill snapshots of contamination enable us to assess progress in clean-up efforts.
What’s the simplest way to explain otoliths and “hard-part microchemistry?
See below!

In your study, what question did you ask and answer or do you hope to answer? What other questions might your work lead scientists to ask?
My work with otoliths has been pretty varied. In addition to the work on the Kingston coal ash spill, I have looked at fish habitat use as fish grow and develop and how otoliths have been useful and can continue to be useful for understanding fish populations. I hope that my work will lead to the expanded use of these techniques in freshwater fish biology and a greater understanding of fish populations.
Not to sound harsh, but why should someone NOT in the field of freshwater sciences care about your work? What’s a bigger picture implication, in other words?

A house surrounded by coal ash after the spill.

A little background on the Kingston coal ash spill: In the middle of the night on December 22nd, 2008, a coal ash retention pond dike ruptured at the Tennessee Valley Authority’s Kingston Fossil Plant in Kingston, Tennessee, spilling >1 billion gallons of coal ash slurry into the Clinch River in Tennessee. This spill was so massive that it completely blocked the Clinch River for a time and destroyed several homes. Aside from the landslide-like effects of this spill, coal ash, the byproduct of coal combustion, is potentially dangerous to humans because it contains elevated levels of toxic heavy metals like arsenic, mercury and selenium that can end up in water and fish consumed by humans. Our work on the Kingston coal ash spill is important to non-scientists because it evaluates how well the cleanup efforts of the Clinch River are working, especially since we don’t know how high levels of these heavy metals were in the Clinch River prior to the spill.
What do you love about your work? What do you love, well, not-so-much?

I love so many things about my work: I get to do something different every day, I get to be creative in in so many ways, I get to work with super-interesting people, my work helps to influence environmental policy and decisions. I really try not to focus on negative aspects of my work. There will always be those few things, but the work I am doing right now is so exciting that I usually forget about the things I don’t love not-so-much. I am so lucky to be a scientist!

To read more about Brenda’s work at ORNL, go here.

3 thoughts on “Field Samples: Fish Earbones Tell Story of Kingston Coal Ash Spill”

  1. My first MS from UW Wisconsin under Dr Hasler in 1975 studied otoliths and found a correlation between water temperature and diet. In those days, I used a scanning electron microscope and home made lapidary system to prep and examine the otoliths which I marked by feeding the fish tetracycline which produced a florescent ring under UV light. It is fascinating to see the technological advances. I am curious to know is there a correlation between blood levels of elements of interest such as selenium and water chemistry. I would expect a stronger correlation to diet so gut concentrations I expect would show a stronger correlation. Is there a paper or reference that I can find out more information?
    Best Wishes

    1. Hi Warren, that is a question for the pros! (I’ll ask one). Thanks for sharing, though. Cool to see how folks used to do it versus what they use now. The tetracycline part is brilliant!

      1. Hi Warren – here’s Brenda’s answer:
        “Actually, very little of the chemical composition of the otolith comes from the diet—something like 99% of the elemental composition of otoliths comes from water. You can reference them my new paper on hard-part microchem”
        Pracheil, B. M., Hogan, J. D., Lyons, J., & McIntyre, P. B. (2014). Using Hard-Part Microchemistry to Advance Conservation and Management of North American Freshwater Fishes. Fisheries, 39(10), 451-465.
        It should be available through CFL. If not, I’ve attached a PDF. At one point, I addressed this question in this paper, but not sure if it’s in the final version. If not, there are loads of refs that will answer that question. Thanks for asking!

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