Diatom identification guide & ecological resource

for water resource managers, ecologists, taxonomists, analysts, systematists, students, and the public.

The site will be down today, JULY 31, from 5 PM to 6 PM western diatom time.

We aim to provide everyone with accurate information about diatoms of the United States.

Expert contributors are submitting text and images for freshwater genera and North American species, including taxonomic and ecological information.

Diatom "bird guides" are included for all taxa (examples to the right). For many species, environmental response plots and geographic distribution maps are included.

Our editorial review board is prioritizing taxa for treatment in species pages and ensuring the scientific merit of each submission.

Navicula lanceolata


148 Completed
24 Underway
689 Completed
141 Underway

Getting Started

About this website

What are diatoms?

Identify your taxa

Special News

25 March, 2011

Information for contributors


16 July, 2015

2015 North American Diatom Symposium, 9-13 September

30 June, 2015

The Air You’re Breathing? A Diatom Made That

More news...


Diatoms from the Crown of the Continent

Ecology and Systematics of Diatoms course, 2014

Artist Feature - Renee Robbins

More projects...