An Agate Original
A giant intellect, a Renaissance man, an early ecologist, a prolific and talented writer, brilliant but modest, remembered with deep respect and fondness by his colleagues. The man whose research provided the scientific underpinning for what became one of Minnesota’s most hotly-debated environmental regulations. A gentle scholar with high professional standards who helped to lay the groundwork for the scientific rigor the Minnesota DNR is known for today.
John Briggs Moyle was born in Union Grove, Wisconsin, in 1909. He received a B.A. from the University of Minnesota in 1933, and then a Ph.D. in botany in 1938. With his fellow graduate students, Moyle helped pioneer the nascent discipline of ecology. At the University of Minnesota’s Cedar Creek Ecosystem Science Reserve, an internationally known field station, he and a friend, Raymond Lindeman, studied energy flow through the Cedar Bog Lake ecosystem. How energy of various kinds flows through natural systems is a concept central to the study of ecology, but it was so new in the early 1940s that journals at first rejected Lindeman’s paper. But it influenced Moyle’s thinking throughout his career.
In his Ph.D. thesis, Moyle asked how the chemistry of the water in Minnesota’s lakes influenced the types of plants growing in them. At the time, most ecologists were not well-versed in chemistry, and so generally stayed away from such questions. To answer it, Moyle sampled water and inventoried the species of plants in 225 lakes distributed across Minnesota, from the deep, acidic lakes of the northeastern conifer forests to the shallow, calcium-rich lakes of the southwestern prairies. From these data, Moyle concluded that “water chemistry appears to be the most important single factor influencing the general distribution of aquatic plants in Minnesota.” This study remains today one of the largest systematic surveys of lake water chemistry and plant communities anywhere. Although his classification of Minnesota’s lakes according to the chemistry of their waters has been modified with additional data, it remains the basis of lake management in Minnesota and elsewhere. Moyle’s influential scientific paper on this research was truly cutting edge and has been cited nearly 300 times in other scientific papers and some of the leading textbooks of lake ecology. It continues to be widely cited even today.
After completing his Ph.D. thesis in 1938, Moyle worked for the Minnesota Department of Conservation (the former name of the DNR) until he retired in 1974. In the early years he was a field researcher, continuing the line of research he pioneered in his thesis, taking water samples and listing plant and animal species he observed in lakes and rivers in the various biomes of the state, from Lake Superior in the north to Big Stone Lake in the west and the Zumbro River in the south. He was named Supervisor of Fisheries Research in 1952, and Supervisor of Wildlife in 1956. In 1966 he became the Technical Assistant to the director of the Department, essentially the assistant director.
The roots of the wild rice/sulfate law
During the field work for his thesis, Moyle observed that wild rice generally does not grow well in sulfate-rich waters, and this observation became the basis of Minnesota’s 1973 law requiring water used to grow wild rice to have less than ten milligrams of sulfate per liter of water.
In an early test of the new law, complications arose. In 1975, Minnesota Power objected to the sulfate limit for its Boswell generating station, a coal-fired power plant on the Mississippi River near Cohasset. The Minnesota Pollution Control Agency consulted Moyle, who was retired. In a prescient memo, he speculated that the conversion of sulfate by bacteria to sulfide in oxygen-poor sediments “may well inhibit the germinating of the seed or growth of young plants, but this remains to be investigated.” Forty years later, his suggestion was confirmed. The flowing water of the Mississippi River in this particular location brought oxygen into the sediment, which is probably why the rice could survive at higher sulfate levels there.
But the 10 mg per liter sulfate standard for wild rice waters was rarely enforced after 1975. In recent years, tribes and environmental groups began pressing the MPCA to dust off the regulation and start to enforce it. Industry cried foul, and the legislature intervened. Iron Range legislators ridiculed Moyle’s science as old and unreliable; they required the MPCA to undertake a complex and many-faceted research project to update the limit. That research ultimately confirmed Moyle’s observations and conclusions, although the chemistry of some lakes and rivers might make it possible for wild rice to survive at slightly higher sulfate levels. After the research was completed, someone produced buttons proclaiming, “John Moyle was right.”
“My dad didn’t like controversy,” recalled Moyle’s son, Peter. Luckily, the bitter controversy over the sulfate/wild rice rule didn’t blow up until years after Moyle’s death in 1977.
A respected colleague who brought scientific rigor to the DNR
There are only a few DNR old-timers who remember Moyle personally, but they are universally delighted to talk about him.
Dennis Anderson, a DNR fisheries researcher from 1969 to 2002, recalled meeting John Moyle as “a green rookie summer employee in my college years,” doing lake surveys in the Brainerd area. “We were told if we found any aquatic plants we couldn’t identify, we should preserve them and get them to John Moyle and he would tell us what they were,” said Anderson. He had only heard of Moyle and was feeling pretty intimidated when his supervisor directed him to Moyle’s lab. “I couldn’t believe his reaction: he thanked me for giving him the opportunity to exercise one of the greatest pleasures of his life—to look at something real. He was world-famous, but so unassuming and humble. I’ll never forget that.”
Anderson had come to the department as it was in transition. In the early days, there was near-total emphasis on stocking fish, Anderson said. “Those old-school people didn’t have any science; they were good at hatching walleye eggs. They weren’t looking at the habitat, at water fertility. When I came in, we had the science. The old guys grumbled about the new kids coming out of college, and maybe we young ones were a little snooty too,” he admitted.
Moyle was an influential figure during that transition. His first love was plants, and he developed a key for the field staff to use in identifying aquatic plants. Moyle frequently took groups of biologists into the field for lessons on natural history. He wanted his colleagues to learn how to identify aquatic plants and common flowering plants. He offered these training opportunities so generously that the DNR sometimes lost the staff he taught to the federal government, which paid better. “It meant more work for him,” said his son Peter. “But he was proud of training these scientists who spread out all over the country as biologists for other agencies.”
Another member of the young generation of DNR scientists, Duane Shodeen, worked at the St. Paul headquarters for several months before he learned who Dr. Moyle was. “I’d see this guy—he wasn’t dressed really neatly—I thought he was a janitor. Then someone told me that was Dr. John Moyle! I just couldn’t believe it. He was a really intelligent man but a down-to-earth guy too. He could talk to anybody about the science.” Shodeen said Moyle worked well with the DNR field staff. “Often the people in the field didn’t have a lot of respect for the people in the central office, but they had respect for Moyle; I never heard anybody say a bad thing about John Moyle.”
Like Dennis Anderson, Shodeen recalled the elaborate but often futile system of stocking fish before Moyle’s work prompted dramatic changes. “Back in the day, at the fish hatchery on Warner Road they’d hatch walleyes, dump them in cream cans and ship them on trains around the state,” Shodeen said. “Guys from sports clubs would wait at the railroad station, pick up the cream cans, and truck them out to the lake. That’s what they did.” Moyle’s manuals outlining proper methods for surveying lakes and streams eventually forced a more scientific approach. “You collect information on the fish populations over time and you can start to assess whether the stocking is working or not,” Shodeen explained. “If you’ve been stocking walleyes for ten years and there’s no walleyes in there, it probably isn’t working.” Moyle’s protégé, Dennis Schupp, analyzed 20 years’ worth of lake survey data to bring an even higher level of scientific rigor to fish management. Schupp later developed a lake classification system for Minnesota lakes that is widely used today by lake ecologists and fisheries managers and which is based in part on Moyle’s original Ph.D. work.
Shodeen was impressed with Moyle’s understanding of the interdependence of things. “He was the first environmentalist I ever met.” That holistic thinking was evident in Moyle’s observations of the habitat needs of wild rice. “He mapped it out,” said Shodeen. “He had maps of water chemistry and maps of aquatic vegetation. He’d overlay the plant maps on the water chemistry maps, and you could see the connections. You could see that it makes sense, but it took somebody like him to tie it together.”
Jim Lilienthal started in fisheries management with the DNR in 1969. He recalled a regional meeting he attended at the St. Paul Hotel in 1970. Years before the Clean Indoor Air Act, about 300 biologists from around the Midwest gathered to talk about wildlife. “It was a pretty pungent odor with all those cigars and pipes, and you’d have to listen hard, with the sound of guys pounding their pipes into ashtrays,” Lilienthal remembered. Moyle gave a long, “memorable” speech. “It was about the connection that all things have in the environment, how we really need to have a very holistic look at how we do things in our fisheries management activities. It was directed at making sure you’re looking at the big picture, not focused too much on one small aspect of it. That was a message that really stuck with me.”
Moyle’s rigorous mind, wide interests, and gentle manner could have cast him as a classic professor. He was even absent-minded: one colleague remembered that he often had two cigarettes going at once, and occasionally came to the office wearing two ties! At scientific conferences, after the papers were presented and the dinners consumed, Moyle would play the piano and sing.
Moyle’s career in fisheries biology was an extension of his Ph.D. work on water chemistry and plant species. In many of his later writings, Moyle made the point that water chemistry determines the plant species which are the basis of the food web, all the way up to Minnesota’s famed walleye and lake trout game fish. Pay attention to the water chemistry and the lake’s fish populations will thrive, he said. The University of Minnesota and the DNR today are internationally known for the detailed attention given to the relationship between lake chemistry, plant communities, and fish populations. It is no exaggeration to say that John Moyle’s research as both a Ph.D. student and with the DNR is one of the foundations of that reputation.
At the peak of his career, Moyle pushed for a broader mandate for the DNR. With nearly the entire budget of the agency going to research and management of fish and game, Moyle was among those advocating for broadening the agency’s scope to include non-game species. The then-Director of the Fish and Wildlife Division, Roger Holmes, agreed, and shortly after Moyle retired, Holmes directed Moyle’s salary to be used to hire Carrol Henderson as the first (and only recently retired) supervisor of the new Nongame Wildlife program. Funded by the loon checkoff donations on state income tax forms, the program now protects more than 700 species, and conducts a dozen projects ranging from Lights Out Twin Cities to citizen monitoring of loons, eagles, frogs, and dragonflies.
Moyle also played a central role in creating Minnesota’s system of Scientific and Natural Areas. In a 1966 issue of the Minnesota Conservation Volunteer magazine he explained the importance of setting aside sites across the state to protect natural features of exceptional scientific or educational value. These sites serve as a repository for genetic diversity and help to prevent the loss of important species, natural communities, and features. Moyle served on an advisory committee which settled on definitions and classifications and recommended special lands to be protected. He worked with other committee members to create a list of species of special concern and advocated for more research on habitat needs of those species, both plant and animal. The first piece of land was acquired for the program in 1974; today there are 168 Scientific and Natural Areas protecting nearly 200,000 acres. Moyle continued to serve on the advisory group for three years after he retired.
One measure of influence is whether a scientist’s work continues to be used by other researchers. According to the DNR’s current lead expert on lake habitat management, Paul Radomski, the protocols for lake sampling that Moyle established in the 1950s are still very much in use. “The consequence is that the DNR has a wealth of lake data; the extent and depth of these data are likely the best in the nation,” said Radomski in email correspondence with Agate. Useful historical data are also available for mercury concentrations in fish, thanks to Moyle’s leadership. And fisheries managers around the country regularly depend on Moyle’s careful analysis of gill net catches, which are used to count fish populations.
A family man
Moyle’s wife Evelyn had a master’s degree in zoology, an unusual accomplishment for a woman in the 1930s. They had four children. Peter became a freshwater ecologist, Susan specialized in mosses and liverworts, Ginny taught biology, and Joe, whom Peter referred to jokingly as the black sheep of the family, was a diplomat.
Peter and Susan remember an idyllic childhood. “I learned bird-watching from my mom,” Peter said. “In the spring we’d look at fairy shrimp and tadpoles in the pond.” They lived on Lake Minnetonka, and learned a lot from living there. “We always had sampling equipment—nets and seines. My sisters kept injured birds. If we had an injured tern, we’d need to “sample” the fish to feed the bird,” he said with a smile in his voice.
The children were free to wander in the woods and along the lakeshore. “Mother always made really good dinners, so we wanted to be home for dinner,” Peter laughed. “They both loved showing us basic biology—anything moving or growing.”
Most weekends they spent outdoors at state parks or in the Moyles’ big garden. Every summer they took a long camping trip. On one of those trips, John Moyle pointed out the trash along the road. He told the children, “Every time we come to a new state, we’re going to do a couple of counts of cans along the road for half a mile.” Then he’d slow the car and the kids would estimate or count the number of beer cans. “And later he published a story about it in the Minnesota Conservation Volunteer, trying to promote the idea that we should all be picking up the trash,” said Peter.
John and Evelyn collaborated to produce a classic book, “Northland Wildflowers,” still in print. “They liked doing things together, and the book was another reason to get out and do things,” said Peter. “Dad wrote the text and Mother took the pictures and did a lot of editing.” The book came out shortly before John Moyle’s death in 1977. Years later, in 2001, Evelyn produced a new edition. New photos by a professional photographer may have been prettier, Peter said, but they didn’t show the plants as effectively.
The wildflower book was just one item in a prodigious output of elegant, yet accessible, prose. John Moyle wrote dozens of technical reports for the DNR, exploring and explaining everything from his own lake surveys to forest succession, from walleyes to hawks, from copper sulfate for algae control to DDT’s impact on fish. He published research papers regularly in peer-reviewed scientific journals.
He also edited the work of his colleagues, a habit that was an unusual source of complaints. “Usually when a person moves up in the office, you get grumbling from people in the ranks,” said Dennis Anderson. “The only time I heard grumbling about Moyle was (about) his editing. It was going to be almost perfect when he was done or he wasn’t going to send it out.”
For ten years he produced monthly newsletters, called The Latest Word, for DNR researchers, field workers, and game wardens. These were typed and mimeographed, ranging from four to sixteen pages long, offering summaries of the latest research on natural resources, both in Minnesota and elsewhere. He covered topics as wide-ranging as wood ticks, how milkweed seeds are dispersed by the wind, a grouse that ate a snake, the smell of the woods, the colors of fish, and goldenrod galls, among many others. His combined interests in science and music were evident in the following observation: “The wings of a mosquito beat 300 times per second. The mosquito zeroing in on your hide should be tuned to D, just above middle C on the piano.” Each newsletter ended with a humorous or inspiring quote from other writers, a joke (some would not be considered politically correct today), a poem, or a homily. One notable quote he offered came from John Muir: “When we try to pick out anything by itself, we find it hitched to everything else in the universe.” This quote reflected Moyle’s holistic approach to science and nature.
“I waited every month for the next newsletter,” recalled Dennis Anderson. “They provided so much information; it was a really nice thing for someone near the top of the organization to send these out. He really felt he was providing information for the staff that they should have, or at least should be interested in. It may not apply to your own job, but it’s nice to be able to see what someone else is doing, for example, in forestry,” Anderson said. “Moyle was focused on fish and wildlife but he could see beyond that. He had a full understanding that what happened on the land affected the water and so on.”
In addition to his rigorous scientific writing, John Moyle had a gift for turning technical information into clear prose that could be understood and enjoyed by anyone. During his career he wrote at least 75 articles for the Minnesota Conservation Volunteer. The first, published in December of 1941, was “Minnesota’s Wild Rice Crop: A Lesser Known Natural Resource.” It described “at least 30,000 acres of this wild grain growing throughout the northern half of the state in the shallow water of mucky-bottomed lakes, bays and potholes and along the margins of slow streams.” It outlined recent regulations meant to protect the resource. And it pointed to the economic significance of the harvest: “The Minnesota wild rice crop on the average provides seasonal employment for about 4,000 persons each year, and has a retail value of approximately $400,000.”
John Moyle’s essays in the Minnesota Conservation Volunteer are reminiscent of the essays in Aldo Leopold’s famous book, “A Sand County Almanac.” Moyle and Leopold not only advocated a responsibility for the land based on the latest scientific findings, they also had an uncanny knack for explaining scientific issues clearly to people without scientific training. Moyle’s essay for hunters, “A Barrel of Rabbits” in the July 1957 issue, remains one of the best explanations of carrying capacity, one of the bedrock concepts in scientific ecology. In this essay, he likened carrying capacity for rabbits to the volume of a barrel which is partly controlled by habitat, which he called “rabbitat.” In the article’s humorous sketches, new rabbits born every year fill the barrel from a faucet overhead and the surplus rabbits that the habitat cannot support flow out of leaks in the barrel to become “roast rabbit or plain dead.”
A later piece, “The Uncommon Ones,” published in the fall of 1975, is a presentation for the public of his last major research project. It celebrates the “biological citizenry” of Minnesota’s diverse biomes, and lists 64 species in need of “special management consideration.” In it he writes: “Not only sportsmen, but all Minnesotans have a responsibility—call it an obligation—to help preserve the wonderfully diverse forms of life that have developed over eons of time. But this will not be accomplished by conquering the land. Instead, we must learn to live in harmony with it.” Moyle’s emphasis on living in harmony with nature is an outgrowth of his holistic scientific approach to ecology. Holistic thinking was a rarity in those days, and it still is. For some, it can verge on the spiritual, and “That’s the way many people felt about Moyle,” said Moyle’s colleague, Jim Lilienthal. “He was considered our Aldo Leopold.”
John Pastor is Emeritus Professor of Biology at The University of Minnesota – Duluth and has studied the effects of sulfate on wild rice growth, which is when he first learned about John Moyle.