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Special Sessions

SS02: Analyses of Long-term Data in Marine Ecosystems

Oral Talks

Alexandra Kraberg, Alfred Wegener Institute for Polar and Marine Research, Alexandra.Kraberg@awi.de; Karen Helen Wiltshire, Alfred Wegener Institute for Polar and Marine Research, Karen.Wiltshire@awi.de; Maarten Boersma, Alfred Wegener Institute for Polar and Marine Research, Maarten.Boersma@awi.de; Heinz-Dieter Franke, Alfred Wegener Institute for Polar and Marine Research, Heinz.Dieter-Franke@awi.de

Climate-related changes in the physical/chemical marine environment and the elucidation of their biological consequences in the plankton require detailed long-term data sets.  Only by analyzing such data can true long-term trends be separated from short-term variation. High quality long-term data are also vital for the parameterization of models. The research questions that can be addressed using long-term datasets range from changing species composition and phenology via investigations of physical and chemical drivers causing these changes to low-frequency events e.g. regime shifts. However, in addition to being a unique source of information long-term data also present a logistical and financial challenge. The Helgoland Roads plankton and environmental dataset is an impressive example of meeting these challenges without sacrificing scientific excellence. Since 1962 this dataset has been used to monitor temperature increases, changing foodweb and bloom dynamics.  To celebrate its 50th anniversary this session is dedicated to presentations of long-term data analyses demonstrating key long-term trends in the oceans but also describing operational challenges, quality control mechanisms and statistical analysis techniques of the respective data series. Bringing together major operators and users of long-term timeseries we can foster co-operation between operators to facilitate the most efficient use of these vital tools.

SS03: Groundwater-Surface Water Interactions in Freshwater and Marine Environments

Oral Talks | Poster Presentations

Isaac Santos, Southern Cross University, Australia, isaac.santos@scu.edu.au; Makoto Taniguchi, Research Institute for Humanity and Nature, Japan, makoto@chikyu.ac.jp; Meinhard B. Cardenas, The University of Texas, USA, Cardenas@jsg.utexas.edu; William Burnett, Florida State University, USA, wburnett@fsu.edu

Porewater (or groundwater) advection can effectively transport solutes and heat between permeable sediments and rivers, lakes, estuaries, and the coastal ocean. Pressure gradients due to currents, waves, tides and regional groundwater flow drive exchange at the sediment-water interface over a continuum of spatial scales (millimetres to kilometres) and temporal scales (milliseconds to years). These fluids can represent either a source or sink of many ecologically significant components including oxygen, carbon, nutrients, trace metals, and contaminants and thus control the biogeochemistry of both porewater and surface waters. This session will address several relevant questions including when, where, and how surface waters may travel through subterranean pore spaces? How can we use recent technological advances to separate the relative contribution of small and large scale porewater flows? How do multi-scale porewater advection and submarine groundwater discharge influence biogeochemical cycles in surface waters? How will local and global changes influence groundwater-surface water interactions? How can we best bridge disciplines such as biogeochemistry, hydrology, and oceanography to resolve these interdisciplinary questions? Contributions addressing physical, biogeochemical, and ecological aspects of groundwater-surface water interactions at the local, regional and global scales in both freshwater and marine systems are welcome.

SS04: Food-Web Effects on Ocean Biogeochemical Processes: Environmental Control and Interactions

Oral Talks | Poster Presentations

Richard B. Rivkin, Memorial University of Newfoundland, rrivkin@mun.ca; Toshi Nagata, The University of Tokyo, nagata@aori.u-tokyo.ac.jp; Louis Legendre, Laboratoire d'Oceanographie de Villefranche, legendre@obs-vlfr.fr

The structure, functioning and activity of marine pelagic food webs have profound influences on ocean’s biogeochemical cycles and on the fluxes of carbon to both the atmosphere (via respiration) and the deep sea (via export). The food-web meditated transformation of organic and inorganic nutrients leads to strong feedback controls among biota, biogeochemistry and climate. The microbial food web is central to controlling the fluxes of inorganic and organic nutrients, and the cycling or generation of climate active gasses. However, there are many uncertainties about how changes in characteristics of the environment (e.g. light, temperature, pH, nutrients concentrations and ratios) and ecosystems (e.g. community structure, competition, mortality) interact to influence food-web dynamics, elemental fluxes and ultimately biogeochemical processes. This session invites papers from field and laboratory studies that provide insights into the functioning of marine pelagic food webs and their interactions with biogeochemical processes, and from modelling studies that address these characteristics across a broad spectrum of spatial and temporal domains. Bringing together the experimental and modelling communities will lead to a more comprehensive and integrated understanding of these important processes.

SS05: Carbon Storage and Evasion in Natural Wetlands and Freshwater Reservoirs

Oral Talks

Marco Aurelio dos Santos, Energy Planning Program/COPPE/UFRJ, aurelio@ppe.ufrj.br; John Melack, University of California - Santa Barbara, john.melack@lifesci.ucsb.edu

Natural wetlands and freshwater reservoirs can sequester considerable amounts of carbon in their sediments and release methane and carbon dioxide to the atmosphere.  The rates and amounts of burial and release depend on the inputs and processing of carbon and vary across latitude and among catchments.  Recent evidence that some tropical reservoirs emit considerable methane while others do not has led to increased study of carbon biogeochemistry in reservoirs.  In light of the large potential for construction of hydroelectric and multi-purpose reservoirs throughout the tropics, it is important to engage the international community in dialogue about the currently available information and the needs for further investigation. Submissions are encouraged that deal with all aspects of carbon cycling in natural wetlands and freshwater reservoirs with particular focus on tropical systems and the sequestration of organic carbon and evasion of greenhouse gases.

SS06: Interaction of Physical, Chemical and Biological Processes in Aquatic Ecosystems: Past, Present, and Future

Oral Talks | Poster Presentations

Prof. Ilia Ostrovsky, Israel Oceanographic and Limnological Research, ostrovsky@ocean.org.il; Prof. Sally MacIntyre, Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, USA, sally@icess.ucsb.edu; Prof. Michio Kumagai, Lake Biwa Environmental Research Institute, Otsu, Japan, kumagai-m@lberi.jp; Prof. S. Geoffrey Schladow, Dep. Civil and Environmental Engineering,  University of California, Davis, CA, USA, gschladow@ucdavis.edu

Physical processes (heat fluxes, wind, thermal stratification, water movements, inflows, etc) and chemical and biological regimes are closely related in a large variety of aquatic ecosystems. Recent studies have displayed significant progress in understanding the importance of physical processes in controlling the spatial and temporal dynamics of nutrient loading, sedimentation, fluxes at the sediment-water interface, succession of planktonic organisms, and changes in trophic status. The scales of the interactions between various variables depend on the morphometry of water bodies, physical processes, nutrient loads, etc. Changes in climate, anthropogenic pressure (water use, eutrophication, pollution) require operative measures of ecosystem management and require deep understanding of the basic processes. The goal of this session is to bring together physical limnologists, ecologists, and biogeochemists to discuss new developments and to fill gaps in communication, develop interdisciplinary collaborations, and define key problems requiring immediate joint effort.

SS07: Hyper-Eutrophication of Lake Taihu: A “looking glass” for large aquatic ecosystems worldwide impacted by human activities and climate change

Oral Talks | Poster Presentations

Kumud Acharya, Desert Research Institute, USA, Kumud.Acharya@dri.edu; Hans W. Paerl, University of North Carolina, Chapel Hill, USA, hans_paerl@unc.edu; Boqiang Qin, Nanjing Institute of Geography & Limnology, China, qinbq@niglas.ac.cn; Yiping Li, Hohai University, China, liyiping@hhu.edu.cn

Lake Taihu, China’s third largest freshwater lake, has experienced tremendous population and economic growth in its watershed over the last few decades.  Resulting rapidly-increasing nutrient loads from surrounding urban centers, industries, and agricultural activities have  accelerated eutrophication, accompanied by increased frequencies and magnitudes of harmful algal blooms (HABs).  This has severely disrupted use of the lake for drinking water, fishing and recreational purposes. Unprecedented human population growth and development represents a serious threat to the long-term use and sustainability of large lake ecosystems worldwide.  In addition to negative impacts of nutrient over-enrichment  global warming and perturbation of hydrologic cycles has further compounded the problem by synergistically promoting eutrophication and HAB expansion.  Lake Taihu provides scientists with a unique opportunity in that this lake serves as a “looking glass” for future degradation in similar lakes around the world that have yet to exhibit symptoms of advanced cultural eutrophication combined with the effects of climate change. This session will bring together researchers and managers with an interest in causes, consequences and controls of eutrophication and harmful algal blooms in severely nutrient-impacted marine and freshwater ecosystems.

SS09: Biogeochemical and Microbial Processes of Large Lakes of the World

Oral Talks

Robert Sterner, University of Minnesota - Twin Cities, stern007@umn.edu; R. Michael McKay, Bowling Green State University, rmmckay@bgsu.edu; George S. Bullerjahn, Bowling Green State University, bullerj@bgsu.edu; Sergei Katsev, University of Minnesota - Duluth, skatsev@d.umn.edu

Most of Earth’s liquid surficial fresh water is held in a relatively small number of lakes of surface area greater than 500 km2.  In spite of the known importance of these lakes in providing freshwater, transportation, protein, in supporting biodiversity, and in modulating regional climate and affecting humans in myriad other ways, their basic microbiology and biogeochemistry is in most cases poorly understood.  This session will bring together researchers working in large lakes systems to explore the biological, chemical, and physical modulation of cycling of elements in large lakes around the world.  Questions of relevance include: what is unique or emphasized in large lakes that is not representative of smaller bodies of water?  How sensitive are large lakes to global change?  Do they have characteristic microbial communities? What features of large lakes are more oceanic than lacustrine?  How do these characteristics vary with lake latitude, trophic status, depth, or other parameters? What are today’s major knowledge gaps?

SS10: River Systems – Ecological Situation and Human Dimension

Oral Talks | Poster Presentations

Thomas Hein, Wassercluster Lunz & University of Natural Resources and Life Sciences, Vienna, thomas.hein@boku.ac.at; Takashi Asaeda, Saitama University, Department of Environmental Science, asaeda@mail.saitama-u.ac.jp

River systems have been intensely changed over the last hundreds of years and are threatened globally. These impacts have had far reaching consequences on the ecosystem functioning, biodiversity aspects of rivers, their adjacent landscape elements and coastal systems and even global biogeochemical cycles. We invite presentations on the most recent developments in our understanding of river systems and effects of human activities on these systems. Examples of river restoration and the role of rivers as connecting corridors as well as scientific aspects of river management are welcomed. Presenters will be invited to submit a manuscript for a special issue in the journal River Systems.

SS11: Biogeochemical and Ecological Impacts of Expanding Oxygen Minimum Zones

Oral Talks

Damian Grundle, University of Victoria, dgrundle@uvic.ca; Mark Altabet, University of Massachusetts, maltabet@umassd.edu; Deborah Bronk, Virginia Institute of Marine Science, bronk@vims.edu

There is mounting evidence for new and expanding oxygen minimum zones (OMZs) in coastal and oceanic waters. As a principal determinant of redox state, oxygen availability plays a key role in regulating biogeochemical processes and reduced oxygen will likely alter oceanic nutrient cycles. For example, a reduction in dissolved oxygen availability favoring N-loss to N2 or P sequestration in sediments would result in nutrient loss and lowered marine productivity. Reduced oxygen may also enhance the production of greenhouse gases such as nitrous oxide leading to climate-related ocean-atmosphere feedbacks. In addition, the horizontal and vertical expansion of OMZs will reduce the habitat availability for living marine resources and have damaging consequences for ecosystem processes. There is, thus, an urgent need to increase and broaden our understanding of the impacts that expansions of OMZs will have on biogeochemical and ecological processes in the ocean. Papers are invited that address the impact that expanding OMZs may have for biogeochemical and ecological processes, as well as those which aim to further our understanding of the magnitude and geographic pattern of dissolved oxygen losses that will likely occur in the future.

SS13: Consequences of Cross-Ecosystem Resource Subsidies for Freshwater Foodwebs

Oral Talks | Poster Presentations

Takuya Sato, Kyoto University, takuya@species.jp; Takuya Sato, Kyoto University, takuya@species.jp; John S. Richardson, University of British Columbia, john.richardson@ubc.ca

Resource subsidies to and from freshwaters are common fluxes of energy and nutrients, and recent advances have formulated theory about how recipient populations and communities may respond.  These resources include leaf litter, groundwater DOC, terrestrial invertebrates, salmon carcasses, pollen, and others. Experimental studies in streams and lakes have begun to address hypotheses about the dynamics of the responses by consumers, and how use of allochthonous inputs may change within-system process rates.  In this symposium we will seek a synthetic understanding of these resource subsidies to various components of flowing and still water environments, and their coupling with the surrounding landscapes.

SS14: Parasitism in Aquatic Microbial Ecology

Oral Talks | Poster Presentations

Télesphore Sime-Ngando, CNRS, University Blaise Pascal, France, telesphore.sime-ngando@univ-bpclermont.fr; Claire Gachon, Scottish Marine Institute, United Kingdom, claire.gachon@sams.ac.uk; Nathalie NIQUIL, University La Rochelle, France, nathalie.niquil@univ-lr.fr; John DOLAN, CNRS, University Paris VI, Villefranche-sur-Mer, France, kristine_sowl@fws.gov

Next Generation Sequencing technologies are increasingly revealing that microbial taxa likely to be parasites or symbionts are probably much more prevalent and diverse than previously thought. Every well studied free-living species has parasites; parasites themselves can be parasitized. As a rule of thumb, there is an estimated 4 parasitic species for any given host, and the better a host is studied the more parasites are known to infect it. Therefore, parasites and other symbionts should represent a very large number of species and may far outnumber those with 'free-living' lifestyles. Paradoxically, free-living hosts, which form the bulk of our knowledge of biology, may be a minority!  Microbial parasites typically are characterized by their small size, short generation time, and high rates of reproduction, with simple life cycle occurring generally within a single host. They are diverse and ubiquitous in aquatic ecosystems, comprising viruses, prokaryotes and eukaryotes. This session invites contributions that address all aspects of parasites and other symbionts in aquatic microbial ecology: method development, life cycle, interactions with hosts and competing microbes, coevolution, effects on food webs and biogeochemical cycles, etc.

SS17: SS 17: Microbial Diversity and Functions

Oral Talks | Poster Presentations

Shin-ichi Nakano, Center for Ecological Research, Kyoto University, nakano@ecology.kyoto-u.ac.jp; Fereidoun Rassoulzadegan, Laboratoire d’Océanographie de Villefranche, Université de Paris VI, UPMC/CNRS, rassoul@obs-vlfr.fr

Given enormous microbial diversity and rapid dynamics in various aquatic systems, an important question is whether there is enough functional redundancy such that there is "always" enough biochemical and physiological diversity to maintain DOM-bacteria coupling in different systems and trophic states. The DOC accumulation during P limitation of bacteria may show example of the interplay between microbial diversity and biogeochemistry. One would have thought that in both freshwater and marine environments bacterial taxa functionally better suited for P acquisition will become dominant and be able to tighten bacteria-DOC coupling, but this does not always happen. Further, there are other instances and hypothesized causes of “malfunctioning” of the microbial loop that result in transient organic matter accumulation with significance for carbon biogeochemistry. Thus, intriguing questions remain unanswered on how the biogeochemical dynamics reflect interplay among genetic and functional diversity in the aquatic ecosystem context. The purpose of the present session is to stimulate cross-system discussion of the fundamental mechanisms of microbial food web structure and biogeochemical processes; whether they share fundamentally similar mechanisms despite documented differences in community phylogenetic composition among microbial assemblages in oceans, lakes and rivers. Perhaps the microbiological dictum: “everything is everywhere and the environment selects (census Baas-Becking 1934)”, should be replaced by “every microbial process is everywhere but the milieu selects.”

SS19: Food Web: Its Structure, Dynamics and Ecosystem Consequences

Oral Talks | Poster Presentations

Michio Kondoh, Ryukoku University, mkondoh@rins.ryukoku.ac.jp; Andrea Belgrano, Swedish Board of Fisheries, Institute of Marine Research, Lysekil, Sweden, andrea.belgrano@slu.se

Food web, a network describing “who eats whom” within an ecosystem, has been a key concept in ecology. From the viewpoint of ecosystem a food web represents the path through which energy or material is transferred and provides a conceptual framework to understand functional group and its diversity within an ecological community. Population and community ecology have shown that the structure of food web determines interspecific direct and indireact effects and affects population dynamics, species coexistence and its response to external perturbations. In addition, the recent development in technique of theoretical modeling and network analysis, accompanied with the accumulation of large, complex food-web data, has allowed us exploring the pattern behind the “entangled bank”, or complex web of interspecific interactions and its ecological implications. Yet, despite it potential to offer an important framework to link together those ecological issues at multiple organization levels, food-web study is still segmented between different approaches. The aim of this session is to provide a common forum for researchers to exchange, integrate and develop new idea and knowledge in the variety field of food-web study.

SS20: Active Fluorescence Measures of Photosynthetic Physiology and Primary Production

Oral Talks | Poster Presentations

Greg Silsbe, Netherlands Institute of Ecology, g.silsbe@nioo.knaw.nl; Jacco Kromkamp, Netherlands Institute of Ecology, j.kromkamp@nioo.knaw.nl; Ondrej Prasil, Academy of Sciences of the Czech Republic,  Laboratory of Photosynthesis, prasil@alga.cz; Tetsuichi Fujiki, Japan Agency for Marine-Earth Science and Technology, tfujiki@jamstec.go.jp

The unparalleled resolution at which active fluorescence can be measured in situ has enhanced our understanding on how photosynthetic physiology varies through space and time and across physical and taxonomic gradients.  Yet when active fluorescence measures are scaled to derive electron transport rates and compared against parallel measurements of photosynthetic carbon fixation or gross oxygen evolution, the measurements are often equivocal.   In the past decade significant research has highlighted the variable fate of absorbed photosynthetic energy beyond carbon fixation.  Through this research a better understanding of photosynthetic physiology in general and pathways that decouple electron transport from carbon fixation in particular is now emerging.  Whether in lakes, oceans, or cultures, this session invites all research examining rates and fates of photosynthetic electron transport. Though this session is aimed towards researchers employing active fluorescence techniques, other relevant techniques are also welcome.

SS21: Long-Term Ecosystem and Biodiversity Dynamics: Time-Series and Paleoecological Studies

Oral Talks | Poster Presentations

Moriaki Yasuhara, The University of Hong Kong, moriakiyasuhara@gmail.com;Narumi K. Tsugeki, Ehime University, narumi.tsugeki@gmail.com

Increasing paleoecological evidence shows that earth's ecosystems are strongly affected both by natural climatic variability and human-induced environmental change ranging from decadal to millennial timescales. In contrast, instrumental time-series have revealed seasonal to decadal scale-ecosystem dynamics over the past few decades. Although these two approaches are apparently complementary, mutual understanding is far from the satisfactory level. Unified understanding of long-term ecosystem dynamics from seasonal to multi-millennial time-scale will provide us a comprehensive view on our changing planet and its ecosystems and a robust baseline to predict how earth's ecosystems will respond to the future human-induced climate and other environmental changes including global warming, air pollution, ocean acidification, and eutrophication. Enhanced cooperation between researchers using ecological and paleo-approaches will enable us better understanding of drivers of large-scale ecological patterns. We welcome contributions coming from (macro) ecological and paleoecological approaches on long-term ecosystem and biodiversity changes.  Interdisciplinary approaches trying to integrate ecological and paleoecological results are highly welcomed.

SS23: Ecosystem Change and Predictability of Aquatic Ecosystems

Oral Talks

Elisa Benincà, Institute for Biodiversity and Ecosystem Dynamics University of Amsterdam, e.beninca@uva.nl; Vasilis Dakos, Aquatic Ecology Group, Wageningen University & Integrative Ecology Group, Estación Biológica de Doñana, CSIC, vasileios.dakos@wur.nl; Chih-hao Hsieh, Institute of Oceanography National Taiwan University, chsieh@ntu.edu.tw

Under global environmental pressure, the risk of unwanted changes in aquatic systems is high. Such changes occur across different scales and take a variety of forms depending on the properties of the ecosystem itself. For example, regime shifts may occur among multiple states, communities may change in composition and structure, ecosystem dynamics can shift from stable states to oscillatory regimes. As we still lack proper understanding of the mechanisms behind these phenomena, predicting system changes, anticipating their risk, and above all identifying their main drivers have a crucial role for the conservation and the management of aquatic ecosystems. This session will draw upon the expertise of empirical and theoretical aquatic ecologists to present methods, theories and evidence of understanding and anticipating changes in aquatic systems.

SS24: Automated Technologies for Freshwater Bio-Monitoring

Oral Talks

Marie-Eve Garneau, Institute of Plant Biology, University of Zurich, me.garneau@gmail.com; Stefan Bertilsson, Dept. of Ecology & Genetics, Limnology, Uppsala University, stebe@ebc.uu.se; Cedric Pradalier, Autonomous Systems Lab, Swiss Federal Institute of Technology (ETH) Zurich, cedric.pradalier@mavt.ethz.ch; François Pomerleau, Systems Lab, Swiss Federal Institute of Technology (ETH) Zurich, francois.pomerleau@mavt.ethz.ch

While oceanic observation networks are being increasingly developed around the world, remote sensing technologies and automated robotics systems have received less attention for freshwater research. This session addresses multi-disciplinary studies for extended monitoring of limnetic systems over multiple spatial and temporal scales. Such technologies are urgently needed for improved understanding and management of the world’s freshwater resources, which face increasing demands for drinking water while at the same time experiencing accelerated eutrophication, the rising occurrence of harmful cyanobacterial blooms, and the impacts of rapid climate change. The session aims at grouping presentations that investigate aspects of these critical topics using (1) remote sensing technologies, from microscale biosensors and imagery to large-scale observation networks; (2) autonomous sampling systems, including underwater vehicles, autonomous surface vessels and automated fixed platforms; and (3) automated data acquisition techniques, as well as computational tools and interpolation methods used to analyze large environmental datasets. Researchers in oceanography as well as limnology are invited to contribute to this session on the application of advanced research and monitoring technologies to lakes and reservoirs.

SS26: International Student Symposium: The World Water Crisis

Oral Talks | Poster Presentations

Charles R. Goldman, University of California Davis, crgoldman@ucdavis.edu; Geoff Schladow, University of California, Davis, gjschladow@ucdavis.edu

Giving students from around the world the opportunity to participate in a symposium has in the past been extremely beneficial to the students through contact with the graduate thesis projects of other students throughout the world. The meeting at ILEC in China and the Tahoe/Austin meeting have evidenced the importance of getting young students together with the older members of the profession. This builds self-confidence, a sense of purpose, and enables them to network with other students of their own age. The student involvement both past and present has contributed substantially to the future of river, lake and ocean sciences. In this symposium, we will especially focus on issues of the world water crisis. Limnological and/or oceanographical strategies for anticipating and mitigating the impacts of climatic change on the world’s waters will also be emphasized. We welcome presentations by students who study any aspects of environmental and ecological issues related with aquatic and marine ecosystems.

SS27: Acoustic Tomography and Environmental Modeling in Coastal Seas, Estuaries, Rivers and Lakes

Oral Talks | Poster Presentations

Arata Kaneko, Graduate School of Engineering, Hiroshima University, akaneko@hiroshima-u.ac.jp; Prof. Bruce M Howe, Department of Ocean and Resources Engineering, University of Hawaii, bhowe@hawaii.edu; Prof. Xiaohua Zhu, Second Institute of Oceanography, SOA, China, xhzhu@sio.org.cn; Prof. Xinyu Guo, Center for Marine Environment Studies, Ehime University, guoxinyu@sci.ehime-u.ac.jp

Ocean acoustic tomography is an innovative technology for obtaining snap shots of the current and temperature structure in the ocean. It was proposed as a deep-sea instrument by Walter Munk in 1970s and has been applied by Hiroshima University and others to coastal seas, characterized by various environmental conditions. The cross-domain measurement from multiple acoustic stations located near shore on the periphery of observational domain does not disturb fisheries and shipping. Acoustic tomography provides certain advantages when applied to estuaries, rivers and lakes. The tomography data acquired at short intervals as snap shots also provide boundary conditions and volume constraints for circulation and ecological models; the data can be used for validation or assimilation purposes. In this session, the natural coupling of acoustic tomography and environmental models in coastal/terrestrial environment studies is emphasized. The modeling studies with no relevance to acoustic tomography at the present time are also strongly expected for promoting a future progress.

SS28: Mixotrophy in Aquatic Systems: From Physiology to Ecological Impact

Oral Talks | Poster Presentations

Susanne Wilken, Netherlands Institute of Ecology, The Netherlands, s.wilken@nioo.knaw.nl; Robert Ptacnik, University of Oldenburg, Germany, ptacnik@icbm.de; Stefanie Moorthi, University of Oldenburg, Germany, stefanie.moorthi@uni-oldenburg.de; Per Juel Hansen, University of Copenhagen, Denmark, pjhansen@bio.ku.dk

Mixotrophy is increasingly recognized as an important nutritional strategy in many aquatic ecosystems. The importance of mixotrophs is well known from systems like humic lakes, under ice communities, and oligotrophic lakes and oceans. Nevertheless, their contribution to primary productivity and predation on bacteria and other protists  in both marine and freshwater ecosystems has long been neglected. Mixotrophy is widespread among different phylogenetic groups ranging from phagotrophic microalgae to protozoans and metazoans hosting phototrophic symbionts. These organisms may rely on primarily photosynthesis or on primarily food uptake, depending on species identity, but also on environmental factors such as light, dissolved nutrients and prey concentrations. Given their diverse functions in aquatic communities, mixotrophs increase the complexity of trophic interactions and of matter and energy flow. A better understanding of their role in aquatic systems therefore requires a better understanding of their diverse nutritional strategies, both in terms of their physiological traits and their ecological role in food webs. In this session, we invite contributions on mixotrophs including their physiology, their role in the food web, and their effects on biogeochemical cycles and ecosystem functioning. Contributions linking several levels of complexity are particularly encouraged. 

SS29: Heterospecific Mating Interactions

Oral Talks

Wataru Makino, Tohoku University, makinowataru@m.tohoku.ac.jp; Syuhei Ban, University of Shiga Prefecture, ban@ses.usp.ac.jp

Studies to date have described various aspects of heterospecific mating interactions between closely related plankton species such as copepods.  Potentially, heterospecific mating interactions are important for the ecology and evolution of co-occurring plankton species.  For example, genetic introgression between species could occur when the level of heterotrophic mating interactions is high.  Even when no hybrid offspring are produced between species, heterospecific mating interactions can still be important because conspecific may suffer from fertilization limitation through the reproductive interference by heterospecific, which in turn negatively affect the population dynamics of conspecific.  Theoretical studies show that the reproductive interference may work in nature as an efficient mechanism to cause habitat partitioning in either time or space between species (sexual competition).  But in aquatic ecosystems, the consequence of heterospecific mating interactions at a population level (or greater) is yet understood comprehensively.  Thus this session seeks researchers who argue the implication of heterospecific mating interactions for the ecology and evolution of aquatic populations/communities.  Researches involving the reproductive interference are particularly encouraged.

SS30: The Impacts of Tsunami and The Fukushima Dai-Ichi Nuclear Power Plants on Oceans and Coastal Environments

Oral Talks | Poster Presentations

Ken Buesseler, Woods Hole Oceanographic Institution, kbuesseler@whoi.edu; Mitsuo Uematsu, The University of Tokyo, uematsu@aori.u-tokyo.ac.jp

The triple disaster of the March 11, 2011, earthquake, tsunami and subsequent radiation releases at Fukushima Dai-ichi are unprecedented events for the oceans.  This session seeks to bring together studies focused on the impacts and fate of Fukushima Dai-ichi nuclear power plant radionuclides that were released to the ocean.  This includes studies of the relative path and magnitude of the radioactive releases, range of radionuclides released, dose assessments, levels of contaminants in the sea water, sediment and biota, dispersion patterns measured and predicted for both near and far fields.  Related studies of atmospheric transport pathways and deposition on land, as they relate to ocean studies, are also appropriate for this session.  Studies of the transport of radionuclides to the ocean via rivers, run-off and groundwater are also encouraged.  Reports can include both field and modeling results, as well as new radionuclide analytical methods used to understand the impacts of Fukushima radionuclides on the oceans.

SS31: Light, Transport and Mixing in Lakes: 100 Years after Forel

Oral Talks

Warwick F. Vincent, Laval University, warwick.vincent@bio.ulaval.ca; Sally MacIntyre, University of California,  Santa Barbara, sally@icess.ucsb.edu; Alfred Johny Wueest, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Alfred.Wueest@eawag.ch

The year 2012 marks one century since the death of François-Alfonse Forel, and 120 years since the publication of the first volume of his 3 - volume treatise that founded “limnology”, and defined it as the ‘oceanography of lakes’ (Forel, F.-A. 1892. Le Léman - Monographie Limnologique, Vol. 1, 543p). His research on Lake Geneva (Lac Léman) encompassed a broad sweep of limnological topics ranging from fundamental work on surface seiches, stratification, geochemistry and hydrobiology, to an economic assessment of ecosystem services, specifically the commercial fishery of the lake. Forel was also greatly interested in the physics of radiative transfer and the causes of variation in lake transparency, and he established a color scale for comparisons of natural waters. This session will first review these early contributions of Forel, and solicits papers that focus on new insights in physical limnology, with emphasis on hydrologic optics (including remote sensing), stratification-mixing regimes or physical-biotic interactions.

SS32: High Latitude and Altitude Aquatic Ecosystems in a Changing Environment

Oral Talks | Poster Presentations

John P. Smol, Queen's University, smolj@queensu.ca; Warwick F. Vincent, Laval University, warwick.vincent@bio.ulaval.ca

High latitude lakes, rivers and wetlands are currently experiencing the effects of multiple stressors including rapid climate change, shifts in water balance, decreasing ice conditions, increasing UV-B exposure, the arrival of exotic species, and the input of long range contaminants, combined in some cases with local pollutants and nutrient enrichment. Some of these waters, especially permafrost thaw lakes, are also biogeochemical hotspots for globally significant emissions of greenhouse gases, and are undergoing large, but regionally variable changes in surface area. This session aims to bring together limnologists and paleolimnologists to examine how aquatic ecosystems in polar and subpolar regions have responded to rapid environmental change in the past, and their present and future responses to ongoing change.

SS33: Freshwater Biodiversity: Monitoring, Forecasting, and Management Strategies

Oral Talks | Poster Presentations

Takehito Yoshida, University of Tokyo, cty@mail.ecc.u-tokyo.ac.jp; Klement Tockner, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, IGB, Berlin, Germany, kristine_sowl@fws.gov

Freshwaters are among the most degraded ecosystems world wide, and their biodiversity is being lost at an unprecedented rate. Protecting and restoring biodiversity in rapidly changing water-dependent environments pose key challenges for research and management. It is becoming more and more evident that the present strategies are insufficient to protect biodiversity and the related ecosystem functions and services in a long-term, sustainable way. This session will (i) explore the current status of freshwater biodiversity at genetic, species, and ecosystem levels, (ii) disentangle the underlying mechanisms responsible for its rapid change, and (iii) introduce innovative management  measures for rivers, lakes, ground waters and wetlands. We particularly welcome presentations by researchers from Asian and other megadiversity countries in order to discuss geographical differences in the status and the driving mechanisms of biodiversity change, as well as the implementation of conservation strategies for freshwaters.

SS34: Modeling Biogeochemical and Ecological Functions in Aquatic Ecosystems

Oral Talks | Poster Presentations

Takafumi Hirata, Hokkaido University, tahi@ees.hokudai.ac.jp; Scott Doney, Woods Hole Oceanographic Institution, sdoney@whoi.edu; Yasuhiro Yamanaka, Hokkaido University, galapen@ees.hokudai.ac.jp; Meike Vogt, Eldgenossische Technische Hochschule Zurich, meike.vogt@env.ethz.ch

Recent advances in the biogeochemistry and ecological studies, as well as in situ data collection and computer technology, brought a new opportunity to marine ecosystem modeling; A number of sophisticated marine ecosystem models, which explicitly include biogeochemical and ecological functions of marine organisms, have increasingly been developed worldwide. The new opportunity led biogeochemistry-ecosystem modelers to a launch of an international project, MARine Ecosystem Intercomparision Project (MAREMIP), in order to resolve by the new generation models several important scientific questions; for example, (1) what are the main physical, chemical and biological process that determine the global marine biomass and its regional distribution of functional groups of organisms, (2) what are the impacts of global environmental changes on marine ecosystems, including climate change and ocean acidification, (3) what is the feedback from marine ecosystems to climate, (4) what is the role of ecosystem structure and biodiversity for biogeochemical fluxes, marine resources and climate, (5) what observation are necessary for better understanding of marine ecosystems, etc. Ecosystem modelers and observationists interested in the development of the next generation ecosystem models are invited to learn the latest results from different models.

SS35: Frontiers in Organic and Inorganic Matter Flux Across Ecosystems: Consequences to Terrestrial

Oral Talks

Hiromitsu Kamauchi, Akkeshi Marine Station, Field Science Center For Northern Biosphere, Hokkaido University, kamauchi@fsc.hokudai.ac.jp; Tomoya Iwata, Department of Ecosocial System Engineering, University of Yamanashi, tiwata@yamanashi.ac.jp

Subsidization across ecosystem boundaries often controls the structure and dynamics of communities and maternal cycling in recipient ecosystems. Although the effects of biotic and abiotic flux from terrestrial to aquatic ecosystems have been intensively studied so far, the role of flux in the opposite direction, namely aquatic-to-terrestrial subsidies, has been elucidated insufficiently. In addition to resource subsidies, moreover, recent studies have identified the existence of hitherto unknown pathway of cross-system impact propagations from aquatic to terrestrial ecosystems, such as thermal flux from sea to land. Effective distance of aquatic subsidy from the shoreline, spatial arrangement of ecosystems in landscape, and subsidy consequences depending on ecological function of flux are also an issue that has been spotlighted recently. This session will present the current knowledge of; “aquatic to terrestrial linkage” to explores the frontiers in studies of ecosystem interaction at landscape level.

SS36: Carbon and Nitrogen Stable Isotope Studies in Aquatic Ecosystems

Oral Talks | Poster Presentations

Joanne Oakes, Southern Cross University, Joanne.Oakes@scu.edu.au; Bradley Eyre, Southern Cross University, Bradley.Eyre@scu.edu.au; Eric Boschker, Netherlands Institute of Ecology, E.Boschker@nioo.knaw.nl; Bart Veuger, Netherlands Institute of Ecology, B.Veuger@nioo.knaw.nl

Stable isotopes are a powerful tool for following flows of carbon and nitrogen through biogeochemical processes and the lower food web. This session invites contributions that have used small scale or whole system stable isotope labeling or novel applications of natural abundance stable isotopes as a tool for elucidating carbon and nitrogen flows in freshwater, brackish and marine aquatic ecosystems. Of particular interest are studies that have investigated the flow of carbon and/or nitrogen through both biogeochemical processes and the lower food web and studies that have applied compound-specific isotope analysis and stable isotope tracers.

SS37: Terrestrial Subsidies and the Resilience of Aquatic Ecosystems

Oral Talks

Sabine Hilt, Leibniz-Institute of Freshwater Ecology and Inland Fisheries Berlin (Germany), hilt@igb-berlin.de; Michael J. Vanni, Miami University (USA), vannimj@muohio.edu; Michael L. Pace, University of Virginia (USA), mlp5fy@virginia.edu 

Ecological resilience (the magnitude of disturbance a system can absorb without shifting to an alternative stable regime) and the importance of allochthonous carbon (C) subsidies to freshwaters are two fundamental ecological concepts that have recently gained major attention due to rapid environmental change. Organizers propose a symposium that will link these concepts, which have generally been viewed independently. Recently, increased concentrations of dissolved organic carbon have been observed in rivers and lakes throughout Europe and North America. Terrestrially-derived particulate organic carbon inputs into freshwaters may likewise increase due to deforestation, overgrazing, row crop cultivation, and increased flux of C from plants to soils following increased terrestrial primary production in response to elevated atmospheric CO2 concentrations. The potential ecological implications of changing C fluxes are expected to be wide-ranging. The subsidy of aquatic food webs by higher flows of terrestrial organic matter may affect system resilience, and organizers thus propose a synthesis of the resilience and allochthony concepts and aim to show how linking these concepts may help in addressing urgent environmental concerns. In this symposium, presentations are encouraged utilizing different approaches such experimentation, modelling, comparative studies and long-term research, in all types of aquatic habitats.

SS40: Lakes and Their Environmental Records

Oral Talks | Poster Presentations

David T. Long, Michigan State University, long@msu.edu; Michio Kumagai, Lake Biwa Environmental Research Institute, kumagai-m@lberi.jp; Bryan Pijanowski, Purdue University, bpijanow@purdue.edu

Lakes are an invaluable worldwide resource by providing food, drinking water and recreational opportunities.  They are also an invaluable resource in that their sediments provide historical records of the environment.  Sediments give insights into environment change and the natural and anthropogenic processes causing change at large scales (e.g., global climate change), intermediate scales (e.g., local watershed), and small scales (e.g., within lake processes).  Further, individual lake temporal records can be integrated for regional analysis.  This special session invites papers that not only study the above but also those that examine methods for the interpretation of lake sediment records.  All lake records whether large or small or those from man-made impoundments are of interest.

SS41: Mixing and Internal Motions in Lakes, Reservoirs and Oceans

Oral Talks | Poster Presentations

Hidekatsu Yamazaki, Tokyo University of Marine Science and Technology, hide@kaiyodai.ac.jp; Alfred Wueest, Eawag, Alfred.Wueest@eawag.ch

Recent developments in observational technology, such as microstructure systems, allow studying details of mixing processes in lake and reservoir. Also the computing capacity has drastically expanded which increasing provides possibilities for 2- and 3-dimensional modelling. In this session, we focus on all types of baroclinic motion, such as waves, solitons, surges, and interior-boundary interactions, to name a few. All directions of internal physical processes, is it from laboratory to oceans, as well as numerical modelling and the coupling of biological and physical processes are welcome.

SS42: New Frontiers of Isotope Tools for Biogeochemistry, Ecology and Environmental Sciences

Oral Talks | Poster Presentations

Ichiro Tayasu, Center for Ecological Research, Kyoto University, Japan, tayasu@ecology.kyoto-u.ac.jp; Naohiko Ohkouchi, Institute of Biogeosciences, Japan Agency for Marine-Earth Science and Technology, nohkouchi@jamstec.go.jp

While isotope tools have been widely used in aquatic science, recently emerging new techniques were also introduced and applied during the last decade. They include compound-specific stable- (2H, 13C, 15N) and radioisotope (14C) ratios of various types of organic molecules (e.g. lipids, amino acids, and carbohydrates), isotopomers, and isotope ratios of heavy metals (e.g. Sr, Pb, Mg, Fe). This session will discuss these recent advances in the new tools and their applications as new frontiers of biogeochemistry, ecology, and environmental sciences, in combination with traditional use of C, N, H, O, S bulk isotope analysis. This session encourages submissions that report new techniques and approaches for the investigation of the aquatic environment.

SS44: Research Frontiers in Harmful Algal Bloom Prediction, Mitigation and Prevention

Oral Talks | Poster Presentations

Ichiro Imai, Graduate School of Fisheries Sciences, Hokkaido University, imai1ro@fish.hokudai.ac.jp; Kanako Ishikawa, Lake Biwa Environmental Research Institute, ishikawa-k@lberi.jp; Hak-Gyoon Kim, Pukyong National University, hgkim7592@yahoo.co.kr

Asian cuisine cultures have been supported by wide variety of fisheries products which were provided in bulk by aquaculture, but these industries have long suffered from the threat of harmful algal blooms (HABs). In addition, the occurrences of HABs including toxic blooms represent a significant and expanding threat to human health and fisheries resources throughout the world. Toxic cyanobacterial blooms in freshwater ecosystems also pose risks to human and ecosystem health through production of toxins and other metabolites. Therefore, investigations are essential to protect public and ecosystem health, encourage and support aquaculture development, and contribute to policy decisions on coastal zone issues and water resource management. Strategies for reducing negative impacts of HABs can be categorized into prediction, mitigation and prevention. This session will highlight leading-edge research aimed at reducing negative impacts of HABs through prediction (based on understandings of mechanisms), mitigation and prevention in both marine and freshwater ecosystems.

SS45: DOM Dynamics and Transport from Land to the Ocean, through Rivers, Lakes and Ground Waters

Oral Talks | Poster Presentations

Yuko Sugiyama, University of Hyogo, sugiyama@shse.u-hyogo.ac.jp; Nobuhito Ohte, University of Tokyo, nobu@fr.a.u-tokyo.ac.jp; Kortelainen Pirkko, Finnish Environment Institute, pirkko.kortelainen@ymparisto.fi

Terrigenous dissolved organic matter (DOM) is continuously discharged from land to the ocean through limnetic waters such as rivers, lakes and ground waters. However, its dynamics of generation and transformation during water movement within the terrestrial and limnetic ecosystems including coastal ocean remain poorly quantified. In order to understand the role of terrigenous DOM in the ocean carbon cycling it is crucial to understand the major physical, chemical and biological processes contributing to the fate of DOM. This session aims to exchange up- to-date knowledge about DOM dynamics within a variety of limnetic ecosystems and transportation through each system including land, river, lake, groundwater, coastal water and the ocean.

SS46: Climate and Global Environmental Changes in Aquatic Ecosystems

Oral Talks | Poster Presentations

Yu-Heng Tseng, Department of Atmospheric Sciences, National Taiwan University, yhtseng@as.ntu.edu.tw; Dr. Takeshi Okunishi, National Research Institute of Fisheries Science, okunishi@affrc.go.jp; Yu-San Han, Department of Life Science & Institute of Fisheries Science, National Taiwan University, yshan@ntu.edu.tw; Bo Qiu, Department of Oceanography, University of Hawaii at Manoa, bo@soest.hawaii.edu

Multi-scale climate effects on the marine ecosystem have been well recognized and continue to be critical as the observational period gets longer. A typical example is the strong linkage between several different climate indices and the fluctuation of long-term fish population (or fish recruitment) through the ocean circulation, which is forced by the global climate variability. In order to better understand the ecosystem response to climate impacts, the physical and oceanographic linkage plays a pivot role and the complex ocean-atmospheric interaction is never negligible. More important of all, different marine ecosystem may response differently at different time scales, ranging from daily to multi-decadal variability. This session invites all contributions from, but not limited to, the climate variability and their linkage of marine ecosystem as well as the observation, experimentation, and modelling approaches. The physical and ecological processes that structure the variability of marine ecosystems are also emphasized.

SS47: Vertical Structure of Aquatic Ecosystems: Observations, Experiments, and Theories.

Oral Talks

Kohei Yoshiyama, River Basin Research Center, Gifu University, kyoshi@gifu-u.ac.jp; Chris Klausmeier, Kellogg Biological Station, Michigan State University, klausme1@msu.edu; Elena Litchman, Kellogg Biological Station, Michigan State University, litchman@msu.edu

Light, nutrients, oxidants, and kinetic energy are supplied from different vertical locations in water columns and in sediments, creating a markedly heterogeneous habitat in pelagic and benthic environments. In response to the vertical heterogeneities, algae and other microbes form a variety of vertical distributions and may coexist and diversify through niche segregation. In recent years, new theoretical findings such as chaos, bistability, and the evolutionary-stable-strategy depth, and the empirical findings such as vertical niche partitioning of species or ecotypes have emerged in phytoplankton ecology. In addition, researchers have developed state-of-the-art experimental water columns in order to test hypotheses that arose from theoretical studies. This session aims to bring together researchers from theoretical and empirical sides, who work on vertical structure of aquatic ecosystems including pelagic and benthic, to synthesize our current understanding, and to suggest future directions.

SS48: Trace Element Biogeochemistry

Oral Talks | Poster Presentations

Celine Gueguen, Trent University, Canada, celinegueguen@trentu.ca; Claude Fortin, Institut national de la recherche scientifique, Canada, Claude.Fortin@ete.inrs.ca

Trace metals play a key role in environmental and biological systems. Anthropogenic activities since industrialization have contributed to increase the mobility of essential and non-essential elements. The different forms in which they occur, commonly referred to as speciation, are critical in determining their bioavailability and fate in natural aquatic systems. It is thus of importance to distinguish between different forms or species of a metal in solution and to understand the mechanisms regulating metal bioavailability. Our understanding of the complex processes involving natural ligands such as the ubiquitous dissolved organic matter is still in its infancy. These heterogeneous and polyfunctional molecules can bind metals but can also react with biological surfaces (e.g. algal membranes, fish gills, etc.) and there is a need to better understand these interactions and their influence on the biota. Significant progress was achieved in the last decade with equilibrium approaches such the Biotic Ligand Model to predict metal uptake and toxicity to aquatic organisms but their universal application remains a challenge. This session welcomes abstract submissions related to all aspects of speciation and biodynamics of bio-reactive elements in aquatic systems.

SS49: Recent Advances in Phytoplankton Pigment Studies in Oceanography

Oral Talks | Poster Presentations

Koji Suzuki, Hokkaido University, kojis@ees.hokudai.ac.jp; S. W. Wright, Australian Antarctic Division, Simon.Wright@aad.gov.au; Takafumi Hirata, Hokkaido University, tahi@ees.hokudai.ac.jp; Stanford B. Hooker, NASA, stanford.b.hooker@nasa.gov

Phytoplankton pigments have been used as biomarkers to estimate the dynamics of algal assemblages in the world’s oceans. Recently, the number of in situ and remote-sensing applications using algal pigments has further increased in order to detect phytoplankton biomass, major taxonomic groups and/or functional types through changes in the color of seawater. This session invites all participants who are interested in the recent development of pigment-based phytoplankton chemotaxonomy in the sea and its verification using microscopy, flow cytometry, and DNA analyses. Algal pigment-related physiological and ecophysiological studies (e.g., variable chlorophyll fluorescence analysis) are also welcome for presentation. Furthermore, we also expect intensive discussions on the methodology and applications to detect phytoplankton functional types from space. Next-generation satellite missions are emphasizing the estimation of uncertainties in derived data products, so contributions that assess uncertainties in applicable calibration and validation activities are encouraged.

SS51: Nitrogen Limitation in Freshwater -  Is Nitrogen Reduction Ecologically Meaningful and Economically Feasible?

Oral Talks | Poster Presentations

Claudia Wiedner, Department of Freshwater Conservation, Brandenburg University of Technology, Cottbus, Germany, wiedner@tu-cottbus.de; Roxane Maranger, Université de Montréal, Groupe de Recherche en Limnologie, Dépt. des sci. biologique, Montréal, Québec Canada, r.maranger@umontreal.ca; Tobias Vrede, Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden, tobias.vrede@slu.se

Phosphorus has been considered the main driver of eutrophication in freshwaters and control measures have therefore aimed at the reduction of phosphorus loads. These measures have improved the ecological status of some but by no means all lakes. However, high nitrogen loads may also be a cause of eutrophication in freshwaters and this has led to demand for procedures to ensure the reduction of nitrogen input. The question of whether these actions are ecologically effective cannot be answered at present because the necessary information about the origin, turnover, and effects of nitrogen across a broad range of freshwater systems is lacking. This session welcomes contributions focusing on different aspects of nitrogen input and turnover as well as the ecological significance of nitrogen versus phosphorus in controlling the regulation of phytoplankton and eutrophication of freshwaters. Abstracts are encouraged that address the above issues through freshwater monitoring, experimental studies, statistical and modeling approaches.

SS52: Ecology and Management of Dams and Their Watersheds

Oral Talks | Poster Presentations

Takashi Asaeda, Saitama University, Japan, asaeda@mail.saitama-u.ac.jp; Kunihiko Amano, National Institute for Land and Infrastructure Management, Japan, amano-k92ta@nilim.go.jp

Construction of dams for flood control, power generation and irrigation has been a common affair for decades. By the end of 20th century, more than 4,700 large dams and numerous smaller dams have been constructed over half of the total river systems of the world. The limnoecological characteristics of the associated reservoirs of these dams vary and they are greatly influenced by their location, prevailing ecosystems, and characteristics in watershed including demographic trend, urbanization, and land use pattern. Therefore, different types of management systems for these dams and reservoirs should be evolved and adopted to mitigate the environmental impact of dams. This session will focus on the commonness, as well as the dissimilarities of dams of the world in a view to gather more sound management practices from ecological viewpoints. The major topics will be the limnology and ecology of reservoirs, the ecology and management of dam-regulated streams and riparian areas, the interfaces between watersheds and reservoirs, and the ecological impacts of dams on downstream river and ocean.

SS54: The Multifaceted Functions of Natural Biochemicals in Aquatic Ecosystems

Oral Talks

Patrick Fink, University of Cologne, Germany, patrick.fink@uni-koeln.de; Alexander Wacker, University of Potsdam, Germany, kristine_sowl@fws.gov

Organic compounds (biochemicals) play a multitude of roles in aquatic systems. They participate in the regulation of processes critical for ecosystem functioning such as trophic transfer of matter and energy and communication within and across species. For example, recent research has highlighted the importance of essential biochemicals in determining the nutritional quality of resources for consumers. This obviously has also impact on the human use of aquatic resources, e.g. by fisheries. Further, biochemicals involved in active and constitutive defence mechanisms such as infochemicals and toxins have strong impact on trophic interactions. In this context, one so far underrepresented aspect is multifunctionality of compounds, i.e. interactive effects of different compounds and multiple different functions of the same compounds on different species. This session aims to integrate investigations on ecologically relevant biochemicals across marine and freshwater systems, but also across functions on multiple levels of organization.

SS55: Linking Organisms’ Small-Scale Processes and Their Environments to Global Effects

Oral Talks | Poster Presentations

Soeren Ahmerkamp, MPI Bremen, sahmerka@mpi-bremen.de; Dr. Eva-Maria Zetsche, Vrije Universiteit Brussel, ezetsche@vub.ac.be; Prof. Dr. Arzhang Khalili, Max Planck Institute for Marine Microbiology, akhalili@mpi-bremen.de

The aim of this session is to provide insight into the interactions between organisms and their environment on a microscale and link this to large scale processes. Recent experimental and mathematical advances have improved our knowledge of small-scale physical and chemical influences on the biology and ecology of organisms. This interdisciplinary session therefore invites scientists from marine microbiology, ecology, physics and mathematics to share their contributions; studies on the swimming behavior of microscopic organisms, from copepods down to bacteria, the effects of turbulence and flow fields on their behavior, and, the chemotactic responses of organisms, are as welcome as studies on particles such as marine snow aggregates, an important source of organic material for numerous organisms, or the development of new technologies to address these small-scale processes.

SS56: Dietary Biomarkers in Aquatic Food Webs – Trophic Transfer and Stability

Oral Talks | Poster Presentations

Martin J. Kainz, WasserCluster Lunz, Austria, martin.kainz@donau-uni.ac.at; Michael T. Brett, University of Washington, Seattle, mtbrett@u.washington.edu; Hiroaki Saito, National Research Institute of Fisheries Science, Yokohama, Japan, hiroakis@affrc.go.jp; Nicole Richoux, Rhodes University, South Africa, N.Richoux@ru.ac.za; Rana El-Sabaawi, University of Victoria, Canada, rana@uvic.ca

Dietary biomarkers within aquatic food webs are a critical measure for evaluating diet sources, trophic relationships, and nutritional status of aquatic consumers. In addition to gut content analysis for assessments of recent diet success, aquatic food web research heavily relies on biochemical tracers such as stable isotopes and fatty acids. Although food web research has advanced considerably in recent decades, efforts to link dietary biomarkers with their trophic stability and physiological implications are rare. The aim of this session is to build a more comprehensive understanding of what regulates the input, alteration, and trophic retention of dietary biomarkers in consumers within aquatic food webs.  We invite talks that, a) propose the application of new biomarker research, and, b) integrate current research challenges regarding retention, biochemical stability, and physiological implication of dietary biomarkers at all trophic levels and aquatic ecosystems.

SS57: The Temperature Dependence of the Carbon Cycle in Aquatic Ecosystems

Oral Talks | Poster Presentations

Gabriel Yvon-Durocher, Queen Mary, University of London, g.yvon-durocher@qmul.ac.uk; Paul del Giorgio, University of Quebec and Montreal, del_giorgio.paul@uqam.ca; Mark Trimmer, Queen Mary, University of London, m.trimmer@qmul.ac.uk

Photosynthesis and respiration drive the carbon cycle. The balance between these two processes largely determines atmospheric CO2 concentrations and thereby modulates the global climate. The sensitivity of ecosystem respiration (ER) and gross primary production (GPP) to temperature will therefore be a primary factor governing the capacity of the biosphere to sequester anthropogenic CO2 emissions under a future warmer climate and will be key in determining the magnitude of future positive feedbacks between the climate and the planet’s biota. Aquatic ecosystems cover ~70% of the planet’s surface and are responsible for ~50% of its carbon cycling, thus, developing a mechanistic understanding of how the carbon balance of these systems will respond to the temperature increases predicted for the end of the century is of paramont importance. Recent work is beginning to reveal consistent patterns in the temperature dependence of the key components of the carbon cycle across aquatic ecosystems. However it is also evident that the factors – e.g. community structure, allochthnous carbon inputs – that can modulate this temperature sensitivity at the ecosystem level are complex, and require synthesis in order to develop a coherent understanding across aquatic ecosystems. This session will bring together leading scientists working on temperature and the carbon cycle in aquatic ecosystems in an attempt to synthesise the growing body of research into the temperature dependence of the carbon cycle in aquatic ecosystems.

SS58: Nitrogen Biogeochemistry and Perturbation in Terrestrial - Freshwater Systems

Oral Talks | Poster Presentations

Muneoki Yoh, Tokyo University of Agriculture and Technology, yoh@cc.tuat.ac.jp; Keisuke Koba, Tokyo University of Agriculture and Technology, keikoba@cc.tuat.ac.jp; Yoshiyuki, Inagaki, Forestry and Forest Products Research Insititute, yinagaki@affrc.go.jp

This symposium will discuss biogeochemical cycling of bioelements, especially nitrogen, in watersheds of different scales and aspects including forests, streams, rivers, lakes, and estuaries. Nitrogen is essentially a limiting nutrient in many systems, but its concentration or availability may have been elevated significantly due to several anthropogenic activities, probably leading to a number of environmental problems.  Nitrogen saturation due to atmospheric deposition, ecosystem acidification, eutrophication in freshwater systems or estuaries, and their ecological/ biogeochemical implication and consequences will be expected topics of considerable interests.

SS59: Dynamics of Habitat Structure and Aquatic Assemblages

Oral Talks | Poster Presentations

M. Tokeshi, Kyushu University, tokeshi@ambl-ku.jp; Y. Takemon, Kyoto University, takemon.yasuhiro.5e@kyoto-u.ac.jp

While there is a long tradition of ecological studies on how aquatic systems are influenced by various physico-chemical factors, there has been a renewed interest in the dynamic nature of habitat structure and the patterns and functioning of aquatic assemblages.  This theme has broad implications relating not only to basic ecological issues but also to applied aspects such as habitat restoration, species conservation and biodiversity management.  A series of natural disasters that have recently plagued Japan, i.e. devastation of coastal environments due to earthquakes and tsunamis in the north and typhoon-associated flooding and river valley collapses in central Japan, highlights the need for understanding the spatio-temporal dynamics of habitats and aquatic assemblages.  This symposium is intended to explore the linkages between variable habitat structure and aquatic assemblages on all spatial/temporal scales, from very small to very large.

SS60 Impacts of Climatic and Environmental Changes on Inland Waters

Oral Talks | Poster Presentations

Prof. Rolf Kipfer, EAWAG, Swiss Federal Inst. of Aquatic Science and Technology, kipfer@eawag.ch; Rolf Kipfer, EAWAG, Swiss Federal Inst. of Aquatic Science and Technology, kipfer@eawag.ch; Frank Peeters, University of Konstanz, frank.peeters@uni-konstanz.de; David M. Livingstone, EAWAG, Swiss Federal Inst. of Aquatic Science and Technology, living@eawag.ch

Changes in climate and in other environmental factors are exerting their influence on all conceivable types of continental water bodies, from lakes, lake sediments, rivers and groundwater to the fluid inclusions present in stalagmites. This session will bring together recent results from various different types of continental aquatic systems over a broad range of time-scales with the intention of giving a comprehensive overview of the influence of climatic and environmental change on all types of continental water bodies. At the same time, the session will explore the potential of relevant new methodological approaches - such as the analysis of gases in sediment porewaters and the analysis of high-resolution groundwater time-series - in assessing both the quantitative and qualitative aspects of the past and likely future responses of inland water bodies to climatic and environmental change.

SS61: The Global Ocean Ecosystem: Patterns, Drivers and Change

Oral Talks | Poster Presentations

Susana Agustí, IMEDEA, CSIC-UIB, Malllorca, Spain, sagusti@imedea.uib-csic.es; Carlos M. Duarte, IMEDEA, CSIC-UIB, Spain, carlosduarte@imedea-uib-csic.es; Josep M. Gasol, ICM, CSIC, Barcelona, Spain, pepgasol@icm.csic.es; Xose A. Alvarez-Salgado, IIM, CSIC, Vigol, Spain

The assessment of global patterns in the structure and functioning of the ocean ecosystem is a fundamental requisite to understanding the drivers of ocean ecosystems and predict their response to global change. This session will gather contributions addressing global patterns and drivers in key properties of the ocean ecosystem, spanning from biodiversity to biogeochemical process, and their response to global change. Global assessments of the ocean ecosystem derive from syntheses of existing data and studies, results from global expeditions, such as the Malaspina 2010 expedition, and model studies. A global understanding of the ocean ecosystem can also be derived from the comparative analyses of ocean regions and biogeographic provinces, helping resolve global patterns that may help elucidate the role of fundamental properties, such as temperature and nutrient inputs, in driving the ocean ecosystem

SS62: Biodiversity-Ecosystem Functioning Relationships Across Trophic Levels and Gradients in the Context Of Global Change

Oral Talks

Christopher T. Filstrup, Iowa State University, filstrup@iastate.edu; Adam J. Heathcote, Iowa State University, aheathco@iastate.edu; W. Stanley Harpole, Iowa State University, harpole@iastate.edu

Recently, terrestrial and aquatic scientists have been giving increased attention to relationships between biodiversity and ecosystem functioning which has largely been driven by growing concerns of biodiversity loss in ecosystems worldwide. Conservationists often cite the paradigm that high biodiversity supports maximum ecosystem functioning and provision of goods and services as an argument for preserving biodiversity. However, several studies have challenged this paradigm by demonstrating that ecosystem functions achieve maximum rates at low diversity levels, typically quantified as species richness. Investigators have cautioned that species richness is only one component of biodiversity and other metrics, such as evenness, should also be considered. Likewise, focus on single metrics of ecosystem function may greatly underestimate the consequences of biodiversity loss if species play important roles for different functions or in different contexts. At the same time, global change is not only causing loss of species diversity but also creating novel ecological contexts in which the roles of species diversity and species identity are poorly understood. This session invites contributions from studies that investigate biodiversity-ecosystem functioning relationships across trophic levels and trophic gradients from various ecosystems. Especially encouraged are studies that investigate how biodiversity influences multiple ecosystem functions in the context of global change. Organizers hope to identify commonalities in biodiversity-ecosystem functioning relationships in alternative systems and to highlight potential differences among trophic levels and across trophic gradients.

SS63: Lake Biwa Story: Past, Present and Future

Oral Talks | Poster Presentations

Chunmeng Jiao, Lake Biwa Environmental Research Institute, jiao-c@lberi.jp; Kasuhide Hayakawa, Lake Biwa Environmental Research Institute, hayakawa-k@lberi.jp; Hiroki Haga, Lake Biwa Museum, haga@lbm.go.jp

Lake Biwa has a long history as one of the ancient lakes in the world. About 400,000 years ago, it is said that the lake arrived at the present location. Since then, it has cultivated various fauna and flora including its original organisms; say endemic species to the lake. Because of rapid urbanization, industrialization and population increase in its watershed after 1950s, Lake Biwa faced eutrophication symbolized by freshwater red tide which started in 1977 and the blue-green algae blooms in 1983. Through about 30 years of continual efforts of the Shiga Prefectural Government and its local residents, 84% of the watershed is now covered with the sewerage networks. Point-source pollution has almost been solved, non-point pollution can be getting under control and the difficult eutrophication problems seem to be successfully overcome. Of particular note, the ecosystem in the highly urbanized South Basin of the lake experienced a regime shift, moving from high turbid water conditions dominated by blue-green algae to clear water conditions dominated by submerged macrophytes. The experiences in Lake Biwa provide a world excellent example where coordinated efforts at many levels of government as well as community actions helped to overcome the difficult problems of eutrophication in lakes. This session provides discussions about tectonic history, lake eutrophication, integrated watershed management, biodiversity and ecosystem rehabilitation, lush growth of submerged macrophytes and hypoxia in the deep basin.

SS64: Changes in the Biogeochemistry and Primary Productivity of the Western Arctic and Subarctic Seas: Regional Processes and Large-Scale Connectivity

Oral Talks | Poster Presentations

Jean-Éric Tremblay, Université Laval, jean-eric.tremblay@bio.ulaval.ca; Kevin Arrigo, Stanford University, arrigo@stanford.edu; Roxane Maranger, Université de Montréal, r.maranger@umontreal.ca

The Arctic Ocean is a globally significant biogeochemical hub that connects the North Pacific to the North Atlantic. Yet key questions on its ecological functions and responses to climate change remain unanswered. Denitrification removes nitrate on the shallow shelves of the Bering Sea, creating a nitrogen (N) deficit that maintains anomalous nutrient ratios and constrains marine productivity downstream in the western Arctic and subarctic western Atlantic. Since the resulting surplus of phosphorus (P) is favorable to diazotrophs, N fixation en route to the temperate North Atlantic hypothetically restores N:P ratios toward the Global average and enables diatoms to exploit the silicon surplus.  Information on rates of denitrification and N fixation as well as their sensitivity to environmental change is very sketchy in cold seas. Changes in the influx of inorganic and organic nutrients from Rivers and the Bering Strait are also bound to affect productivity on High Arctic shelves. These changes will have remote consequences because the particles produced on shelves sink and the combined action of shelf-basin transport and bacterial decomposition releases nutrients into the Arctic halocline. The halocline propagates over large distances and episodically comes in contact with the euphotic zone through vertical mixing, upward doming eddies or upwelling, which may become more common under low ice conditions. This session invites contributions dealing with interactions between the physical environment, nutrient fluxes and stoichiometry, microbial processes, sinking fluxes, lower food web productivity and the production of climate-active gases in Arctic and subarctic seas. Results from field, modeling and remote sensing work at regional and basin scales are equally encouraged.

SS66: Lake Pollution and Restoration

Oral Talks | Poster Presentations

Rosa Galvez, Laval University, rosa.galvez@gci.ulaval.ca; Serge Leroueil, Laval University, serge.leorueil@gci.ulaval.ca

Human activities (agriculture, energy, natural ressources exploitation) and other activities cause eutrophication and pollution of lakes and rivers, with the consequent impacts: loss of water quality, loss of water uses, loss of habitats, loss of biodiversity. Lake and watershed studies can serve to identify pollution sources, pathways and mechanisms of pollution difussion, impact evaluation and to design sound restoration plans. Papers on pollution studies, ecosystem response, restoration techniques, environmental impact assessment and case studies are welcome to this symposium.

SS67: Responses of Lake Ecosystems to Global Changes: planktonic organisms as indicator

Oral Talks

Syuhei Ban, University of Shiga Prefecture, ban@ses.usp.ac.jp; Sami Souissi, University of Lille 1, sami.souissi@univ-lille1.fr

Planktonic organisms in lakes and reservoirs act as natural environmental indicators. Variations in abundance and community structure can be used to reconstruct a trajectory of change in lakes. The use of long-term observational and instrumental time-series of lake plankton communities allows the assessment of ecosystem variability on time-scales of years to several decades. Change plankton communities may also be used to distinguish between the relative importance/or impact of natural (e.g. climate) and human-induced disturbances (e.g. eutrophication, acidification). Moreover, these time-series provide information about the resilience of aquatic ecosystems to future disturbances and serve as the basis for establishing baseline conditions as needed for restoration targets. Organizers invite presentations highlighting analyses of long-term plankton records from lakes or reservoirs to better understand these ecosystems with regard to their natural, long-term development as well as their reaction and resilience to external disturbance. Theoretical and methodological studies are also welcomed as well as all scientific approaches, particularly those promoting inter-ecosystem and/or inter-site comparisons.

SS69: Underwater Imaging and Sensing with Innovative Technologies

Oral Talks | Poster Presentations

Tamaki Ura, University of Tokyo, ura@iis.u-tokyo.ac.jp; Blair Thornton, University of Tokyo, blair@iis.u-tokyo.ac.jp; Tatsuhiko Fukuba, University of Tokyo, bafuk@iis.u-tokyo.ac.jp; Kei Okamura, Kochi University, okamurak@kochi-u.ac.jp

Instrumentation of underwater platforms, such as ROVs and AUVs, for rapid, sensitive and selective detection is an active area of research with applications in biological and chemical oceanography, pollution monitoring, detection of health hazards, and exploration of submerged mineral resources. The diversity of interests drives new directions in sensor design, bringing together experts from different fields in an effort to identify techniques that can address major outstanding problems in underwater research, determine the technological barriers to applying these technologies and how these can be overcome. This session will discuss conceptualization, development, testing and deployment of new and innovative approaches to in situ underwater sensing, emerging technologies in analytical chemistry, micro-fluidics, spectroscopy and biosensing, as well as techniques for miniaturization of complex instrumentation and automation of their measurements.

SS73: Coastal Processes and Mixing

Oral Talks | Poster Presentations

Hidekatsu Yamazaki, Tokyo University of Marine Science and Technology, hide@kaiyodai.ac.jp; Jin Hwan Hwang,  Dongguk University, jinhwang@dongguk.edu

Fresh water discharged from a river forms plume and is mixed with coastal water.  Land origin of chemical and biological, even nuclear material, are eventually mixed with the open water and diffuse away due to numerous complex coastal processes.  This session focuses mixing phenomena in the coastal region based on field experiments and numerical works. Any new thought on mixing in the coastal water is also welcome.