special session descriptions

Special Session: Zoogeochemistry in freshwaters: Integrating animal conservation with biogeochemistry

Organizers: Jonathan Lopez, Carla Atkinson & Taylor Michael

The term “zoogeochemistry” refers to any animal-driven impact on biogeochemical cycling. Zoogeochemical effects can be disproportionally large relative to animal biomass in the ecosystem because animals not only have biomass-dependent direct effects, but also indirect effects that propagate through the community. However, since the zoogeochemistry framework was formalized less than a decade ago, it has primarily been applied to terrestrial systems. Zoogeochemistry is a particularly useful paradigm in freshwater systems as: (1) freshwater ecosystems are critical components of global biogeochemical cycles, serving as key pathways for the transformation, transport, and storage of matter and energy; (2) freshwater animals are highly imperiled, creating a race against time to quantify and conserve their ecosystem-level effects.

In this session, we call for freshwater ecologists to begin considering ways in which they can create interdisciplinary synergy between animal conservation and biogeochemistry, as these subdisciplines remain largely separated in the freshwater science community. Presentations will deal with any type of animal-biogeochemical interaction, with emphasis on studies that place those interactions in an ecosystem-level context by comparing animal-driven pools and fluxes to background pools and fluxes.

The freshwater zoogeochemical patterns that drive ecosystem-scale patterns in structure and function are inextricably linked to the global-scale problems associated with biogeochemical change and biodiversity loss. The ultimate goal of this session is to facilitate discussion and consider ways to more effectively meet local, regional, and ultimately global ecological challenges by linking conservation and ecosystem science.

Special Session: Biogeochemical cycling in human-made freshwaters

Organizers: Jacqueline Gerson, Anika Bratt, Audrey Goeckner & AJ Reisinger

Human activity has drastically altered landscapes, including through the creation of new freshwater environments. These artificial or novel ecosystems can be either isolated instances across the hydroscape or the dominant freshwater feature. They occur in a variety of forms, with examples including stormwater ponds, mining ponds, ditches, canals, reservoirs, agricultural ponds, and artificial wetlands, amongst others. Human-created freshwater ecosystems are often understudied, even though biogeochemical cycling in these ecosystems likely differs from naturally created waterbodies. We invite presentations to this session that consider nutrient and contaminant cycling within these waterbodies.

Special Session: Contaminant Ecology

Organizers: Jessica Brandt & Calin Sinclair

Contaminants are agents of global change that operate at ecosystem scales and are a tell-tale signature of modern human activity. Environmental contaminant research has strong roots in ecosystem ecology, and we’re seeing a renewed emphasis on understanding contaminant behavior and influence on large spatial and temporal scales. The emerging sub-discipline of contaminant ecology aims to coordinate this research for a more holistic understanding of contaminant interactions with ecological processes. We propose that the scope of this discipline includes contaminant biogeochemistry, fate and transport, mediation of organismal fitness and ecosystem services, and contaminants as tracers for elucidating ecological pathways and processes. This will be the fourth offering of a contaminant ecology session at SFS since 2021. The session aims to highlight recent findings and to continue developing the network of researchers working at the intersections of ecology, ecosystem science, and ecotoxicology. We invite abstracts highlighting new and ongoing research on these and related topics from scientists across career stages working in diverse ecosystems and contaminant scenarios. In line with the theme of the 2026 meeting, we hope to feature contaminants research in the context of ecosystem and community resilience.

Special Session: The other half of the river: elevating non-academic contributions to freshwater science

Organizers: Christina Linkem & Benjamin Block

The Society for Freshwater Science (SFS) has long served as a hub for academic scientists, including students, postdocs, professors, and research staff—who collectively comprise approximately 66% of the society’s membership. However, the remaining 34% work in a wide array of non-academic sectors, such as state and federal agencies, tribal governments, utilities, private consulting firms, non-profits, and other NGOs. These professionals bring unique perspectives, skill sets, and approaches to freshwater science, reflecting their daily work managing, protecting, and restoring ecosystems on the ground. This session aims to spotlight the breadth of non-academic work and career pathways in freshwater science by inviting practitioners and professional scientists whose work bridges research and application. These positions offer not only applied management experience, but also distinctive lenses into aquatic conservation, policy, and community engagement. The session will begin with a brief introduction to the scope and importance of non-academic contributions, followed by a series of presentations from professionals working in diverse roles outside academia. Speakers will share the unique aspects of their work, highlighting how their applied science informs—and is informed by—academic research. In addition to exploring technical insights, the session will showcase the career pathways and professional experiences of non-academic scientists, offering students and early-career attendees a clearer picture of the opportunities available beyond universities.

Special Session: Assessment and management of wastewater in urban and suburban streams

Organizers: Abel Porras & Christina Bryant

The discharge of treated wastewater in urban and suburban streams can adversely impact stream health by inputting excess nutrients and other harmful pollutants, contributing to harmful algal blooms (HABs), and depleting dissolved oxygen. Furthermore, these discharges can have negative human outcomes that range from reduced recreational opportunities to potential health issues. Thus, the assessment of treated wastewater discharge (as both volume and concentration) through modeling and experimental design is necessary to identify the extent of its impact and to assess potential solutions and strategies for mitigation and improved stream resilience. This session will explore the assessment and management of treated wastewater, which can include monitoring and modeling programs, optimized treatment processes, and nature-based solutions, among others.

Special Session: Operationalizing remote sensing for water security and freshwater ecosystem integrity in dryland regions

Organizers: Erik Nati-Johnson, Colin Martin & Juan Camilo Rojas Lucero

Managing freshwater in the face of intensifying drought and chronic water scarcity is a critical challenge of the 21st century. Dryland regions make up over 40% of global landmass, and competing demands from intensifying agriculture, urban growth, and fragile ecosystem conditions place immense strain on limited water supplies. In the Western US, freshwater ecosystems and their interfaces with terrestrial habitats have a disproportionate impact on landscapes relative to their size. While freshwater ecosystems make up less than 2% of Western landscapes, over half of fauna rely on them at one point in their life cycle, and they have the highest bird, mammal, plant, and insect biodiversity of any terrestrial landscape. Generating comprehensive and continuous assessments of these systems through traditional field sampling is hindered by their wide dispersal and limited accessibility. Decision makers urgently need accurate, timely, and transparent data in order to improve management of freshwater ecosystems, and recent advancements in remote sensing are filling the gaps left by traditional sampling. This session invites speakers who are leveraging remote sensing to monitor various water cycle components and freshwater ecosystems, such as snowpack that feeds rivers, riparian corridors that retain water in the landscape, and evapotranspiration from crops. Discussions will highlight accessible tools that translate data and models into actionable information for natural resource managers. This session focuses on bridging the gap between complex data and land management decisions, demonstrating how remote sensing is becoming an indispensable tool for building resilience and ensuring water security in a changing climate.

Special Session: The fire’s leading edge: Exploring the paradoxical effects of fire on freshwater ecosystems to support more resilient watersheds and communities

Organizers: Maricela Alaniz, Jeremy Brooks & Jake McArtor

Fire scientists face a paradox in which fires can be either a threat or a boon to freshwater biodiversity and ecosystem function, and understanding the complex drivers leading to these contradictions is needed to support more resilient ecosystems. Fires that burn in mosaics with varying severity may promote ecosystem resilience, whereas homogeneously severe fires may degrade it. Nutrients stored in terrestrial ecosystems can be released by fire and lead to pulses of productivity in aquatic ecosystems, but fires can also mobilize contaminants, like PFAS and metals, that disrupt aquatic communities and ecosystems. Burned riparian canopies may promote aquatic primary production and grazing invertebrates, meanwhile reducing leaf litter and shredding invertebrates. A fire mosaic may simultaneously create opportunities for these diverse organic matter pathways and communities, promoting resilient ecosystems. Alternatively, a fire that mobilizes contaminants may ubiquitously degrade them. Rather than searching for generalizable understandings and conservation practices regarding the effects of fire on freshwater ecosystems, this special session embraces the “fire paradox.”

In this session, we encourage researchers to share their leading-edge research into the complex drivers of the “fire paradox” and to explore how these findings can be leveraged to build more resilient watersheds and communities. We encourage research that uses diverse approaches (e.g., mesocosm experiments, field observation studies, and remote sensing) to study a variety of freshwater ecosystems (e.g., streams, rivers, ponds, and lakes) and their response to fire. We also welcome presentations from a variety of disciplines, including biogeochemistry, community ecology, ecotoxicology, and restoration ecology.

Special Session: Non-perennial freshwater ecosystems: Resilience in a drying world

Organizers: Shannon Speir, Erin Seybold, Rachel Stubbington & Adam Price

Despite being among Earth's most widespread freshwater habitats, non-perennial ecosystems remain poorly understood compared to their permanent counterparts. Today, human pressures, such as climate change and water resource use, are causing more freshwater habitats to experience variable inundation. The expansion of drying behavior globally has spurred a rapid increase in interdisciplinary research on non-perennial freshwaters. However, our understanding of the effects of wet-dry cycles on physical, biogeochemical, and biological processes in non-perennial ecosystems are still developing. These ecosystems exist at the terrestrial-aquatic interface, requiring us to bridge across disciplines, regions, and cultures. As such, insights across various freshwater ecosystems must inform one another. Given the importance of non-perennial systems for regulating water quality, we must not only understand the systems, but also the drivers and effects of wet-dry cycles and their far-reaching societal consequences. In this session, we aim to showcase research encompassing, but not limited to, the hydrology, biogeochemistry, ecology, geomorphology, sociology, management restoration of non-perennial ecosystems. By expanding understanding of ecosystem structure and function, the session will promote the resilience of these dynamic ecosystems as they adapt to global change. Our special session will provide a platform to expand and inspire interdisciplinary thinking and actions, facilitating broader approaches and advancing our collective knowledge around non-perennial streams. We welcome contributions from researchers across career stages, disciplines, spatial and temporal scales, and using observational, experimental, and modeling and other approaches.

Special Session: Biogeochemical Perspectives on Resilience in Agriculturally Influenced Freshwater Systems

Organizers: Kathleen Cutting, Karessa De La Paz, Nellie Little & Mahima Quazi

Across the globe, agriculture is one of the largest drivers of land use change, through deforestation, irrigation, and cultivation. Significant inputs of fertilizers in agricultural watersheds have driven shifts in baseline biogeochemical cycling in aquatic ecosystems, yielding increased nutrient runoff. As climate change progresses, pressures on agricultural systems will increase, causing further strain on biogeochemical patterns. Shifts in precipitation and temperature are driving increased groundwater/surface water withdrawal, fertilizer usage, runoff management, and cultivation practices in agricultural watersheds. Thus, it is important to understand how freshwater systems are being affected in agricultural areas and how we can work to increase their resiliency to these pressures. Improving our understanding of agriculturally related controls on biogeochemical cycling is necessary to reduce our impact on freshwater systems and bridge the gap between farmers and science.

Our session will provide insight on how broader agricultural and best management practices are impacting biogeochemical cycles across a variety of aquatic systems and diverse flow regimes. We seek presentations that explore agricultural impacts on aquatic biogeochemistry and assess how aquatic systems are adapting to their agricultural settings within the biogeochemical realm. We encourage presentations that study nutrients, carbon, dissolved gasses, greenhouse gas emissions, and sediment nutrient cycling sources in agricultural aquatic systems. The study of freshwaters embedded in the agricultural landscape is essential to build resilient watersheds and communities that can adapt to increasing anthropogenic and environmental pressures.

Special Session: State of the science of the Spokane Valley Rathdrum Prairie Aquifer and its watershed

Organizers: Meg Wolf & Seth Oliver

The Spokane Valley–Rathdrum Prairie (SVRP) Aquifer is a transboundary groundwater system of critical regional importance to both Idaho and Washington, serving as the sole source of drinking water for over half a million residents in the greater Spokane and Coeur d’Alene area. This glacially derived aquifer is characterized by highly permeable coarse sediments, resulting in rapid groundwater flow and strong hydraulic connectivity with surface waters. Its sensitivity to land use change, population growth, and climatic variability underscores the need for an integrated scientific understanding of aquifer dynamics and watershed processes. This session, co-convened by the Idaho Water Resources Research Institute (IWRRI) and the Idaho Department of Environmental Quality (IDEQ), will synthesize current research and monitoring efforts to assess the state of the science for the SVRP Aquifer and its contributing watershed. Topics will include the influence of land use on groundwater quality, advances in methods for tracing recharge and characterizing aquifer–surface water interactions, and the role of headwater systems in sustaining aquifer inputs. Contributions addressing hydrologic responses to drought, climate variability, and ongoing regional development are also encouraged. This session aims to advance interdisciplinary understanding and support science-based management of one of the most dynamic and socioeconomically significant groundwater systems in the inland Northwest.

Special Session: The past, present, and future of freshwater invasion ecology and management: A career retrospective for David M. Lodge

Organizers: Matthew Barnes, John Drake, Eric Larson & Lindsey Reisinger

Biological invasions have had severe consequences for native species, ecosystems, human health and economies. As a form of global environmental change, biological invasions have had especially acute impacts in freshwater ecosystems due to their isolation from one another. Over the past four decades, few researchers have done more than Professor David M. Lodge to help us understand the causes and consequences of biological invasions, whose work over time increasingly translated and transferred scientific knowledge to environmental management and policy. To celebrate Professor Lodge’s retirement this year, we convene a special session to review the past half century of progress in invasion biology, while also identifying lessons and future directions informed by his work. Talks are anticipated to include an emphasis on bioeconomics, risk analysis, ecological forecasts, long-term data, methods for surveillance and early detection (e.g., environmental DNA), and the science/policy interface.

Special Session: Quantifying flow in urban streams

Organizers: Christina Bryant & Abel Porras

Hydrology is a known driver of change in stream geomorphology, hydraulics, water quality, and aquatic ecology. Accurate discharge monitoring is therefore essential for programs that monitor and manage storm and freshwater quantity and quality, ecological health, and environmental change. Most stormwater programs focus on high flow events; however, it is also essential to have accurate low flow measurements to accompany biological assessments. Urban streams often exhibit altered hydrologic regimes due to increased impervious cover, altered stream morphology and engineered drainage systems. Streamflow quantification can be further complicated in urban systems due to increased flashiness, backwater effects from infrastructure, altered stream hydraulics, highly variable flow, and random or episodic events, such as illegal discharges, leaking infrastructure, or irrigation inputs. It is difficult to account for each of these issues while monitoring because they will impact different portions of the hydrograph. Additionally, monitoring equipment is frequently disrupted by debris, damage, and vandalism. This session will explore innovative tools and technologies for monitoring, techniques and methods for data validation and modeling, and best practices for quantifying high and low flow in urban systems.

Special Session: Lakes, ponds, and wetlands oh my! Drivers, feedbacks, and responses of the carbon cycle under changing climate and anthropogenic stressors

Organizers: Phoenix Rogers, Shuo Chen, Carla Lopez Lloreda & Natalie Griffiths

More than 20% of the world’s surface freshwater is stored in lakes, ponds, reservoirs and wetlands, which plays a significant role in mediating the Earth’s carbon cycle. These lentic systems influence the fate of organic matter, sequestering it in sediments, releasing it back to the atmosphere as greenhouse gases (GHGs; e.g. CO2 and CH4) or sending it downstream to the ocean. The quantities and forms of carbon following each pathway are often influenced by biophysical conditions (e.g., temperature, precipitation, hydrology) and anthropogenic stressors (wastewater inputs, vegetation removal, nutrient enrichment). However, we have a limited understanding of the interactive effects of biophysical and anthropogenic drivers on reshaping carbon biogeochemistry in lakes, ponds, reservoirs, and wetlands, or how the sources and transformations of organic carbon alter microbial metabolic processing, potentially affecting lentic ecosystem functions and future climate change. This session seeks for answers to these questions and discusses novel approaches for simultaneously integrating and disentangling the biophysical and anthropogenic stressors affecting lentic carbon cycling across local-, regional-, continental-, and global-scales. The featured submissions are not only limited to organic carbon processing, but also related to lentic metabolism, emission of greenhouse gases and other carbon-related biogeochemical processes. We encourage submissions from work in underrepresented regions as well as from students, early-career researchers, and individuals from BIPOC, LGBTQIA+, and other marginalized communities.

Special Session: Unraveling wetland invertebrate dynamics: Connecting small-scale responses to landscape-level influences

Organizers: Julia Portmann & Elizabeth Sicking

Freshwater wetlands are highly abundant and diverse across landscapes and are important for nutrient cycling, carbon storage, and biodiversity. Underlying these essential ecosystems are their invertebrate communities. Wetland macroinvertebrate assemblages have unique patterns of community development that are not fully understood, but depend on several factors including connectivity, hydrology, vegetation, and anthropogenic influence. Wetland invertebrates are vital resources in aquatic and terrestrial food webs, with their consumers being of great conservation interest due to their reliance on wetlands for breeding and migration ground. Invertebrates in wetlands tend to be understudied in comparison to their charismatic consumers, leaving gaps in our understanding of their responses to change and their potential resilience. In contrast to stream ecosystems, which heavily utilize macroinvertebrates for monitoring and restoration, wetland conservation, restoration, and management standards often underemphasize invertebrate communities. Studies on wetland invertebrates can be extremely broad in scope and topic, making it difficult for those focusing on wetland invertebrate communities to connect despite common research interests. Our goal for this session is to provide a common space to share research and ideas that lead to improved foundational understanding of wetland invertebrate communities, management policies, and ultimately watershed resiliency. We anticipate that talks will span topics including food web ecology, larval and adult invertebrate dynamics and dispersal, global biodiversity patterns, and land use impacts on wetland ecosystems, but welcome any talk tangential to wetland invertebrates.

Special Session: Mining and streams: Best practices and impacts on stream food webs and water quality

Organizers: Sherri Johnson, Frank McCormick & Christina Murphy

Mining activities have a long history of negatively impacting stream habitats, aquatic communities, and downstream water quality. Yet mining, whether it be for metals, minerals, coal, or sand and gravel, provides key resources for society. As the global demand for metals continues to rise in support of technology and energy efficiency programs, it becomes even more crucial to analyze and understand the dynamics of prior impacts of mining activities on aquatic ecosystems and devise best practices for future extraction and mitigation. In many areas, regulations and guidelines are antiquated - for example, environmental protections during mining on federal US lands are still administered under the 1872 Mining Act. This Special Session encourages abstract submissions from all sectors (academia, private, philanthropies, government, consortia, etc.) describing research into what is being done, what could be implemented and/or what needs to change to protect aquatic and riparian ecosystems during mining.

Special Session: Sym-Poff-ium: A celebration of and reflection on the impact of N. LeRoy Poff’s career in riverine ecology science and practice

Organizers: Chris Funk, Julian Olden, Deb Finn, John Matthews & David Lytle

LeRoy Poff is considered by many to be among the most influential scientists in freshwater ecology and management. His research spans vast domains of riverine ecology, from pioneering new frontiers in basic hydro-ecological science to advancing science-based management for river conservation to developing a globally significant multi-disciplinary approach to freshwater sustainability and resilience. In a time that ecologists largely remained in the confines of the “Ivory Tower,” Poff crossed the moat to the messy world of practice to blend cutting-edge freshwater science into policy that both advanced river health and resiliency and respected decision making processes. Throughout his entire career, he has engaged through impactful scholarship and careful listening, linking theory‐driven basic ecological science to pragmatic applications, often in collaboration with disciplinary scientists (hydrologists, geomorphologists, social scientists) and engineers, NGOs, and government institutions. His papers on the natural flow regime, environmental flows, and ELOHA (the ecological limits of hydrological alteration) were global game-changers in the way managers and practitioners think about and implement river management and climate adaptation. In this session, Poff alumni, collaborators, and other colleagues will give talks encompassing the many dimensions of Poff’s impactful career. The goal of this “Sym-Poff-ium” will be to celebrate his accomplishments, reflect on their impact in the field of freshwater science and on the Society for Freshwater Science, and, importantly, highlight the “bleeding edge” in the areas of freshwater science and practice crafted and advanced by Poff.

Special Session: Across ecosystem linkages: quantifying aquatic-terrestrial reciprocal connections to support resilient watersheds

Organizer: Amaryllis Adey, Gisella Depiazza, Maggie Herrmann & Conner Gruntz

Aquatic ecosystems and their surrounding watersheds are linked by reciprocal flows of energy, nutrients, and organisms. The strength of these connections can vary across landscapes and various interacting stressors associated with disturbances such as floods, droughts, and land-use changes that act as key regulators of how much material and energy moves across boundaries. These interactions create feedbacks that can either strengthen or weaken the resilience of both aquatic ecosystems and their watersheds. Yet, as scientists, we lack shared terminology and clear methods to measure the magnitude and variability of these connections. Identifying the specific connections that mediate stability in adjacent aquatic-terrestrial systems and determining their relative importance across spatiotemporal scales may enable “connection strength” to serve as a currency for assessing watershed resilience. This session will bring together researchers developing and applying approaches to measure aquatic-terrestrial linkages through field experiments, long-term monitoring, and modeling. Talks will explore terrestrial-aquatic connections and the magnitude and variation of impact on associated ecological processes such as contaminant pathways, nutrient enrichment, and gene flow. By focusing on how we define and quantify these connections, this session will advance our understanding of their role in mediating ecosystem responses to global change and inform applied efforts that support the management and resilience of healthy watersheds and their communities.

Special Session: Advancing environmental flow management: Holistic approaches for sustaining aquatic ecosystems

Organizers: Kris Taniguchi-Quan, Sooyeon Yi & Ted Grantham

Freshwater ecosystems rely on adequate streamflow, yet increasing pressures from climate change, prolonged drought, and growing human water demands are making it more difficult to satisfy ecosystem water needs. Environmental flow programs seek to establish quantitative criteria to manage water in ways that sustain biodiversity and support the services that healthy freshwater ecosystems provide. However, many flow programs are limited in spatial scale and focus on the habitat needs of a few threatened or endangered species, often overlooking broader ecosystem processes and outcomes. This session will:

Highlight novel research on the functions, values, and methodologies that inform environmental flow management in rivers and estuaries;

Explore the science that underpins environmental flow programs aiming to deliver outcomes at a range of scales; and

Examine policy, management, and interdisciplinary approaches that strengthen the implementation and scalability of environmental flows.

We welcome case studies, field-based investigations, and modeling approaches that assess the effects of flow interventions on ecosystem function, species of interest, and indicators of ecosystem health, as well as their broader implications for ecosystem services and societal values. Additionally, we seek contributions that explore the implementation of environmental flows, including policy mechanisms, management strategies, and interdisciplinary approaches that enhance the effectiveness and scalability of flow programs.

Special Session: From dead ends to discovery: Embracing Failure as a Pathway to Scientific Progress

Organizers: Elise Snyder & Amaryllis Adey

Scientific progress is inextricably linked to failure – experiments do not go as planned, projects hit dead ends, data does not yield exciting results, etc. Although our training as scientists tells us that all results are important, in practice, the publication process often excludes “failed” studies and null results. Additionally, learning to fail presents a challenge for students and early career scientists who are experiencing tribulations that come with pursuit of knowledge for the first time. The aim of this session is to provide a venue to discuss failure in our research. Broadly, talks will cover science that did not go as planned, and discuss how these projects became or will become pathways to forward progress. Further, we encourage presentations on everything from the nitty gritty of projects in progress to broad reflections on how failure has shaped a career. The session will open with an invited presentation by a well-established SFS member (to be recruited after session acceptance) to introduce the topic of failure in science and discuss how their career and path in science have been shaped by “failures”. In keeping with the SFS 2025 theme of “Gathering to Build Resilient Watersheds and Communities ”, this session will stimulate attendees to build resilience by thinking beyond the entrenched norms of success, having open discussions about the scientific process, and fostering an open-minded approach to the scientific process.

Special Session: Scholarship of teaching and learning in freshwater science

Organizers: Elizabeth Sudduth, Patina Mendez & Fredric Govedich

Today’s students will be tomorrow’s decision and policymakers. Therefore, informing and engaging students from all disciplines in the field of freshwater sciences is essential, especially considering the rate, magnitude, and impacts of current environmental changes. This is particularly important considering the range of public awareness and acceptance to current environmental issues. We propose a special session focused on pedagogy, research, and assessment of teaching and learning in the freshwater sciences. The goal of this session is to support educators in improving STEM instruction by promoting the adoption of best practices of teaching and learning in our field. This special session will support our Society’s mission of promoting further understanding of freshwater ecosystems and fostering the exchange of scientific information among the membership, especially educators. We encourage session contributors to share specific STEM teaching practices, techniques, goals, modules, and experiences. Pedagogical techniques related to all areas of freshwater science that could be applied to the classroom/lab/field are welcome to participate in the session. We also encourage participants to contribute inquiry-based activities and resources used in the classroom/lab/field to build and enhance educational materials offered to our membership in both formal and informal educational settings. Ultimately, we hope that the information shared in this session will help educators to better engage students, creating better scientists, active advocates for environmental issues, and better-informed decision and policymakers.

Special Session: Swimming together: Successful freshwater collaborations across multiple organizations to generate actionable science

Organizers: Erin Larson & Audrey Huff

Coproducing rigorous freshwater science that can successfully inform management requires coordination across multiple disciplines and entities. These types of efforts require trust-building, agreement on a common vision, and understanding of the distinct strengths and challenges inherent to different types of academic institutions, government agencies, and non-profit organizations. Contributors will share examples of projects that involved multiple collaborators from different types of organizations and addressed a freshwater management issue with scientific and societal implications. By showing concrete examples of these types of efforts, we hope to demonstrate that the investment required to co-produce actionable science has a great payoff in societal benefit and to help the next generation of freshwater scientists see clear pathways for engaging in knowledge co-production.

Special Session: Beavers and Beyond: Patterns and Processes Driven by Ecosystem Engineers

Organizers: Abigail Hullihen & Emily Arsenault

Ecosystem engineers strongly influence their environments by altering abiotic properties, which in turn affect biotic responses such as habitat suitability, resource availability, and community composition. From beavers modifying hydrology and water chemistry, to invertebrates transforming nutrient cycling dynamics, to net-spinning caddisflies stabilizing stream beds, or macrophytes regulating light availability to benthic species, these species fundamentally reshape the ecosystems they inhabit. This session, “Beavers and Beyond: Patterns and Processes Driven by Ecosystem Engineers,” highlights the diverse ways in which ecosystem engineers modify their surroundings; physically, chemically, and ecologically. Talks in this session may be focused at a variety of scales from individual to landscape and explore a variety of topics from exploration of ecosystem engineer influence on nutrient cycling, biodiversity, and food web structure, to management for system recovery following disturbance. This session will integrate diverse perspectives to reveal the ways in which ecosystem engineers structure, sustain, and transform freshwater ecosystems.

Special Session: Positive biotic interactions in freshwater; importance, prevalence, and drivers

Organizers: Samuel Fritz & Lindsey Albertson

Research surrounding the importance of biotic interactions in freshwater systems has flourished in recent years. Concepts like ecosystem engineering have challenged long held assumptions about the dominance of abiotic factors as determinants of structure and function in freshwaters. While negative biotic interactions like competition and predation have often been discussed, positive interactions like commensalism and mutualism have received comparatively less attention. Though progress has been made, determining the prevalence and importance of these interactions remains challenging. Furthermore, the lines between positive and negative interactions frequently blur when outcomes change in sign or strength under different conditions, a phenomenon known as context dependency. As humans continue to alter freshwater systems, understanding factors influencing the outcome and importance of biotic interactions will become both more difficult and more important. This session is intended for talks which address the importance, prevalence, or drivers of these interactions, with special emphasis on understudied positive interactions. Discussion of context dependent outcomes is also encouraged, whether these interactions are primarily positive or negative. This might include indirect positive interactions which are underlain by negative direct interactions, or interactions which include positive and negative tradeoffs.

Special Session: Claws and effect: the role of crayfish across ecosystems

Organizers: William Ota, Jose Colon Gaud & Julian Olden

Crayfish play an important role in freshwater ecosystems. As native species, they are recognized as critical ecosystem engineers that structure habitats, recycle nutrients, and sustain biodiversity. As invaders, they are associated with concerns regarding their impacts on food webs, habitat stability, and the challenges they pose to management and conservation efforts. As crayfish species become more common in the retail trade, efforts continue to prevent new and subsequent introductions of potentially harmful non-native species. The dichotomy of impacts between native and invasive crayfish in ecosystems provides a valuable example to understand both the vulnerability and resilience of freshwater systems.

This session—Claws and Effect: Crayfish Impacts Across Ecosystems—will explore how crayfish shape ecological processes, influence community dynamics, and intersect with human management and conservation. Presentations will span native and invaded systems, emphasizing how crayfish ecology informs our understanding of disturbance, recovery, management, and watershed health. Contributions offering new insights into species diversity and distributions will also be encouraged.

By integrating studies of population ecology, behavior, management interventions, and community engagement, this session highlights how crayfish science can advance the 2026 meeting theme: building resilient watersheds and communities. Through this lens, crayfish serve as both a warning and an opportunity—illuminating how understanding species’ impacts can guide more adaptive and inclusive freshwater stewardship.

Special Session: The fluvial pharmacy: Pharmaceuticals and their residuals in freshwater ecosystems

Organizers: Emma Thrift-Cahall, Mitchell Liddick, Ashley Hennessey, Jennifer Tank & AJ Reisinger

The presence of pharmaceuticals in freshwater ecosystems represents an enduring challenge of the Anthropocene. Pharmaceuticals and their residues have become ubiquitous in aquatic ecosystems through their extensive use in human and livestock populations. However, the influence of these synthetic chemicals on ecosystem structure and function is not fully understood. The environmental impacts of pharmaceuticals are particularly complex because exposure extends beyond the parent compounds, as pharmaceuticals undergo transformations, interact with other contaminants, and are modified as a result of their interplay with organisms and microbial communities. These complex interactions generate cascading and often unanticipated effects on ecological and human health. Through this session, our goal is to advance the emerging subdiscipline of the ecology of pharmaceutical contaminants by integrating perspectives from ecotoxicology, biogeochemistry, and ecosystem science. We welcome research addressing the fate, transport, and transformation of pharmaceuticals in aquatic systems, and their effects on organismal dynamics, antimicrobial resistance, and ecosystem processes. We particularly encourage submissions examining how land cover change, wastewater infrastructure, agricultural intensification, and climate change are altering pharmaceutical and residue loading, antimicrobial resistance, biogeochemical cycling, and ecological risk in freshwater ecosystems. Through this session, we will build a collaborative network aimed at exploring pharmaceuticals not only as toxicants but also as modulators of ecosystem services, tracers of hydrological connectivity and contaminant sources, and drivers of community composition.

Special Session: The Changing Cryosphere and Its Impacts on Downstream Freshwaters

Organizers: Matthew Dunkle, Holly Harris, Ryan Bellmore & Jeffrey Muehlbauer

The cryosphere—the portion of Earth’s surface that is seasonally or permanently frozen—plays a critical role in regulating the global water cycle and sustaining freshwater ecosystems. Snow and ice influence the timing and magnitude of streamflow, the chemistry and clarity of surface waters, and the structure of aquatic and riparian communities. Yet, rapid climate warming is transforming the extent, persistence, and seasonal dynamics of the cryosphere across alpine and subarctic landscapes. Shrinking glaciers, declining snowpack, and earlier melt are expected to alter both the quantity and quality of meltwater inputs, reshaping hydrologic regimes and biogeochemical processes that underpin freshwater productivity and biodiversity. Past studies have indicated that changes to the cryosphere will impact hydrology, biogeochemistry, and habitat availability. However, we lack a mechanistic understanding of how these changes may alter aquatic food webs, community assemblages, and the population dynamics of specific taxa. Understanding these linkages is essential for predicting how cold-region ecosystems will respond to ongoing climatic shifts. This session will bring together research examining the structure and dynamics of freshwater ecosystems influenced by permanent ice and snow, the effects of changing climatic conditions on the seasonal cryosphere and downstream waters, and the ecological responses of organisms and food webs to altered meltwater contributions. By integrating studies across gradients of latitude, elevation, and cryospheric influence, this session aims to advance a mechanistic understanding of how climate-driven changes in snow and ice are cascading through freshwater systems—from headwaters to lowlands—and to identify emerging patterns and vulnerabilities in these rapidly changing environments.

Special Session: Chew on This: The Role of Beavers in Building Resilient Landscapes

Organizers: Sandra Clinton & Camille McNeely

There are many factors that have contributed to wetland loss in North America, including draining, land use change, and the removal of beavers. Prior to the European fur trade it was estimated that there were 100-400 million beavers in North America and their presence strongly shaped habitat complexity across local to watershed scales. Beavers are known as “nature’s ecosystem engineer” whose dams, ponds, and wetlands have long been studied by freshwater scientists. Recently beaver populations have been increasing and there is a renewed interest in understanding their role across a diversity of landscapes (ecoregions, land use) and the ecosystem services, and perhaps disservices, they provide. In this session we will bring together both scientists and practitioners who are asking questions about beaver ecosystems related to hydrology, greenhouse gases, biogeochemistry, biodiversity and the role of beavers in restoring freshwater resilience. We are interested in case studies and recent research that highlight the processes through which beavers foster adaptive capacity in freshwater ecosystems facing climate change, land use pressures, and biodiversity loss.

Special Session: Advances in freshwater biogeochemistry using open data across networks of sites

Organizers: Ashif Hasan Abir, Wilfred Wollheim, Erin Hotchkiss & Kelly Aho

With the increasing amount of data from research networks, expanding analytical capabilities and open science policies, there is a paradigm shift from single-site to macro-scale analyses incorporating many ecosystems to tackle knowledge gaps in freshwater biogeochemistry at regional to global scales. We welcome submissions that leverage publicly available data (continuous sensor measurements, field sampling or combination of both) collected across different spatial and temporal scales from multiple sites to advance freshwater biogeochemistry. We are particularly interested in studies utilizing established sensor and measurement networks such as the National Ecological Observatory Network (NEON) Long-term Ecological Research (LTER) networks, Global Lake Ecological Observatory Network (GLEON), and Critical Zone Observatories (CZO) for cross-scale studies . We welcome studies adopting interdisciplinary approaches that use standardized observations, coupled terrestrial and water measurements, high frequency sampling, process-based and/or machine learning models, or any combination of these approaches. Cross-scale studies addressing biogeochemical processes at the interface of terrestrial and aquatic systems such as riparian corridors, hyporheic zones, and different freshwater ecosystems are also encouraged. Throughout this session, we hope to stimulate innovative ideas, approaches and discussions to push our knowledge in freshwater biogeochemistry.

Special Session: The ecology and diversity of our unprotected waters

Organizers: Susan Colvin & Sandra Clinton

Our understanding of the ecological underpinnings and diversity of headwater streams, springs, wetlands, and groundwater is largely uncoupled from policy and protections across the globe. Waters of the United States are those waters protected by the U.S. Clean Water Act and historically they are for the most part waters that have permanent flow, are navigable waters or connected to navigable waters. This definition, and other similar policies, leave a large proportion of the watershed above and below ground, and the important processes and biodiversity therein, unprotected. In this session, we would like to feature the important ecology, chemistry, hydrology, and biodiversity of these largely unprotected waters with a lens examining their fragile and unprotected state. Examples of protected headwaters are welcome as are policy submissions and restoration efforts aimed at reestablishing the function of these systems.

Special Session: Practical Tools for Urban Waterway Management

Organizers: Brian Murphy & Mateo Scoggins

Urban waterways provide benefits that support human communities and wildlife, and yet those waterways are challenged on so many fronts, socially, ecologically, and economically. Urban aquatic ecosystems, for example, are often highly modified, and their physical characteristics and ecological functions can be very different from natural ecosystems. However, urban waterways provide unique opportunities for community connection and can be the essence of a community. Waterway managers, therefore, require the best tools and knowledge available to effectively manage these complex systems. This session will bring together diverse perspectives, integrating cutting-edge social and environmental science, with the goal of providing practical, effective solutions for managers, researchers, planners, and the public. Presenters will provide examples and case studies of decision support tools, monitoring methods, and management frameworks as well as the latest urban ecosystem research.

Special Session: Identifying and protecting high quality waters and healthy watersheds

Organizer: David Gillet

Most monitoring and assessment programs spend the majority of their effort identifying and tracking streams or other waterbodies that do not meet designated quality targets. We have a robust and sophisticated set of tools to determine the degree of degradation in a given waterbody, its cause, and strategies for improving conditions. Conversely, much less time is spent focusing on high quality, non-degraded systems and protecting them from the potential stressors that may lead to their degradation. In our experience, this is partially due to a lack of visibility/management prioritization and also a dearth of assessment tools to guide protection and conservation activities. The goal of this session is to gather different perspectives on the best ways to identify or characterize healthy watersheds, as well as the high-quality water bodies they contain. Beyond identification, we are seeking to highlight frameworks designed to assess and predict the biggest threats – development, climate, water management – to maintaining the high quality of these waters in the future. Lastly, we want to include examples of conservation success stories where the management community has been able to implement protections to high quality waters that ensure their continued health going into the future. This session will serve as an initiation point for the research and management communities to start giving more attention to healthy ecosystems and how they can be protected, rather than solely focusing on degraded and failing systems.

Special Session: Building Resilience in Large Rivers of the Northwest

Organizers: Brooke Long-Fox & Lisa Kunza

Large, regulated rivers of the Northwest anchor biodiversity, Tribal lifeways, and regional economies. Yet hydropower, land-use change, and climate stressors have reshaped flow, thermal regimes, sediment and nutrient dynamics, floodplain connectivity, and food webs. This session highlights the cross-disciplinary and community collaboration needed to build resilience in large rivers, with a special focus on monitoring, management, and restoration practices. We invite practitioners and scientists across agencies, Tribes, and universities to share research or programs that directly inform resilient watershed management. Talks may link community-based monitoring and integrative indicators (e.g., whole-river metabolism, production, food-web quality, thermal refugia, eDNA/bioassessment, sensor and remote networks) to management actions (including Indigenous-informed decisions) and to restoration effectiveness in floodplains, side channels, and riparian areas.

Special Session: Restoring Freshwater Ecosystems to Build Resilient Watersheds and Communities: Insights from Europe and North America

Organizers: Sebastian Birk & Christopher Frissell

Freshwater ecosystems form the lifeblood of resilient landscapes and human communities. Across both Europe and North America, river, wetland, and floodplain restoration efforts are striving to reverse centuries of degradation while preparing for the mounting challenges of climate change, pollution, and land-use pressures. Although the ecological goals are shared, governance structures, policy frameworks, and restoration traditions differ across continents—offering rich opportunities for mutual learning.

This session will bring together scientists, practitioners, and policymakers to explore how restoration can reconnect hydrological and social systems at the scale of whole watersheds. We invite contributions that highlight innovation in restoration planning, nature-based solutions, adaptive management, community engagement, and long-term governance. Comparative case studies and cross-continental reflections are especially encouraged.

By linking European experiences—such as the large-scale initiatives under the EU Green Deal and Nature Restoration Regulation—with North American examples of watershed restoration, this session aims to identify transferable lessons and shared principles for strengthening ecosystem and community resilience across diverse freshwater landscapes.

Special Session: Honoring the memory and scholarship of Mark Wetzel: Taxonomy, Life History, and Life Cycles of Aquatic Invertebrates

Organizer: Sally Entrekin

Mark Julian Wetzel was a beloved member of the Society for Freshwater Science and a research scientist at the Illinois Natural History Survey. Mark devoted his life to the study and stewardship of freshwater ecosystems and was a passionate NABS/SFS member. Trained in zoology at Eastern Illinois University and the University of Illinois, he became known for his unparalleled expertise in aquatic annelids—especially freshwater oligochaetes, earthworms, leeches, branchiobdellidans, and related groups. We would like to honor his work by inviting research on the invertebrate that ignites their passion for freshwater. The only criteria for this session is to share your expertise on a single group of organisms that others can learn from and possibly expand how they approach their own freshwater communities. We aim for this session to bring together researchers developing and applying taxon-specific approaches to classify, identify and use aquatic invertebrates across different ecological contexts from the fundamental understanding to the application in freshwater assessments. Any stories you would like to share as you present will be most welcome but not expected.

Special Session: Challenges associated with bridging science and tribal perspectives

Organizers: Colden Baxter & Laurel Grizoli