From diatom taxonomy to freshwater ecology
Patrick completed her Virginia doctorate in 1934. Philadelphia’s Academy of Natural Sciences attracted her through its diatom collection; she initially worked as a volunteer and did not receive a regular salary until 1945.
She organized and expanded specimens and taxonomic references. In 1947 she founded the Academy’s limnology department, connecting microscopic classification with research on lakes, streams and rivers.
The Conestoga watershed survey of 1948
In 1948 Patrick directed a survey of Pennsylvania’s Conestoga watershed, comparing reaches affected by agricultural runoff, sewage and industrial pollution with less affected sites.
The team investigated water chemistry, pollution sources, bacteria, algae, protozoa, invertebrates and fish. Community changes supplied evidence of environmental conditions rather than relying on the presence or absence of one indicator group alone.
References: [1]
Comparing diatom colonization
Patrick’s diatometer held glass microscope slides in a floating frame where diatoms could attach and grow. Researchers then removed the slides for microscopic examination.
Standardized slides reduced some differences associated with natural substrates, helping comparisons among river sites. She also investigated how species numbers and abundance patterns differed under different kinds of pollution.
References: [1]
Basic research and freshwater protection
In 1967 Patrick worked with the Stroud family and the Academy to establish the Stroud Water Research Center. Its teams combined hydrology, chemistry, microbes, algae, insects and fish to investigate stream functioning and watershed connections.
She also communicated freshwater evidence to public agencies and industry. Her programme linked practical pollution assessment with basic research on the functioning of less disturbed streams.