Species composition and abundance of diatoms in streams and rivers are a crucial measure of biotic condition as diatoms are sensitive to impacts caused by human activities such as urbanization, flow alteration, and the loading of contaminants, nutrients and sediment. Regional surveys of rivers by the U.S. Geological Survey
(USGS) National Water Quality Assessment Program (NAWQA) were designed to evaluate the effects of these stressors on aquatic organisms, including diatoms.

Algal samples were collected at 108 sites in 2014, from streams representing gradients in chemical and physical alteration across the southeast region. More than 375 taxa were identified during analysis for species composition and abundance. A flora of diatoms in the region was published:

Bishop, I.W., Esposito, R.M., Tyree, M. and Spaulding, S.A. 2017. A diatom voucher flora from selected southeast rivers (USA). Phytotaxa.

A number of taxon pages were developed based on this material. In addition, a workshop on species of Gomphonema was based primarily on specimens from the southeast.


  • US Geological Survey

    Rocky Mountain Cooperative Ecosystem Study Unit (CESU) Agreement - Diane McKnight


Ian Bishop

Content Editor, Araphid Diatoms Diatoms of North America, Editoral Review Board

Graduate Student Graduate School of Oceanography, University of Rhode Island

Meredith Tyree Polaskey

Medical Student Chicago Medical School, Rosalind Franklin University of Medicine and Science

Sarah Spaulding

Content Editor, Symmetric Biraphid Diatoms Diatoms of North America, Editoral Review Board

Ecologist US Geological Survey

Alec Camp

Laboratory Assistant Environmental Studies, Ecology and Evolutionary Biology, University of Colorado

Tanya Hannis

Undergraduate Student University of Colorado, Boulder

Rhea Esposito

Cary Institute of Ecosystem Studies

Paul Bliznik

University of Colorado

Leanna Jo Clarkson

University of Colorado

Little Cahaba River
Image Credit: Alan Cressler
Little Cahaba River, above Cahaba Beach
Blackburn Fork  Little Black Warrior River
Image Credit: Alan Cressler
Blackburn Fork Little Black Warrior River, above Dumas Bridge Road
Luticola Mobilensis Guide
Image Credit: Meredith Tyree
Luticola mobilensis is, so far, only known from southeast states. It grows in soils and moist, aerophilic habitats, but also occurs as an incidental in rivers.
Sellaphora Diversity 20161107
Image Credit: Doug Haller
The number of species in the genus Sellaphora were particularly high in the SESQA survey.