News Story

International Diatom Symposium Workshops



01 April, 2016

Sarah Spaulding

International Diatom Symposium Workshops
Quebec City, Canada
21-16 August 2016

This year, five workshops will be held during the IDS meeting. Each workshop, presenter, scheduled time and abstract are listed below. If you are interested in attending one or more of these workshops, please contact the workshop presenter by email to register by July 1. The local organizing committee needs everyone to register so that they can secure appropriate space for each session. There is no fee for workshops.

W1 Freshwater Monoraphids - Dr. Marina Potapova
Monday August 22 18:30

Are you confused by the new genera names in this group or overwhelmed by the diversity of Achnanthidium in your samples? Wonder whether it makes sense trying to separate varieties of A. minutissimum? Puzzled by a monoraphid that may be an undescribed species? Don’t know how to tell a monoraphid from biraphid diatom? Bring your slides, SEM images, or just questions, and together we will try to solve your problems. We will first briefly talk about the current state of taxonomy and systematics of monoraphids (~30 minutes) and then examine materials brought by participants. Only four microscopes will be available, so it is important that participants inform Dr. Potapova beforehand whether they are planning to bring diatom slides. The workshop is free and open to all IDS attendees, but student members of the International Society for Diatom Research will have the first access to microscopes.

W2 Marine Benthic Diatoms - Dr. Andrzej Witkowski and Dr. Matt Ashworth
Tuesday August 23 18:30

Internet Database on Atlantic Ocean Benthic Diatoms
The margins of the Atlantic Ocean are framed with a diverse array of rich coastal habitats, ranging from the polar coasts to temperate upwelling zones to coral reefs. It is well known that benthic diatoms are significant contributors to primary production in the coastal system, but our knowledge of the benthic marine diatom flora in general and on Atlantic Oceans coasts is rather poor and fragmentary. Even where diatom assemblages of American (Canada, USA, Caribbean, Brazil, Argentina) and European (Baltic, North Sea, Great Britain, France, Mediterranean) coasts are at places quite well studied, there is still much we don’t know about the ecology of these assemblages. Even estimates of total diversity in the Atlantic (genera and species) are likely to be underestimated, and with the increased reliance on high-throughput DNA sequencing to generate ecological models, the paucity of curated and vouchered benthic marine diatom DNA available in public databases, diatom diversity will likely continue to be underestimated and undervalued. Based on our own recent culture based projects, largely dedicated to diversity, taxonomy and molecular phylogeny of the Atlantic Ocean benthic diatoms we aim to correct this underestimation with a coordinated effort to sample and characterize these diatoms using microscopy and molecular tools, with the ultimate goal of establishing an internet data base on Atlantic Ocean benthic diatoms. The project shall in large resemble the existing database of “The Diatoms of the United States” including a peer review system for posting taxa and ecological data with distribution records for taxa. Our plan is to invite diatom researchers from both sides of the Atlantic Ocean, representing the best studied regions, to contribute with their knowledge and with their resources as a start to this webproject. We hope to supplement distribution and ecological records with DNA data from our own or existing cultures. Our own resources include well over 1000 strains isolated from the Atlantic Ocean realm including the Sub-Arctic/Arctic and Antarctic Peninsula taxa and the most fertile and productive systems including the whole Benguela Current. The only continent from which we do not have cultures the yet is South America.

We hope this project will also serve as an anchor-point for study into the geographic distribution of marine benthic taxa (cosmopolitan vs endemic taxa). With the magnitude of data possessed we are already able to identify some marine taxa which are likely cosmopolitan: morphologically and genetically identical with a wide distribution. However, poor taxa sampling is still the major obstacle in the discussion on the distribution of diatom taxa. The ideas behind the grounding of the project on Atlantic Ocean diatoms and examples of globally distributed taxa will be presented during the workshop. We also expect that during the workshop a group of diatomologists willing to join our project will crystalize during the workshop and recognize this will be a great opportunity for researchers who work on marine benthics to get together and share knowledge and expertise.

W3 Terminology - Dr. Eileen Cox and Dr. Ric Jordan
email:; Wednesday August 24 8:30

The guidelines on diatom terminology published during the 1970s continue to be cited but are now in dire need of revision. Thus, a working group (called DIATERM) was set up in St. Paul (21st IDS) with subsequent meetings held in Ghent (22nd IDS) and Nanjing (23rd IDS). Small teams of diatomists were given the task of reviewing and revising the terms associated with particular structures (e.g., the raphe, portulae, striae, ribs, pore types, etc.), with a view to producing an authoritative, highly illustrated, account of morphological terminology for diatoms (excluding terminology around sexual reproductive stages, see Kaczmarska et al. 2013). These teams have been asked to prepare posters for the 24th IDS, so that they can receive feedback on the definition and usage of each term. The importance of consistent terminology cannot be over-stressed. The correct application of terminology underpins our understanding of structures, potential homologies and taxonomic decision-making based on morphology. Inconsistent usage or the creation of duplicate terms for the same structure, leads to confusion and the need to repeat observational studies. Therefore, we would like to invite everyone to visit our posters and to join our discussion on what still needs to be done.

Kaczmarska, I., Poulíčková, A., Sato, S., Edlund, M.B., Idei, M., Watanabe, T. & Mann, D.G. 2013. Proposals for a terminology for diatom sexual reproduction, auxospores and resting stages Diatom Research 28:263-294.

W4 Web-based Diatom Reference Sites - Dr. Sarah Spaulding
email: Wednesday August 24 8:30

The Diatoms of the United States web project ( has now been available online since 2010. In that time, the project has grown from 3 contributors to over 80 and from 25 species pages to over 700.

The project was established to increase diatomist’s access to accurate taxonomic information in order to reduce errors and uncertainty in documenting diatom biodiversity. That is, the project was established to increase taxonomic consistency and accuracy, primarily for survey and monitoring programs in North America.

Is the project on the right track? What are the next steps for online identification tools for diatoms? What is the potential for computer aided identification? The project has developed based on input from the scientific community. This IDS workshop is an opportunity for the community to provide input to direct the future of the resource.

The workshop will include a discussion of copyright and what constitutes fair use as it relates to taxonomic descriptions. We will also consider errors introduced by large databases and the dangers that accompany large data. Participants are also invited to submit topics for discussion, especially to submit topics during the registration process.

W5 Gomphonemoids - Dr. Pat Kociolek
email: Thursday August 25 18:30

This group has over 1000 described taxa, and with a notoriety of significant variation within individual species, the freshwater gomphonemoid diatoms are usually considered one of the most taxonomically difficult groups. There is significant confusion about the circumscription and distribution of the genera, as well as species. The workshop will contain 3 sections.

The first section of this workshop will present an overview of the group, including the history of the 4 extant genera (Gomphonema, Gomphoneis, Gomphocymbella and Gomphosinica) and their phylogenetic relationships. We also will discuss briefly the unrelated genus Gomphosphenia. A discussion of valve features will be offered, and the features used to identify subgroups within each genus will be illustrated and discussed. We will examine typical size diminution series for members of this group, which is important to understand species circumscription. The biogeography of each genus, and the subgroups within each genus, will be presented. And this section of the workshop will conclude with a list of the most helpful publications for identifying species of each genus. The second section of the workshop will include showing species of each genus, to illustrate how to distinguish the genera and certain species within each genus.

Finally, in the third section, workshop participants will be invited to show specimens of this group to illustrate species and for help in identifying previously-described species or those that may be new to Science. If you are interested in bringing specimens to examine with light microscopy, please let the workshop leader know ahead of time so that we can allocate time to this aspect of the workshop appropriately.