Announcing the fall series...

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. Our zoom link:


Tuesday October 11 2022
10 AM - 11 AM (mountain time, US and Canada)
18:00 Central European Time
Blanca Hinojosa, Metro Water Recovery
Establishing a diatom flora library of the South Platte River from Denver to Platteville, Colorado

Description: The South Platte River headwaters are located within the Colorado Mosquito Mountain Range. This river travels 380 miles throughout the state before moving towards Nebraska. Diatoms have not been studied on the South Platte River, potentially due to the river’s many water diversions making ecological sampling difficult and unpredictable. The South Platte River has approximately 10,000 diversions on the river or on smaller tributaries that feed the river for different water usage. These diversions cause difficult hydrological uniformity within the South Platte River. I will be presenting on a proposal to study diatoms within the South Platte River from Denver to Platteville, Colorado.

Audience: General scientific audience with interest on diatoms and phytoplankton involving urban/suburban limnology, ecology, hydrology, sampling procedures, and human impacts.

Tuesday October 25 2022
10 AM - 11 AM (mountain time, US and Canada)
18:00 Central European Time
Stacy Levy, Artist
Ecology and Art: new ways of seeing the invisible patterns of nature

Description: Nature is usually pictured as a landscape scene, or a botanical detail— but what happens when you want to show the invisible or microscopic aspects of the natural world? How do we show the presence of micro-organisms inhabiting the rivers, soils and puddles around us? Stacy Levy is an urban forester turned artist, who investigates the processes of nature. She works to show the amazing architecture of diatoms. She will unveil Diatom Lace, a new commission for the New York City Parks about to be installed along the new esplanade on the East River in Manhattan.Stacy will show how natural forms can be brought front and center into our minds, so that ecology is not a distant concept, but part of our urban (and suburban) fabric.

Audience: This talk will be of interest to all wishing to gain different perspectives of science and art and perception.

Tuesday November 8 2022
10 AM - 11 AM (mountain time, US and Canada)
18:00 Central European Time
Ed Theriot, University of Texas, Austin
If you think there are cryptic species, it’s because you don’t understand species concepts

Description: There are many claims in the literature of “morphological species” subdivided by “molecular cryptic species”. But both “morphological species” and “molecular species” are not concepts at all and are meaningless outside the context of a deeper analysis of “What is a species in the first place?” I will (over-)simplify the basic ideas of three popular approaches: the Biological Species Concept, the Phenetic Species Concept, and the Phylogenetic (Autapomorphic) Species Concept. All three make use of heritable traits of all kinds (behavioral, physiological, gene sequence, morphology, etc.) There is no reason to believe that one type is superior (for empirical analysis) to the other in all cases. In fact, I will show that in Stephanodiscus at least, morphological evolution has outpaced change in several so-called bar-code genes (i.e., analysis of morphology recovers multiple lineages within each of several different molecular species.) Other examples will include phylogenetic analysis of chloroplast and mitochondrial genomic data, barcode gene data, and qualitative and quantitative morphological data in the genera Cyclostephanos and Stephanodiscus (and apparent phylogenetic constraints on environmentally induced morphological variation in S. niagarae.)

Audience: Diatom taxonomists and systematists, those interested in using species level taxonomy for ecological monitoring studies, those interested in systematics and ecology of Stephanodiscus and Cyclostephanos, those curious about “cryptic species”.

Tuesday November 22 2022
10 AM - 11 AM (mountain time, US and Canada)
18:00 Central European Time
Elizabeth Axelson, University of Minnesota, Duluth
in the context of long-term monitoring

Tuesday December 13 2022
10 AM - 11 AM (mountain time, US and Canada)
18:00 Central European Time
David Burge, Science Museum of Minnesota
of the Great Lakes



Tumaini Kamulali
Holocene productivity of southern Lake Tanganyika inferred from diatom fossils

Matt Ashworth
or Odontella? A comparative guide to morphology

Joe Mohan
Diatoms from the 3rd dimension: integrating 3D computer modeling with diatom research

Peter Siver
A siliceous potpourris of freshwater organisms from the Cretacous through the Eocene with a focus on diatoms

Kalina Manoylov
Species diversity and community dynamics of diatoms in the Savannah River estuary

Ian Bishop
Seascape genomics of Southern Ocean diatoms

Sylvia Lee
Introduction to the Level 2 Diatom Species Exam