Centennial Story 66: Craig Kastelle (BS, 1982; MS, 1991)

In high school, I had an engaging teacher, Steve Ufer, who inspired me to pursue a chemistry degree in college. So chemistry was my first interest when I started at Western Washington University. My interests roamed after about two years, and I started considering a degree in some other realm of science. It was during a summer job, sliming fish in an Alaskan salmon cannery, when I heard about the fisheries program at the University of Washington. Soon thereafter, I transferred to the then College of Fisheries. The program was a perfect fit, and I became hooked. I had two concentrations for my BS degree, fish culture and aquatic resource management. The variety of course work and hands-on work was ideal. In the mornings, I may have been guided by Professor Emeritus Lauren “Doc” Donaldson in chasing salmon to spawn them at the salmon return pond. Then in the afternoon, I might have been carrying a stack of punch cards to the Computer Center, usually just to see how many errors I had made in the FORTRAN code. I think one of the more unique classes that I took was a population dynamics class taught by Gordie Swartzman; the final exam was a challenging take-home test, and for the in-class final he sang sea shanties.

Otoliths from Greenland halibut
Otoliths from Greenland halibut

The trajectory of my career was set by a class field trip on a small trawler where we went fishing on Puget Sound. We extracted otoliths from some of the catch and tried to determine the age of the fish. It was impossibly difficult, and I vowed that, “I would never work with otoliths again.” About one year later, after working as a hydroacoustic technician on the Columbia River and an observer on a small Japanese stern trawler, I got a job reading otoliths at the then Northwest and Alaska Fisheries Science Center in the Age and Growth Program. My supervisor at the time, George Hirschhorn, cautioned me to “never say never.” Now, after more than three decades, I am still working with otoliths.

Craig preparing an otolith for radiocarbon analysis
Craig preparing an otolith for radiocarbon analysis

My studies with otoliths have expanded from age determination to various microchemical analyses to assess the accuracy of age estimates, make inferences about fish life histories, and estimate ambient water temperatures. Determining fish ages (counting otolith growth zones) for stock assessments is very important and necessary, but it was only the start. After about two years working with otoliths, I went back to earn a MS degree at the School of Fisheries (SOF) while still working at the Alaska Fisheries Science Center (AFSC). How many people know that there was a Laboratory of Radiation Ecology in the basement of the Fisheries Center whose main goal was to measure environmental radioactivity left by atomic bomb testing in the South Pacific? It was in that lab that I was coached by Ahmad Nevissi in measuring naturally occurring radionuclides in otoliths. My MS degree program was supervised by Don Gunderson as chair, Loveday Conquest, Ahmad Nevissi, and my then supervisor at the AFSC, Dan Kimura. For my thesis, I measured radioactive lead and radium in sablefish otoliths to estimate their longevity. Once when Don was looking at some of the radiochemical results, he poked fun at other research and said, “Wow, this is real science.”  These days I do not remember how many classes I took from Loveday, but there were many, and I remember they were challenging. In class, she was tenacious and skilled at finding different ways to explain concepts; the students benefited from that, including me.

Craig describes otoliths at a National Oceanic and Atmospheric Administration, Alaska Fisheries Science Center open house.
Craig describes otoliths at a National Oceanic and Atmospheric Administration, Alaska Fisheries Science Center open house.

I may be atypical because I have worked at AFSC for all of my career, but the world of otolith-based research has grown exponentially, and I have been lucky to be part of advances made in that field. At the SOF, the variety of the course work and the teaching of critical thinking was a great experience that prepared me for this line of work. The fun part of all this otolith research is how it has circled back to my early interest in chemistry. Little did I know.

This would not have been possible without the teaching, mentoring, and patience of my high school teacher, Steve Ufer, Don Gunderson, Dan Kimura, and my current supervisor and SAFS affiliate faculty member, Tom Helser.

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