We are expanding the number of webinars in the Diatom Web Academy during the pandemic.

Sessions are recorded and can be accessed for later viewing. You are invited to join us, wherever you may be, from anywhere around the world.


Tuesday October 27, 2020
10 AM - 11 AM (mountain time, US and Canada)
Andy Alverson, University of Arkansas

Microbial biogeography through the lens of an invasive species: The intercontinental disjunction of Discostella asterocostata as a case study

The large population sizes and unlimited dispersal potential of microbes has led to the hypothesis that microbial species should be found in all suitable open habitats worldwide. Consequently, microbes should not exhibit the kinds of biogeographic patterns seen in macroorganisms. This paradigm is challenged by the growing list of invasive microbes with biogeographic disjunctions that highlight natural limitations on microbial dispersal. We sampled water bodies in the United States and compiled records from the literature and public databases to characterize the distribution of Discostella asterocostata, a freshwater planktonic diatom that was thought to be restricted to the Far East. We report its presence in ecologically similar water bodies in the United States. Populations from the U.S. and China are indistinguishable morphometrically, suggesting a recent separation. This hypothesis is supported by paleolimnological data, which point to an introduction into the U.S. as recently as the mid-1980s. Discostella asterocostata appears to be a recent invasive that has rapidly spread across the eastern U.S. The overlapping distributions of D. asterocostata and invasive carp species, both globally and in the U.S., highlighted Asian carp as a possible vector for the introduction. The growing list of invasive diatoms highlights natural constraints on microbial dispersal, resulting in biogeographic distributions that can be upended through human activity.

Target Audience: This presentation is intended for those interested in the geographic distribution of diatoms and the introduction of an increasing number of diatoms as invasive species. The presentation is directed to a general audience and does not require specialized expertise.

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Meeting ID: 982 3349 0068
Passcode: 834613130 +1 646 558 8656 (New York)
Find your local number: https://umn.zoom.us/u/adqkzWHW...

Tuesday November 10, 2020
10 AM - 11 AM (mountain time, US and Canada)
Kateřina Kopalová, Institute of Botany of the Czech Academy of Sciences
The genus Luticola

Tuesday November 17, 2020
10 AM - 11 AM (mountain time, US and Canada)
Andrea Burfeid & Michael Kloster, Beszteri Lab, University of Duisburg-Essen, Germany
Virtual Diatomology

Tuesday December 8, 2020 (tentative)
10 AM - 11 AM (mountain time, US and Canada)
Zlatko Levkov, St. Cyril and Methodius University
Diatom flora - approach, challenges, perspectives and implications on future diatom applications


David Williams, The Natural History Museum London
Diatom classification and (some) other stories

Maria Kahlert, Swedish University of Agricultural Sciences
Intercalibration/harmonization in the Nordic Baltic network

Sarah Spaulding and Meredith Tyree, University of Colorado
Composition of diatom assemblages

Vicky Chraibi, Tarlton State University, and Shelly Wu, Texas Christian University
Golden(-brown) Opportunities: Diatoms in Education

Paula Furey, St. Catherine University
The genus Eunotia

Susanna Theroux and Raphael Mazor, Southern California Coastal Water Research Project
California Algal Assessment

Marina Potapova and Mark Edlund
Navigating diatom nomenclature

Sylvia Lee, Sarah Spaulding, Meredith Tyree and Mark Edlund
What is a diatom species?

Jeffery Stone, Indiana State University
Directional selection observed in diatom lake records from western North America

Meredith Tyree, Institute of Arctic and Alpine Research (INSTAAR), University of Colorado
Voucher Floras

Mark Edlund and David Burge, University of Minnesota
Diatoms and paleolimnology: Lake history through the lens of a frustule

Nicholas Schulte, Institute of Arctic and Alpine Research (INSTAAR), University of Colorado
Using diatom DNA in environmental assessments: techniques and timeline to operation

Marina Potapova, Academy of Natural Sciences of Drexel University
The genus Planothidium: taxonomic revisions and common freshwater species of North America

Jan Stevenson, Michigan State University
Using diatoms in ecological assessment

Sarah Spaulding, U.S. Geological Survey / INSTAAR, University of Colorado
Introduction to Diatom Web Academy

Sylvia Lee, U.S. Environmental Protection Agency
Diatom Taxonomic Certification

Euan Reavie, University of Minnesota, Ely
Tiny things, Great Lakes