200 Years. 200 Stories. Story 97: “Pennsylvania Diatoms ”

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scientist collecting diatoms in a small stream
Dr. Marina Potapova collects diatoms from Cole Run, a headwater stream in northcentral Pennsylvania.

Pennsylvania Diatoms

Diatoms, microscopic algae encased in intricately structured glass “shells,” have been a mainstay of environmental research at the Academy since Dr. Ruth Patrick’s pioneering work in the 1940s. Various federal and state agencies also use diatoms for monitoring water quality in rivers, lakes, and wetlands. Efforts to develop reliable diatom indicators of water quality have been limited by our failure to explore the species of diatoms found in pristine habitats unaffected by pollution and other human disturbances. We also don’t know much about how natural diatom communities differ from one region to another.

To address these shortcomings, Dr. Marina Potapova, assistant curator of the Academy’s Diatom Herbarium, recently conducted a comprehensive inventory of diatoms from 140 mostly pristine sites in north-central Pennsylvania. She found a total 622 species, including many known to have wide geographic ranges. However, some diatoms she found are new to science, while others are either rare or currently are found only in this part of the world.  In addition to the inventory, Dr. Potapova analyzed the occurrence of different species in relation to water quality. The results provide clear patterns for diatom communities found in pristine waters and those impacted by pollution. When compared to data that will be gathered in the future, this information will help researchers assess how the drilling of the Marcellus Shale Formation impacts stream ecosystems.

Read more about our important diatom research.

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