Donald A. Thomson, A Remembrance
By: Chris InAlbon and Christine Flanagan
Donald A. Thomson, 90, passed away on May 20, 2022 his family by his side at his home in Tucson, Arizona. His research produced important contributions to knowledge about the Gulf of California, its ecosystems, and especially its ichthyofauna. He published more than 35 scientific papers and book chapters but many who travel to the Gulf know of him only by The Tide Calendar of the Northern Gulf of California, published annually from 1967 to 1994 (and later by CEDO), or by two books. His Reef Fishes of the Sea of Cortez, originally published in 1979 by John Wiley and Sons with Lloyd Findley and Alex Kerstitch, remains the definitive reference on reef fishes in the Gulf. It was preceded by Gulf of California Fishwatcher’s Guide, with Nonie McKibbin (1976), a modest 79-page paperback with precise line drawings beautifully illustrated by Jenean Thomson, his wife.
This first ever field guide to Gulf fishes was self-published by Golden Puffer Press, sold out of his home, and marketed mostly by word-of-mouth, but nevertheless gained wide popularity and went through several printings. Its 209 species included the fishes most likely to be encountered by fishers and divers on near-shore reefs and sandy bottoms and in the tide pools of the northern Gulf. The Guide was significant in its time because it facilitated research and detailed observation of fishes and encouraged conversation among students, sport divers, and fishermen. Likely tattered, it can still be found in many personal libraries, having earned its place there as a storehouse of treasured memories.
These publications were culminations of years of careful field work that began in the summer of 1963, when as freshly minted PhD from the University of Hawaii, he moved his family to Tucson to take a position in the Department of Zoology as part of a fledgling marine science program. In his own words:
Those words, penned in 2015, at the age of 83, convey the energy, collegial spirit and sense of wonder that propelled him throughout his 36-year career. But his appreciation for the Gulf transcended love—he soon grasped that a semi-enclosed sub-tropical ocean spanning more than 8° latitude, surrounded by harsh desert, headed by one of our nation’s most significant rivers, and framed by wild and scientifically accessible coastline shaped by enormous tides and active tectonics offered limitless opportunities and inspiration for the study of marine systems and the spectrum of evolution. There was no shortage of possibilities. He was the major professor for over 40 M.S./Ph.D. students and served on the committees of many more. His enthusiasm and passion for learning was contagious—and he had a gift for awakening it in others. Many of his students, in academics and in government, produced ground breaking research and worked to establish significant conservation efforts in the Gulf of California and beyond. Jeff Seminoff, Sarah Mesnick, Richard McCourt, Matt Gilligan, Fernando Zapata, Wayne Van Voorhies, Peggy Turk-Boyer, Phil Hastings, Lloyd Findley, Richard Brusca, and many others became accomplished leaders in their fields, changing the course of research, conservation, and education on local, national and international levels. CEDO itself would likely not have endured without his constant support and encouragement. No matter their eventual course in life, his students were forever introduced to the power of observing nature and seeing it firsthand.
He shared his love of the intertidal and the Gulf with literally 1,000’s of undergraduates through his Oceanography, Ichthyology, and Marine Biology classes. They had a reputation, not only for his engaging teaching style, but for their infamous field trips to Mexico. To this day, mention his name and field-trip stories abound—tales of the orgy-like grunion run on the beach in El Golfo, the five-weeks of camping and diving along the coasts of Baja, the crack-of-dawn tide pooling, the oppressive heat, relentless mosquitoes, broken down Volkswagens, and the line for the showers—but they all end with how the experience changed their lives. Many were forever imprinted with a love of marine ecology and a passion for the conservation of our oceans.
Some students changed majors mid-course: Jeff Leis, who as a pre-med undergraduate student took his Ichthyology class, credits him with opening the door to a life of research, a PhD from the University of Hawaii, and eventual recognition as a world authority on marine larval fishes.
His students called him DAT, an eponym given in the early 70s, by a graduate student caught up in the infamous BioEast Basement competition for field equipment. It was in constant churn and travel back and forth to Mexico for research and teaching, and always in short supply. To discourage “mal-appropriation” the equipment was eventually all individually marked JRH or DAT in big letters depending on whose grant paid for it. Hence the name DAT—which he readily embraced. Only fifty years later did we learn that he detested Donald, his given name.
Much of DAT’s early research focused on the Gulf grunion. Grunion come onto the beach to spawn, depositing eggs in the sand on a descending series of high tides, with subsequent hatching and return to the sea of the larvae a fortnight later in the next series of high tides. He and his students worked out the precise conditions that determined the pattern of spawning in the Gulf. Today DAT might be called a “grunion whisperer”.
He could tell you the most probable day and approximate time of the run by looking at the tide calendar, but on the beach he would watch, evaluate the conditions, sometimes for several hours, and then say, “they’ll start coming in within the next 5 minutes”, and they did. For years he was the expert consulted by international film crews travelling to the Gulf for the purpose of filming a run.
DAT’s mentoring power lay in his innate teaching skills, his love of life-long learning, and his patience. He was approachable, memorable, and lacked any trace of hubris, qualities that encouraged young students. He understood the power of hands-on experiences and of letting students discover their own answers. He knew when to push, state the obvious or give a supporting hug. He could be gruff at times, demanding honesty and integrity from those around him and questioning—What did you see? How would that idea make sense? What does that behavior mean? One student on a trip down Baja casually reported noticing how body sizes declined in blennies over decreasing latitudes and the challenge immediately came: “Back it up with data!” But what many will remember was his willingness to share the spotlight. He encouraged his students to lead, seek their passions and be their best. Those of us that were fortunate to have DAT as a professor, mentor and friend carry that love of learning in all we do, and many of us have become educators in our own fields. It is a fitting tribute that Matt Gilligan (PhD, 1980) credits DAT with taking him on as a graduate student after being discouraged in other UA faculty interviews: “DAT was my last meeting of the day…[He] was interested in my undergraduate research project . We connected.” Matt went on to be a well-known scientist with more than 30 publications, including the first field guide to the fishes of the Georgia coast. He developed a thriving marine science program at Savannah State College, the first at a historically black university. In 2018, Matt was honored at the White House with the national Presidential Award for Excellence in Science, Mathematics and Engineering Mentoring. DAT saw the potential but we will never know the far-reaching significance of Matt’s leadership as his efforts to promote diversity in marine sciences cascade across generations.
DAT also understood the importance of teaching those that might not ever reach the shores of the Gulf about its importance and need for protection. With his guidance and support, students created a marine ecology program for school age children that brought the ocean into schools, and children onto the University of Arizona campus. Children across Southern Arizona had the opportunity to learn about the species found in the Gulf, and how many of those species were affected by our actions here in Arizona. DAT himself engaged in the outreach, spending time at his granddaughter’s school sharing his knowledge with her classmates.
The success of the marine program and most of his students lay in the Gulf itself, wholly contained within the Republic of Mexico. He was grateful for the welcome he received there and for the international cooperation he enjoyed with many Mexican scientists over the years. He was also grateful for the financial and administrative support for the marine program by the University of Arizona, and for the efforts of Al Mead and John Hendrickson, Joe Schreiber and others who also were early supporters.
No memories of DAT would be complete without acknowledging how generously he shared his family with his students. We all knew Jenean, Erin, Kurt, Lisa, and Madelon. Erin’s memories are revealing of how much his family supported him in those early years.
Starting a marine program in the Gulf was not easy:
Son Kurt was on many of the summer trips, in the beginning just a kid, but with OJT (“on the job training”) and keen interest he grew into his role as chief outboard motor mechanic. Later, he was also the general go-to trip mechanic tasked with the nearly impossible job of keeping his father’s Volkswagen busses on the road when they would inevitably break down. During the academic year, we all attended weekly student seminars in the Thomson home and shared the room with his loquacious African Gray parrot, Charlie, who had the timing of a comedian. More than once a statement timorously offered for consideration was followed by a raucous “WHAT!”
We are all a product of our times. DAT’s career spanned a period of breakneck developments in research, theory, technology, and computing across the spectrum of biological sciences. In the final decade of his career the Department of Ecology and Evolutionary Biology, bore little resemblance to the Department of Zoology that he joined in 1963. Older colleagues had retired, and many of the new hires brought research interests focused in evolutionary theory and investigations based in the growing field of molecular biology. They also brought new ideas about educating students. Many programs, marine science included, were restructured to reflect wider trends in academics. Some of the courses DAT taught live on, and he took heart that his student, Katrina Mangin (Ph.D., 1991) became a prominent part of the marine science presence in today’s EEB.
DAT retired in 1998. He lived long enough to see his legacy —based in teaching, field observations and research, collections and mentorship— contribute to a foundation for the science – and scientists – we need today to face the challenges of Earth’s (and humanity’s) future. He never lost his love for the Gulf, nor his faith in nature and enthusiasm for research itself.
In the closing words of a speech sent to N-Gen on receiving their Distinguished Service award in 2015 he wrote: “I envy all of you for tackling the exciting and innumerable challenges facing you both within and beyond this region. You know them better than I. Just remember that the oceans with your help, have great resilience.”
As CEDO enters its 43th year and works to conserve ecosystems in the northern Gulf it brings DAT’s vision full circle: the answer to preserving the health of our oceans lies in working with those who rely on the Gulf for livelihoods to deepen their connections through knowledge, action, and commitment.
And lest we fail to mention: he also never lost his love for baseball, dogs, and devilled eggs.