In the summer of 1948, Dr. Ruth Patrick, an upstart female scientist from The Academy of Natural Sciences in Philadelphia, and her hand-picked crew of about a dozen descended on Lancaster County.

During the next three months of summer heat, they waded and scooped up plants, fish and microscopic algae from the Conestoga River — then called Conestoga Creek — and eight of its tributaries.

What Patrick found here 64 years ago became as sweeping an environmental landmark as Rachel Carson's later expose of the far-reaching dangers of the insecticide DDT.

The "Patrick Principle" as it is known today, proved that the most reliable way to determine the effects of man-made pollution on the health of a stream is by sampling the types and numbers of organisms living in it.

Using biodiversity — with an emphasis on microscopic organisms — to measure stream health remains today standard procedure in regulating discharges of industrial pollutants, farm runoff, sewage-treatment plant effluent and other sources.

Patrick's aquatic ecology research here was the first comprehensive water quality monitoring effort in North America.

Its repercussions may be found in everything from the Clean Water Act — which Patrick helped draft — to mankind's efforts to achieve sustainable development here on earth.

And she was the first to advance the "team approach" as a more efficient way of tackling scientific projects.

Some have labeled Patrick the "Den Mother of Ecology."

"Wow, what a giant in our field and one of the most productive scientists ever in aquatic biology," says Dr. John R. Wallace, a biology professor at Millersville University.

Wallace is personally grateful to Patrick. He and his students have an ongoing study of crayfish in Lancaster County. Patrick's 1948 study here provided a much-needed benchmark.

Patrick is a living legend. She is now 104 and lives in a retirement home outside Philadelphia. She has health issues and no longer grants interviews.

But the woman known for her insatiable thirst to learn continues to do so. Dr. Bern Sweeney, director of the Stroud Water Research Center in Avondale, which Patrick helped found, visited Patrick just a few months ago.

He found her reading the Transactions of the American Philosophical Society.

Patrick continued to work at the Academy five days a week, heading its Patrick Center for Environmental Research, until her legs gave out at age 97.

Born in Topeka, Kan., in 1907, Patrick was only 7 when her father gave her a microscope and this advice: "Don't cook, don't sew. You can hire people to do that. Read and improve your mind."

She did. She received her doctorate in biology from the University of Virginia. The microscope steered her to an interest in the new field of limnology, the study of inland freshwater rivers and lakes.

She became especially transfixed by the possible uses of diatoms, microscopic algae with different species that inhabit specific types of water quality.

That drew her in 1933 to the Academy of Natural Sciences, which had the best collections of diatoms in the world. She started out as a volunteer in microscopy as she was told that women scientists were not paid.

For living expenses, she taught at the University of Pennsylvania School of Horticulture and made chick embryo slides at Temple University.

To get more diatoms to study specific species, Patrick knew they were found inside tadpoles. So she had museums all over the country send her their tadpole collections.

Then, she'd very carefully slit them open, remove the intestines, stitch them back up and ship back the collection.

In the late 1940s, she gave a lecture on the diatoms of the Poconos and their potential for monitoring pollution.

In the audience was an oil company executive who was so impressed that he offered to support Patrick's research.

She was ready. In the spring of 1948, she got the state Sanitary Water Board to request a biological study of the  streams of the Conestoga Basin.

Patrick chose the Conestoga Creek because it could be easily waded and had a range of industrial  and sewage pollution.

 At the time, attempts to measure stream pollution relied on dissolved oxygen levels for industrial waste and oxygen and coliform levels for sewage discharges.

But, as Patrick knew, such methods may detect pollution but they tell you nothing about their effects on the health of the stream.

Similarly, chemical sampling won't determine if a stream's animal and plant life is impaired. Indeed, many indicator organisms can live in varying levels of polluted conditions.

What was needed was a way to identify specific biological organisms that consistently gauged stream conditions.

Enter Patrick's beloved diatoms.

She was able to match numbers and types of diatoms in the Conestoga and tributaries to the extent of pollution.

Biological diversity is a reliable key that's now used universally in judging healthy ecosystems in water bodies.

The publication of "A Proposed Biological Measure of Stream Conditions, Based on a Survey of the Conestoga Basin, Lancaster County, Pennsylvania," in 1949 launched Patrick's career.

She went on to study 850 rivers worldwide. In the 1950s and 1960s, she conducted more pioneering studies to show wetlands — long reviled and drained as swamps — can cleanse water by absorbing pollutants. Thus, the Tinicum Marsh on the edge of Philadelphia International Airport is now protected as part of the John Heinz National Wildlife Refuge.

In 1986, diatoms were used to study the extent of radiation in organisms from the nuclear accident at Chernobyl. She helped determine that the Great Salt Lake was once a freshwater lake by finding diatoms in deposits.

She helped draft the federal Clean Water Act.

Early on, she saw the looming danger of global warming. She said this in a 1989 interview with the Philadelphia Inquirer: "We're going to have to stop burning gasoline. And we're going to have to conserve more energy, develop ways to create electricity from the sun and plants, and make nuclear power both safe and acceptable."

Patrick has received a blushingly high number of worldwide awards and honorary degrees. In 1996, President Bill Clinton presented her the National Medal of Science.

She was an advisor to President Lyndon B. Johnson on water pollution and President Ronald Reagan on acid rain.

Dr. Clyde Goulden, one of Patrick's students who later taught with her at the University of Pennsylvania, recalls that whenever Patrick would take issue with something said by a male, she would always preface her remarks with,   "My dear young man."

Says Sweeney, who worked with Patrick at the Stroud Water Research Center, "I always felt that, to her, every day was a day available to explore science and to find out something new."

"She had little time for trivial pursuits and was impatient with those who wasted time on them. More than anything, she was a wonderful person and was willing to help you or to work on a project that you felt was important."

acrable@lnpnews.com

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