by Walter Fox

Dr. Ruth Patrick, 105, a freshwater ecologist whose pioneering research on water pollution set the stage for the modern environmental movement, died Sept. 23 at The Hill at Whitemarsh in Lafayette Hill.

A longtime resident of Chestnut Hill, Dr. Patrick was a world authority on freshwater ecosystems. She developed key methods to monitor water pollution and to understand its effects on aquatic organisms of all kinds.

A recipient of the National Medal of Science, she is credited, along with author Rachel Carson, as being largely responsible for drawing widespread attention to the health of the environment.

Dr. Patrick, whose career at at the Academy of Natural Sciences of Drexel University in Philadelphia spanned nearly eight decades, assembled the definitive collection of diatoms, single-celled plants that she identified as key indicators of environmental quality. The collection is a major resource at the academy.

Dr. Patrick developed an “ecosystem approach” to assessing the health of a water body that has become the current standard in river monitoring. It involves not only examining the chemistry of the water itself, but also evaluating the number, kinds and health of the plants, insects, fish and other organisms living in the water.

Even at 100 years old, she still was a familiar site at the academy, where she maintained an office to work on her book series on rivers. On her 100th birthday she was celebrated with a gala at the academy and received tributes from around the world, including from former Vice President Al Gore.

Born in Topeka, Kan., Dr. Patrick spent most of her childhood in Kansas City, Mo. Thanks to her father, Frank Patrick, a lawyer with a passion for the natural world, she enjoyed an unconventional upbringing for a girl at that time. Her father would lead young Ruth – then about 5 years old – and her sister on Sunday strolls through nearby woods, where they collected bits of nature and put them in a can they carried at the end of a stick.

Dr. Patrick’s father gave her a microscope of her own when she was 7 years old. Such interest in nurturing a young girl’s pursuit of science was unusual for the time, and she credited these experiences with launching her lifelong passion for the environment. One of the many values her father instilled in her, Dr. Patrick often said, was: “Leave the world a better place for having passed through it.”

Dr. Patrick attended Sunset Hill School, now Pembroke Hill School, in Kansas City, Mo. Despite her mother’s desire that she simply learn social graces and marry well, she went on to study biology. She received a B.S. from Coker College in Hartsville, S.C., and a master’s degree and a Ph.D. in botany, both from the University of Virginia. In 2008, Coker College named her its “Alumna of the Century.”

Dr. Patrick’s long association with the Academy of Natural Sciences began in 1933 when she came to Philadelphia as a graduate student to study diatoms. In 1937, she became an unpaid assistant curator of microscopy. In 1945, she was finally put on the payroll, and two years later she established the Department of Limnology, later called the Patrick Center for Environmental Research.

She was the first researcher to notice that different species of diatoms live in different environments and, therefore, are key indicators of water quality.

According to conservation biologist Thomas Lovejoy, she demonstrated that biological diversity could be used to measure environmental impact.

”I call that the Patrick Principle and consider it the basis for all environmental science and management,” he said.

Dr. Patrick later expanded her research to include general ecology and biodiversity in rivers, studying hundreds of streams, rivers and lakes in North and South America. She invented the Catherwood diatometer, which allows scientists to collect diatoms growing in a water body.

In the 1950s, the Atomic Energy Commission asked her to assess the ecological status of Georgia’s Savannah River near the DuPont Company’s nuclear power plant. In 1975, she became the first woman and the first environmentalist to serve on the DuPont board of directors. She held positions on many boards, including those of the Pennsylvania Power and Light Co. and the World Wildlife Fund.

Dr. Patrick was an advisor to President Lyndon Johnson on water pollution and to President Ronald Reagan on acid rain. In the 1960s, she worked with Congress to help draft legislation that resulted in the Clean Water Act, the primary federal law governing water pollution. For the next 30 years she was called to Capitol Hill for frequent appearances as an environmental expert.

From 1973 to 1976, she served as the first female chair of the Academy of Natural Sciences board of trustees and later held the academy’s Francis Boyer Chair of Limnology. She formed the academy’s Environmental Associates, a group of corporate executives concerned about the environmental effects of industrial activities.

She taught limnology and botany at the University of Pennsylvania for more than 35 years and wrote more than 200 scientific papers and a number of books on the environment, including the five-book series, “The Rivers of the United States.”

In 1970, Dr. Patrick was elected to the National Academy of Sciences, and in 1974 was elected to the American Philosophical Society. She received the John and Alice Tyler Prize for Environmental Achievement in 1975 and was awarded the National Medal of Science from President Bill Clinton in 1996.

She received lifetime achievement awards from the American Society of Limnology and Oceanography and the National Council for Science. Other awards included the Pennsylvania Award for Excellence in Science and Technology, the Eminent Ecologist Award from the Ecological Society of America, the Gold Medal from the Royal Zoological Society of Belgium, and the Benjamin Franklin Award for Outstanding Scientific Achievement from the American Philosophical Society..

She received 25 honorary degrees, including ones from Princeton University and the University of Pennsylvania, and in 1996 was inducted into the South Carolina Hall of Science and Technology. In 2009, she was inducted into the National Women’s Hall of Fame.

Dr. Patrick was married to the late Charles Hodge IV and the late Lewis H. Van Dusen, Jr. She is survived by one son, Charles Hodge V of Kansas City, Kan., and several stepchildren and grandchildren.

A memorial service is being planned.