Arthur Hasler, UW limnology pioneer, dies at age 93

Arthur Hasler, one of the leading figures in 20th century freshwater ecology, whose research answered an intriguing mystery of nature – how migrating salmon precisely identify their “home” waters – died on Friday (March 23) after a long illness. He was 93.

Hasler, a professor emeritus of limnology who spent 41 years on the faculty at UW–Madison, made a number of enduring contributions to the field of lake research. His most famous research came in the late 1940s, when Hasler developed ways to demonstrate how “olfactory imprinting,” a finely honed and ingrained sense of smell, enabled salmon to journey literally thousands of miles to spawn in the precise stream of their birth.

The idea for the study occurred to Hasler when he visited a mountain stream near his hometown in Utah, and was struck by how the smells of native plants seemed to rekindle childhood memories. Hasler’s research formed the basis for better management practices on an international scale, and impacted salmon management programs in the Great Lakes, the Pacific Northwest and Europe.

“Many people who work on ecological problems today remain awed by the insightfulness of Hasler’s research,” says John Magnuson, retired director of the UW–Madison Laboratory of Limnology and longtime colleague of Hasler. “He was a big thinker and had grand ideas, but he also believed you were not done with your research until you dealt with its applications in society.”

Hasler, a 1969 inductee to the National Academy of Sciences, also pioneered a new way to study ecological problems by creating controlled experiments of entire lake ecosystems. Magnuson says Hasler recognized that lake ecosystems were too complex to be studied piecemeal in a laboratory setting. His most famous “whole lake manipulation” was at Michigan’s Peter Lake and Paul Lake in the 1950s. Hasler constructed a barrier in the middle of the hourglass-shaped, connected lakes and used one side as a control, while using the other side to measure the effects of water chemistry on aquatic life. Whole-ecosystem experiments are widely used today in lakes, streams, forests and oceans. Scientists who trained under Hasler have founded research centers that follow his model in the U.S. and Canada.

Hasler’s research also helped define the importance of land-water interactions as a primary variable in the water quality and ecological health of lakes. His work on problems such as “cultural eutrophication,” or the excessive loading of nutrients into lakes surrounded by urban and agricultural land, helped inform efforts to divert sewage and control fertilizer runoff and soil erosion in lakes, including Lake Mendota in Madison and the Yahara River chain of lakes.

Hasler served as an advisor to 52 doctoral students during his tenure at UW–Madison, and was author of more than 200 publications and seven books on the field of limnology. He was a past president of the American Society for Limnology and Oceanography, the American Society of Zoologists and the Ecological Society of America. He was also a founder and first director of the Institute for Ecology. He was elected to the American Academy of Arts and Sciences in 1972, and holds many lifetime service and achievement awards from limnology and ecology professional societies, both national and international.

At UW–Madison, Hasler played key roles in the development of the Laboratory of Limnology, built along Lake Mendota, and the Trout Lake Biological Station in northern Wisconsin. Both lakeside research labs have helped further UW–Madison’s international prominence in the study of freshwater ecosystems.

UW–Madison had been known as the birthplace of lake research in North America by the time Hasler first came to Madison as an instructor in 1937. Two zoologists, E.A. Birge and Chancey Juday, essentially created this science in the early 1900s using Wisconsin lakes. Both leaders were aging when Hasler began, Magnuson says, and Hasler rekindled the study in a second generation of scientists.

Magnuson says that Hasler made a profound impression on many of his students, both graduate and undergraduate, not only for his science, but also for the social responsibility he conveyed. He taught ecology of fishes and limnology to undergraduates for most of his Madison career. “He used to read German poetry in his classes about the beauty of lakes. He imparted a moral and ethical sense of the value and beauty of nature,” Magnuson says.

One project Hasler attempted to stimulate during his emeritus years was called “Salmon for Peace.” He hoped to bring the governments of Russia and China together around the shared goal of salmon management in the Amur River, which shares borders with both countries. The river’s salmon population is collapsing due to overfishing. He hoped his studies could be used to reestablish lost salmon runs, but the two countries never came together on the idea.

Hasler was born in 1908 in Lehi, Utah, and graduated from Brigham Young University with a bachelor’s degree in 1932. He earned his Ph.D. in zoology from UW–Madison in 1937. Hasler spoke fluent German, and in 1945, he served as a research analyst with the U.S. Air Force Strategic Bombing Survey in post-World War II Germany. He appreciated the opportunity to visit laboratories and meet with natural scientists that had survived the war, some of whom became longtime colleagues.

Hasler is survived by his wife, Hatheway, and his children, Sylvia (Thatcher), A. Frederick, Bruce, Mark, Galen and Karl. Visitation is planned for Thursday, March 29 from 4 to 7 p.m. at the Cress Funeral Home, 3610 Speedway Road. The funeral service will be held at 11 a.m. Friday, March 30, at the Church of Jesus Christ of Latter Day Saints, 4505 Regent Street, with memorial visitation beginning at 10 a.m.

In lieu of flowers, the family suggests donations be made to the Arthur Davis Hasler Limnology Fund at the UW Foundation, 1848 University Ave. in Madison, WI 53706.