Special Sessions

SS01 Water on Earth: Analogues for Other Worlds

Organizers: Cristina Takacs-Vesbach, University of New Mexico, cvesbach@unm.edu and John Priscu, Montana State University, jpriscu@montana.edu

Where there is water on Earth, there is life. Virtually anywhere we have water on this planet, we find life, even in seemingly inhospitable conditions. Exploration of Earth’s “extreme environments” have expanded our definition of the biosphere and habitability. Icy lakes, sea ice, frozen soils, caves, thermal springs, deep sea hydrothermal vents, playas, and briney waters on Earth can provides clues about the potential for the existence of life on extraterrestrial systems such as Mars, Europa and Enceladus where water is thought to exist. Studies of these Earthly systems will also provide important information that can be used to design planetary protection protocols to ensure the integrity of data collected from extraterrestrial bodies as well protect them from Earth bound contaminants. This session will focus on Earth’s aquatic systems that align with conditions thought to exist on other worlds. Studies of a diverse range of Earthly analogues emphasizing how microbial diversity and metabolic functionality reflects the physical and chemical environment are welcome.

SS04 Dissolved Organic Matter Quality: Linking Environmental Dynamics to Molecular Structure

Organizers: William J. Cooper, University of California, Irvine, Rudolf Jaffe, Florida International University, jaffer@fiu.edu, Thursten Dittmar, Florida State University, dittmar@ocean.fsu.edu, and Leigh McCallister, Rutgers University, leigh@vims.edu

Dissolved organic matter (DOM) in aquatic ecosystems is among the largest reservoirs of carbon on the planet. While rough estimates exist for the contribution of DOM processes to the total carbon cycle, its molecular composition, the controlling biogeochemical processes and its importance as a driver in ecosystem dynamics remain largely unknown or are not completely understood. Little is known about the interplay between external and internal biogeochemical processes in relation to changes in DOM quantity and quality, and in fact, while quantitative measurements of DOM are becoming standard in long-term ecological studies, DOM quality measurements remain rare. This symposium will focus on linking molecular features and/or chemical composition of DOM to its environmental dynamics and biogeochemical processing (e.g. microbial- and/or photo-degradation) in diverse aquatic environments.

SS05 Hypoxia Impacts on Aquatic Food Web Composition, Dynamics, and Production

Organizers: David G Kimmel, University of Maryland Center for Environmental Science Horn Point Laboratory, dkimmel@hpl.umces.edu and Stuart A Ludsin, NOAA Great Lakes Environmental Research Laboratory, Stuart.Ludsin@noaa.gov

The prevalence of low dissolved oxygen (hypoxia) in marine, coastal, estuarine and freshwater systems has increased in recent decades. The mechanisms for the generation and persistence of hypoxic areas are generally understood. Also well established is the fact that hypoxia can affect individual organism physiology, behavior and survival. It is clear that hypoxia alters the distribution of biota through both space and time. However, the impact that hypoxia has on aquatic food webs is less clear. Further understanding of how hypoxia affects carbon flow through the food web and production at higher trophic levels (e.g., zooplankton, fish) is essential. This knowledge will be necessary for ecosystem-based management of living resources in areas with chronic hypoxia. As such, we encourage submissions that explore the role of hypoxia in affecting aquatic food webs, including their structure, function, dynamics and production.

SS06 Biofilms in Aquatic Food Webs

Organizers: Willem Goedkoop, Dept. Environmental Assessment, Swedish Univ. Agricult. Sci., willem.goedkoop@ma.slu.se and Alan Decho, Dept. Environmental Health Sciences, USC, Awdecho@gwm.sc.edu

Biofilms are biologically highly active structures in marine and freshwater systems. They occur as suspended aggregates in the water-column, and at the interfaces between sediments, plants and other particulates and the surrounding water. Their important roles in aquatic ecosystems are multifaceted. Biofilms serve as a food source for grazers and scrapers and play key roles in the turnover of nutrients and energy at the base of aquatic food webs. Moreover, biofilms are sites of contaminant sorption/desorption and may serve as a vector for contaminant introduction into food webs. We anticipate contributions that address the multitude of structural and functional aspects of biofilms in aquatic systems, including chemical and biological characterization, nutrient/energy turn-over, trophic relationships, and interactions with contaminants.

SS07 Carbon Cycling at the Land-Ocean Interface

Organizers: Antonio Mannino, NASA Goddard Space Flight Center, antonio.mannino@nasa.gov, Marjorie Friedrichs, Old Dominion University, marjy@ccpo.odu.edu, and Dale Haidvogel, Rutgers University, dale@imcs.rutgers.edu

There is growing recognition that organic carbon production and transformations in estuarine and continental shelf systems are major components of the global ocean carbon cycle. Results from multidisciplinary observational and modeling programs are providing new insight into the many factors that control carbon exchange with terrestrial and open ocean systems, carbon processing in estuarine systems and on continental shelves, and feedbacks to biogeochemical processes in estuarine and continental shelf systems. These studies highlight the coupling of physical and biological phenomena over a wide range of temporal and spatial scales. This special session is intended to provide a framework for synthesis and exchange of information on carbon cycling within the land-ocean interface. We especially encourage papers that consider aspects of carbon transformation and processing that highlight: 1) linkages between physical and biological phenomena; 2) effects of climate variability on estuarine and continental shelf ecosystems and biogeochemical cycles; 3) applications of remotely-sensed data to understanding carbon cycling and budgets; and 4) observations and modeling studies, including data assimilative and hydrological modeling.

SS08 Recruitment of Marine Larvae: Experimental and Modeling Studies

Organizers: Donal T. Manahan, University of Southern California, manahan@usc.edu and Eileen Hofmann, Old Dominion University, hofmann@ccpo.odu.edu

Predicting recruitment success remains a major issue in marine ecology, species conservation, and fisheries management. Most marine animals have distinctive larval and adult phases as parts of a complex life history strategy. Larvae of such species can remain in the plankton for weeks-to-months (possibly years for some species) and are typically subject to high mortality rates that result in variable recruitment to adult populations. This special session is intended to bring together scientists from diverse disciplines in fields of experimental biology and oceanographic modeling to provide a synthesis and exchange of information on current and future approaches required for the study of the complex problem of recruitment in the marine environment. We especially encourage contributions from the areas of developmental and evolutionary biology, and quantitative genetics, which are now providing new insights into larval processes. This session will consider the recruitment “problem” and place special emphasis on results from recent multidisciplinary research programs that focus on physical variability and feedbacks to population dynamics. The session will highlight: 1) dispersal and transport of larvae in systems that range from large-scale (e.g. the Southern Ocean) to continental shelf systems; 2) genetic studies of population connectivity; 3) physiological and biochemical studies of marine larval biology; 4) application of genomic analysis to understanding marine recruitment success; 5) effect of climate variability on marine food webs as they might affect larvae; and 6) modeling studies, including individual-based models of larval population dynamics.

SS09 Studying the Ecology, Biodiversity, and Abundance of Aquatic Animals

Organizers: David Bailey, Oceanlab, University of Aberdeen, UK, d.bailey@abdn.ac.uk and Nikki King, Oceanlab, University of Aberdeen, UK, n.king@abdn.ac.uk

Counting animals in the marine environment, and determining their biomass and population structure is extremely difficult. All techniques from visual census by divers, to fisheries catch data have limitations and biases. In topographically complex, deep, or fragile habitats these problems are exacerbated and the range of assessment techniques available is greatly reduced. An increasingly widely used approach is to census marine animals using baited cameras. A range of systems is in use worldwide, providing replicable census data on the rough terrain of reefs and ocean ridges, and on the abyssal plains. As well as providing abundance data these systems allow the study of animal behavior, and particularly insights into the roles of scavengers in the marine environment.

This session will bring together the growing community of baited camera users, and other scientists interested in the behavior of marine scavengers, sensory biology, and the hydrodynamics of aquatic environments. This session will review the technology currently in existence and the associated methods used to study animals and calculate population parameters from camera data. The key aims of the session will be to share experiences and expertise, plan the future development and testing of baited camera methods, and draft a set of “best practice” guidelines for the use of baited cameras in science and management.

SS10 Desert Riparian Ecosystems: Multidisciplinary Investigations of Environmental Change

Organizers: Thomas Meixner, University of Arizona, tmeixner@hwr.arizona.edu, Julie Stromberg, Arizona State University, jstrom@asu.edu, Steve Stewart, University of Arizona, SStewart@hwr.arizona.edu, and Paul Brooks, University of Arizona, brooks@hwr.arizona.edu

Changes in climate, land use, land cover, and water management collectively have altered riparian ecosystems in arid and semi-arid regions, complicating efforts to restore degraded systems. In few biomes is the transition between upland and riparian so sharp, the coupling of physical and biological processes so tight, and the impact of anthropogenic activities so extreme. Maintaining and restoring these hotspots of ecological diversity and biogeochemical function requires coordinated research in historically disparate fields of ecology, hydrology, geomorphology, engineering and economics. This session invites the submission of abstracts from physical, biological, and social scientists whose research addresses riparian systems in arid and semi-arid environments. We encourage a broad range of approaches including basic research, applied examples of restoration, relationships between restoration and human use, and theoretical under-pinnings related to desert riparian ecosystem structure and function.

SS11 Form and Function of Zooplankton

Organizers: J Rudi Strickler, WATER Institute, University of Wisconsin – Milwaukee, jrs@uwm.edu, Petra Lenz, PBRC, University of Hawaii, petra@pbrc.hawaii.edu, and Gus Paffenhofer, Skidaway, cmp@skio.peachnet.edu

For over 200 years, scientists have asked the question of whether a certain form has an associated function. For example, in 1886 Chun in his monograph “Atlantis” suggested that the spines and setae of copepods serve as a “parachute” to slow sinking. Wolterek, in 1913, was the first one to note that the addition of spines and helmets, as in Daphnia, results in greater energy expenditure for swimming. More recently, predator-induced defenses were added to the long list of explanations. This broad category includes specialized sensory structures, optimization of locomotory performance and inhibiting predation through spines. Few of these explanations have subjected to rigorous testing.

This session will give researchers the chance to analyze their observations within the context of form and function. We invite all to sieve through their data and see whether or not there are correlations between observed shapes and behavior patterns and suggested functions. The importance of such analyses is that recent advances in evolutionary developmental biology (EvoDevo), molecular biology, computational fluid dynamics and digital video holography allow testing of different hypotheses. In this session we expect to review existing data on form and function in zooplankton, as well as discuss the potential of novel techniques for elucidating form-function relationships.

SS12 ASLO Multicultural Student Symposium

Organizer: Benjamin Cuker, Hampton University, benjamin.cuker@hamptonu.edu

The Student Symposium is a forum for undergraduate and beginning graduate students to present their work and research plans. It is sponsored by the ASLO Multicultural Program. This is a regular feature of the ASLOMP.

SS13 Calcification in Aquatic Ecosystems: Physiology, Biogeochemistry, and Response to Environmental Change

Organizers: Jean-Pierre Gattuso, CNRS-University of Paris, gattuso@obs-vlfr.fr and Joanie Kleypas, National Center for Atmospheric Research, kleypas@ucar.edu

The goal of this session is to report recent advances in the field of calcification in both marine and freshwater ecosystems. All spatial and temporal scales will be included, from molecular to global, and across geologic time through the present and future. Topics of interest include, but are not limited to: (1) molecular control, (2) transport pathways, (3) estimates of calcification at the organism, community and global scales, and (4) response to elevated pCO2 and temperature. Both experimental and modeling approaches are welcome.

SS14 New Technologies for the Study of Continental Margin Benthic Ecosystems and the Need for Benthic Observatories

Organizers: Dr. Christophe Rabouille, Laboratoire des Sciences du Climat et de l’Environ, rabouill@lsce.cnrs-gif.fr and Dr. Elanor Bell, Potsdam University, ebell@rz.uni-potsdam.de

Marine coastal ecosystems are among the most productive and diverse communities on Earth and are of global importance to climate, nutrient budgets and primary productivity. Continental margin sediments and their associated biota represent a reservoir for biodiversity, and a key environment for carbon and nutrient recycling in the ocean. Yet, these benthic ecosystems are compromised by human-induced stresses, including over-fishing, habitat destruction and pollution, which compromise biodiversity, ecosystem stability and biogeochemical processes. However, the relationship between tightly coupled biological and geochemical processes on continental margins is poorly defined with respect to their temporal and spatial variability, and human impacts.

In this session, we propose to present and discuss recent technological developments that are advancing our interdisciplinary, in situ observation and experimentation of this complex, remote and poorly understood environment. Sediment imagery, microelectrodes, planar optodes, manipulated benthic chambers, ‘smart’ data systems, advanced cable networks and more, are enhancing our fundamental understanding of the interactions between benthic biota and their environment and facilitating informed management of human impacts on coastal ecosystems. In parallel, conceptual frameworks and communication tools are being developed using visualization software and sophisticated numerical tools to link scientific results with environmental policy, measures and approaches. The session will discuss the current “state of the art” as well as new initiatives in continental margin in situ observation and experimentation.

SS16 Quantifying Ecological Subsidy and Resource Sheds

Organizer: David Raikow, NOAA Great Lakes Environmental Research Laboratory, david.raikow@noaa.gov

Recognition of ecosystem connectivity is embodied in ecological subsidy, in which resources originate not at the location of exploitation but from distant areas often outside the geographic range of exploiting organisms. Patterns of ecological subsidy can be described spatially by the delineation of resource sheds, or geographic areas contributing resources to a point location, population, or organism. In lotic ecosystems, for example, ecological conditions at a point location of interest are heavily influenced by the position of the location within the easily visualized nested spatial contexts of the channel, the drainage network, and the watershed. Coastal and lentic ecosystems, in contrast, have internal spatial contexts that are more difficult to characterize. Yet analysis, explanation, and ultimately prediction of many ecological phenomena including physical drivers of fish production, harmful algal blooms, hypoxia, benthic community change, and pollutant distribution arguably require a landscape perspective, and thus would benefit from explicit delineation of resource sheds. Hence, in order to review progress in the quantification of subsidies and resource sheds this session focuses on the process of ecological subsidy in aquatic ecosystems. We invite contributions describing models of resource shed delineation in and between watersheds and coastal ecosystems, field studies generally examining the spatial origins of resources, and investigations of resource-specific or organism-specific resource sheds.

SS17 A New Look at Darwin’s Last Idea: Bioturbation and Bio-irrigation in Aquatic Sediments

Organizers: Filip Meysman, Netherlands Institute of Ecology, f.meysman@nioo.knaw.nl and Yoko Furukawa, Naval Research Laboratory, yoko.furukawa@nrlssc.navy.mil

In 1881, one year before he died, Charles Darwin published his last scientific book “On the Formation of Vegetable Mould”, which was entirely devoted to bioturbation, the biological reworking of the subsurface. Burrowing activities modify the physical structure of soil/sediment matrix, enhance of solute transport via bio-irrigation, and mediate the dispersal of particles, both abiotic (organic matter, metal oxides, contaminants) and biotic (bacteria, viruses, fungal spores, protists, metazoan eggs, meiofauna). Darwin was the first to realize that such small-scale reworking activities could have dramatic consequences on far larger scales, such as the landscape or ecosystem scale. Nowadays, bioturbation is studied in a wide range of disciplines (ecology, paleontology, geology, contaminant dispersal), reflecting the many different effects that bioturbation has on the physical, chemical and biological functioning of aquatic sediments. One hundred and twenty five years after Darwin, the objective of this special session is to make a cross-disciplinary round-up of our understanding of bioturbation. Biogeochemists stress the role of biologically induced transport in the cycling within aquatic sediments. Environmental scientists focus on bioturbation for its role in contaminant dispersal. Geotechnical engineers contemplate the effect of burrowing on seabed mechanical properties. Modern ecologists investigate burrowing organisms as prime examples of ecosystem engineers. Paleontologists consider bioturbation as a key adaptive pressure in the Cambrian explosion. To our session, we invite experimental and modeling contributions from all these disciplines, touching upon the various modern and paleo aspects of bioturbation.

SS18 Predicting the Effect of Changes in the Terrestrial Environment on Aquatic DOC

Organizers: Kevin Bishop, Swedish Univ. of Agricultural Sciences Dept. of Environmental Assessment, kevin.bishop@ma.slu.se, Rick Bourbonniere, Environment Canada, Rick.Bourbon@ec.gc.ca, and Tom Clair, Environment Canada, tom.clair@ec.gc.ca

Dissolved organic carbon (DOC) exerts a profound influence on the chemistry and ecology of both soils and surface waters. Thus the complex properties of DOC figure prominently in many environmental issues from the production of greenhouse gases (e.g. methane and carbon dioxide), through mineral weathering, nutrient mobilization and uptake as well as metal/toxic transport and transformation (such as the production of methylmercury). The terrestrial environment, usually the more organic-rich soils of a catchment, is an important source of the DOC in many surface waters. Both natural and anthropogenic changes in the biogeochemical cycling of DOC in soils and wetlands may therefore alter the aquatic environment dramatically, together with the potential for sustainable use of natural resources. Despite the significance of DOC, though, many questions remain about the biogeochemical cycles that steer the creation, transformation, and degradation of DOC, as well as the ultimate delivery of DOC to surface waters. This special session will provide a forum for the exchange of information, understanding and ideas on how natural and anthropogenic influences on the terrestrial environment will alter the amount, quality and dynamics of DOC in the aquatic environment. In particular, we want to examine the hypothesis that factors associated with climate change are responsible for the increase in freshwater DOC concentrations that has been noted during the past decade in some regions of Europe and North America.

SS19 Supply-side Ecology: What Have We Learned Since (Lewin) 1986?

Organizers: Gil Rilov, Oregon State University, rilovg@science.oregonstate.edu and Sarah Dudas, Oregon State University, Sarah.Dudas@science.oregonstate.edu

In a Science paper published in 1986, Lewin coined the term ‘supply-side’ ecology to highlight the importance of the level of propagule supply of organisms with complex life cycles in shaping aquatic ecological communities. This followed two decades in which research emphasized the importance of post-settlement processes like competition, predation and disturbance. Since then, many studies focused on the nature of spatial and temporal variation in larval supply, settlement and recruitment, and how do they affect coastal population dynamics and community processes. In short, the rate of onshore larval supply and settlement will depend mainly on larval abundance offshore, onshore transport mechanisms, larval behavior and, when the larvae arrive onshore, settlement cues, substrate availability and micro-hydrodynamics.

The development of modern oceanographic tools has led to huge advancements in understanding the dynamics of coastal oceans. Alongside these advancements, the growing collaboration between oceanographers and ecologists has sprouted new insights into supply-side ecology. In the first decade since Lewin’s paper, research focused largely on meso-scale coastal processes, such as upwelling regimes, which are still under intense study. Recently, however, increasing attention has also been directed to local, very nearshore transport mechanisms. Studies now look at fine temporal and spatial variability in both supply and settlement and the relationship between them. There is a growing effort to try to tie these biological signals to fine scale oceanographic features such as internal waves and tidal bores and to local shoreline topography. Studies have also focused on the relationships between oceanography, larval life history and behavior; all of which affect dispersal ranges and pathways, and connectivity among populations.

This symposium will focus specifically on nearshore larval transport and delivery mechanisms, complementing the symposium “Recruitment of marine larvae: Experimental and modeling studies” which focuses on larger-scale systems. We would like to bring together researchers that study several aspects of supply-side ecology: (1) oceanographic meso- and nearshore larval transport mechanisms; (2) influence of larval behavior on nearshore larval supply and onshore transport and settlement; (3) scales of variability in supply, settlement and recruitment to coastal ecosystems, and (4) the interaction between larval supply and population and community dynamics. We want people to review current knowledge in the field, describe exciting new findings and identify the gaps in knowledge that need to be resolved.

SS20 Advances in Biogeochemical Modeling: Bridging Physics, Chemistry, and Biology

Organizers: Parisa Jourabchi, Utrecht University, parisa@geo.uu.nl, Sandra Arndt, Utrecht University, arndt@geo.uu.nl, and Philippe Van Cappellen, Utrecht University, pvc@geo.uu.nl

Biogeochemical systems are characterized by complex interactions between physical, chemical and biological processes. Interdisciplinary approaches are required to further our understanding of the functioning of biogeochemical systems, and to predict their behavior on variable spatial and temporal scales. This session will focus on recent advances in the quantitative modeling of the biogeochemical dynamics of aquatic environments. We invite contributions that exemplify the application of models to systems governed by strong coupling of their biology, chemistry and physics. The topics include, but are not limited to, nutrient cycling and phytoplankton dynamics in rivers, lakes, estuaries and the coastal zone, benthic-pelagic coupling, early diagenesis, non-linear systems, and global biogeochemical cycles.

SS21 Production and Cycling of Dissolved Organic Matter in Aquatic Systems Studied Through Experimental, Field, and Modeling Approaches

Organizers: Daniel Repeta, Woods Hole Oceanographic Institution, drepeta@whoi.edu, Craig Carlson, Ecology, Evolution and Marine Biology, University of California, carlson@lifesci.ucsb.edu, and Raleigh R. Hood, University of Maryland Center for Environmental Science, Horn Point Laboratory, rhood@hpl.umces.edu

Enormous quantities of carbon and nutrients are sequestered as dissolved organic matter (DOM) in both marine and freshwater systems. Sources of DOM include direct release by metabolically active phytoplankton, viral lysis, and release through excretion by micro- and mesozooplankton. However, the time-space variability in the relative importance of each mechanism, the quality of organic matter released, and its impact on the microbial loop are still under investigation. The fate of DOM is even less well understood than the sources. It has long been known that bacteria consume DOM, but different bacterial communities (i.e., deep vs. shallow and coast vs. open ocean) appear to target different fractions of DOM and have different metabolic requirements. Some autotrophs can also utilize specific components of DON and DOP by mobilizing extracellular enzymes such as alkaline phosphatase. This session seeks contributions that focus on improving our conceptual and mechanistic understanding of DOM production, consumption and cycling through field, laboratory and modeling studies in both marine and freshwater systems.

SS22 Evolutionary Responses of Plankton Communities to Natural and Human-induced Stress

Organizer: Alison Derry, Queens University, derrya@biology.queensu.ca

Evolutionary processes are increasingly recognized to occur over a contemporary, ecological timescale. Ecological interactions with abiotic and biotic components of ecosystems can be selective forces for rapid evolution, which in turn has potential to alter the outcome of simultaneous ecological processes. Since plankton occupy bottom and intermediate energy links in the food chains of aquatic and marine ecosystems, the evolutionary ecology of plankton has potential to affect multiple trophic levels as well as community dynamics. Further, because of short generation times, large population sizes, variety of mating systems, and dispersal mechanisms through time and space, plankton are excellent systems for investigating overlap between ecology and evolution such as the maintenance and role of genetic diversity in communities and adaptive responses to natural (predation, parasites, geographical isolation) and human-induced (pollution, climate change, habitat fragmentation) change.

SS23 Conundrums and Controversies: What Contributes to the Vertical Flux of Carbon, Nitrogen and Phosphorus in Aquatic Ecosystems?

Organizers: Tammi Richardson, University of South Carolina, richardson@biol.sc.edu and Claudia Benitez-Nelson, University of South Carolina, cbnelson@geol.sc.edu

Relationships between primary production, nutrient uptake, particle formation and export are among the most studied, yet enigmatic problems in oceanography and limnology. This is due to the wide variety of transformations that underlie these processes, all of which must be characterized for a complete understanding of global carbon and nutrient cycles, food webs and trophic relationships, and related anthropogenic impacts. Following the theme of the Santa Fe ASLO meeting, this session will seek to challenge our current understanding of the factors that enhance and control carbon and nutrient fluxes in aquatic ecosystems. We encourage submissions that examine biological, chemical, physical, or geological processes that influence carbon, nitrogen, and phosphorus fluxes on any scale. Topics of particular interest are food web process studies, modeling, particle formation, sinking, and remineralization, and dissolved organic matter cycling.

SS24 The Aquatic Gel Phase, Its Role in Biogeochemical Cycles

Organizers: Pedro Verdugo, University of Washington, verdugo@u.washington.edu and Peter H. Santschi, Texas A&M University, Santschi@tamug.edu

This symposium will focus on the complex interaction among biological, physical and chemical processes that result in the formation and cycling of gels in fresh and ocean water. Gels are among the most critical, complex and yet least explored subjects in aquatic sciences. Regardless of their source, size, or composition, gels resulting from decomposed tissue of marine biota, from exopolymer released by bacteria, or from phytoplankton blooms, play critical roles in the water. Their unique ion exchange properties allow them to concentrate trace metals, undergo crystalline mineralization of their polymer matrix, or nucleate hydrates among other properties. Most significant however, they are a rich source of microbial nutrient. Although the importance of the role of gels in aquatic carbon cycling had not been fully appreciated, the discovery that moieties found in the DOM pool can spontaneously and reversibly self assemble forming microscopic gels imply the existence of a global scale process of far reaching implications. DOM assembly follows a nonlinear second order kinetics, it is reversible, and has an equilibrium thermodynamic yield of about 10% (Chin et al, Nature 1998). Considering the magnitude of the DOM stock (~7 x 10^17 gC), the gel pool could reach up to up ~7 x 10^16 gC. Within the scales of “size-related bioreactivity” gels could represents one of the richest and most readily accessible pools of bioreactive carbon and the largest volume of distributed “patchiness” available for microbial degradation. These findings introduce a fundamental change in the way that aquatic scientists think about processes linking the microbial loop and biological pump to the rest of the biosphere and the geosphere (Wells, Nature 1998).

The main goal of this symposium will be to attract an interdisciplinary panel of investigators from geochemistry, polymer physics, and microbiology to present their work and discuss the multiple implications of this emerging field, particularly in regard to global carbon cycling.

SS25 In Search of Allochthony

Organizers: Joel Hoffman, Virginia Institute of Marine Science, Hoffman.Joel@epa.gov and Deborah Bronk, Virginia Institute of Marine Science, bronk@vims.edu

Studies across a variety of aquatic ecosystems, including lakes, large rivers, and river-estuary complexes, have identified varying roles of allochthonous matter in metazoan food webs. Allochthonous matter is important in some lake ecosystems, particularly humic lakes, where it can increase production of zooplankton and fish. Yet, in large rivers and coastal zones, metazoan food webs are often fueled by endogenous-produced phytoplankton and allochthonous matter may have little importance. The increasingly widespread access to techniques for identifying sources of organic matter fueling aquatic food webs, including stable isotope approaches, have resulted in a rapidly expanding literature. This session on the sources of matter fueling metazoan food webs will examine case studies investigating the sources and quality of allochthonous matter to aquatic ecosystems, evidence of instances where allochthony is important to upper trophic levels (i.e. zooplankton, macroinvertebrates, and fish), and cross-system comparisons or ecosystem-based research in search of generalities in allochthony, particularly its causes and consequences. Studies from across the spectra of aquatic ecosystems are welcomed.

SS26 Understanding and Modeling Aquatic Ecosystems Using Fundamental Laws

Organizers: Joe Vallino, Marine Biological Laboratory, jvallino@mbl.edu and Lora Harris, Marine Biological Laboratory, lharris@mbl.edu

Numerical representations of systems usually require some tradeoff among various modeling objectives. Biogeochemical models designed for the lake or marine environment typically describe ecosystem functions with empirically derived relationships that are frequently calibrated for a particular location and set of environmental circumstances. This limits the generality of these models and may ultimately negate their predictive use under conditions beyond those considered for the calibration.

This symposium will provide examples of alternative approaches that attempt to use quantifiable first principles in the design of predictive ecosystem models. Ecosystems are hierarchical collections of individuals, populations, and communities that exhibit self-organization in response to the physical and chemical environment. Darwinian natural selection has served as the most prevalent theory for understanding the origin of self-organization, but provides no obvious explanation for system evolution. Fundamental laws are needed to provide the motivation for systems-level organization, which is not explained by species-specific fitness maximization. Once established, such laws can be used within numerical models to provide predictions not currently possible, such as the coordination of ecosystem metabolic networks that govern biogeochemistry. For example, non-equilibrium thermodynamics can be used as an organizing principle that simultaneously predicts adaptive behavior and system evolution. We encourage submissions that explore fundamental laws as a basis for predictive models of ecosystem dynamics.

SS27 Trace Metals, Microbial Processes, and Biogeochemical Cycles Through Space and Time

Organizers - Kathy Barbeau, Scripps Institution of Oceanography, UC San Diego, kbarbeau@ucsd.edu, Alison Butler, Dept. of Chemistry and Biochemistry, UC Santa Barbara, butler@chem.ucsb.edu, and Felisa Wolfe-Simon, Arizona State University, fwolfe@asu.edu

Trace metals play an important role in structuring aquatic microbial communities by virtue of their function as essential micronutrients and toxins. Modern environments show marked spatial variability in trace metal bioavailability, and over geologic time scales changes in Earth’s redox state have dramatically affected trace metal geochemistry. Both of these gradients are hypothesized to constrain the selection of elements for biological usage in microbial communities; however, the interaction between bioinorganic and environmental chemistry is only beginning to be understood, and due to the complex set of feedback cycles involved a multidisciplinary approach is warranted. Evidence from the rock record examined synergistically with physiological and genomic data on extant organisms will be required to fully appreciate and understand the evolution of bioinorganic chemistry, including the modern employment of novel metalloenzymes (e.g. utilizing metals such as Ni, W, Cd, V). Current studies of trace elements and their biogeochemical cycles are taking advantage of molecular-level knowledge of trace element speciation, new stable isotope analytical techniques, and increasingly sophisticated field incubation methods. At the same time, the availability of partial and complete genomic information for model organisms and microbial assemblages is enabling researchers to elucidate the function of trace elements at the organism and ecosystem level. We invite a wide range of papers, with an aim to engage researchers from diverse fields interested in synthesis of the information in this emerging field, which embraces biochemistry, paleoceanography, molecular genomics, inorganic chemistry, microbiology, and geochemistry. Topics will include metal speciation and bioavailability, biogenic metal chelating agents, metalloenzymes, metals as limiting micronutrients or toxins, the role of microbes in trace element transformations, and genomic studies of metal function, acquisition or cellular homeostasis.

SS29 Apex Predators in Aquatic Food Webs

Organizers: Douglas Biggs, Dept of Oceanography, Texas A&M University, dbiggs@ocean.tamu.edu and Bruce Mate, Hatfield Marine Sciences Center, Oregon State University, bruce.mate@oregonstate.edu

Recent research has emphasized the importance of apex aquatic predators in top-down control of marine and freshwater food webs, and a variety of technologies have allowed new insights into their population ecology and habitat preferences. As one example, our research on sperm whales in the Gulf of Mexico in summers 2002-2005 utilized a convergence of different approaches: descriptive work; manipulative field studies such as controlled exposure experiments; analysis of the trajectory of radio-tagged individuals; remotely-sensed study of surface habitat; and acoustic study of subsurface habitat. Others working in different geographic regions and in freshwater as well as marine systems have gained new insight, as well, into the population biology of additional species of predators, and into how predators create and modify patterns of abundance and biomass across more than one trophic level (i.e. the trophic cascade). Our intent for the proposed symposium is to bring together this diversity of research, as both overviews/tutorials and contributed presentations, and to pose “next steps” questions for future research.

SS30 Stirring and Mixing in Biological and Ecological Systems

Organizer: John Crimaldi University of Colorado, crimaldi@colorado.edu

This session is intended to bring together people from a variety of disciplines who share an interest in stirring and mixing processes in biological and ecological systems. While the focus is on the physical processes of stirring and mixing, we encourage studies that investigate the biological and ecological impacts of these processes. The session is open to topics that range from oceanic and atmospheric scales down to organismal scales, and in both turbulent and laminar regimes.

SS31 Mortality Among Microbes

Organizers: Janice Lawrence, University of New Brunswick, jlawrenc@unb.ca and Kay Bidle, Rutgers University, bidle@marine.rutgers.edu

The population dynamics of organisms are governed by the balance between growth and loss processes over spatial and temporal scales. Until quite recently grazing was considered the major loss process for most, if not all microbes in aquatic ecosystems, and other sources of mortality received little attention. Recent developments have illustrated the importance of cell death in microbial dynamics; some estimates suggest that upwards of 50% of phytoplankton growth, for example, is lost due to lysis. While the importance of microbial death is recognized, the process is poorly understood. However, there seem to be a number of fundamental similarities in the process of mortality among microbes, whether triggered by programmed cell death, infection, parasitism, or other environmental or physiological cues. Perhaps by examining these similarities and any differences further we will gain a better understanding of the specific mechanisms that coordinate and orchestrate cell death in aquatic microbes.

For this session we invite field, laboratory and theoretical examinations of microbial death in freshwater and marine systems. It is our goal to bring together researchers studying a variety of forms of cell death, including programmed cell death, parasitism and infection in prokaryote, microeukaryote and virus systems.

SS33 Microbiology of Contaminants in Polar Regions

Organizers: Alexandre Poulain, Université de Montréal, alexandre.poulain@umontreal.ca, Tamar Barkay, Rutgers University, barkay@aesop.rutgers.edu, and Marc Amyot, Université de Montréal, m.amyot@umontreal.ca

With increasing impacts of environmental changes on polar ecosystems, the main pathways of pollutant transformations in cold areas may shift from mostly abiotic (e.g. photochemistry) to mostly microbially-mediated. Although there is increasing concerns about Polar systems health, little is currently known about the biological transformations of organic contaminants or metals, with respect to global change. This topical session will focus on the role played by psychrophilic and psychrotrophic microbes on contaminants transformations. We encourage submission of studies with a strong field component working with natural consortia.

SS34 Phytoplankton Nutrient Uptake and Requirements: From Molecular Mechanisms to Ecosystem Impacts

Organizers: Adam Kustka, Princeton University, kustka@princeton.edu and Elena Litchman, Michigan State University, litchman@msu.edu

The ability to take up nutrients or to alter nutrient requirements (primarily phosphorus, nitrogen, iron, copper, and other trace elements) are key traits that may influence the success of different functional groups of phytoplankton. The resultant effects on net primary productivity and community composition should, in turn, impact higher trophic levels and biogeochemical cycles. Significant advances are being made towards unraveling how different phytoplankton can outcompete others for limiting nutrients. This has been facilitated by the availability of whole genome sequences of model organisms. But the ecosystem- level effects of these differences in situ are less clear. We assert that new breakthroughs are possible by establishing a better dialogue among researchers from disparate fields.

This session that will bring together diverse fields of molecular biology, physiology, ecology and biogeochemistry dealing with either mechanisms of nutrient uptake or differences in elemental requirements for growth. We invite contributions that address a) the molecular underpinnings of nutrient acquisition, b) physiological differences in nutrient requirements and c) the ecological and biogeochemical consequences of these differences. We especially welcome studies that connect different levels of phytoplankton organization and use models to explore the mechanisms and impacts of these differences on ecosystem functioning.

SS35 Oxygen Uptake Dynamics at the Sediment-Water Interface

Organizers: Bernhard Wehrli, Eawag and ETH, wehrli@eawag.ch and John Little, Virginia Tech, jcl@vt.edu

Oxygen uptake is modulated by microbial activity at benthic boundary layers, which in turn is affected by the availability of oxygen, boundary layer mixing and by the bioavailability of organic substrates and reduced substances in the sediment. This session will stimulate interdisciplinary exchange among physicists, biogeochemists, microbiologists and engineers interested in both natural and engineered oxygenation of bottom sediments in rivers, lakes, reservoirs, estuaries and marine systems. We invite innovative contributions on new sensor systems, new modeling concepts, and new oxygenation technologies. Potential applications of interest include transient processes affecting sediment oxygen demand; spatial and temporal variability in sediment deposition, accumulation, and composition; the impact of surface and internal waves on oxygen uptake dynamics; the use of oxygenation systems to suppress the release of iron, manganese and other anoxic species in drinking water reservoirs; and the potential use of oxygenation to inhibit the formation of methyl-mercury species in aquatic systems contaminated with mercury. Interdisciplinary investigations integrating transport physics, sediment geochemistry, and microbial kinetics will encourage healthy cross-disciplinary scientific debate.

SS36 Dynamics of Trace Metal Stoichiometry in Plankton: Causes, Effects, and Implications

Organizers: Stephen B. Baines, Stony Brook University, sbaines@ms.cc.sunysb.edu and Benjamin S. Twining, University of South Carolina, twining@mail.chem.sc.edu

The elemental stoichiometries of plankton can vary substantially with growth conditions, ambient chemistry, and community composition. Over the last two decades, a theoretical framework has developed to explain this variability with respect to the major nutrient elements N, P and C. This stoichiometric framework has been slow to incorporate trace metals, however. There have been attempts to establish extended Redfield ratios for phytoplankton that include trace metals. However, the stoichiometries of trace metals in natural plankton may vary substantially due to the multifaceted and sometimes interchangeable roles that these elements play in biological processes, the complex chemistry that affects their bioavailability, the role that evolutionary history has played in establishing different optimal stoichiometries among species, and the large variability in rates of supply to surface waters. Understanding the determinants and implications of variability in trace metal stoichiometry is necessary if we are to develop predictive models of coupled biogeochemical systems.

This session will focus on the causes and implications of variability in trace metal stoichiometry in plankton. We invite papers addressing three general aspects of this topic. 1) Biological causes, mechanisms and consequences of variability in trace metal stoichiometry including optimal stoichiometric composition among different taxa, relationships between physiological state and trace element stoichiometry, the degree to which intracellular trace element contents are actively regulated, sensitivity of trace element stoichiometry to different sorts of nutrient limitation, linkages between cellular concentrations of trace and major elements, the use genomics to infer the biological functions played by various trace elements, and the effectiveness of various acquisition strategies under different environmental scenarios. 2) Chemical controls on trace metal stoichiometry including spatial and temporal patterns in ligand abundance and affinity, the role that ligands and free metal play in controlling uptake of trace metals by biota, the relative importance of adsorption as a mechanism for accumulation of trace metals, competitive inhibition of uptake, and the role of photochemical reactions in controlling speciation and uptake of trace metals by phytoplankton. 3) Biogeochemical consequences of stoichiometric variability in the plankton including the relationship between variability in seston stoichiometry and carbon cycling in the water column, differences in retention times for nutrients within the water column, and the response of the biological pump to different modes and frequency of nutrient supply.

SS37 The Influence of Global Climate Change on Biological Processes in Surface Waters

Organizers: Steven W. Wilhelm, Department of Microbiology, The University of Tennessee, wilhelm@utk.edu, David A. Hutchins, College of Marine Sciences, The University of Delaware, dahutch@udel.edu, and Giacomo R. DiTullio, Hollins Marine Lab, College of Charleston, ditullioj@cofc.edu

The realities of global climate change, be it natural variation or due to anthropogenically driven processes, necessitate a better understanding for the biological implications of effects of changes in atmospheric temperature and carbon dioxide concentrations. While many efforts have modeled how these physiochemical changes may specifically alter surface temperatures and dissolved CO2 in marine systems as well as large lakes, little is known about the biological implications. This session invites participants to present experimentally derived data and observations concerning the biological implications of global climate change for globally important surface waters. Levels of biological organization from viruses to zooplankton, featuring results from the North Atlantic Spring Bloom (2005) experimental survey will be presented to highlight how current biological communities may respond to predicted changes.

SS39 River Plume Dynamics and Biogeochemistry

Organizers: John Reinfelder, Rutgers University, reinfelder@envsci.rutgers.edu and Tom Frazer, University of Florida, frazer@ufl.edu

Terrestrial materials, including major nutrients, trace elements, carbon, and inorganic and organic pollutants, are transported by rivers to large lakes and coastal ocean systems. Once entrained within river plumes, these materials are subject to various physical, chemical, and biological processes that often result in their transformation and influence their transfer from land to lake and sea. Depending on river discharge, wind direction and intensity, and ambient circulation, river plumes can form water masses with unique optical properties visible via ship- and satellite-based observation platforms and which remain distinct from surrounding waters over the course of days allowing for long-range (tens to 100 kilometers) transport of material and its transformation. This session seeks contributions addressing the physical structure and dynamics of river plumes, their biological and chemical characteristics, and the interactions of external and internal physical forces with plume biogeochemical processes.

SS41 Research Experiences of Undergraduates

Organizers: Russell L. Cuhel, Univ. of Wisconsin Great Lakes WATER Institute, rcuhel@uwm.edu and Carmen Aguilar, Univ. of Wisconsin Great Lakes WATER Institute, aguilar@uwm.edu

Undergraduate research in the 21st century is often well mentored and can rival professional presentations in quality of the work presented. These efforts provide an opportunity to showcase fine undergraduate scholars and to facilitate networking among themselves (future peers) and with active current professionals (future advisors or supervisors). This session is open to any undergraduate research presenter, offering them an opportunity to present their research findings in a collegial but lower-stress poster session amid the showcase of full-spectrum aquatic science presentations. Engaging in one of the premier aquatic science meetings a year, networking, and personal interaction, broadens perspectives and facilitates recruitment of top candidates into the career path progression.

SS42 Gelata On the Edge: Innovative Approaches to Understanding the Diversity and Ecology of Gelatinous Organisms

Organizers: Rebecca Scheinberg Hoover, Monterey Bay Aquarium Research Institute, rebecca@mbari.org and Steven H.D. Haddock, Monterey Bay Aquarium Research Institute, haddock@mbari.org

Understanding the diversity and ecology of the gelatinous zooplankton is often limited by collection and laboratory techniques. Recent advances in both of these areas have inspired scientists to investigate the numerous and often substantial roles that gelata play in the aquatic environment. The goal of this session is to bring together researchers who are using innovative tools to investigate gelatinous zooplankton and their relationships to other organisms. We welcome studies from a wide variety of disciplines that provide a novel perspective on the role of gelata in marine ecosystems.

SS43 Aquatic Viruses – Friends or Foes?

Organizers: Mya Breitbart, University of South Florida, mya@marine.usf.edu and John Paul, University of South Florida, jpaul@marine.usf.edu

Although aquatic viruses are the most numerous biological entities on the planet, we have only begun to understand their roles. If we view them as purely lytic agents, then viruses (sensu bacteriophages) should have caused the extinction of their hosts eons ago. Clearly viruses have established a mutualistic relationship with their hosts that enable the survival and proliferation of both. Viruses also cause pathologies of higher organisms either through direct infection or as prophages encoding toxic genes in aquatic bacterial pathogens.

This session will cover a wide range of topics dealing with the function of prokaryotic and eukaryotic viruses in marine and freshwater systems, including: Ecological studies with natural populations, functional genomic interpretation and expression analysis of cultivated phage host systems, viral metagenomic studies, role of prophages in organism pathology, and virus infections of aquatic plants, invertebrates, and vertebrates.

SS44 Plankton as an Artistic Inspiration

Organizers: Peter Williams, School of Ocean Sciences, University of Wales, pjlw@bangor.ac.uk, and Hilairy Hartnett, Departments of Geological Sciences and Chemistry & Biochemistry, Arizona State University, h.hartnett@asu.edu

Plankton in Art is one of the themes of the Santa Fe Meeting. The poster session will complement the other artistic activities that will play a novel part of the Santa Fe meeting. We place no boundaries on the art form – painting, sculpture, photography, music, poetry, jewellery – this we leave to your imagination and creativity. The only one constraint is that it must be plankton (or low Reynolds number processes – so we can engage the non-biologists) inspired, as we are anxious to maintain a thematic focus. Poster boards will be available for flat work, tables can be provided for 3D objects, but we will have no access to secure display cabinets. The submission should follow the regular procedure with a description of what is being exhibited and how it relates to plankton/laminar environments. If wished, an image of the piece of art can additionally be sent to the topic co-chairs – this will only be taken as supplementary information. It has been agreed that the art posters would be in addition to a scientific presentation and there would be no additional “cost” other than registration.

SS45 The Paradox of Didymosphenia geminata

Organizers: Craig Cary, University of Waikato and the University of Delaware, caryc@waikato.ac.nz, Max Bothwell, Environment Canada, bothwellm@pac.dfo-mpo.gc.ca, and Sarah Spaulding, US Geological Survey & EPA Region 8, spaulding.sarah@epa.gov

The diatom Didymosphenia geminata (Lyngbe) Schmidt is emerging as an organism with an extraordinary capacity to impact stream ecosystems on a global scale. In recent years, streams in New Zealand, North America, Europe, and Asia have been colonized by unprecedented masses of “didymo” and its extra cellular stalks. This diatom is able to dominate the stream benthos by covering up to 100% of substrates with thicknesses of greater than 20 cm, greatly altering physical and biological conditions within streams. This species is expanding its geographic range primarily through human activity, at a rate that nuisance blooms are increasingly reported by the public and local media, yet little scientific investigation of the phenomenon in North America has ensued. In this special session, presentations will address the biology, impacts, and ecosystem roles of didymo.

Didymo causes us to question our fundamental understanding of streams and rivers. First, didymo presents the paradox to limnologists: How is such excessive biomass produced in low nutrient streams and rivers, over short periods of time? Second, didymo produces a muco-polysaccaride stalk that is resistant to biodegradation by bacteria and fungi. What is the unique composition and structure of the stalk and how does the stalk itself play a role in the success of didymo? Third, didymo has direct and indirect impacts across aquatic trophic levels. What is the long-term legacy of stalks that are resistant to decomposition and trap fine sediment past the life span of the organism? Furthermore, macroinvertebrates and fish respond to nuisance levels of didymo with community and population level shifts in composition, abundance, and size class. Finally, has there been a genetically based physiological change in this organism that can be traced to its behavior? Molecular markers present the opportunity to trace the relationships of nuisance outbreaks and those records can be compared with models of predicted global distribution.

SS46 Mystery Session!

Ever get those ‘end-of-the-meeting-blues’? Burnt-out on topical sessions? Or do you just want to try something a little different? If so, maybe we’ve got an answer for you!

One session at this year’s meeting will be devoted to a tasty smorgasbord of talks carefully assembled from some of the most innovative, integrative, and exciting abstracts to create stimulating pairings and groupings that address overarching themes of broad interest to limnologists and oceanographers alike. The trick is: you won’t know “who” or “what” until you arrive at the session! The regular sessions are great, but the some of the best talks this week will be in the Mystery Session!


Contributed Sessions

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