Conserve and sustainably use the oceans, seas and marine resources for sustainable development

Marie Kurz is seen at a pond on the campus of Oak Ridge National Laboratory.  Carlos Jones/ORNL

From California canyons to German creeks: Science is personal and practical for ORNL scientist Marie Kurz

Kristen Coyne is a writer for Oak Ridge National Laboratory.

OAK RIDGE — Spanning no less than three disciplines, Marie Kurz’s title — hydrogeochemist — already gives you a sense of the collaborative, interdisciplinary nature of her research at the Department of Energy’s Oak Ridge National Laboratory. Still, those six syllables only hint at the vast web of relationships encompassed in her work.  

Kurz studies how rivers flow through landscapes; what kinds of nutrients, contaminants and other material sail through them; and how they transform along the way. As an experimentalist, her favorite part of the job is getting into the field. Depending on the season, Kurz can be found clad in tights, gloves reaching her shoulders, a neon vest and a ponytail-taming cap as she sloshes in olive hip waders through the particular stream under her scrutiny. The getup, she said, always makes her feel a bit like the Michelin Man.

This grounded bald eagle at a wildlife refuge in Missouri eventually succumbed to lead poisoning. Lead from bullets and shot are the latest threat to bald eagles, the recovery of which is an American conservation success story.  Betty Thompson

Once again bald eagles are in trouble: This time the threats are a deadly recipe of lead and neurotoxins.

The recovery of America’s bald eagles is one of the greatest environmental success stories of the past 50 years. From an estimated overall population of about 800 at the depth of their decline, they have rebounded to about 100,000 today living near water in Alaska, Canada and all of the lower 48 states.

Hellbender Press has covered the success story that brought our national symbol, the bald eagle, back from the brink of extinction.

The cause of that long-ago calamity was ferreted out with the help of an early citizen-scientist, a retired Canadian banker living in Florida named Charles Broley, who became interested in eagles and obtained a permit to band eaglets. Between 1939 and 1946 he banded a total of 814 of them in the nest before they fledged.

As the years passed Broley observed a population decline and initially thought habitat loss was to blame. But in an Audubon article he penned in 1958, Broley concluded, “I am firmly convinced that about 80 percent of the Florida bald eagles are sterile.”

But why? Broley was the first to speculate that the use of organochlorine pesticides, most notably dichlorodiphenyltrichloroethane, or DDT for short, was somehow the cause; but he had no proof and didn’t know how the chemical compound actually affected adult eagles.

Broley’s suspicions and others were brought to national attention by Rachel Carson in her landmark 1962 book, “Silent Spring.” DDT was outlawed in 1972 and the eagle population slowly began to recover.

And today? Bald eagles still face problems — both old and new.

The old one is lead poisoning.

Dr. Brian MIller

MTSU researchers document hellbender’s accelerating decline in Middle Tennessee

(Author’s note: I was aware of the hellbender before interviewing Brian Miller, but did not know the giant salamanders were present on the Highland Rim of Tennessee. Subsequent reading and interviews with other researchers, including Dr. Bill Sutton at Tennessee State University, Nashville, confirm Miller’s statements that hellbenders are vanishing from large portions of Tennessee, and Missouri. The healthy populations in portions of the Great Smoky Mountains and Cherokee National Forest may be an exception to a general trend toward extirpation and, ultimately, extinction).

Brian Miller has been researching hellbenders for decades. He serves on the faculty of Middle Tennessee State University where he teaches in the biology department and mentors younger researchers, many of whom publish their research.

He has even developed a digital “Guide to the Reptiles and Amphibians of Middle Tennessee.” The guide began more than 30 years ago as a dichotomous key for students in his vertebrate zoology class and now includes hundreds of photographs and exceeds 400 pages.

Dr. Miller researches the hellbenders of the Highland Rim, the upland that surrounds Nashville and the Great Basin. Populations of hellbenders in streams of this region are perhaps Tennessee’s most endangered.

QUESTION: I noticed that you specialize in herpetofauna. Most of the research listed on your faculty page is focused on amphibians, but with some papers on snakes. Can you comment about your research?

ANSWER: You are correct that amphibians are my primary research interest, particularly salamanders. However, I also have strong interests in reptiles, and my students and I have conducted research on various species of snakes and turtles.

When did you become interested in hellbenders?

Hellbenders have been of interest to me since I first encountered them while enrolled in a course on herpetology at the University of Missouri in 1977. I was fortunate that the professor of that course, Dean Metter, was involved with research on hellbenders and I began to assist with his research in 1978, in collaboration with Robert Wilkinson at Southwest Missouri State University in Springfield, Missouri.

Chris Petersen was working on his master’s degree with Dr. Wilkinson at that time and he matriculated to the University of Missouri a couple of years later to start on his Ph.D, which was also with hellbenders. Chris and I spent time in the field gathering data for his Ph.D. project until I moved to Washington State to work on my Ph.D.

I was hired into the biology department at Middle Tennessee State University in 1989 and began working with hellbenders in this state in 1990. At that time, I was able to locate populations in several rivers in Middle Tennessee, including a large population in the Collins River. I decided to concentrate my efforts on this population and one in the Buffalo River.

Of note, the population I worked with in the Collins River was dominated by large adults, whereas the population in the Buffalo River consisted of many age classes, including young individuals.

The Collins River situation was like what I was familiar with in Missouri and Arkansas populations. Unfortunately, by the early 2000s the population I was working with in the Collins River was gone; however, populations remain in the Buffalo River. My research with hellbenders during the past decade has been concentrated in streams in the Western Highland Rim.

Do you work with both subspecies, the Ozark, and the Eastern hellbender?

I worked with both subspecies while a student at the University of Missouri when assisting with projects in the Metter lab, but since I moved to Tennessee, I have worked only with Tennessee populations.

What do you perceive as the greatest threats to hellbender populations?

I am not certain why most populations of hellbenders are in decline rangewide, but suspect that habitat alteration, including sedimentation, and disease are involved in many if not all areas where declines are occurring. Lack of recruitment of young is a common theme of populations that decline.