Diatom of the Month September 2018 - Do diatoms need a stronger presence at aquatic ecology conferences?

by Annika Vilmi, Luca Marazzi and Xavier Benito  

Diatoms inhabit nearly all aquatic ecosystems on Earth, constitute a crucial component at the base of food chains, and are the most diverse group of algae in rivers and lakes (Mann 1999). Our beloved glass-encased algae are powerful indicators of past and present environmental conditions and changes in many ecosystems, ranging from oceans to deep lakes, from springs to wetlands. While diatoms have captivated scientists since the times of Charles Darwin, are they represented enough at general aquatic ecology conferences in the 21stcentury? Below is a summary of the presence of diatoms in three international scientific meetings that we attended last summer.

SIL2018 was held last August in Nanjing, China. During this meeting, around 30 oral and poster presentations dealt with diatoms, at least partly, but only seven had ‘diatom(s)’ in their title (~ 6% and 1% out of 521 contributions, respectively). Diatom-related talks featured in sessions on phytoplankton ecology, benthic ecology, paleolimnology and water quality, alongside other freshwater algae or organisms. A number of talks described temporal or spatial patterns of diatoms and other groups of algae. It was exciting to learn about the more out-of-the-box, applied approaches. For instance, Wei Dai informed how stable isotopes of biofilm could be utilized for monitoring changes in the aquatic environment. Maja Grubisic introduced us on the effects of night-time artificial light on diatoms and other groups of algae. Yuemin Hu told about the importance of rainfall patterns on phytoplankton dynamics. Chao Wang explained how the percentage of curved filaments of Aulacoseira granulatacan inform us about water quality. Our latest findings from the Large-scale ecology laboratory and Jianjun Wang’s lab discussed how diatom niche parameters, biological traits and taxonomic relatedness affect interspecific variation in occupancy and abundance.

The massive conference banner at SIL2018 (Photo by Annika Vilmi).

Water lotus in Lake Xuanwuhu in Nanjing, eastern China (Photo by Annika Vilmi).

2) AQUATROP Congress, Ecosistemas aquáticos tropicales en el Antropoceno

The first AQUATROP Congress was held last July in Quito, Ecuador. During this great meeting  with many talks given in Spanish, ‘diatom(s)’ featured only in 11 titles out of > 350 oral and poster presentations (~3%), but there was a whole session on Ecuadorean diatoms. Alongside taxonomic and water quality studies, the all-diatom session featured research on bioprospecting in the Amazon for wastewater treatment, using DNA to characterize the diversity of epilithic diatoms, and describing diatom ecological niches using cell morphology. Other presentations discussed paleoecology findings in an Antarctic glacier, diatoms as a food source for chironomids in a lagoon in Cuba, the ecology of diatoms in páramo lakes, and our latest findings from the Florida International University Periphyton Ecology Group on how benthic diatom assemblages change in relation to hydrology, nutrient, and salinity in the Everglades.

Dr. Mariana Meerhoff during her plenary presentation at AQUATROP (Photo by Luca Marazzi).

The páramo wetland ecosystem near the Laguna de Papallacta (~60 km southeast of Quito) (Photo by Luca Marazzi)

3) Society for Freshwater Science (SFS 2018), “Navigating Boundaries in Freshwater Science

The 2018 Annual Meeting of the SFS was held last May in Detroit, US. During the conference, only 8 talks and 1 poster out of >900 contributions had “diatoms” in their title (~1%), but a special session on algae featured diatoms in relation to periphyton patterns and processes. Diatoms were also featured by 2018 Award of Excellence Mary Power, from UC Berkeley, who explained us how hydropeaking (artificial flow events in the river caused by dam operation) affect species traits composition in the US South West. Taxonomic, paleolimnology and molecular works were covered. Sarah Spaulding presented the most up-to-date “Diatoms of North America” web diatom flora, a wonderful resource for every diatom scholar. Bo Liu talked about a paleolimnology approach to infer historic asynchronous trophic status in lakes using diatoms. Naicheng Wu explained how flow regimes filter diatom species traits and modify riverine ecosystem services. Valentin Vasselon demonstrated the potential of DNA metabarcoding to assess water quality status in rivers. Isabelle Lavoie gave compelling evidence of the recent warming trends in circumpolar arctic lakes studying spatio-temporal distributions of subfossil diatoms. The Fritz lab presented a landscape palaeolimnology study to assess drivers of recent limnological changes in lakes of the tropical Andes.

Mary Power, from the University of California Berkeley, receiving the 2018 SFS Award of Excellence (Photo by Xavier Benito).

Beautiful sunset in Detroit after the conference dinner (Photo by Xavier Benito).

Aquatic ecology conferences host scholars working on a vast array of organisms and topics, but invertebrates, vascular plants, fish and carbon cycling often seem to dominate these meetings. We have roughly measured the diatom presence as % of presentation titles containing “diatom(s)” so that we can draw comparisons with future conferences, for instance, at SFS 2019 (Utah, US) or SIL 2020 (Republic of Korea) and beyond. An encouraging note is that Evelyn Gaiser’s keynote presentation at this year’s Association for the Sciences of Limnology and Oceanography summer meeting in Victoria, Canada, featured diatoms as sentinels of environmental change in lakes and wetlands. There is a clear potential for more frequent collaborative studies involving diatoms to address big-picture research questions in phylogeneticsbiogeographymetacommunity ecology and food web dynamics through integrated and interdisciplinary approaches. So, if you mostly attend conferences on algae or diatoms, why don’t you try one of these other excellent meetings to broaden your scientific horizons and connect your research with other aquatic (and even terrestrial) ecologists? After all, diatoms are everywhere!


Mann, D.G., 1999. The species concept in diatoms. Phycologia38, 437–495. 


  1. At 23 Congress of Polish Hydrobiologists (4-7 Sept. 2018) there was a paper about diatoms used in freshwater monitoring in Poland according to Water Framework Directive (in Polish: Zgrundo Aleksandra, Peszek Łukasz, Poradowska Anita, Noga Teresa, Panek Piotr "Monitoring fitobentosu w Polsce – kompromis pomiędzy teorią, a praktyką") and two posters with diatoms in title.

  2. Thank you very much Piotr! We are very appreciative to your feedback and we hope this will help to acknowledge the presence of diatom-related (and other algal groups) talks in aquatic conferences.


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