SESSIONS

Please find the session titles and descriptions under each category. Some sessions appear in more than one category.

Biodiversity Dynamics

Marco Cantonati, MUSE – Museo delle Scienze, Italy                       
marco.cantonati@muse.it
Kalina Manoylov, Georgia College, GA, USA

The monitoring and assessment of inland water quality based on benthic algae has become an important element of the methodological toolkit adopted by water authorities and in limnological research. The topic is particularly timely now that such environmental assessments are sparking growing interest worldwide and discussions and revisions of methods and procedures have been initiated. The integration of metagenomic methods into the established approaches is a particularly important development. We invite contributions to the session on all aspects of inland water assessments and monitoring based on benthic algae, continuing a long tradition of international symposia on the use of algae for monitoring rivers and comparable habitats. Thus, the session will provide an opportunity to review and discuss algae-based monitoring in different countries around the globe, as well as improvements to methods and techniques, their use in the implementation of legislation and regulations, and the discussion of novel approaches. We consider assembling a set of selected solicited or unsolicited papers presented at the session for publication in a special issue of an international journal, as has been the case in previous symposia organized on the topic.

Andras Abonyi, WasserCluster Lunz, Austria
abonyiand@gmail.com
Evangelia Smeti, Hellenic Centre for Marine Research, Greece
Jana Isanta-Navarro, University of Montana, MT, USA
Robert Ptacnik, WasserCluster Lunz, Austria
Maria Stockenreiter, Ludwig-Maximilians-Universität Munich, Germany

Biodiversity enhances community resource use efficiency and ecosystem stability. This relationship has received increasing attention with recent decline in global biodiversity, fragmentation of habitats, and the more frequent dominance of invasive and harmful species. In this session, we aim to enhance communication among researchers working on different aspects of plankton biodiversity. We welcome presentations that combine any aspect of biodiversity (as causes) with effects on any of the various ecosystem functions (as consequences). Presentations may cover, but are not limited to 1) testing biodiversity-ecosystem functioning relationship (BEF) beyond primary production, addressing, for example, trophic transfer efficiency, biogeochemistry and stoichiometry; 2) mechanisms underlying community assembly and diversity under global change, considering, for example, the more frequent occurrence of harmful/invasive taxa in the context of BEF; 3) BEF studies considering historic and spatial effects (species pools). We invite presentations based on field observations, laboratory experiments, modelling studies, and conceptual work. We especially encourage talks that combine the effect of global environmental change and human impacts (e.g. warming, fragmentation, extreme events, regime shifts) with biodiversity or community assembly and corresponding alteration in ecosystem functioning.

Luciana Gomes Barbosa Federal University of Paraiba, PB, Brazil
lucianabarbosa@cca.ufpb
Rachel Stubbington, Nottingham Trent University, UK

Manuela Moraes
University of Evora, Portugal
Carlos Lopez
Polytechnic School of the Coast, Ecuador

Global climate change is expected to intensify drying in temporary freshwater ecosystems around the world, altering their biodiversity and functioning. Drying can cause biodiversity to decline, reducing the resilience of ecosystems facing climate change and other intensifying human pressures. These ecosystems—including temporary lakes, wetlands, rock pools, man-made reservoirs, ponds, rivers and streams—provide many ecosystem services, and understanding their biodiversity and functioning is thus critical to inform effective conservation and management strategies. This session will showcase the latest, most exciting limnological research exploring drying freshwaters. Our scope is broad, and we invite contributions regarding any type of drying freshwater ecosystem, from tiny ephemeral pools to the marginal sediments of large, perennial rivers. We will explore drying freshwaters from biological, biogeochemical, ecological, hydrological, physical and wider interdisciplinary perspectives, as well as recognizing these ecosystems as socioeconomic systems. A diverse range of drying freshwaters occur across all continents, and we seek to represent international advances made by scientists studying systems from hot, arid lands to cold, wet regions. As their extent increases in our changing world, our multidisciplinary session will show how collaboration between global scientists and managers is transforming our understanding of temporary freshwater ecosystems and thus our capacity to manage them effectively. Our ultimate goal is to unite scientists and managers who seek to safeguard biodiversity in drying inland freshwaters for the next 100 years.

Gonçalo Duarte, University of Lisbon, Portugal                                          goncalofduarte@isa.ulisboa.pt

Afroditi Grigoropoulou, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany

Paulo Branco, University of Lisbon, Portugal

Maria Üblacker, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany

Freshwater ecosystems host a variety of complex processes that can be approximated through the distinct spatial and temporal patterns they create. In the Anthropocene, ecosystems are increasingly impacted by anthropogenic occupation and actions. Considering that all land areas are draining to a river course and that river networks are hierarchical, dendritic and directional, using a riverscape approach provides a sound methodological perspective for freshwater ecological studies. Moreover, exploring how patterns in species occurrences, environmental characteristics and human stressors vary across different spatial and temporal scales is of particular relevance for a better understanding of freshwater biodiversity and processes.  This session aims to: i) showcase studies revealing spatial trends, threats, pressures or management applications concerning river ecosystems across distinct riverscales; ii) focus on spatio-temporal modelling efforts aiming at describing and/or predicting both ecological processes and biodiversity patterns; iii) connect researchers working on riverscape approaches to anthropogenic impacts on river ecosystem features and; iv) allow researchers to be exposed to concepts and methods used in multiple and distinct topics of freshwater ecology. This session also wishes to attract contributions regarding novel approaches of species distribution models and hierarchical models, with a special emphasis on spatially explicit methods. Theoretical, field, methodological, cross-topic and applied perspectives are welcome to spark debate towards acknowledging future research on freshwater ecosystems.

Vadim Panov, Regional Euro-Asian Biological Invasions Centre, Finland vepanov@gmail.com

Invasions of non-native species in aquatic and terrestrial ecosystems are considered a global environmental problem. Aquatic ecosystems seem at particular risk from invasive alien species (IAS) given the threats to biodiversity and water resources. Biological invasions in freshwater ecosystems have a number of potential impacts on community structure and ecosystem function. The objective of this special session is to provide a forum for international scientists to address designated themes to exchange information on ongoing fundamental and applied research, establishing scientific collaboration and informing management and policy development in this increasingly important topic. This session will cover the following themes: invasion ecology of freshwater IAS; freshwater invasions in a time of global social and climate change; impacts of IAS; pathways and vectors for the spread of IAS; risk management, control and prevention of the secondary spread of IAS; international networking in research, information exchange and management of IAS.

Rafaela A. Almeida, KU Leuven, Belgium
rafaela.almeida@kuleuven.be
Kristien I. Brans, KU Leuven, Belgium
Lynn Govaert, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany
Toni Klauschies, University of Potsdam, Germany

Anthropogenic-induced environmental changes strongly affect the composition and structure of natural communities and food webs with consequences for biodiversity and the functioning of ecosystems. During the past decades, studies have collected ample evidence of rapid contemporary evolution to environmental change and its impact on ecological processes. The fact that species often exhibit substantial phenotypic and genetic trait variation that allow them to rapidly respond and evolve to an altered selection pressure has strong implications for research primarily focusing on the ecological interactions and resulting population dynamics. Adaptive evolution can buffer against extinction and species loss, may generally promote species coexistence, and potentially mitigate predicted ecosystem-wide detrimental effects (e.g., regime shifts). However, it may also inhibit species coexistence, reduce genetic diversity potentially leading to evolutionary bottlenecks upon disturbance, and consequently lower ecosystem resilience. These contrasting results indicate that rapid evolution potentially plays an important role in various ecological processes and thus should be regarded in the context of ecological dynamics. Moreover, taking intraspecific genetic variation and eco-evolutionary feedbacks into account in ecology will enable to better predict changes in species coexistence patterns, ecosystem functioning and associated implications for nature’s contribution to people, especially for landscapes and waters under anthropogenic disturbance. We aim to gather researchers that focus on the importance of rapid evolution and eco-evolutionary feedback for ecological dynamics such as population resilience, species coexistence, biodiversity conservation and ecosystem-wide stability in anthropogenically disturbed landscapes and waters (e.g. in the context of urbanization, conventional and organic agriculture, industrial land use, fishery, and extreme weather events).

Cécilia Barouillet, INRAE UMR CARRTEL, France
cecilia.barouillet@gmail.com
Laura Epp, University of Konstanz, Germany
Ebuka Nwosu, GFZ Helmholtz Center Postdam, Germany
Eric Capo, ICM-CSIC, Spain

The sedimentary DNA approach is rapidly evolving, opening new avenues to the field of aquatic ecology and paleoecology. In the context of freshwater habitats, molecular archives have allowed us to give a broad perspective about biological change, and new insights into ecosystem functioning, food-web dynamics and biodiversity of aquatic ecosystems over long time scales (i.e. centennial to millennial). Moreover, sedimentary DNA-based methods represent innovative ways towards the reconstruction of full trophic networks. In this session, we invite contributions from scientists applying the sedimentary DNA approach to study past changes in freshwater ecosystems. The goal of this session is to provide an overview of the research conducted in the field by using various sedimentary DNA techniques (e.g. qPCR, DNA metabarcoding, shotgun sequencing, hybridization capture) and diverse sites in order to demonstrate how the approach can help improve our understanding of the long-term dynamics of freshwater habitats in a complex multi-stressor world (e.g. eutrophication, invasive species, catchment alteration). We especially encourage presentations that provide insights into how information gained through sedimentary DNA research can help to improve freshwater management and conservation issues related to human-induced stressors in the context of climate change.

 

Carbon Cycling

Renske Vroom, Radboud University, The Netherlands
renske.vroom@ru.nl
Sarian Kosten, Raboud University, The Netherlands

Humans are excellent ecosystem engineers and have historically modified and created water bodies to serve their manifold needs. This includes food production, water storage, energy production and modifications for recreational use. Human alterations of freshwater systems drastically affect hydrology and carbon cycling. These systems, from which emissions can be exceptionally high, have been estimated to contribute more than half of the global methane emissions. In addition, they increasingly contribute to global nitrous oxide emissions. These ecosystems often receive high amounts of carbon and nutrients, resulting in the accumulation of anoxic, methanogenic sediments and the establishment of conditions favourable for greenhouse gas production. The global areal extent of human-made freshwater systems is expected to increase due to urbanization and the demand for alternative food and energy sources. Moreover, sedimentation rates and greenhouse gas emissions are enhanced by eutrophication and climate feedbacks. However, greenhouse gas emissions from these systems remain understudied and this hampers accurate incorporation in global emission estimates. A better understanding of carbon cycling in human-made freshwater systems is also essential for construction and management strategies that effectively minimize greenhouse gas emissions. For this session, we invite speakers working on greenhouse gas emissions and carbon burial in human-made freshwater systems, including aquaculture ponds, urban and agricultural artificial water bodies, and reservoirs.

Scott D.Tiegs, Oakland University, MI, USA
tiegs@oakland.edu
M. Eric Benbow, Michigan State University, MI, USA
Gwendoline David, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany
Mark Gessner, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany

Plant and animal remains comprise leaf litter and large wood as well as carcasses of both small arthropods and large vertebrates ranging from fish to mammals. While plant litter has been most thoroughly studied, the role of animal remains has also been increasingly recognized as an important component of carbon and nutrient cycling in streams and rivers, littoral zones of lakes, wetlands, and other ecosystems where land meets water. Even in pelagic systems of inland waters can this type of organic matter play a notable role. We invite contributions to this session that report results of experimental and theoretical studies on the dynamics of diverse types of plant litter and animal remains. This includes studies on inputs to inland waters, storage, transport, and the decomposition and use by microbes and detritivores, and how the structure of communities, species interactions, environmental conditions such as temperature, nutrient and oxygen supply, anthropogenic stressors and climate change affect these processes. The goal is to bring together researchers from diverse backgrounds. Spatial scales can range from specific sites to global. Conceptual contributions, meta-analyses and other syntheses are also all welcome.

 

Sebastian Sobek, Uppsala University, Sweden
sebastian.sobek@ebc.uu.se
Raquel Mendonça, Federal University of Juiz de For a

Sediments are a metabolically highly active compartment of freshwater systems, and the cycling of organic matter in inland water sediments largely affect the global carbon cycle and the climate. Organic carbon burial in sediments removes carbon to long-term storage in the geosphere, and therefore has a cooling effect on climate. On the other hand, organic matter degradation in sediments produces greenhouse gases (carbon dioxide, methane, nitrous oxide), which has a warming effect on climate. Despite the global significance of these fluxes, freshwater sediments remain poorly understood. While past studies have provided insights into many aspects of sediment organic matter cycling (e.g. the effectiveness of organic carbon burial, the extent of methane ebullition and oxidation, the magnitude of nitrous oxide production, the effect of drying-rewetting cycles), most of these insights are based on the small scale of individual lakes or sediment cores. The application of this small-scale knowledge at larger scales (regionally or globally) remains a challenge, and requires verification from other systems. In addition, the potential anthropogenic perturbation to sediment organic matter cycling in inland waters is currently unknown. Here we invite presentations and discussions with an empirical and theoretical focus related to freshwater sediments and their dual role as carbon sinks and sources of greenhouse gases. We welcome contributions reporting field measurements, laboratory experiments and modelling, and spanning spatial scales from individual sediment cores to the globe.

Zhe Li, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, China
lizhe@cigit.ac.cn
Bertram Boehrer, Helmholtz Centre for Environmental Research – UFZ, Germany
Yves Prairie, Université de Québec à Montréal, QC, Canada

Gases and gas release from inland waters have recently received great interests in the limnological research as essential players in the carbon cycle: released gases such as carbon dioxide and methane are the most important contributors to the greenhouse effect. However, the relevance of gases goes far beyond this. Gases play a central role in limnology. Oxygen is a central agent for the metabolism of higher organisms, while carbon dioxide is a requirement for photosynthesis. Some lakes store immense amounts of gas which, when sudden released, threatens animals and humans on land. Degassing due to instantaneous pressure change and strong turbulence mixing upon discharge from reservoirs not only results in significant emissions of methane, but also causes oversaturated dissolved gases in water, threatening downstream fish species. Our further understanding of interactions between inland waters and the atmosphere under global change is limited. We invite presentations covering a wide range, such as the nature of gas production via microbial processes, transport of gases, solubility, ebullition, diffusive exchange at the air-water interface and gas tracing. We also welcome presentations of methodological development or the application of novel methods ranging from micro-scale experiments to upscaling exercises.

Katrin Attermeyer, WasserCluster Lunz, Austria
katrin.attermeyer@wcl.ac.at
Maximilian Lau, TU Bergakademie Freiberg, Germany

Inland waters process and transport large amounts of dissolved and particulate organic matter (DOM and POM, respectively). Both fractions contribute differently to carbon and nutrient cycling through specific forms of transport, processing, and mineralization. Evidence is emerging that suspended particles and their interactions with dissolved matter during transport in inland waters critically affect key ecosystem properties such as carbon processing and burial. However, the role of reactions associated with both natural and synthetic particles (i.e., POM, flocs, microplastics) and the consequences for the transformation and removal of DOM from solution has not been widey acknowledged. This session aims at bringing together the dissolved and particulate world of organic matter to develop a new perspective on an emergent topic in aquatic organic matter research. We invite contributions focusing on particle composition and dynamics, particle-attached microbial communities and their functioning, and transit between the organic matter domains such as dissolution/disaggregation or flocculation/formation reactions. We particularly seek presentations reporting on novel biogeochemical, analytical, molecular biological, experimental, field or modeling approaches directed towards obtaining a fundamental, mechanistic understanding of the particles and their links with dissolved organic matter.

Mina Bizic, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany
mina.bizic@igb-berlin.de
Hans-Peter Grossart, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany

Methane accumulation in oxic aquatic environments has been reported for almost half a century. Yet, this has been acknowledged only in recent years and has led to discussions about the contribution of oxic methane production to global methane fluxes. The phenomenon contradicts common knowledge that methane is produced solely by methanogenic Archaea under strictly anoxic conditions, and it has hence been termed “The Methane Paradox.”Several biological mechanisms contribute to oxic methane production, including demethylation of methylphosphonates, methylamines, and DMSP, photosynthesis by phytoplankton, and classical methanogenesis in anoxic microniches hidden in the oxic environment, such as the guts of zooplankton. Additionally, several studies have found that methane locally produced in oxic layers of some aquatic environments can contribute to most of the methane flux to the atmosphere. The scientific community is currently divided regarding the local production of methane in oxic waters with some stating that methane transport from anoxic sediments is the main contributor to methane fluxes to the atmosphere from oxic aquatic environments. Consequently, methane emissions from the oxic surface waters remain one of the largest uncertainties in the global methane budget. Despite recent progress, the isotopic signature of methane produced in oxic environments is largely unknown and, therefore, cannot be incorporated into current atmospheric stable isotope mixing models. Similarly, little is known about the contribution of methanotrophs to the methane budget in oxic surface waters. To stimulate discussion on recent advancements and uncertainties in methane dynamics in oxic surface waters, we invite contributions discussing any aspect of methane production and oxidation in this environment as well as the resulting atmospheric fluxes.

Data Analysis and Modelling

Marco Toffolon, University of Trento, Italy
marco.toffolon@unitn.it
Robert Ladwig, University of Wisconsin-Madison, WI, USA
Samantha K. Oliver, U.S. Geological Survey, WI, USA
Sebastiano Piccolroaz, University of Trento, Italy
Tom Shatwell; Helmholtz-Centre for Environmental Research – UFZ, Germany

Smart monitoring technologies have seen a thriving development in the last decades. Earth observation is providing freely usable data at increasingly higher spatial and temporal resolution. Low-cost computational power has supported the use of brute force in the application of complex algorithms. Because of this, in general we are observing a shift of paradigm towards the development and application of data-driven models and hybrid mechanistic-statistical models, which require data for their training and validation. This is true for all fields of environmental science, including limnology, where the rising availability of high-quality data of different type and nature allows the application of models to an extent that was hardly imaginable before. Overall, the emerging field of theory-guided data science brings exciting novel research opportunities and applications, but the question remains: What is the perspective for the future? The session welcomes contributions dealing with the development and application of models of different type (e.g., machine-learning, statistical, deterministic, hybrid, etc.) using a variety of data (e.g., remote sensing, high-frequency data) in the field of limnology (e.g., lakes, ponds, lagoons, reservoirs, rivers, groundwater), with a particular focus on data-driven models and on the synergy between data science and modeling.

Gonçalo Duarte, University of Lisbon, Portugal
goncalofduarte@isa.ulisboa.pt
Afroditi Grigoropoulou, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany
Paulo Branco, University of Lisbon, Portugal
Maria Üblacker, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany

Freshwater ecosystems host a variety of complex processes that can be approximated through the distinct spatial and temporal patterns they create. In the Anthropocene, ecosystems are increasingly impacted by anthropogenic occupation and actions. Considering that all land areas are draining to a river course and that river networks are hierarchical, dendritic and directional, using a riverscape approach provides a sound methodological perspective for freshwater ecological studies. Moreover, exploring how patterns in species occurrences, environmental characteristics and human stressors vary across different spatial and temporal scales is of particular relevance for a better understanding of freshwater biodiversity and processes. This session aims to: i) showcase studies revealing spatial trends, threats, pressures or management applications concerning river ecosystems across distinct riverscales; ii) focus on spatio-temporal modelling efforts aiming at describing and/or predicting both ecological processes and biodiversity patterns; iii) connect researchers working on riverscape approaches to anthropogenic impacts on river ecosystem features and; iv) allow researchers to be exposed to concepts and methods used in multiple and distinct topics of freshwater ecology. This session also wishes to attract contributions regarding novel approaches of species distribution models and hierarchical models, with a special emphasis on spatially explicit methods. Theoretical, field, methodological, cross-topic and applied perspectives are welcome to spark debate towards acknowledging future research on freshwater ecosystems.

Behnam Zamani, Thünen Institute for Climate Smart Agriculture, Germany
behnam.zamani@thuenen.de

Physics and biogeochemistry are inextricably linked in lakes. The physics provides the background and drives biogeochemistry, which, in turn, feeds back to the physics and on itself. Coupling hydrodynamic and biogeochemical models is per se challenging and progress in the approach depends on an effective communication between modelers on either side of the physics/biogeochemistry divide. This communication across the divide, is particularly important to predict impacts of climate change out to decades or centuries. Predictions of the consequences of climate change for lakes generally require moving our models into regimes, where calibration and validation data might no longer apply. Thus, it is not only critical to consider inherent uncertainties in the physical or biogeochemical models, but also those resulting from interactions across the divide, i.e., when models are coupled. This session will provide a communication platform to raise and discuss important questions on coupling of physical and biogeochemical models, where modelers of lake biogeochemistry ideally present results that are of interest to modelers of lake physics, and vice versa. Therefore, we would particularly welcome contributions to focus their efforts on crossing the current disciplinary divide rather than informing only their own discipline. To address and evaluate the gaps of modeling aspects and skills that might exist between the two groups of lake modelers, we seek contributions reflecting (i) issues at the boundaries between physics and biogeochemistry, (ii) challenges in advancing discipline-based models that have implications across the physics/biogeochemistry divide, and (iii) model uncertainties that affect predictions under climate change.

Abolfazl Irani Rahaghi, Eawag, Switzerland
abolfazl.irani@eawag.ch
Tiit Kutser, University of Tartu, Estonia

During the first one hundred years the limnological research has been predominantly based on in situ sampling in a limited number of waterbodies. Broadening of research problems (climate change, global carbon cycle, etc.) as well as technological advances in the last decades (automated buoy systems; airborne, surface and underwater drones, etc.) opened new possibilities for inland water research and monitoring. The launch of Sentinel satellites in the frame of the Copernicus Programme opened a new era in satellite remote sensing – moving from one-off scientific missions to long-term monitoring with confirmed funding for decades to come. Advancements in numerical modelling allow better understanding of the processes in inland waterbodies. On the other hand, they allow limnological research and monitoring to reach a new level where remote sensing, in situ data, and modelling are merged like in operational climate and weather services. This session aims at presenting the latest achievements in inland water remote sensing and integrated use of in situ data, remote sensing, and models. In particular, we invite contributions that demonstrate the development and employment of remote sensing for limnological research and monitoring as well as in investigating the underlying physical and biological processes by means of model simulations. This session will also provide researchers a chance to shape the future of Copernicus inland water services as the outcomes will be used in preparing a Roadmap for Future Copernicus Water Services that is to be developed in the future.

Ecosystem Coupling

Stella A. Berger, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany
stella.berger@igb-berlin.de
Sabine Wollrab, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany

Globally, inland waters face rising temperatures, shifts in precipitation patterns and an increased frequency of extreme weather events such as flooding and droughts. Forecasting long-term effects of global change at larger spatial scales needs regional assessments of lakes, rivers, wetlands and ponds with a focus on connectivity between local aquatic systems and their surrounding terrestrial matrix. In this special session we invite researchers working on connectivity of aquatic systems from different angles. We welcome contributions of theoretical approaches such as meta-ecosystem theory as well as empirical studies for regional coverage of response patterns of aquatic ecosystems and its dependence on connectivity. Empirical studies can range from small-scale to large-scale experiments, and include field studies as well as long-term data of river-lake networks, wetlands and pond systems. Ideas on future environmental monitoring and interpretation of available data to support more effective integrated management of connected inland waters for the mitigation of eutrophication impacts or other environmental challenges are appreciated.

Ralf Schulz, University Koblenz-Landau, Germany
schulz@uni-landau.de
Pablo Urrutia Cordero, Lund University, Sweden
Andreas Lorke, University of Koblenz-Landau, Germany
Alessandro Manfrin, University of Koblenz-Landau, Germany
John Strand, Hushållningssällskapet Halland, Sweden
Björn Klatt, Hushållningssällskapet Halland and Lund University, Sweden

The close connection between aquatic ecosystems and adjacent terrestrial land has been a long-standing paradigm of limnological research. Existing concepts, however, mainly focus on the terrestrial input into freshwater ecosystems and the consequences for aquatic life. The flux of resources and pollutants from aquatic to terrestrial systems has been less studied. Recently intensified research revealed that material fluxes mediated, e.g., by emerging insects and hydrological connectivity, are of high ecological relevance, particularly for the receiving ecosystem including ecosystem services. In addition, these fluxes are increasingly affected by anthropogenic and climatic stressors, such as micropollutants, toxic cyanobacterial blooms, invasive species, and hydrological alterations. The session invites contributions from all aspects of resource and stressor transfer from aquatic to terrestrial ecosystems. We also invite contributions that assess the vulnerability of terrestrial systems to alterations of these fluxes by stressors acting on inland waters.

Dominik Martin-Creuzburg, Brandenburg University of Technology Cottbus–Senftenberg, Germany
dominik.Martin-Creuzburg@b-tu.de
Martin Kainz, WasserCluster Lunz, Austria
Tarn Preet Parmar, University of Konstanz, Germany
Margaux Mathieu-Resuge, WasserCluster Lunz, Austria; Cornelia Twining, Eawag, Switzerland

Emergent insects have been classified and quantified in the last two centuries as they can provide important information into ecosystem biodiversity, health, and response to environmental changes. More recently, they have also been studied as an important cross-ecosystem subsidy providing aquatic-derived nutrients to terrestrial food webs. Food web techniques (i.e., fatty acid analysis and stable isotopes) have been used to track aquatic-derived nutrients from aquatic primary producers all the way to riparian predators, such as birds and spiders. Recent interest has been focused on quantifying polyunsaturated fatty acids (PUFAs) that are exported from rivers, ponds, and lakes. Although PUFAs have important energetic and physiological functions, this session is not limited specifically to PUFA-related research. Instead, we would like to bring together researchers who focus on emergent aquatic insects as important cross-ecosystem vectors. One focus of the session will be on recent research that provides the framework for determining the current environmental status of inland waters using emergent aquatic insects. In addition, we would like to highlight the prospect of using biochemical and/or isotopic analysis (established and new) as a way to determine and detect changes in ecosystem health and services provided by emergent insects. This session builds on the Chironomidae and the foundation laid by August Thienemann, one of the SIL visionaries, and highlights the importance of studying emergent aquatic insects and the possibility of using them as indicators of ecosystem functionality.

Gonçalo Duarte, University of Lisbon, Portugal
goncalofduarte@isa.ulisboa.pt
Afroditi Grigoropoulou, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany
Paulo Branco, University of Lisbon, Portugal
Maria Üblacker, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany

Freshwater ecosystems host a variety of complex processes that can be approximated through the distinct spatial and temporal patterns they create. In the Anthropocene, ecosystems are increasingly impacted by anthropogenic occupation and actions. Considering that all land areas are draining to a river course and that river networks are hierarchical, dendritic and directional, using a riverscape approach provides a sound methodological perspective for freshwater ecological studies. Moreover, exploring how patterns in species occurrences, environmental characteristics and human stressors vary across different spatial and temporal scales is of particular relevance for a better understanding of freshwater biodiversity and processes. This session aims to: i) showcase studies revealing spatial trends, threats, pressures or management applications concerning river ecosystems across distinct riverscales; ii) focus on spatio-temporal modelling efforts aiming at describing and/or predicting both ecological processes and biodiversity patterns; iii) connect researchers working on riverscape approaches to anthropogenic impacts on river ecosystem features and; iv) allow researchers to be exposed to concepts and methods used in multiple and distinct topics of freshwater ecology. This session also wishes to attract contributions regarding novel approaches of species distribution models and hierarchical models, with a special emphasis on spatially explicit methods. Theoretical, field, methodological, cross-topic and applied perspectives are welcome to spark debate towards acknowledging future research on freshwater ecosystems.

Emma Kritzberg, Lund University, Sweden
emma.kritzberg@biol.lu.se
Ryan Sponseller, Umeå University, Sweden
Martin Skerlep, Umeå University, Sweden

Einar Naumann recognized a century ago the importance of the surrounding landscape in shaping the physicochemical conditions and subsequently the ecological structure of freshwaters. Geology, land cover, and climate all have profound influences on what solutes and suspended matter reach aquatic systems. Now in this era of environmental change, shifts in material loading are observed due to changes in land-use, atmospheric deposition, temperature, precipitation, and extreme events such as fires, floods, and drought. It is crucial to understand how this diversity of change on land affects biogeochemical fluxes, ecosystem processes, and ecosystem services of receiving freshwater systems. In this session we aim to host presentations that explore novel links between landscapes and surface water chemistry, including organic carbon, nutrients, minor elements, and pollutants. We invite contributions that identify the trends, drivers, processes, variance of such links. We invite also submissions that examine chemical, biological, or physical impacts of these links.

Katrin Wendt-Potthoff, Helmholtz Centre for Environmental Research – UFZ, Germany
katrin.wendt-potthoff@ufz.de
Martin Blettler, National Institute of Limnology (INALI) CONICET-UNL, Argentina

Plastic pollution is mainly recognized in the oceans, but i relevant also in rivers, estuaries, lakes and wetlands. Composition of plastic debris, transport pathways and interaction with biota show similarities, but also important differences to marine systems, which are not yet well understood. Knowledge gaps result, among others, from inconsistent monitoring or sampling strategies and geographic bias. We therefore encourage presentations covering systematic assessments of all sizes of plastic in inland water systems, observations related to extreme weather or pandemic, and studies at the freshwater-ocean or freshwater-terrestrial interface. Moreover, plastic interactions with water-associated biota beyond ingestion will be of special interest.

Pieter Lemmens, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany; KU Leuven, Belgium
pieter.lemmens@kuleuven.be
Biljana Rimcheska, Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, Bulgaria
Lena Fehlinger, WassercLuster Lunz, Austria
Sandra Brucet, Universitat Central de Catalunya and Catalan Institution for Research and Advanced Studies (ICREA), Spain

Ponds are the most numerous freshwater ecosystems on Earth. They are important habitats for aquatic biodiversity, provide vital ecosystem services, and are key elements of blue landscape connectivity. Ponds can also play a pivotal role in mitigating and adapting to global change. Despite their importance, ponds are mostly neglected in current policies and conservation programs. This is surprising since ponds are increasingly exposed to multiple anthropogenic stressors that undermine their ecological integrity and related ecosystem services, including social, environmental and economic aspects. Understanding how land-use intensity, connectivity and the ecological quality of ponds in landscapes feeds back to exacerbate or ameliorate local and regional anthropogenic impacts is crucial for the development of effective conservation strategies that aim to enhance the capacity of ponds to increase resistance and resilience to global change. The overarching aim of this session is to obtain a holistic picture of current research by synthesizing knowledge on how ponds and their biota respond to global change, how this translates in effects on ecosystem services, how local scale processes interact with regional landscape scale processes, and how management strategies can improve the capacity of ponds to mitigate and adapt to global change. We explicitly aim to interconnect early career researchers in fundamental research, approaches of citizen science, conservation and restoration management.

Ecosystem Functioning

Núria Perujo, Helmholtz Centre for Environmental Research – UFZ, Germany
nuria.perujo-buxeda@ufz.de
Anna Freixa, Catalan Institute for Water Research (ICRA), Spain

Aquatic microorganisms have been affected – and will continue to be so – by global climate change and their responses are a growing concern for aquatic ecosystems. We understand global climate change as the set of climatic alterations in temperature and precipitation patterns as well as an increased frequency of extreme climate events. Microbial biofilms that develop on riverbed surfaces (i.e. sediments, cobbles, leaves, etc.) are key players of freshwater ecosystems as they are the base of trophic networks and due to their small size and fast generation time they respond very quickly to environmental changes. The main goal of the session is to understand how microbial biofilms respond to climate change and their potential to act as early warning indicators of ecosystem health. This session calls for contributions on the effects of climate change on microbial aquatic biofilms, including microbial community composition, functional diversity, phenotypic microbial traits, biofilm functioning and physiological responses. Original field studies of biofilms across biogeographical regions, experiments that manipulate global-change-related variables, and modelling studies using microbial variables as proxies of ecosystem health are welcome. In an increasingly changing future, knowing how microbial communities – and their functions – respond to it will help us to predict the impacts of global change in freshwater ecosystems.

Andras Abonyi, WasserCluster Lunz, Austria
abonyiand@gmail.com
Evangelia Smeti, Hellenic Centre for Marine Research, Greece
Jana Isanta-Navarro, University of Montana, MT, USA
Robert Ptacnik, WasserCluster Lunz, Austria
Maria Stockenreiter, Ludwig-Maximilians-Universität Munich, Germany

Biodiversity enhances community resource use efficiency and ecosystem stability. This relationship has received increasing attention with recent decline in global biodiversity, fragmentation of habitats, and the more frequent dominance of invasive and harmful species. In this session, we aim to enhance communication among researchers working on different aspects of plankton biodiversity. We welcome presentations that combine any aspect of biodiversity (as causes) with effects on any of the various ecosystem functions (as consequences). Presentations may cover, but are not limited to 1) testing biodiversity-ecosystem functioning relationship (BEF) beyond primary production, addressing, for example, trophic transfer efficiency, biogeochemistry and stoichiometry; 2) mechanisms underlying community assembly and diversity under global change, considering, for example, the more frequent occurrence of harmful/invasive taxa in the context of BEF; 3) BEF studies considering historic and spatial effects (species pools). We invite presentations based on field observations, laboratory experiments, modelling studies, and conceptual work. We especially encourage talks that combine the effect of global environmental change and human impacts (e.g. warming, fragmentation, extreme events, regime shifts) with biodiversity or community assembly and corresponding alteration in ecosystem functioning.

Scott D.Tiegs, Oakland University, MI, USA
tiegs@oakland.edu
M. Eric Benbow, Michigan State University, MI, USA
Gwendoline David, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany
Mark Gessner, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany

Plant and animal remains comprise leaf litter and large wood as well as carcasses of both small arthropods and large vertebrates ranging from fish to mammals. While plant litter has been most thoroughly studied, the role of animal remains has also been increasingly recognized as an important component of carbon and nutrient cycling in streams and rivers, littoral zones of lakes, wetlands, and other ecosystems where land meets water. Even in pelagic systems of inland waters can this type of organic matter play a notable role. We invite contributions to this session that report results of experimental and theoretical studies on the dynamics of diverse types of plant litter and animal remains. This includes studies on inputs to inland waters, storage, transport, and the decomposition and use by microbes and detritivores, and how the structure of communities, species interactions, environmental conditions such as temperature, nutrient and oxygen supply, anthropogenic stressors and climate change affect these processes. The goal is to bring together researchers from diverse backgrounds. Spatial scales can range from specific sites to global. Conceptual contributions, meta-analyses and other syntheses are also all welcome.

 

Luciana Gomes Barbosa Federal University of Paraiba, PB, Brazil
lucianabarbosa@cca.ufpb
Rachel Stubbington, Nottingham Trent University, UK

Manuela Moraes
University of Evora, Portugal
Carlos Lopez
Polytechnic School of the Coast, Ecuador

Global climate change is expected to intensify drying in temporary freshwater ecosystems around the world, altering their biodiversity and functioning. Drying can cause biodiversity to decline, reducing the resilience of ecosystems facing climate change and other intensifying human pressures. These ecosystems—including temporary lakes, wetlands, rock pools, man-made reservoirs, ponds, rivers and streams—provide many ecosystem services, and understanding their biodiversity and functioning is thus critical to inform effective conservation and management strategies. This session will showcase the latest, most exciting limnological research exploring drying freshwaters. Our scope is broad, and we invite contributions regarding any type of drying freshwater ecosystem, from tiny ephemeral pools to the marginal sediments of large, perennial rivers. We will explore drying freshwaters from biological, biogeochemical, ecological, hydrological, physical and wider interdisciplinary perspectives, as well as recognizing these ecosystems as socioeconomic systems. A diverse range of drying freshwaters occur across all continents, and we seek to represent international advances made by scientists studying systems from hot, arid lands to cold, wet regions. As their extent increases in our changing world, our multidisciplinary session will show how collaboration between global scientists and managers is transforming our understanding of temporary freshwater ecosystems and thus our capacity to manage them effectively. Our ultimate goal is to unite scientists and managers who seek to safeguard biodiversity in drying inland freshwaters for the next 100 years.

K. Ali Ger, Federal University of Rio Grande do Norte, RN, Brazil
aligerger@gmail.com
Lisette N. De Senerpont Domis, Netherlands Institute of Ecology (NIOO/KNAW), The Netherlands

Plankton dominates the food web of many aquatic ecosystems and therefore regulates key ecosystem functions like material cycling and energy transfer. Given this role, it is likely that plankton contributes significantly to multiple ecosystem services such as food provision, water quality, and climate regulation. Yet, little is known about how plankton community structure or the ecosystem function of pelagic waters is associated with specific ecosystem services. Given that plankton communities are shifting in response to multiple global changes (e.g., climate, eutrophication, salinization), predicting the effects on ecosystem services is a timely and relevant topic. Thus, this session will showcase studies that highlight how plankton provide one or more of the ecosystems services as defined by the Millenium Ecosystem Assessment (i.e., supporting, regulating, provisioning and cultural), and how global change is expected to affect these services. We welcome contributions that span the full breadth of the freshwater domain, ranging from observational studies to modeling studies. We especially encourage early career scientist to apply, in recognition of the role of the next generation to the fast changing world.

Gudrun Bornette, CNRS, France
gudrun.bornette@univ-fcomte.fr
Charles Henriot, Université de Franche Comté, France

The session will open the debate on the relationship between the functioning of wetlands (including their trophic and physical functioning and the consequences on specific and functional biodiversity) and human and/or animal health. Impacts, conservation or restoration operations of wetlands rarely take this link into consideration, neglecting the possible consequences of mismanagement of these ecosystems. Furthermore, wetlands can contribute to reducing environmental risks related to pathogens, but studies on this topic remain scarce and rarely consider the ways in which wetland functioning may alter this reduction. The aim of the session is to take stock of this knowledge and to open the debate on the scientific issues related to these questions, which are particularly important in the context of global change.

Global Change

Núria Perujo, Helmholtz Centre for Environmental Research – UFZ, Germany
nuria.perujo-buxeda@ufz.de
Anna Freixa, Catalan Institute for Water Research (ICRA), Spain

Aquatic microorganisms have been affected – and will continue to be so – by global climate change and their responses are a growing concern for aquatic ecosystems. We understand global climate change as the set of climatic alterations in temperature and precipitation patterns as well as an increased frequency of extreme climate events. Microbial biofilms that develop on riverbed surfaces (i.e. sediments, cobbles, leaves, etc.) are key players of freshwater ecosystems as they are the base of trophic networks and due to their small size and fast generation time they respond very quickly to environmental changes. The main goal of the session is to understand how microbial biofilms respond to climate change and their potential to act as early warning indicators of ecosystem health. This session calls for contributions on the effects of climate change on microbial aquatic biofilms, including microbial community composition, functional diversity, phenotypic microbial traits, biofilm functioning and physiological responses. Original field studies of biofilms across biogeographical regions, experiments that manipulate global-change-related variables, and modelling studies using microbial variables as proxies of ecosystem health are welcome. In an increasingly changing future, knowing how microbial communities – and their functions – respond to it will help us to predict the impacts of global change in freshwater ecosystems.

 

Núria Catalán, Laboratoire des Sciences du Cimat et de l’Environement (LSCE-CNRS), France
ncatalangarcia@gmail.com
Warwick F. Vincent, Laval University, QC, Canada
Ada Pastor, Aarhus University, Denmark
Weidong Kong, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, China
Anne Kellerman, Florida State University, FL, USA
Rachael Morgan-Kiss, Miami University, OH, USA
Nicolas Valiente, University of Oslo, Norway
Laure Gandois, Laboratoire Ecologie Fonctionnelle et Environnement (UMR CNRS-UPS-INPT), France

Global climate change has focused attention on the cryosphere because of its sensitivity to warming. High latitude (Arctic and Antarctic) and high altitude (the ‘Third Pole’) environments are now the most rapidly warming regions of the world, with wide-ranging impacts on the cryosphere (glacier and ice sheet retreat, loss of ice-cover, permafrost thaw, snow to rain transformation) and associated landscape and hydrological processes (greening, thermokarst, runoff, water balance). The abundant lakes, rivers and wetlands in these regions are highly sensitive to all of these changes. Additionally, they encompass an enormous diversity of limnological conditions, including extreme environments and their associated biota that provide models for wider biogeochemical and ecological understanding. In this session, we aim to showcase studies on how climate-induced changes are affecting the structure and function of different types of aquatic ecosystems of polar and alpine sites, and analyses evaluating limnological similarities and differences among the Three Poles. Contributions will be welcome on topics such as biogeochemical cycling, ecosystem function, biodiversity, biogeography, sentinel taxa and food web ecology, with emphasis on climate impacts on polar and alpine aquatic ecosystems.

Luciana Gomes Barbosa Federal University of Paraiba, PB, Brazil
lucianabarbosa@cca.ufpb
Rachel Stubbington, Nottingham Trent University, UK

Manuela Moraes
University of Evora, Portugal
Carlos Lopez
Polytechnic School of the Coast, Ecuador

Global climate change is expected to intensify drying in temporary freshwater ecosystems around the world, altering their biodiversity and functioning. Drying can cause biodiversity to decline, reducing the resilience of ecosystems facing climate change and other intensifying human pressures. These ecosystems—including temporary lakes, wetlands, rock pools, man-made reservoirs, ponds, rivers and streams—provide many ecosystem services, and understanding their biodiversity and functioning is thus critical to inform effective conservation and management strategies. This session will showcase the latest, most exciting limnological research exploring drying freshwaters. Our scope is broad, and we invite contributions regarding any type of drying freshwater ecosystem, from tiny ephemeral pools to the marginal sediments of large, perennial rivers. We will explore drying freshwaters from biological, biogeochemical, ecological, hydrological, physical and wider interdisciplinary perspectives, as well as recognizing these ecosystems as socioeconomic systems. A diverse range of drying freshwaters occur across all continents, and we seek to represent international advances made by scientists studying systems from hot, arid lands to cold, wet regions. As their extent increases in our changing world, our multidisciplinary session will show how collaboration between global scientists and managers is transforming our understanding of temporary freshwater ecosystems and thus our capacity to manage them effectively. Our ultimate goal is to unite scientists and managers who seek to safeguard biodiversity in drying inland freshwaters for the next 100 years.

Erik Sperfeld, University of Greifswald, Germany
erik.sperfeld@uni-greifswald.de
Jason Stockwell, University of Vermont, VT, USA
Eleanor Jennings, Dundalk Institute of Technology, Ireland
Alexander Wacker, University of Greifswald, Germany

Interest in understanding the effects and consequences of environmental variability in abiotic and biotic drivers of change on ecological systems has grown in recent decades. This interest has arisen from a spectrum of observational scales – from growing concerns related to increases in the occurrence and frequency of climatic extremes to appreciation of the limits of using constant environmental conditions in experiments that naturally represent dynamic systems. Environmental variability may weaken or intensify the effects of antecedent environmental conditions on biological systems, and conversely, antecedent conditions may mitigate or exacerbate the effects of environmental variability. Hence, understanding the effects of such variability on the state of an ecosystem, and the potential cascading impacts on the physiology, demography and interactions of aquatic biota, is necessary for predicting the consequences of ongoing environmental change on aquatic communities, water quality, and ecosystem services. This session calls for contributions from across the range of approaches (theoretical, experimental, observational, and modeling) that can be used to investigate the effects of environmental variability and extremes on all aspects of freshwater ecosystems, from individual organisms to cross-lake system comparisons. Broadly defined, environmental drivers include seasonal or periodic fluctuations in temperature, oxygen, pH, light, nutrient supply, food quantity/quality, and disease, or extreme events such as droughts, heat waves, or storms. This session will offer a platform to share the most recent research and ideas in a topic area that is growing, but still underexplored, in aquatic ecology.

Jordi Catalan, CREAF – CSIC, Spain
j.catalan@creaf.uab.cat
Fengzhi He, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany
Leopold Füreder, University of Innsbruck, Austria
Xiling Deng, Senckenberg Research Institute and Natural History Museum, Frankfurt, Germany
Sonja Jähnig, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany
Sami Domisch, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany
Davnah Urbach, Global Mountain Biodiversity Assessment, Switzerland

Life in high-mountain waters remains understudied despite that these ecosystems experience rapid environmental change, including warming, altered precipitation regimes, and increasing human activities. Most previous studies focusing on high-mountain streams were conducted in Europe and North America. Our knowledge of biodiversity in high-mountain aquatic ecosystems at a global scale, their importance, and their vulnerability to global change remains limited. This session aims to bring together scientists focusing on different subdisciplines of limnology to evaluate the status, trends, and drivers of change in aquatic biodiversity in high-mountain regions. Following Global Mountain Biodiversity Assessment working group priority themes, contributions are expected to: identify changes in and threats to biodiversity across the planet; provide long-term monitoring guidelines; and discuss strategies for conservation, restoration, and sustainable management of high-mountain aquatic ecosystems. Presentations will highlight innovations in biodiversity research (e.g., eDNA), including genetic, taxonomic, and functional facets, and conservation of high-mountain aquatic ecosystems. Studies across taxonomic groups (from microbe to vertebrates), habitats (e.g., lakes, streams, and wetlands), small and large areas, and temporal scales (e.g., paleolimnology, future scenarios) are welcome together with experimental and observational approaches that enhance the knowledge and understanding of the high-mountain aquatic biodiversity under global change. We expect a diverse group of scientists to contribute to this session, presenting their research on high-mountain aquatic biodiversity from different regions worldwide. The session will provide an excellent platform to extend global research networks focusing on biodiversity in high-mountain aquatic ecosystems.

Simon Belle, Swedish University of Agricultural Sciences, Sweden
simon.belle@slu.se
Carsten Meyer-Jacob, Queen’s University, OT, Canadameyer-jakob
Hucai Zhang, Yunnan University, China
Cheng Zhao, Nanjing University, China
Frank Riedel, Freie Universität Berlin, Germany

Arctic and alpine ecosystems are experiencing rapid and extensive changes driven by accelerated climate warming, which alters run-off patterns, biogeochemical cycles, and biodiversity dynamics, potentially triggering cascading effects at regional and global scales. Understanding how Arctic and alpine ecosystems were affected by climate change in the past is key to understanding how these sensitive environments will respond to projected climate change in the future. Long-term datasets – from monitoring to paleolimnological studies – provide unique insights into paleoclimate variability, evaluate the effects of long-range transport of pollutants, and track ecological changes that are not evident over shorter time periods. This session aims to share and discuss new crucial scientific knowledge related to climate-induced changes in arctic and alpine ecosystems and identify future key research questions. We invite contributions related to long-term monitoring and paleolimnology of Arctic and alpine freshwaters aiming to explore the complexity of ecosystem responses to climate change and other anthropogenic stressors, and provide insights into future trajectories of Arctic and alpine ecosystems.

 

Pieter Lemmens, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany; KU Leuven, Belgium
pieter.lemmens@kuleuven.be
Biljana Rimcheska, Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, Bulgaria
Lena Fehlinger, WassercLuster Lunz, Austria
Sandra Brucet, Universitat Central de Catalunya and Catalan Institution for Research and Advanced Studies (ICREA), Spain

Ponds are the most numerous freshwater ecosystems on Earth. They are important habitats for aquatic biodiversity, provide vital ecosystem services, and are key elements of blue landscape connectivity. Ponds can also play a pivotal role in mitigating and adapting to global change. Despite their importance, ponds are mostly neglected in current policies and conservation programs. This is surprising since ponds are increasingly exposed to multiple anthropogenic stressors that undermine their ecological integrity and related ecosystem services, including social, environmental and economic aspects. Understanding how land-use intensity, connectivity and the ecological quality of ponds in landscapes feeds back to exacerbate or ameliorate local and regional anthropogenic impacts is crucial for the development of effective conservation strategies that aim to enhance the capacity of ponds to increase resistance and resilience to global change. The overarching aim of this session is to obtain a holistic picture of current research by synthesizing knowledge on how ponds and their biota respond to global change, how this translates in effects on ecosystem services, how local scale processes interact with regional landscape scale processes, and how management strategies can improve the capacity of ponds to mitigate and adapt to global change. We explicitly aim to interconnect early career researchers in fundamental research, approaches of citizen science, conservation and restoration management.

Human-Freshwater Relationships

Karsten Rinke, Helmholtz Centre for Environmental Research – UFZ, Germany
karsten.rinke@ufz.de
Karl-Erich Lindenschmidt, University of Saskatchewan, SK, Canada
David Hamilton, Australian Rivers Institute, Griffith University, QLD, Australia

Many studies on climate change impacts predict signifcant changes for lakes and reservoirs with respect to physical and thermal structure, biogeochemical processing and ecosystem dynamics. Therefore, we are facing a growing demand (and pressure) to develop adaptation strategies. Reservoirs offer flexible operational options and ongoing changes in climate and catchment structure require adaptive management in order to fulfil the multiple purposes they are needed for. Even more, the services from reservoirs will most likely be more important in a warmer world and the expectations on their service-provisioning will rise. This leads to a situation where, on the one hand, ecosystem services of reservoirs are increasingly demanded and exploited but, on the other hand, the safe operating space for the ecological integrity of reservoirs and their upstream/downstream river networks will shrink. This session is intended to explore the expected risks, potential adaptation strategies as well as new approaches to monitoring, forecasting, and adaptive management.

Renske Vroom, Radboud University, The Netherlands
renske.vroom@ru.nl
Sarian Kosten, Raboud University, The Netherlands

Humans are excellent ecosystem engineers and have historically modified and created water bodies to serve their manifold needs. This includes food production, water storage, energy production and modifications for recreational use. Human alterations of freshwater systems drastically affect hydrology and carbon cycling. These systems, from which emissions can be exceptionally high, have been estimated to contribute more than half of the global methane emissions. In addition, they increasingly contribute to global nitrous oxide emissions. These ecosystems often receive high amounts of carbon and nutrients, resulting in the accumulation of anoxic, methanogenic sediments and the establishment of conditions favourable for greenhouse gas production. The global areal extent of human-made freshwater systems is expected to increase due to urbanization and the demand for alternative food and energy sources. Moreover, sedimentation rates and greenhouse gas emissions are enhanced by eutrophication and climate feedbacks. However, greenhouse gas emissions from these systems remain understudied and this hampers accurate incorporation in global emission estimates. A better understanding of carbon cycling in human-made freshwater systems is also essential for construction and management strategies that effectively minimize greenhouse gas emissions. For this session, we invite speakers working on greenhouse gas emissions and carbon burial in human-made freshwater systems, including aquaculture ponds, urban and agricultural artificial water bodies, and reservoirs.

K. Ali Ger, Federal University of Rio Grande do Norte, RN, Brazil
aligerger@gmail.com
Lisette N. De Senerpont Domis, Netherlands Institute of Ecology (NIOO/KNAW), The Netherlands

Plankton dominates the food web of many aquatic ecosystems and therefore regulates key ecosystem functions like material cycling and energy transfer. Given this role, it is likely that plankton contributes significantly to multiple ecosystem services such as food provision, water quality, and climate regulation. Yet, little is known about how plankton community structure or the ecosystem function of pelagic waters is associated with specific ecosystem services. Given that plankton communities are shifting in response to multiple global changes (e.g., climate, eutrophication, salinization), predicting the effects on ecosystem services is a timely and relevant topic. Thus, this session will showcase studies that highlight how plankton provide one or more of the ecosystems services as defined by the Millenium Ecosystem Assessment (i.e., supporting, regulating, provisioning and cultural), and how global change is expected to affect these services. We welcome contributions that span the full breadth of the freshwater domain, ranging from observational studies to modeling studies. We especially encourage early career scientist to apply, in recognition of the role of the next generation to the fast changing world.

Michio Kumagai, Ritsumeikan University, Japan
mkt24354@se.ritsumei.ac.jp
Ryusuke Kimitsuki, University of Alberta, AB, Canada

Due to the rapid changes in society and global climate, we urgently need to prepare for near-term future risks, including severe ecosystem degradation as well as natural catastrophes. In this session, we are calling for young people (such as high school or university students) to join us and have the opportunity to openly discuss with senior scientists on how and what we can do to contribute to save our hydrosphere and its associated biodiversity and ecosystem services. Presentations referring to diverse global water issues and solutions are welcome. We will cover diverse problems including microplastics pollution, endangered species, eutrophication, floods and water shortages. The session will include talks on ideas about potential solutions to these problems, towards the overall objective of keeping our planet safe for future generations.

Sandra Poikane, EC Joint Research Centre , Italy
sandra.poikane@ec.europa.eu
Ken Irvine, IHE-Delft, The Netherlands
Bryan Spears, UK Centre for Ecology & Hydrology, UK
Stuart Warner, United Nations Environment Programme, Ireland

New sustainability ambitions are upon us, yet, our approach to managing freshwater ecosystems remains stuck in the past. Emerging international policy initiatives (e.g., the UN Sustainable Development Goals (SDGs) & Decade on Restoration; European Green Deal & Biodiversity Strategy 2030) call for a widening of the lens on freshwater management beyond the control of biophysical stressors and ecological responses to include sustainability- and use-based benefits (e.g., inclusivity, net zero carbon, and socio-economic gains). To achieve this will require improvements and coordination of target setting, design and implementation of restorative and preventative measures, and monitoring and assessment systems from catchment to global scales. Monitoring systems are lacking in some countries as are targets for historical (e.g., nutrient pollution) and novel pressures (climate change, digital economy wastes, etc.). There is an urgent need to understand the relationships between biophysical and ecological processes with wider sustainability indicators, accounting for social and economic ambitions and international commitments. This is essential to support countries as they develop sustainability-based monitoring and assessment systems for the first time, for example, as required by the UN SDG 6.3.2. This session will share international experiences on the development of sustainable freshwater management programmes. We welcome real-life critical evaluations of past successes and failures as well as new perspectives on enhancing sustainable freshwater management to meet the challenges and ambitions of the 21st Century. This session is supported by the UNEP coordinated World Water Quality Alliance Workstream on Ecosystem Restoration in partnership with the SIL Working Group on Lake Restoration.

Pieter Lemmens, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany; KU Leuven, Belgium
pieter.lemmens@kuleuven.be
Biljana Rimcheska, Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, Bulgaria
Lena Fehlinger, WassercLuster Lunz, Austria
Sandra Brucet, Universitat Central de Catalunya and Catalan Institution for Research and Advanced Studies (ICREA), Spain

Ponds are the most numerous freshwater ecosystems on Earth. They are important habitats for aquatic biodiversity, provide vital ecosystem services, and are key elements of blue landscape connectivity. Ponds can also play a pivotal role in mitigating and adapting to global change. Despite their importance, ponds are mostly neglected in current policies and conservation programs. This is surprising since ponds are increasingly exposed to multiple anthropogenic stressors that undermine their ecological integrity and related ecosystem services, including social, environmental and economic aspects. Understanding how land-use intensity, connectivity and the ecological quality of ponds in landscapes feeds back to exacerbate or ameliorate local and regional anthropogenic impacts is crucial for the development of effective conservation strategies that aim to enhance the capacity of ponds to increase resistance and resilience to global change. The overarching aim of this session is to obtain a holistic picture of current research by synthesizing knowledge on how ponds and their biota respond to global change, how this translates in effects on ecosystem services, how local scale processes interact with regional landscape scale processes, and how management strategies can improve the capacity of ponds to mitigate and adapt to global change. We explicitly aim to interconnect early career researchers in fundamental research, approaches of citizen science, conservation and restoration management.

Sabine Hilt, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany
sabine.hilt@igb-berlin.de
Soren Brothers, Royal Ontario Museum, OT, Canada
Claire Oswald, Ryerson University, OT, Canada

With half of the world’s population living in cities already today, urbanization is further increasing worldwide. Man-made channels, ponds and other artificial water bodies complement natural aquatic ecosystems in urban areas such as streams and rivers, lakes and groundwater. These urban water bodies provide important ecosystem services. At the same time, they are subject to strong human influences, specifically by massive hydromorphological modifications, chemical pollution, nutrient enrichment, elevated temperatures, noise, artificial light at night and the facilitation of species invasions. Urban waters can thus be viewed as hotspots of global environmental change. Understanding the response of urban inland waters to these multiple stressors is an ongoing challenge. One of the recent research foci are the interfaces between components, subsystems or compartments of the urban water system as a whole. Such interfaces exist at multiple spatial scales, ranging from micrometres in biofilms to metres in drinking water wells, or kilometers in treated wastewater channels linking sewage plants and receiving streams. Major hydrological, biogeochemical and biological processes such as bank filtration, nutrient transformations, benthic primary production or greenhouse gas emissions are located at these interfaces and are potentially affected by the multiple stressors characterizing urban environments. This session invites presentations on responses of urban inland waters to global change. Contributions can span from individual processes or species to communities and ecosystems. The goal is to contribute to an integrative analysis, understanding and modelling of urban inland waters to improve sustainable water resource and ecosystem management in urban areas.

Gudrun Bornette, CNRS, France
gudrun.bornette@univ-fcomte.fr
Charles Henriot, Université de Franche Comté, France

The session will open the debate on the relationship between the functioning of wetlands (including their trophic and physical functioning and the consequences on specific and functional biodiversity) and human and/or animal health. Impacts, conservation or restoration operations of wetlands rarely take this link into consideration, neglecting the possible consequences of mismanagement of these ecosystems. Furthermore, wetlands can contribute to reducing environmental risks related to pathogens, but studies on this topic remain scarce and rarely consider the ways in which wetland functioning may alter this reduction. The aim of the session is to take stock of this knowledge and to open the debate on the scientific issues related to these questions, which are particularly important in the context of global change.

Limnology in Society and History

Michio Kumagai, Ritsumeikan University, Japan
mkt24354@se.ritsumei.ac.jp
Ryusuke Kimitsuki, University of Alberta, AB, Canada

Due to the rapid changes in society and global climate, we urgently need to prepare for near-term future risks, including severe ecosystem degradation as well as natural catastrophes. In this session, we are calling for young people (such as high school or university students) to join us and have the opportunity to openly discuss with senior scientists on how and what we can do to contribute to save our hydrosphere and its associated biodiversity and ecosystem services. Presentations referring to diverse global water issues and solutions are welcome. We will cover diverse problems including microplastics pollution, endangered species, eutrophication, floods and water shortages. The session will include talks on ideas about potential solutions to these problems, towards the overall objective of keeping our planet safe for future generations.

Clara Mendoza-Lera, University of Koblenz-Landau, Germany
mendozalera@uni-landau.de
Anna Lupon, Center for Advanced Studies of Blanes (CEAB-CSIC), Spain
Núria Catalán, Laboratoire des Sciences du Cimat et de l’Environement (LSCE-CNRS), France
Nina Schlotz, Technische Universität Berlin, Germany

The study of freshwaters is full of passionate and fascinating women, who have made vast contributions to our current understanding of freshwater ecosystems. Today, women represent more than half of the total limnologists in training and at early-career stages. However, as in many other scientific disciplines, far fewer women are full professors or are leading research departments and academic institutions. In this session, we aim to raise awareness on the importance of gender equity for the freshwater community, and particularly on the role of women in limnology. We welcome contributions that discuss key vulnerabilities that challenge women’s careers in freshwater ecology, and that identify activities, strategies and solution-based approaches promoting visibility and participation of women at all career stages. Improving the inclusivity of women in freshwater sciences is critical to meet environmental challenges based on different perspectives as well as to progress towards a safer and healthier scientific community.

Elisabeth I. Meyer, University of Münster, Germany
meyere@uni-muenster.de
Astrid Schwarz, Brandenburg University of Technology Cottbus-Senftenberg, Germany

This special session explores the early history of the Societas Internationalis Limnologiae (SIL). “What actually is limnology” was the question that would finally lead to the foundation of SIL. The initial impetus goes back to the early 1920s, when Einar Naumann and August Thienemann got involved in a momentous correspondence that resulted in a highly productive scientific program, which is still ongoing today. We invite to this session contributions dedicated to persons and places, visions and theories, methods and objects in the early period of limnology, which from the beginning was an international and interdisciplinary endeavor. Furthermore, we welcome contributions focusing on the social, political and national contexts of activities in and on aquatic environments in the first half of the 20th century, such as the economics of fish ponds, running waters as receiving streams, or the eco-sociological potential of dams. Questions that might be addressed include: What were the drivers that gave rise to the foundation of a limnological society? Which of the early scientific topics of SIL have persisted until today? To what extent have these topics shaped contemporary discussions about philosophical issues, such as the holism debate? In which ways did technological advances influence activities and developments in limnology?

Methodology

Karsten Rinke, Helmholtz Centre for Environmental Research – UFZ, Germany
karsten.rinke@ufz.de
Karl-Erich Lindenschmidt, University of Saskatchewan, SK, Canada
David Hamilton, Australian Rivers Institute, Griffith University, QLD, Australia

Many studies on climate change impacts predict signifcant changes for lakes and reservoirs with respect to physical and thermal structure, biogeochemical processing and ecosystem dynamics. Therefore, we are facing a growing demand (and pressure) to develop adaptation strategies. Reservoirs offer flexible operational options and ongoing changes in climate and catchment structure require adaptive management in order to fulfil the multiple purposes they are needed for. Even more, the services from reservoirs will most likely be more important in a warmer world and the expectations on their service-provisioning will rise. This leads to a situation where, on the one hand, ecosystem services of reservoirs are increasingly demanded and exploited but, on the other hand, the safe operating space for the ecological integrity of reservoirs and their upstream/downstream river networks will shrink. This session is intended to explore the expected risks, potential adaptation strategies as well as new approaches to monitoring, forecasting, and adaptive management.

Marco Cantonati, MUSE – Museo delle Scienze, Italy
marco.cantonati@muse.it
Kalina Manoylov, Georgia College, GA, USA

The monitoring and assessment of inland water quality based on benthic algae has become an important element of the methodological toolkit adopted by water authorities and in limnological research. The topic is particularly timely now that such environmental assessments are sparking growing interest worldwide and discussions and revisions of methods and procedures have been initiated. The integration of metagenomic methods into the established approaches is a particularly important development. We invite contributions to the session on all aspects of inland water assessments and monitoring based on benthic algae, continuing a long tradition of international symposia on the use of algae for monitoring rivers and comparable habitats. Thus, the session will provide an opportunity to review and discuss algae-based monitoring in different countries around the globe, as well as improvements to methods and techniques, their use in the implementation of legislation and regulations, and the discussion of novel approaches. We consider assembling a set of selected solicited or unsolicited papers presented at the session for publication in a special issue of an international journal, as has been the case in previous symposia organized on the topic.

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Xiufeng Zhang, Jinan University, China
wetlandxfz@163.com
Lars Rudstam, Cornell University, NY, USA

The goal of many biomanipulations is to reduce the abundance of planktivorous fish, either by addition of piscivorous fish or by manually removing or reducing the biomass of undesired fish. The method was originally intended to reduce grazing pressure on zooplankton, thereby increasing grazing pressure on phytoplankton by zooplankton, especially Daphnia, to increase water clarity and promote the growth of aquatic macrophytes. Biomanipulation has become a commonly used technique for improving water quality of lakes and reservoirs after external nutrient load reduction. From a management point of view, biomanipulation is likely to be most successful in the long term in shallow eutrophic lakes. With decades of successful applications as a method for lake restoration, its popularity is increasing in the Northern Hemisphere. However, the effectiveness is questionable in tropical and subtropical regions because Daphnia are less abundant and planktivorous fish may be omnivores and can produce eggs all year round making them harder to control. In addition, large phytoplankton in some eutrophic conditions are difficult to handle by the zooplankton, including Daphnia. Furthermore, in the scenario of global climate warming, biological invasion and the enhancing human activities, the percentage of omnivorous fish increases, which may lead to reduced control of zooplankton on phytoplankton. So, the success of biomanipulation may be challenged also in the temperate zone. In this special session we wish to promote cross-continent comparisons of grazing manipulation-based biotechnology for restoration of eutrophic waters. We encourage contributions discussing results from field studies, experiments, models, and theoretical analyses.

Natacha Tofield-Pasche, EPFL, Switzerland
natacha.tofield-pasche@epfl.ch
Bastiaan Ibelings, University of Geneva, Switzerland

Automated buoys are deployed in many lakes worldwide to collect and transmit an increasingly wide array of data acquired by sensors. Floating platforms have the added advantage of providing safe, dry and weather-protected working conditions, and allow installing laboratory instrumentation directly on the lake. Such automatic data collection has been shown to promote interdisciplinary lake studies with complementary measurements at high vertical and temporal resolution. More and more the integration of these in-situ lake data are being paired with and complemented by remote sensing. As an example of a floating laboratory providing access to different disciplines, we cite LéXPLORE (www.lexplore.info) a partnership of five academic institutions constructed a multipurpose platform for a broad range of scientific investigations on Lake Geneva (France, Switzerland). The scope of this session is to explore scientific investigations based on data collected at high-frequency with automatic buoys or floating platforms. One goal is to learn valuable lessons of established buoys and pioneering platforms, in order to promote such infrastructure elsewhere. Examples of research topics that have benefitted from the collection of diverse types of lake data, thus promoting a deeper understanding across disciplines in natural sciences, are lake gas exchange dynamics, carbon cycling, remote sensing, plankton dynamics, including blooms of toxic cyanobacteria or fish recruitment. Such infrastructure should be part of the next 100 years of sensing and safeguarding lake ecosystems.

Marco Toffolon, University of Trento, Italy
marco.toffolon@unitn.it
Robert Ladwig, University of Wisconsin-Madison, WI, USA
Samantha K. Oliver, U.S. Geological Survey, WI, USA
Sebastiano Piccolroaz, University of Trento, Italy
Tom Shatwell, Helmholtz-Centre for Environmental Research – UFZ, Germany

Smart monitoring technologies have seen a thriving development in the last decades. Earth observation is providing freely usable data at increasingly higher spatial and temporal resolution. Low-cost computational power has supported the use of brute force in the application of complex algorithms. Because of this, in general we are observing a shift of paradigm towards the development and application of data-driven models and hybrid mechanistic-statistical models, which require data for their training and validation. This is true for all fields of environmental science, including limnology, where the rising availability of high-quality data of different type and nature allows the application of models to an extent that was hardly imaginable before. Overall, the emerging field of theory-guided data science brings exciting novel research opportunities and applications, but the question remains: What is the perspective for the future? The session welcomes contributions dealing with the development and application of models of different type (e.g., machine-learning, statistical, deterministic, hybrid, etc.) using a variety of data (e.g., remote sensing, high-frequency data) in the field of limnology (e.g., lakes, ponds, lagoons, reservoirs, rivers, groundwater), with a particular focus on data-driven models and on the synergy between data science and modeling.

Alexander H. Frank, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany
alexander.frank@igb-berlin.de
Tobias Goldhammer, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany

Stable isotope signatures of the light elements CHNOS are well-established tracers for biologically mediated processes and functions in aquatic ecosystems and can be applied on different levels of ecological organization. Recently, the advent of more accessible analytical capabilities, as well as facilitation of sample preparation, have expanded the scope of target phases, molecules, and processes being monitored with increased coverage, enabling improved interpretation than previously possible. In this session, we showcase recent advances in the application of stable isotope signatures of CHNOS that have paved the way to unprecedented insights into key processes and their drivers in freshwater ecosystems. Examples include, but are not limited to photosynthesis and primary productivity, food webs and energy flow in trophic networks, organic matter turnover, and nutrient dynamics, novel biomarkers, and contamination problems such as microplastics.

 

Cécilia Barouillet, INRAE UMR CARRTEL, France
cecilia.barouillet@gmail.com
Laura Epp, University of Konstanz, Germany
Ebuka Nwosu, GFZ Helmholtz Center Postdam, Germany
Eric Capo, ICM-CSIC, Spain

The sedimentary DNA approach is rapidly evolving, opening new avenues to the field of aquatic ecology and paleoecology. In the context of freshwater habitats, molecular archives have allowed us to give a broad perspective about biological change, and new insights into ecosystem functioning, food-web dynamics and biodiversity of aquatic ecosystems over long time scales (i.e. centennial to millennial). Moreover, sedimentary DNA-based methods represent innovative ways towards the reconstruction of full trophic networks. In this session, we invite contributions from scientists applying the sedimentary DNA approach to study past changes in freshwater ecosystems. The goal of this session is to provide an overview of the research conducted in the field by using various sedimentary DNA techniques (e.g. qPCR, DNA metabarcoding, shotgun sequencing, hybridization capture) and diverse sites in order to demonstrate how the approach can help improve our understanding of the long-term dynamics of freshwater habitats in a complex multi-stressor world (e.g. eutrophication, invasive species, catchment alteration). We especially encourage presentations that provide insights into how information gained through sedimentary DNA research can help to improve freshwater management and conservation issues related to human-induced stressors in the context of climate change.

Abolfazl Irani Rahaghi, Eawag, Switzerland
abolfazl.irani@eawag.ch
Tiit Kutser, University of Tartu, Estonia

During the first one hundred years the limnological research has been predominantly based on in situ sampling in a limited number of waterbodies. Broadening of research problems (climate change, global carbon cycle, etc.) as well as technological advances in the last decades (automated buoy systems; airborne, surface and underwater drones, etc.) opened new possibilities for inland water research and monitoring. The launch of Sentinel satellites in the frame of the Copernicus Programme opened a new era in satellite remote sensing – moving from one-off scientific missions to long-term monitoring with confirmed funding for decades to come. Advancements in numerical modelling allow better understanding of the processes in inland waterbodies. On the other hand, they allow limnological research and monitoring to reach a new level where remote sensing, in situ data, and modelling are merged like in operational climate and weather services. This session aims at presenting the latest achievements in inland water remote sensing and integrated use of in situ data, remote sensing, and models. In particular, we invite contributions that demonstrate the development and employment of remote sensing for limnological research and monitoring as well as in investigating the underlying physical and biological processes by means of model simulations. This session will also provide researchers a chance to shape the future of Copernicus inland water services as the outcomes will be used in preparing a Roadmap for Future Copernicus Water Services that is to be developed in the future.

Jens Nejstgaard, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany
jens.nejstgaard@igb-berlin.de
Stella Berger, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany
Maria Stockenreiter, Ludwig-Maximilians-Universität Munich, Germany
Lisette de Senerpont Domis, Netherlands Institute of Ecology (NIOO-KNAW), The Netherlands
Meryem Beklioğlu, Middle East Technical University, Turkey
Paraskevi Pitta, Hellenic Centre for Marine Research, Greece
Robert Ptacnik, WasserCluster Lunz, Austria

Global climate change and other anthropogenic pressures have major impacts on our ecosystems, resulting in new challenges, requiring new scientific strategies. These strategies need to go beyond the classical scientific approaches. As such, they do not only need to yield understanding of ecosystem functioning and allow to predict future responses to increased anthropogenic forcing, but also need to actively suggest and test possible solutions to mitigate these pressures. Only then it is possible to take solution-oriented action for the prevention or restoration of negatively impacted ecosystems. Such new approaches include nature-based solutions and environmental engineering. Mesocosm studies allow for the required upscaling to gain complexity, closeness to nature and assessment of feasibility of solutions. We also propose that optimizing use of already collected data and collaboration across domains would boost the advancement of aquatic sciences. This session invites contributions ranging from curiosity driven basic experimental studies of aquatic ecosystems, modelling of such data, and presentations of novel approaches and experiments to actively mitigate negative effects on all types of aquatic systems, in celebration of the 100-yr anniversary of SIL. Since international networking between early career scientists is important to build tomorrows’ science, -with collaboration being the cornerstone of excellent mesocosm-based science-, we encourage students and early career scientists to present results and ideas to promote future collaboration. Such partnerships could be realized in open networks and funding possibilities such as the AQUACOSM-plus transnational Activities (www.aquacosm.eu). Please join us to look for truly new solutions, beyond our traditional borders.

Microbes in Inland Waters

Christopher Bellas, University of Innsbruck, Austria
christopher.bellas@uibk.ac.at
Ruben Sommaruga, University of Innsbruck, Austria

Viruses are a major component of aquatic ecosystems and they probably infect all living organisms. Recent studies have detected several new groups of viruses in lakes and rivers, demonstrating that we still do not know their full diversity and the implications of virus infection for freshwater bacterial and microeukaryotic populations. This session aims to discuss the diversity, function, and impact of viruses in the planktonic and benthic realm of freshwater ecosystems. Some outstanding questions we would like to discuss are: Do freshwater environments harbour novel groups of viruses? Do lakes have similar or identical virus communities? How do viruses influence the fate of their host populations?

Christian Wurzbacher, Technical University of Munich, Germany
c.wurzbacher@tum.de     

Maiko Kagami,Yokohama National University, Japan

Our environment is constantly changing with freshwater ecosystems being highly sensitive to the multiple stressors of global change. These changes can have profound effects on aquatic life. Rather unknown in this context are aquatic fungi, which are very important as parasites and saprophytes for some aquatic food webs. While we are still struggling to capture their biodiversity in the freshwater ecosystems, their original niches are already changing. This can lead to invasions, extinctions, parasite-host mismatches and other changes in fungal populations. This session welcomes all contributions that address aquatic fungi, their biodiversity and niches, and how their ecology may be affected by global change in the future. This could include zoosporic fungi, yeasts, aquatic hyphomycetes or endophytes and how they respond to, for example, increasing temperatures, habitat degradation, shifting host ranges, trace organic chemicals or pollution.

Núria Perujo, Helmholtz Centre for Environmental Research – UFZ, Germany
nuria.perujo-buxeda@ufz.de
Anna Freixa, Catalan Institute for Water Research (ICRA), Spain

Aquatic microorganisms have been affected – and will continue to be so – by global climate change and their responses are a growing concern for aquatic ecosystems. We understand global climate change as the set of climatic alterations in temperature and precipitation patterns as well as an increased frequency of extreme climate events. Microbial biofilms that develop on riverbed surfaces (i.e. sediments, cobbles, leaves, etc.) are key players of freshwater ecosystems as they are the base of trophic networks and due to their small size and fast generation time they respond very quickly to environmental changes. The main goal of the session is to understand how microbial biofilms respond to climate change and their potential to act as early warning indicators of ecosystem health. This session calls for contributions on the effects of climate change on microbial aquatic biofilms, including microbial community composition, functional diversity, phenotypic microbial traits, biofilm functioning and physiological responses. Original field studies of biofilms across biogeographical regions, experiments that manipulate global-change-related variables, and modelling studies using microbial variables as proxies of ecosystem health are welcome. In an increasingly changing future, knowing how microbial communities – and their functions – respond to it will help us to predict the impacts of global change in freshwater ecosystems.

Rebecca North, University of Missouri, MO, USA
northr@missouri.edu
Mindy Morales, University of Vermont, VT, USA

The world-wide increase in frequency, biomass, duration, and distribution of cyanobacteria harmful algal blooms (cyanoHABs) suggests conditions are becoming more favorable for their growth. Eutrophication is the most parsimonious explanation; increased nutrients are fertilizing phytoplankton and allowing cyanobacteria- superior competitors- to “win.” In remote regions, however, increasing incidences of cyanoHABs are seemingly disconnected from nutrient inputs. We are finding cyanobacteria at unexpected times (e.g., winter) and places (e.g., oligotrophic lakes). We also find weak relationships between traditional water quality parameters and cyanotoxin concentrations. The goal of this session is to explore alternative drivers of cyanoHABs and their toxins. We encourage contributions that extend the traditional nutrient-focused understanding of cyanoHAB ecology. Contributions can include studies at the field scale, lab, modelling, and predictive studies, which investigate both basic and applied research questions related to freshwater cyanoHABs in a range of study systems including lakes, reservoirs, streams, rivers, estuaries, and ponds. Contributions should encourage us to remove our nutrient-centric blinders and question assumptions of when and where to expect cyanoHABs and associated cyanotoxins.

Julia Reiss, University of Roehampton, UK
julia.reiss@roehampton.ac.uk

Free-living freshwater bacteria are ubiquitous in freshwater systems all over the world and a main driver of ecosystem processes such as organic matter decomposition. They are a basal food source in the microbial food web and an important component fuelling freshwater food webs as a whole. There is now a growing body of literature that recognizes the ecological importance of freshwater bacteria and the highly context-specific dynamics of bacterial species and communities in response to grazing and abiotic factors such as micro-pollutants and temperature. This session will bring together researchers working on a wide range of topics relating to bacteria, including topics traditionally explored by biomedical scientist (e.g. effects of antibiotics), with a strong focus on implications for freshwater ecosystems.

Man Xiao, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, China
m.xiao@griffith.edu.au
David Hamilton, Australian Rivers Institute, Griffith University, QLD, Australia
Michele Burford, Australian Rivers Institute, Griffith University, QLD, Australia

Cyanobacteria are ubiquitous in aquatic ecosystems, irrespective of nutrient concentrations. Recent studies have shown that they can grow and even form blooms when concentrations of dissolved inorganic phosphorus and/or nitrogen are below analytical detections limits. Succession or adaptation of species to low and varying phosphorus and nitrogen availability allows for a continuity of growth and reproduction by cyanobacteria. In this session we will explore understanding of the different strategies adopted by cyanobacterial species and strains to nutrient limitation. We will review new tools and developments, from molecular scale to ecological model simulations, that can inform our rapidly evolving understanding of nutrient limitation in cyanobacteria. Of particular interest will be how cyanobacteria adapt to phosphorus and nitrogen deficiency, utilisation of organic phosphorus and atmospherically fixed nitrogen, including the energy requirements for these processes, and how to scale results from laboratory cultures to the field. We seek to explore the eco-evolutionary mechanisms that have led to cyanobacterial diversification, its contribution to population maintenance, and its importance in limiting the applicability of laboratory culture studies. This session will further explore how understanding the strategies of cyanobacteria to circumvent phosphorus and nitrogen limitation is critical for understanding the limitations of nutrient control for cyanobacteria bloom control and mitigation.

Xuexiu Chang, University of Windsor, OT, Canada
xchang@uwindsor.ca
Rainer Kurmayer, University of Innsbruck, Austria

Cyanobacterial harmful algal blooms (cHABs) are infamous for their adverse impacts on water quality and human health, which is caused by the many bioactive metabolites that cHABs produce including well-known toxins such as microcystins, anatoxin-a and saxitoxins. However, the impact that lesser known metabolites have on other organisms is poorly understood. Their benefit for ecological fitness and ecological diversification in cHAB communities is not yet understood. Molecular tools enable studying populations or communities focusing on genotypes with and without the genes for the production of specific metabolites relative to conditions for their growth and dominance. Our aim with this session is to collate the current state of knowledge from this novel research on the genetic basis of cyanotoxins and ecology. This session welcomes presentations that contribute to elucidating factors impacting the genetic regulation of cyanobacterial bioactive metabolites and their possible role on the ecological or evolutionary success of genotypes in cHAB communities.

Multiple Stressors

Ralf Schulz, University Koblenz-Landau, Germany
schulz@uni-landau.de
Pablo Urrutia Cordero, Lund University, Sweden
Andreas Lorke, University of Koblenz-Landau, Germany
Alessandro Manfrin, University of Koblenz-Landau, Germany
John Strand, Hushållningssällskapet Halland, Sweden
Björn Klatt, Hushållningssällskapet Halland and Lund University, Sweden

The close connection between aquatic ecosystems and adjacent terrestrial land has been a long-standing paradigm of limnological research. Existing concepts, however, mainly focus on the terrestrial input into freshwater ecosystems and the consequences for aquatic life. The flux of resources and pollutants from aquatic to terrestrial systems has been less studied. Recently intensified research revealed that material fluxes mediated, e.g., by emerging insects and hydrological connectivity, are of high ecological relevance, particularly for the receiving ecosystem including ecosystem services. In addition, these fluxes are increasingly affected by anthropogenic and climatic stressors, such as micropollutants, toxic cyanobacterial blooms, invasive species, and hydrological alterations. The session invites contributions from all aspects of resource and stressor transfer from aquatic to terrestrial ecosystems. We also invite contributions that assess the vulnerability of terrestrial systems to alterations of these fluxes by stressors acting on inland waters.

Erik Sperfeld, University of Greifswald, Germany
erik.sperfeld@uni-greifswald.de
Jason Stockwell, University of Vermont, VT, USA
Eleanor Jennings, Dundalk Institute of Technology, Ireland
Alexander Wacker, University of Greifswald, Germany

Interest in understanding the effects and consequences of environmental variability in abiotic and biotic drivers of change on ecological systems has grown in recent decades. This interest has arisen from a spectrum of observational scales – from growing concerns related to increases in the occurrence and frequency of climatic extremes to appreciation of the limits of using constant environmental conditions in experiments that naturally represent dynamic systems. Environmental variability may weaken or intensify the effects of antecedent environmental conditions on biological systems, and conversely, antecedent conditions may mitigate or exacerbate the effects of environmental variability. Hence, understanding the effects of such variability on the state of an ecosystem, and the potential cascading impacts on the physiology, demography and interactions of aquatic biota, is necessary for predicting the consequences of ongoing environmental change on aquatic communities, water quality, and ecosystem services. This session calls for contributions from across the range of approaches (theoretical, experimental, observational, and modeling) that can be used to investigate the effects of environmental variability and extremes on all aspects of freshwater ecosystems, from individual organisms to cross-lake system comparisons. Broadly defined, environmental drivers include seasonal or periodic fluctuations in temperature, oxygen, pH, light, nutrient supply, food quantity/quality, and disease, or extreme events such as droughts, heat waves, or storms. This session will offer a platform to share the most recent research and ideas in a topic area that is growing, but still underexplored, in aquatic ecology.

 

Daniel Perkins, University of Roehampton, UK
daniel.perkins@roehampton.ac.uk
Victor Saito, Federal University of São Carlos, SP, Brazil

Degradation and loss of habitat, associated with land use change, are among the most important drivers of global biodiversity loss in freshwaters. Understanding how such widespread environmental change influences food web structure (e.g. the diversity or body size distribution of consumers and resources) and ecosystem functioning (e.g. organic matter decomposition, biomass production) is therefore a pressing challenge. In the Global North, the modification of catchments and impact on freshwaters has been studied for many decades. However, major contemporary transformations are occurring in the developing tropics (e.g. conversion of rainforest to oil palm or sugar cane plantations), and the impending implications for ecosystem integrity is an urgent global concern. This session will bring together researchers working in temperate and tropical freshwater systems with the aim to identify similarities and differences in the responses of these impacted ecosystems across latitudes. Talks will encompass research conducted in both lotic and lentic systems, over broad spatial and temporal scales, and through the lens of multiple theories (network, niche/neutral, metabolic). Doing so will aid our understanding of the general impacts of land use change across the globe and the relative importance of the underlying mechanisms at play, providing a solid basis for empirical and theoretical unification.

Pieter Spaak, Eawag, Switzerland
spaak@eawag.ch
Blake Matthews, Eawag, Switzerland

In the past century, many lakes have undergone extensive changes: untreated sewage and intensive agriculture led to severe pollution of lakes that became nutrient-rich (eutrophication). Many of these polluted lakes have been restored through countermeasures that were taken (re-oligotrophication), but irreversible changes to the communities of aquatic organisms are reported from many systems (e.g. extinction of species). On top of these changes, other stressors (e.g. Climate Change; invasive species; micro pollutants; micro plastics) influence lakes, and their impact is often unclear because different stressors interact. In this session we plan to bring together scientist that study changing lakes and their resilience to better understand these ecosystems, their biodiversity and functioning, as well as the utilisation of lake resources by people.

Elisabeth Gross, Université Lorraine, LIEC UMR 7360 CNRS, France
gross5@univ-lorraine.fr

Shallow aquatic systems are abundant in agricultural landscapes, and due to their high surface-to-volume ratio highly susceptible to suffer from climate warming and agricultural run-off, mixtures of nutrients and pesticides. Such systems include shallow lakes and ponds as well as small streams or ditches. They are important components in landscapes, providing habitat for diverse aquatic communities, representing important elements in habitat connectivity, and being biogeochemical hotspots relevant for e.g. carbon storage and/or greenhouse gas emissions. Their good ecological status – represented by clear water and the presence of diverse submerged macrophytes and associated fauna – is often threatened by multiple stressors acting locally (e.g., pollution, browning, sky glow) or globally (e.g., warming). This session welcomes presentations from laboratory or outdoor experiments, field observations and modelling approaches on multiple stressor effects influencing shallow aquatic systems, either standing or running waters. We welcome studies from different climatic regions and different geochemical settings. The aim of the session is to represent a wide range of different systems, identifying differences and similarities in response to single and combined stressors and stressor interactions. A common theme could be the identification of direct and indirect effects acting on different functional groups. Studies can focus on different ecological levels, from individual species responses to community or ecosystem effects. Findings could assist policymakers finding ‘safe operating spaces’ by identifying feasible mitigation options enhancing the resilience of shallow aquatic ecosystems in a changing world.

Katrin Wendt-Potthoff, Helmholtz Centre for Environmental Research – UFZ, Germany
katrin.wendt-potthoff@ufz.de
Martin Blettler, National Institute of Limnology (INALI) CONICET-UNL, Argentina

Plastic pollution is mainly recognized in the oceans, but i relevant also in rivers, estuaries, lakes and wetlands. Composition of plastic debris, transport pathways and interaction with biota show similarities, but also important differences to marine systems, which are not yet well understood. Knowledge gaps result, among others, from inconsistent monitoring or sampling strategies and geographic bias. We therefore encourage presentations covering systematic assessments of all sizes of plastic in inland water systems, observations related to extreme weather or pandemic, and studies at the freshwater-ocean or freshwater-terrestrial interface. Moreover, plastic interactions with water-associated biota beyond ingestion will be of special interest.

Matthias Liess, Helmholtz Centre for Environmental Research – UFZ, Germany
matthias.liess@ufz.de
Noël Juvigny-Khenafou, University Koblenz-Landau, Germany
Ralf B. Schäfer, University of Koblenz-Landau, Germany

Human activities have strongly increased the diversity and spread of stressors that exert pressure on freshwater ecosystems. These stressors range from habitat degradation over invasive species to pollution including toxicants. Stressors have complex co-occurrence dynamics. For instance, the order of stressor events shapes the response of the recipient system. Further, studies have shown that spatial riverine networks influence the community dynamics with species dispersal as the underlying process. Therefore, understanding alterations in real ecosystems requires a spatiotemporal context. Finally, stressor adaptation of individuals, populations and communities needs to be evaluated for its capacity to compensate stressor effects. However, so far, uniform and consistent approaches have only been identified for certain stressor combinations. The aim of the session is to gather diverse examples of approaches to assessing multiple stressors and subsequent adaptation. This includes empirical and theoretical studies that provide information on the integration of space, time and adaptation to multiple stressors.

Nutrient Relationships

Maria Dittrich, University of Toronto, ON, Canada
m.dittrich@utoronto.ca
Michael Hupfer, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany

Phosphorus is a primary limiting element for various freshwater aquatic systems, controlling primary production, and consequently, eutrophication. The dynamics of external phosphorus loading to inland waters from watersheds is predicted to increase in intensity and frequency with the warming climate. Consequently, P soil legacy will degrade the water quality over time, in scales of decades and perhaps even longer. Understanding the interplay between the P loading and storage in lakes and developing remediation strategies for the P legacy are central objectives of limnological studies over the globe. On the other side, the P internal loading, which is triggered by microbial and geochemical processes at the sediment-water interface, can be affected by a variety of internal and external factors, for example, organic matter mineralization, redox gradients, the presence of invasive species, pollutants loading (e.g., plastics). This session welcomes experimental and modelling contributions focusing on understanding the biogeochemical transformation of phosphorus impacted by lake-internal and climate-driven factors, such as extreme rain events, ice cover, and warming.

Xiufeng Zhang, Jinan University, China
wetlandxfz@163.com
Lars Rudstam, Cornell University, NY, USA

The goal of many biomanipulations is to reduce the abundance of planktivorous fish, either by addition of piscivorous fish or by manually removing or reducing the biomass of undesired fish. The method was originally intended to reduce grazing pressure on zooplankton, thereby increasing grazing pressure on phytoplankton by zooplankton, especially Daphnia, to increase water clarity and promote the growth of aquatic macrophytes. Biomanipulation has become a commonly used technique for improving water quality of lakes and reservoirs after external nutrient load reduction. From a management point of view, biomanipulation is likely to be most successful in the long term in shallow eutrophic lakes. With decades of successful applications as a method for lake restoration, its popularity is increasing in the Northern Hemisphere. However, the effectiveness is questionable in tropical and subtropical regions because Daphnia are less abundant and planktivorous fish may be omnivores and can produce eggs all year round making them harder to control. In addition, large phytoplankton in some eutrophic conditions are difficult to handle by the zooplankton, including Daphnia. Furthermore, in the scenario of global climate warming, biological invasion and the enhancing human activities, the percentage of omnivorous fish increases, which may lead to reduced control of zooplankton on phytoplankton. So, the success of biomanipulation may be challenged also in the temperate zone. In this special session we wish to promote cross-continent comparisons of grazing manipulation-based biotechnology for restoration of eutrophic waters. We encourage contributions discussing results from field studies, experiments, models, and theoretical analyses.

Pieter Spaak, Eawag, Switzerland
spaak@eawag.ch
Blake Matthews, Eawag, Switzerland

In the past century, many lakes have undergone extensive changes: untreated sewage and intensive agriculture led to severe pollution of lakes that became nutrient-rich (eutrophication). Many of these polluted lakes have been restored through countermeasures that were taken (re-oligotrophication), but irreversible changes to the communities of aquatic organisms are reported from many systems (e.g. extinction of species). On top of these changes, other stressors (e.g. Climate Change; invasive species; micro pollutants; micro plastics) influence lakes, and their impact is often unclear because different stressors interact. In this session we plan to bring together scientist that study changing lakes and their resilience to better understand these ecosystems, their biodiversity and functioning, as well as the utilisation of lake resources by people.

Ingrid Chorus, Private address (ex Federal Environment Agency), Germany
ingrid.chorus@gmail.com
Hans Paerl, University of North Carolina at Chapel Hill, NC, USA

Cost-effective eutrophication control has many open question, and while the answers are likely to be situation-specific, understanding generic patterns would support management in setting priorities. For shallow water bodies with pronounced internal P cycling and long water retention times, seasonal N and P co-limitation or exclusive N limitation is common. Reducing N could enhance such phases. Can we find patterns for other waterbodies? Questions which we encourage contributions to address include: 1) How do we best assess current nutrient limitation? Are time series of total and dissolved concentrations of P and N sufficient? Do N:P ratios add insights beyond those gained from the absolute concentrations? 2) Can nutrient addition experiments add insights for planning nutrient control and if so, how must they be designed? 3) Are there examples of successful eutrophication control focusing on reducing both N and P or solely N loads? 4) Are there examples of downstream eutrophication in response to greater N availability when reductions of P loads only limit upstream biomass? 5) How low must P or N target concentrations be to effectively reduce phytoplankton biomass and cyanobacterial blooms? How does this relate to hydrologic conditions? 6) Most data on half-saturation coefficients for nutrient uptake are from experiments performed decades ago, and they cover only selected species. Do we need a more comprehensive compilation of data on dissolved nutrient concentrations at which uptake rates of species are saturated – and at which limitation by that nutrient can therefore be excluded?

Man Xiao, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, China
m.xiao@griffith.edu.au
David Hamilton, Australian Rivers Institute, Griffith University, QLD, Australia
Michele Burford, Australian Rivers Institute, Griffith University, QLD, Australia

Cyanobacteria are ubiquitous in aquatic ecosystems, irrespective of nutrient concentrations. Recent studies have shown that they can grow and even form blooms when concentrations of dissolved inorganic phosphorus and/or nitrogen are below analytical detections limits. Succession or adaptation of species to low and varying phosphorus and nitrogen availability allows for a continuity of growth and reproduction by cyanobacteria. In this session we will explore understanding of the different strategies adopted by cyanobacterial species and strains to nutrient limitation. We will review new tools and developments, from molecular scale to ecological model simulations, that can inform our rapidly evolving understanding of nutrient limitation in cyanobacteria. Of particular interest will be how cyanobacteria adapt to phosphorus and nitrogen deficiency, utilisation of organic phosphorus and atmospherically fixed nitrogen, including the energy requirements for these processes, and how to scale results from laboratory cultures to the field. We seek to explore the eco-evolutionary mechanisms that have led to cyanobacterial diversification, its contribution to population maintenance, and its importance in limiting the applicability of laboratory culture studies. This session will further explore how understanding the strategies of cyanobacteria to circumvent phosphorus and nitrogen limitation is critical for understanding the limitations of nutrient control for cyanobacteria bloom control and mitigation.

Species Interactions

Christopher Bellas, University of Innsbruck, Austria
christopher.bellas@uibk.ac.at
Ruben Sommaruga, University of Innsbruck, Austria

Viruses are a major component of aquatic ecosystems and they probably infect all living organisms. Recent studies have detected several new groups of viruses in lakes and rivers, demonstrating that we still do not know their full diversity and the implications of virus infection for freshwater bacterial and microeukaryotic populations. This session aims to discuss the diversity, function, and impact of viruses in the planktonic and benthic realm of freshwater ecosystems. Some outstanding questions we would like to discuss are: Do freshwater environments harbour novel groups of viruses? Do lakes have similar or identical virus communities? How do viruses influence the fate of their host populations?

Xiufeng Zhang, Jinan University, China
wetlandxfz@163.com
Lars Rudstam, Cornell University, NY, USA

The goal of many biomanipulations is to reduce the abundance of planktivorous fish, either by addition of piscivorous fish or by manually removing or reducing the biomass of undesired fish. The method was originally intended to reduce grazing pressure on zooplankton, thereby increasing grazing pressure on phytoplankton by zooplankton, especially Daphnia, to increase water clarity and promote the growth of aquatic macrophytes. Biomanipulation has become a commonly used technique for improving water quality of lakes and reservoirs after external nutrient load reduction. From a management point of view, biomanipulation is likely to be most successful in the long term in shallow eutrophic lakes. With decades of successful applications as a method for lake restoration, its popularity is increasing in the Northern Hemisphere. However, the effectiveness is questionable in tropical and subtropical regions because Daphnia are less abundant and planktivorous fish may be omnivores and can produce eggs all year round making them harder to control. In addition, large phytoplankton in some eutrophic conditions are difficult to handle by the zooplankton, including Daphnia. Furthermore, in the scenario of global climate warming, biological invasion and the enhancing human activities, the percentage of omnivorous fish increases, which may lead to reduced control of zooplankton on phytoplankton. So, the success of biomanipulation may be challenged also in the temperate zone. In this special session we wish to promote cross-continent comparisons of grazing manipulation-based biotechnology for restoration of eutrophic waters. We encourage contributions discussing results from field studies, experiments, models, and theoretical analyses.

Justyna Wolinska, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany
justyna.wolinska@igb-berlin.de
Klaus Knopf, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany

Parasites are often neglected, as they are relatively small and less noticeable than free-living species. However, parasitism is considered to be the most common lifestyle on earth and parasites account for a substantial fraction of the biomass in ecosystems. Parasites are often perceived as negative disease-causing agents that inflict damage to free-living species and reduce host densities. Yet, there is increasing evidence for positive effects of parasitism in the ecosystem, such as parasites being drivers of diversity and contributors to trophic transfer and nutrient cycling. This session covers the variety of parasite roles in inland waters, as seen not only from epidemiological but also from the evolutionary and ecological perspectives. We invite contributions exploring these different roles and addressing different important organisms in these processes, ranging from micro- to macro-parasites and from unicellular to vertebrate hosts. The aim of this session is to challenge the traditional perception of parasitism as an exclusively negative interaction and to highlight the significant impacts of parasites on ecosystem health, stability and functioning.

Dominik Martin-Creuzburg, Brandenburg University of Technology Cottbus–Senftenberg, Germany
dominik.Martin-Creuzburg@b-tu.de
Martin Kainz, WasserCluster Lunz, Austria
Tarn Preet Parmar, University of Konstanz, Germany
Margaux Mathieu-Resuge, WasserCluster Lunz, Austria Cornelia Twining, Eawag, Switzerland

Emergent insects have been classified and quantified in the last two centuries as they can provide important information into ecosystem biodiversity, health, and response to environmental changes. More recently, they have also been studied as an important cross-ecosystem subsidy providing aquatic-derived nutrients to terrestrial food webs. Food web techniques (i.e., fatty acid analysis and stable isotopes) have been used to track aquatic-derived nutrients from aquatic primary producers all the way to riparian predators, such as birds and spiders. Recent interest has been focused on quantifying polyunsaturated fatty acids (PUFAs) that are exported from rivers, ponds, and lakes. Although PUFAs have important energetic and physiological functions, this session is not limited specifically to PUFA-related research. Instead, we would like to bring together researchers who focus on emergent aquatic insects as important cross-ecosystem vectors. One focus of the session will be on recent research that provides the framework for determining the current environmental status of inland waters using emergent aquatic insects. In addition, we would like to highlight the prospect of using biochemical and/or isotopic analysis (established and new) as a way to determine and detect changes in ecosystem health and services provided by emergent insects. This session builds on the Chironomidae and the foundation laid by August Thienemann, one of the SIL visionaries, and highlights the importance of studying emergent aquatic insects and the possibility of using them as indicators of ecosystem functionality.

Sven Matern, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany
sven.matern@igb-berlin.de
Elias Ehrlich, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany

This session aims to bring together research on different aspects of fish ecology that promotes the understanding of how to successfully conserve, manage and sustainably use freshwater fish. The topics can cover all aspects of trophic interactions, effects of environmental gradients and population dynamics, including physiological, behavioural or evolutionary insights that enhance our understanding of key drivers and future challenges of freshwater fish populations. Specifically, we would like to facilitate ideas on broader ecosystem approaches linking multiple trophic levels and encourage people from different disciplines to find their way to the session. This could include bottom-up and top-down interactions between fish and plankton as well as fish and their predators. Furthermore, we see potential for several other topics here, including the response of fish populations to environmental change, regime shifts, fisheries management and conservation tasks related to habitat management and migration

Eric von Elert, University of Cologne, Germany
evelert@uni-koeln.de
Christine Kiel, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany
Linda Weiss, Ruhr-University Bochum, Germany            Ralph Tollrian, Ruhr-University Bochum, Germany

Natural organic molecules play numerous roles in freshwater ecosystems. In particular, they act as infochemicals by mediating communication or information transfer within and among species in processes such as attractance, deterrence or the initiation of inducible defences. Furthermore, they can be important nutritional compounds and therefore essential mediators in trophic interactions. Recent studies indicate that chemical information transfer can be modified or hampered by environmental change. Thus, knowledge about the chemistry, ecophysiological functions, trait induction of natural organic compounds and their modifications is crucial for a deep understanding of ecological interactions and ecosystem functioning. This session welcomes contributions with a chemical, ecological, evolutionary or omics focus on the role of natural organic molecules in chemical information transfer or food quality and species interactions. The overall aim is to showcase and provide an overview of recent developments in freshwater chemical ecology in diverse organisms, habitats, ecosystems and geographic regions.

Miscellaneous

If your presentation does not fit in the sessions described above, please select “Miscellaneous” as your first choice, although you may still also consider other potential sessions as second and third choice — if appropriate. When all submissions of abstracts have been received in April, we will arrange the sessions to accommodate all submitted abstract in the best possible way. Note that this may involve creating additional sessions (e.g. on eDNA, fish, or any other topic not yet specified), if there is sufficient interest (i.e. number of abstracts).