Diatoms of North AmericaWe are expanding the number of webinars in the Diatom Web Academy during the pandemic.
Each session will be recorded and can be accessed for later viewing. You are invited to join us, wherever you may be, from anywhere around the world.
UPCOMING
Jeffery Stone
Indiana State University
Topic: Directional selection observed in diatom lake records from western North America
Time: June 9, 2020 10:00 AM Mountain Time (US and Canada)
JOIN: https://zoom.us/j/98989176939
Meeting ID: 989 8917 6939
Description: Directional selection is a form of evolutionary change in which an extreme feature of a population is favored and, over time, the population changes to increasingly express that extreme. This talk will explore a paleolimnological record from June Lake California, in which the size of an endemic species of Stephanodiscus increases over less than 3000 years. The talk will explore the nature of the diatom sexual cycle and discuss potential drivers of directional selection using diatom fossil assemblage characteristics and other paleolimnological information observed in the lake record.
Target Audience: Our intended audience are
those people interested in diatom taxonomy, species concepts, the diatom sexual
cycle, paleolimnology, and the implications of long-term changes in diatom
populations through evolution.
ARCHIVE
Meredith Tyree
University of Colorado, Boulder
Voucher Floras (Part I and Part II)
Format: We offered two-part online training in constructing a diatom voucher flora. In the Part 1 webinar, we oriented participants to the process and direct participants to instructions to download an open-access image manipulation software (GIMP) and a set of training images. Participants may work at their own pace, following step-by-step written and video-format instructions using the provided images. In the Part II webinar, participants discussed the process.
Target Audience: This workshop is directed at algal taxonomists who strive for consistent and transparent application of names to species. Analysts will learn how to produce a diatom voucher flora using GIMP.
Mark Edlund and David Burge
University of Minnesota
Diatoms and paleolimnology: Lake history through the lens of a frustule
Description: Paleolimnology, the study of lake sediments to interpret lake history, allows understanding of lakes on annual, decadal, and millennial time scales. Diatom species reflect ambient lake conditions and diatom cell walls (frustules) are preserved in lake sediments. Thus, diatoms in lake sediments are used to interpret a wide range of influences on lakes including eutrophication, watershed alteration, acidification, hydrology, and climatic change. Lake managers, in particular, use paleolimnology to develop nutrient criteria, evaluate lake restoration, and document watershed remediation.
Target Audience: Our intended audience for this webinar is anyone who is interested in general information about the types of information that can be gained by studies of lake sediments. This is an introductory webinar, so you should not expect specialized information, e.g., detailed methods on how to conduct paleolimnological studies.
Nicholas Schulte
Institute of Arctic and Alpine Research (INSTAAR), University of Colorado
Using diatom DNA in environmental assessments: techniques and timeline to operation
Description: DNA-based identification of diatoms has been proposed and, in some places, implemented as a cost-, time-, and expertise-effective alternative to traditional morphological methods for environmental assessment. We will describe the different techniques available (mainly a method called metabarcoding), outline recommendations for collecting DNA samples, review research applying DNA-based identifications to assessments, and discuss implementation of these methods.
Target Audience: This presentation will be directed at managers who are looking for information on the application of molecular sequencing of environmental DNA (eDNA) and bulk DNA in environmental assessments. The talk will cover the current state of the field and the process to obtain organismal information from sequences.
Dr. Marina Potapova
Academy of Natural Sciences of Drexel University
The genus Planothidium: taxonomic revisions and common freshwater species of North America
Description: The diatom genus Planothidium Round and L. Bukhtiyarova includes several morphospecies that are extremely common in freshwaters and along marine coasts, while new species are continuously being described from various habitats and geographic regions. We will review main taxonomic revisions within the genus since its establishment in 1996 and discuss the current state of knowledge of Planothidium diversity and distribution in inland waters of North America.
Target Audience: This presentation will be directed at participants with a specialized interest in diatom systematics and taxonomy. It will be of particular interest to analysts and students working on rivers and lakes of North America. Others, however, from beginners to lay public are welcome to attend.
Dr. Jan Stevenson
Michigan State University
Using diatoms in ecological assessment
Description: The goal of this overview is to describe the relationships among environmental management and the many types of assessment information generated with diatom data. We will review the goals of environmental assessment of aquatic ecosystems relative to the use of diatom data. We will then use case studies to illustrate the value of using diatom metrics for assessing biological condition and pollutants (stressors). We will introduce topics on species traits, indicator taxa, O/E models, multi-metric indices, and thresholds for streams, lakes, and wetlands. We will expand on these topics in future webinars.
Target Audience: Our intended audience for this webinar is anyone who is interested in general information about the use of diatom data in environmental assessments. This is an introductory webinar, so you should not expect specialized information, e.g., detailed methods used to calculate metrics.
Dr. Sarah Spaulding
U.S. Geological Survey / INSTAAR
Introduction to Diatom Web Academy
Description: The goal of this overview is to provide a general introduction to the use of diatoms in assessment and the goals of this series.
Target Audience: Our intended audience for this webinar is anyone who is interested in general information about the use of diatom data in environmental assessments. This is an introductory webinar, so you should not expect specialized information.
Dr. Sylvia Lee
U.S. Environmental Protection Agency
Diatom Taxonomic Certification
Description: This presentation outlines the new Diatom Taxonomic Certification Program supported by the Society for Freshwater Science (SFS). The presentation describes some of the critical aspects for study by potential test-takers.
Target Audience: This presentation is important for managers who use contract labs for analysis of diatom samples. It is also important for analysts, students, or professionals who are interested in becoming certified by SFS.
Dr. Euan Reavie
University of Minnesota, Ely
Description: Sediments at the bottom of lakes tell stories. In this presentation, Dr. Reavie describes how paleolimnology documents historic ecological change in the Great Lakes. The talk presents up-to-date research and how scientists "know what they know".
Target Audience: This presentation is accessible to managers, scientists, analysts, and the lay public.
