Achnanthidium alpestre | Achnanthidium atomus | Achnanthidium deflexum | Achnanthidium druartii | Achnanthidium duthiei | Achnanthidium eutrophilum | Gogorevia exilis | Achnanthidium gracillimum | Achnanthidium kranzii | Rossithidium kriegeri | Achnanthidium latecephalum | Achnanthidium minutissimum | Achnanthidium pyrenaicum | Achnanthidium reimeri | Achnanthidium rivulare | Aulacoseira alpigena | Aulacoseira ambigua | Aulacoseira crassipunctata | Aulacoseira granulata | Aulacoseira granulata var. angustissima | Aulacoseira herzogii | Aulacoseira humilis | Aulacoseira italica | Aulacoseira lirata | Aulacoseira muzzanensis | Aulacoseira nivalis | Aulacoseira nivaloides | Aulacoseira nygaardii | Aulacoseira pusilla | Aulacoseira subarctica | Aulacoseira tenella | Aulacoseira valida | Capartogramma crucicula | Cymbella affinis | Cymbella excisiformis | Odontidium mesodon | Diatoma moniliformis | Diatoma tenuis | Diatoma vulgaris | Eucocconeis alpestris | Eucocconeis flexella | Eucocconeis laevis | Geissleria acceptata | Geissleria decussis | Geissleria kriegeri | Geissleria lateropunctata | Geissleria paludosa | Geissleria punctifera | Hippodonta capitata | Hippodonta capitata subsp. iberoamericana | Hippodonta coxiae | Hippodonta hungarica | Karayevia amoena | Karayevia clevei | Karayevia laterostrata | Karayevia nitidiformis | Platessa oblongella | Karayevia ploenensis var. gessneri | Karayevia suchlandtii | Navicula angusta | Navicula canalis | Navicula escambia | Navicula radiosa | Nupela carolina | Nupela elegantula | Nupela fennica | Nupela frezelii | Nupela impexiformis | Nupela lapidosa | Nupela neglecta | Nupela pennsylvanica | Nupela poconoensis | Nupela scissura | Nupela subrostrata | Nupela vitiosa | Nupela wellneri | Planothidium abbreviatum | Planothidium apiculatum | Planothidium biporomum | Gliwiczia calcar | Planothidium delicatulum | Planothidium reichardtii | Planothidium frequentissimum | Planothidium amphibium | Planothidium holstii | Planothidium joursacense | Planothidium lanceolatum | Planothidium minutissimum | Skabitschewskia oestrupii | Skabitschewskia peragalloi | Planothidium potapovae | Platessa stewartii | Platessa conspicua | Platessa hustedtii | Psammothidium altaicum | Psammothidium bioretii | Psammothidium chlidanos | Psammothidium microscopicum | Psammothidium daonense | Psammothidium didymum


The NAWQA program was designed to collect and interpret data on surface- and ground-water chemistry, hydrology, land use, stream habitat, and aquatic life in parts or all of nearly all 50 states using a consistent study design and uniform methods of sampling analysis. In 1999-2011 scientists at the ANSP were funded by the NAWQA program to identify and enumerate algae to evaluate how river algal communities are affected by human activities and to develop algal-based water quality assessment methods. Over that time, more than 20 taxonomic workshops brought together phycologists and analysts from ANSP and other institutions. The initial goal of the workshops was taxonomic harmonization of the NAWQA algal data, but eventually, these taxonomic revisions led to discovery of several diatom species new to science, furthering our understanding of biodiversity in the US. The development and expansion of the Diatoms of the United States web flora was, in large part, supported by the NAWQA program to further taxonomic consistency and accuracy.


  • U.S. Geological Survey, National Water Quality Assessment Program

    USGS / ANSP Cooperative Agreement - Don Charles, Marina Potapova


Marina Potapova

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

Curator Diatom Herbarium, Academy of Natural Sciences of Philadelphia, Drexel University

Jonathan English

Research Assistant Diatom Herbarium, Academy of Natural Sciences Philadelphia

Eduardo A. Morales

Researcher Laboratório da Água, Universidade de Évora

Barry Rosen

Biologist U.S. Geological Survey

Jen Beals

Ph.D. Student University of Arkansas

Don Charles

Academy of Natural Sciences of Philadelphia, Patrick Center

A Italica
Image Credit: Marina Potapova
Scanning electron micrograph (SEM) of Aulacoseira italica a centric diatom of U.S. waters.
Aulacoseira Valida Guide
Image Credit: Marina Potapove
Example of a "guide image" from the website for Aulacoseira valida.
P Levanderi Guide
Image Credit: Marina Potapova
Marina Potapova is a specialist on the monoraphid diatoms. Psammothidium levanderi is just one of the monoraphid taxon pages she created.
Capartogramma Crucicula Guide
Image Credit: Marina Potapova
Capartogramma crucicula is found in rivers of the southern U.S.
Img 2822
Image Credit: Sarah Spaulding
Marina Potapova on the way to Phelps Lake, Wyoming to look for Psammothidium species.