Conveners: Bente Edvardsen, Pavel Škaloud
This session focuses on the diversity, phylogenetic relationships, and distribution in time and space of algae and cyanobacteria in marine and freshwater ecosystems. It brings together current research on the discovery of novel species, the emerging insights into the phylogeny within and among major lineages and the expanding role of molecular and genomic tools in modern algal systematics. Attention is also given to how life‑cycle strategies, morphological traits, and biological interactions contribute to community structures and biogeographic patterns. The session will also include how physico-chemical processes are shaping algal and cyanobacterial communities. We welcome contributions that employ integrative methodological approaches to investigate algal phylogeny, diversity, distribution, and dynamics, and to refine the identification and delineation of species and populations.
New species discovery
Molecular techniques in algal taxonomy
Phylogenetic relationships among algal groups
Biodiversity
Biogeography
Life cycles
Conveners: Judita Koreivienė, Fredrik Ryderheim
Harmful blooms of algae and cyanobacteria are increasing in freshwater and marine environments worldwide due to climate change, eutrophication, and other anthropogenic pressures. These events pose major ecological, economic, and public health challenges, affecting biodiversity, water quality, ecosystem functioning, and biogeochemical cycling. This session focuses on the mechanisms underlying harmful bloom formation, persistence, and impacts across aquatic ecosystems. We invite contributions on the ecophysiology of bloom-forming taxa, environmental drivers of bloom development, and the production, regulation, and release of toxins and other secondary metabolites, including their ecological roles and impacts on food webs. The session also addresses links between harmful blooms and carbon and nutrient cycling, as well as approaches for bloom monitoring, forecasting, mitigation, and management. Interdisciplinary studies ranging from molecular and experimental research to field observations, modelling, and applied management in freshwater, brackish, and marine systems are welcome.
Ecophysiology
Toxins and other metabolites production, regulation and release
Blooms and their ecological impacts on the entire food web
Blooms and biogeochemistry
Blooms mitigation
Conveners: Marina Montreson, Henrik Pavia
The session covers all aspects of interactions between algae, other organisms, and their external environment. Algae are “holobionts”, complex entities consisting of the algal host and its closely associated microbiome. Secondary metabolites mediate communication, life-cycle transitions, and defence. Interactions between algae and viruses highlight their role as fundamental drivers of global nutrient cycles. Complex mechanisms regulate interactions between algae and their parasites, such as fungi and protists. Algae develop a range of adaptations to their specific environments; climatic changes and increasing human impacts now present new challenges. Contributions based on laboratory experiments, field studies, and functional genomic research are welcome.
Algal interactions in ecosystems (terrestrial, freshwater, marine, and brackish)
Competition and succession
Predation & parasitism
Algal viruses
Conveners: Jason Hall-Spencer, Thomas Wernberg
This session explores the relationship between human activities and the performance, structure, and function of algae and algal communities. The session considers both the threats and opportunities algae present in a warming high CO2 world—emphasizing both impacts on algae and their potential as tools for mitigation and adaptation. Core topics include impacts on algae and algal communities of coastal urbanisation, climate-driven stressors, including rising temperatures, marine heatwaves, pollution including from nutrients, darkening, and ocean acidification, and studies that show how shifts in algal diversity signal broader ecosystem disruptions and how invasive species alter marine food webs and coastal dynamics. This session underscores how conserving and restoring algal systems can bolster ocean resilience and help combat the accelerating effects of climate change and the human use of coastal habitats. This includes presentations that highlight the biogeochemical importance of algae, particularly their roles in carbon sequestration and nutrient cycling, and explores innovative uses of seaweed farming and kelp forest and other seaweed habitat restoration as natural climate solutions.
Algae as indicators of environmental changes
Human impact on algal diversity
Acidification, climate change
Invasive algae
Mitigation and restoration
Algae's role in carbon sequestration and biogeochemical cycles
Impact of rising temperatures and ocean acidification on algal populations
Algae as a tool for combating climate change
Kelp forests and their ecological importance
Seaweed farming and coastal restoration
Convener: ESTER SERRÃO
This scientific session explores the fundamental mechanisms driving the evolution of algae. The presentations focus on local adaptation, examining how populations evolve traits that enhance fitness in specific environmental conditions. A key subject is phenotypic plasticity, exploring the capacity of organisms to modify their phenotype in response to environmental variation.
Controlled laboratory and field studies revealing evolutionary dynamics in real time address the scientific issue of experimental evolution. Presentations examine the interplay between selection and mutation, emphasising how new genetic variation arises and how natural selection shapes its persistence and spread within populations.
The session also addresses the processes leading to speciation, including the evolution of reproductive barriers, ecological divergence, and the genetic mechanisms that promote the formation of new species. By linking microevolutionary processes to macroevolutionary patterns, the session focuses on the origins of biodiversity.
Multicellularity is another aspect of this session, examining how cooperation among cells emerges, how conflicts are resolved, and how multicellular organisation evolves and diversifies across lineages.
This topic provides an integrated view of evolutionary change, from genetic mutations and adaptive responses within populations to the emergence of new species and complex multicellular life. The session aims to foster interdisciplinary discussion and showcase recent theoretical, experimental, and empirical advances that deepen our understanding of evolution in natural and laboratory systems.
Local adaptation
Phenotypic plasticity
Experimental evolution
Selection & mutation
Speciation
Multicellularity
Conveners: Gwenael Piganeau, Thomas Mock
The session focuses on genetic variation and genome architecture. It brings together presentations across molecular genetics, genomics, and evolutionary genomics of freshwater and marine algae.
Presentations on genome architecture examine the structure and dynamics of chromosomes, genes, and non-coding DNA and their influence on biological function and adaptation.
Special attention is given to population genetics and genetic diversity, exploring the mechanisms that generate and maintain genetic variation within and among populations. Contributions include studies on adaptation, evolutionary processes, conservation genetics, and the use of genomic tools to assess biodiversity.
The session features research on population genetic structure, patterns of gene flow, population differentiation, demographic history, and the factors shaping genetic connectivity across spatial and temporal scales. The session also addresses genetic engineering, covering genome editing technologies, synthetic biology approaches, and their applications in basic research, agriculture, industry, and other fields.
Discussions emphasize both technological innovations and the challenges associated with precise genome modification.
Algal genomes
Genome architecture
Genetic engineering
Population genetics and genetic diversity
Population genetics structure
Conveners: Solène Connan, Elin Lindehoff
This session explores the biotechnological applications of micro- and macroalgae as versatile platforms for sustainable innovation. Beyond their primary role as photosynthetic powerhouses, algae are at the forefront of the Blue Bioeconomy. The discussion covers advances in algae-based biofuels and renewable energy, focusing on lipid productivity. It also examines the integration of algae into the human diet as a functional superfood, their emerging pharmaceutical uses, and the production of high-value compounds such as omega-3 fatty acids, pigments, and polysaccharides, across various biotechnological sectors. The session also highlights circular economy models where algae enable resource recycling, waste valorization, and integrated biorefinery processes that align environmental benefits with economic viability.
Algae as biofuels and renewable energy sources
Algae in food and pharmaceuticals
Production of valuable biochemicals (e.g., omega-3 fatty acids, pigments, and polysaccharides)
Circular economy models involving algae
Conveners: Hélène Launay, Peter Kroth
Algae live in highly dynamic environments and have a highly versatile lifestyle. Besides primary production and carbon fixation, they also modify their aquatic and soil ecosystems and global biogeochemical cycles (e.g., O₂ production, alkalization, secretion of dissolved organic carbon species). Their physiology and metabolism adapt and acclimate to a broader range of conditions compared to land plants. Algal metabolism encompasses both autotrophic and, in some species, mixotrophic pathways that enable efficient adaptation and responses to varying stress factors. Investigating the processes of oxygenic photosynthesis, carbon assimilation, heterotrophic nutrition, microaerobic and anaerobic lifestyle, microbial communities, consortia or symbiosis, and other metabolic pathways is essential for understanding the environmental role of algae, but also for biotechnological applications. This session therefore deals with new aspects of algal physiology and metabolism at the community, cellular, and molecular scales.
Photosynthesis and light utilization in algae
Stress responses and adaptation mechanisms in algae
Metabolic pathways in algae
Algal growth and productivity
Nutrition mode (mixotrophy)
Gene regulation
Genes expression
Epigenetics
Conveners: Vespa Laine, Conny Sjöqvist
This session explores the diverse relationships between algae, both micro- and macroalgae, and society through the lenses of art, culture, history, and public engagement. Topics include the cultural significance of algae and seaweed across different societies, historical uses of algae in medicine and nutrition, growing role of algae across the field of art – for example as natural pigments. The session also highlights innovative citizen science and school projects that connect communities with algae research, sustainability, and environmental awareness. By bringing together perspectives from science, education, humanities, and creative practice, the session aims to inspire interdisciplinary dialogue on the societal relevance of algae past, present, and future.
Citizen science projects
School projects
Algae as natural pigments in art and textiles
Historical uses of algae in medicine and nutrition
Cultural significance of seaweed and algae in various societies
Conveners: Filip Pniewski, Maike Lorenz
Algal culture collections constitute essential infrastructure in modern biological research, serving as curated repositories of diverse cyanobacterial and eukaryotic algal strains. They provide stable, traceable biological material that underpins fundamental research and supports the development of innovative biotechnological applications. A key objective of these collections is the refinement of isolation techniques for novel strains, alongside the optimisation of long-term preservation strategies, including advanced culture media and cryopreservation methods designed to maintain physiological integrity and genetic diversity. Beyond strain maintenance, culture collections supply authenticated reference material for taxonomic standardisation and molecular characterisation, including DNA barcoding, which is critical for both research and environmental biomonitoring. Their role also extends to education, providing well-characterised material for teaching and training. Furthermore, culture collections serve as high-quality bioresource centres that support environmental protection and industrial applications, such as bioremediation and biotechnology.
Contributions are encouraged in key areas supporting the advancement of algal culture collections, including the maintenance and stabilisation of recalcitrant species, as well as the characterisation and cultivation of novel symbiotic lineages and complex microbial consortia in the context of cyanobacterial and algal host health. Submissions focusing on the development and long-term maintenance of axenic strains—essential for genomic, transcriptomic, and other omics-based applications—are also welcomed. In addition, contributions on cryopreservation and alternative strategies for long-term strain preservation, as well as the application of genotyping methods for accurate strain identification, are strongly encouraged.