scanning electronmicrography of a centric diatom

The Phycology Section activities focus on ecology and taxonomy of freshwater algae, particularly diatoms. We seek to better understand the distributions of algal taxa throughout the U.S., and the environmental factors influencing both the occurrence of taxa over large scales and the composition of assemblages at individual sites. We are particularly interested in applying knowledge of algal ecology to the assessment of a wide range of environmental issues, but primarily those related to water quality of rivers and streams.

Because there are so many algal taxa, because they live in a wide variety of habitats, and because they have specific ecological requirements, algae are excellent ecological indicators, particularly of water quality. Diatoms especially have a long history of use in ecological assessment. Dr. Ruth Patrick, founder of the Patrick Center, performed important pioneering research on use of diatoms for biomonitoring starting in the 1940s.

The Phycology Section maintains its own website at This resource presents more information on its staff and programs, including the ANSP Algae Image Database, the Diatom Paleolimnology Data Cooperative and Freshwater Autecology resources.


Dr. Don Charles

(More information on the Phycology Section's staff is presented at )


  • Field collection of periphyton and phytoplankton samples
  • Deployment and collection of diatometers
  • Coring of lake and wetland sediments
  • Analysis of periphyton and phytoplankton samples; identification and enumeration
  • Analysis of diatoms in sediment cores; environmental reconstructions
  • Digital imaging of algae specimens; light microscope and SEM
  • Description of new diatom taxa
  • Multivariate analysis of species and environmental data
  • Calculation and development of metrics and other water quality indicators
  • Calibration of inference models for inferring environmental characteristics
  • Water quality assessment based on algal data (e.g., nutrient issues)


The Phycology Section has high quality facilities and equipment. Some are shared with other Patrick Center Sections, which also provide valuable services (e.g., water chemistry analysis). We have a wide variety of field equipment for taking algal samples (water samplers, sediment coring equipment, boats), a separate laboratory for preparing algal samples and making diatom slides, a microwave apparatus for digesting diatom samples, six high quality research microscopes, two digital and two film cameras for the microscopes, local access to scanning electron microscopes, and an extensive reference collection of taxonomic and ecological literature —both in the laboratory and the Academy Library.

Algal analysts work next to the Diatom Herbarium (the largest in North America) and consult regularly with it's curator, Dr. Marina Potapova. All Phycology staff have personal computers connected to the Academy network. The section developed and maintains several applications and databases, including the North American Diatom Ecological Database (NADED), which contains count and other data on over 10,000 samples.