Program & Agenda

Keynotes and Plenaries

Opening Plenary

Sunday, 22 February 2015 - Auditorium Federico Garcia Lorca (Floor 0)
17:00 - 19:00

A reception will follow the opening session.

Welcome by Meeting Co-Chair

Isabel Reche, Departamento de Ecologia, Universidad de Granada, Granada, Spain

Opening Remarks

James J. Elser, ASLO President, School of Life Sciences, Arizona State University

“ASLO returns: otra vez en España!”

Presentation Description: The world’s waters are global and our community is an increasingly interconnected web of collaboration as we seek to unlock the secrets of Earth’s oceans and continental waters and to meet a variety of pressing issues, including climate change, eutrophication, and acidification. Our meeting in Spain represents ASLO’s fifth meeting outside of North America and our second in Spain and this week we celebrate those connections and work to grow them even further and to meet the challenges of this era of accelerating global change.

Welcome Remarks

D. Francisco González Lodeiro, Rector Magnífico de la Universidad de Granada

Biographical Information: D. Francisco González Lodeiro received his doctorate from the University of Salamanca in 1981. He has been a professor at the University of Granada in the Department of Geology for many years, where he teaches Regional Geology, Geomorphology, Structural Geology, Fold and Fracturing, Introduction in Country Geology and Geodynamic Country Work- and in the Degree of Environmental Science.

He has been a member of the Natural Resources Committee of PAI (Plan Andaluz de Investigación), a board member of the Research National Plan, board member and president of the Nature Science Committee of the CNEAI, president of the External Committees of Evaluation of the Geology studies at the University of Salamanca and Barcelona and Geological Engineering at the University of Barcelona and the Technical College of Catalonia, board member of the Advisor Committee for Sciences of the “Agencia per a la Qualitat del Sistema Universitari a Catalunya,” board member of the Executive Committee of the PEACE (Palestinian European Academic Cooperation in Education, UE-UNESCO), member of the ALFA Program for Academic Cooperation between Europe and South America, board member of the Scientific Committee of the MED-CAMPUS Program, board member of the Liaison Committee of the European Rector's Conference (CRE), promoter of the Socrates Program, and a board member of the EU TEMPUS-TACIS Evaluation Commission.

Public Lecture

Narcís Prat, Universitat de Barcelona, Barcelona, Spain

Knowing Ramón Margalef: Naturalist, and master of several generations of Spanish and Latin-American ecologists

Presentation Description: Ramón Margalef (1919-2004) was the founder of Spanish Ecology and had a large influence on the development of this science in the Iberian Peninsula and Latin America. He published some influential papers on Theoretical Ecology, Limnology and Oceanography. Even today some of his papers are a reference for ecologist (e.g Oceanologica Acta, 1978, vol 1:4). He received many awards during his life (e.g. Huntsman’s medal, Naumann-Thienemann medal). One of the ASLO awards has his name (Educational Award) and the Catalonian government has instituted an annual prize with his name. However, although Margalef’s ideas and books are well known in the Iberian Peninsula and Latin America, his extensive work its only in part known for the international non-Spanish speaking community. His last book written in English (“Our Biosphere”) is nearly unknown. On the occasion of the 10th anniversary of his death, we have organized a series of events to remember his memory and work and to examine the actuality of his ideas ( A summary of such activities and the actuality of Margalef’s ideas will be presented in this plenary lecture.

Biographical Information: Narcis Prat earned his PhD. in biology at the University of Barcelona (1978) under the direction of Professor Ramon Margalef. He has been a professor at the Department of Ecology at the University of Barcelona since 1981 (full professor from 1987). His work is focussed in river, lakes and reservoirs, including biomonitoring, the effects of forest fires on Mediterranean streams, intermittent rivers and the taxonomy and ecology of midges. He has advised the regional minister of Environment of Catalonia from 2004 to 2010. During 2014 has been the coordinator of the activities of the 10th anniversary of the death of Professor Margalef.

Opening Plenary Presentation

Carlos M. Duarte, KAUST, Red Sea Research Center, Saudi Arabia

Malaspina Expedition: Seafaring on a New Quest

Presentation Description: On 13 December 2010 two Spanish research vessels departed on a seven-month voyage to assess the impacts of global change on the ocean and explore its biodiversity, particularly that of the dark pelagic ocean. The Malaspina 2010 Circumnavigation Expedition completed its global sampling effort on 15 July 2011. For over three years hundreds of scientists have been busy analyzing samples to yield, once completed, a mosaic describing the status and biodiversity of the world oceans in 2011. With less than a third of the pieces in place, the mosaic is already changing our views on the loads and fluxes of pollutants and nutrients as well as diversity of the pelagic ecosystem. This plenary talk, presented by the coordinator of the Malaspina 2010 Circumnavigation Expedition, will provide a brief outline of results thus far and reflect on how collaborative efforts can accelerate progress in understanding the ocean ecosystem.

Biographical Information: Carlos M. Duarte is the Tarek Ahmed Juffali Chair with the Red Sea Research Center at KAUST, Saudi Arabia, which he joined very recently. He was previously a research professor with the Spanish National Research Council (CSIC) and director of the Oceans Institute at The University of Western Australia.

Carlos’ research focuses on understanding the effects of global change on aquatic ecosystems, both marine and freshwater. He has conducted research across Europe, South-East Asia, Cuba, México, USA, Australia, the Amazonia, the Arctic, the Southern Ocean, and the Atlantic, Indian and Pacific oceans, spanning most of the marine ecosystem types, from near-shore to the deep sea and tropical to polar. From 2008 to 2014 Carlos led the Malaspina 2010 Expedition, a Spanish circumnavigation expedition that sailed the world's oceans to examine the impacts of global change on ocean ecosystems and explore their biodiversity (see He has published more than 550 scientific papers and two books reporting the outcomes of his research.

Carlos served as member-at-large and subsequently president of the American Society of Limnology and Oceanography (2009-2010) and as member of the Scientific Council of the European Research Council (ERC), the highest-level scientific committee at the European Level (2009-2013).

Monday Plenary Session and Awards

Monday, 23 February 2015 - Auditorium Federico Garcia Lorca (Floor 0)
12:00 - 13:30

Plenary Presentation

Jim Elser, ASLO President, School of Life Sciences, Arizona State University, Tempe, AZ, USA

ASLO 2.0: reinventing ourselves to assure relevance, impact, and sustainability

Presentation Description: Just as aquatic ecosystems are experiencing an unprecedented period of impact and change, so is the scientific community, including its scholarly societies. Our aquatic sciences themselves are changing (becoming global, interdisciplinary, driven by big data) while society’s expectations for science and its communication and application are also undergoing radical transformation. The universe of scientific publication is also evolving in unpredictable ways (e.g. open access, journal proliferation) while traditional avenues of support for journals (e.g. library subscriptions) are eroding. To meet these demands, ASLO has undergone an extended series of external and internal reviews and assessments. Growing out of this process is a transformation of ASLO (“ASLO 2.0”). In this talk I will describe these exciting changes, some of which are completed, some of which are underway as we speak, and some of which will appear in the near future. ASLO 2.0: yet more powerful, more fun, more rewarding than ever before!

Biographical Information: James Elser is Regents’ Professor and Distinguished Sustainability Scientist in the School of Life Sciences, Arizona State University. He is a Fellow of the American Association for the Advancement of Science and a foreign associate of the Norwegian Academy of Sciences and Letters. Elser holds a BS degree from the University of Notre Dame, an MS degree from the University of Tennessee, and a PhD (in Ecology) from the University of California – Davis. Recipient of ASLO's 2012 G. Evelyn Hutchinson Award for research accomplishment and its 1990 Lindeman Award, he now serves as ASLO’s President. Author or co-author of more than 210 scientific articles, of the book Ecological Stoichiometry, and co-editor of the recent book Phosphorus, Food, and Our Future, Elser is co-founder of ASU’s Sustainable Phosphorus Initiative ( and leader of the NSF-funded Research Coordination Network (RCN) on Phosphorus Sustainability.

Award Presentation

2015 A.C. Redfield Lifetime Achievement Award presented to David Schindler, Killam Memorial Chair and Professor of Ecology, Department of Biological Sciences, University of Alberta, Edmonton, Canada

The Award: The Lifetime Achievement Award recognizes and honors major, long-term achievements in the fields of limnology and oceanography, including research, education and service to the community and society. In 2004, the ASLO Board renamed the Lifetime Achievement Award in honor of Alfred C. Redfield. Emphasis in selection is given to established aquatic scientists whose work is recognized for its importance and long-term influence.

Plenary Presentation

Roman Stocker, Massachusetts Institute of Technology, Cambridge, MA, USA

The Microscale Biophysics of Ocean Microbes

Presentation Description: Aquatic microorganisms live and interact at the microscale. Yet, our knowledge of the exceedingly important ecosystem functions they play is based mostly on human-scale sampling approaches: rarely has their ecology been accessible at the level of single cells and their microenvironment. This barrier is due both to technical difficulties, given the minute scale and dynamic nature of many microbial processes, and to the counterintuitive physics that distinguishes the micro-scale from the macro-scale. I will show how the combination of microfluidic technology to create controlled, realistic microenvironments, with real-time and high-speed microscopic imaging to capture dynamic microscale processes, provides a powerful approach to begin to understand the microscale biophysics of aquatic ecosystems. I will illustrate this approach by presenting our recent efforts to directly image and thereby quantify the encounters between cyanobacteria and viruses, the chemotactic clustering of heterotrophic bacteria around individual diatoms, the unexpected micro-flows on a coral surface, and the microbial degradation of oil droplets and marine snow particles.

Biographical Information: Straddling microbial ecology and fluid mechanics, Stocker's research has addressed a long-standing challenge in microbial oceanography: to study marine microbes in the context of their microenvironment. Stocker has pioneered the use of microfluidic technology in microbial oceanography, creating microscale model systems of marine processes by generating controlled nutrient landscapes and flow conditions. Combined with high-resolution dynamic imaging, a focus on fundamental physical processes (diffusion, turbulence, settling, motility), and mathematical modeling, this approach has brought an unprecedented level of resolution and thereby a new perspective to the study of marine microorganisms and their interactions (Stocker, Science 2012).

Tuesday Plenary Session and Awards

Tuesday, 24 February 2015 - Auditorium Federico Garcia Lorca (Floor 0)
12:00 - 13:30

Award Presentation

2015 G. Evelyn Hutchinson Award presented to Craig Carlson, Professor of Microbial Oceanography, Department of Ecology, Evolution and Marine Biology, Marine Science Institute, University of California, Santa Barbara

The Award: The G. Evelyn Hutchinson Award has been presented annually since 1982 to recognize excellence in any aspect of limnology or oceanography. The award is intended to symbolize the quality and innovations toward which the society strives and to remind its members of these goals. In lending his name to the award, Hutchinson asked that recipients be scientists who had made considerable contributions to knowledge, and whose future work promised a continuing legacy of scientific excellence. The award is given to mid-career scientists for work accomplished during the preceding five to 10 years.

Plenary Presentations

Scott Doney, Woods Hole Oceanographic Institution, Woods Hole, MA, USA

Changing coastal and open-ocean biogeochemistry in the Southern Ocean

Presentation Description: The Antarctic continental shelf and surrounding open-ocean waters of Southern Ocean play important roles in marine biogeochemistry and the global carbon cycle. Seasonally ice-covered coastal waters are often highly productive, exhibiting large spring and summer drawdowns of nutrients and carbon dioxide and supporting high densities of upper trophic level organisms. Off-shore waters are typically more iron limited with lower plankton standing stock and overall productivity. The Southern Ocean as a whole also acts as a large sink from the atmospheric of anthropogenic carbon dioxide, primarily associated with the offshore upwelling of circumpolar deepwater and formation of mode, intermediate and deep waters. Climate change and ocean acidification are projected to alter substantially future sea-ice distributions, seawater chemistry, and ocean/atmosphere circulation patterns that modulate Southern Ocean marine biogeochemistry. The talk will discuss observational, remote sensing and modeling evidence for changing conditions in the Southern Ocean. A specific focus will be on the western continental shelf of the Antarctic Peninsula, which experiencing some of the most dramatic climate change on the planet, with rapid ocean-atmosphere warming, melting of coastal glaciers, reductions in seasonal ice cover, and shifts in phytoplankton distributions.

Biographical Information: Scott Doney is a Senior Scientist at the Woods Hole Oceanographic Institution (WHOI). His expertise spans oceanography, climate and biogeochemistry, with particular emphasis on the application of numerical models and data analysis methods to global-scale questions. Much of his research focuses on how the global carbon cycle and ocean ecology respond to natural and human-driven climate change including ocean acidification. He has been a long term contributor to the Community Earth System Model. He is also actively involved in programs including US Global Ocean Carbon and Repeat Hydrography, the REgional Carbon Cycle Assessment and Processes (RECCAP), and the Palmer (Antarctic) Long Term Ecological Research (LTER). He graduated with a PhD from the MIT/WHOI Joint Program in 1991, and he was at the National Center for Atmospheric Research from 1991 to 2002.

Anthony Turton, University of the Free State, Bloemfontein, South Africa

The Need for Transdisciplinarity Arising from the Holocene/Anthropocene Transition – Some Ideas from Water Conflict Resolution in South Africa

Presentation Description: While there is no consensus yet on the notion of the Anthropocene, there is a growing body of evidence to suggest that such a transition has occurred. This talk will contextualize the notion of water stress and conflict as a logical product of the transition between two geological epochs (Holocene and Anthropocene). It will thus set the scene for a strategic level discourse on the science underpinning management of water biomes and oceanographic provinces, within the context of a major transition in geological timescales that is likely to result in a fundamental shift in all of the major assumptions on which current knowledge is based. Our transition to the Anthropocene has unlocked three key elements that need to be interrogated by academia if the science, engineering and technology community is required to respond appropriately. These three elements are:

  • Acceleration in the rate of change to biophysical drivers.
  • Increase in the complexity and interconnectedness of previously separate systems.
  • Inappropriateness of our current response to the training of science, engineering and technology professionals.

This talk will unpack these three elements using examples from the gold mining industry in South Africa, where it will be argued that Holocenic thinking has shaped a new generation of wicked problem that only an Anthropocenic approach is capable of solving.

Biographical Information: Anthony Turton holds a professorship in the Centre for Environmental Management at the University of Free State and is a founding director of the Ecological Engineering Institute of Africa. His current work is in the mining sector where he specializes in the development of strategies and technologies to mitigate the risk arising from the uranium contamination of Johannesburg; and acid mine drainage (AMD) as the gold industry reaches the end of its productive life.

Wednesday Plenary Session and Awards

Wednesday, 25 February 2015 - Auditorium Federico Garcia Lorca (Floor 0)
12:00 - 13:30

Award Presentations

2015 Ruth Patrick Award presented to James Cloern, Senior Research Scientist, U.S. Geological Survey, Menlo Park, California, USA

The Award: The Ruth Patrick Award honors outstanding research by a scientist in the application of basic aquatic science principles to the identification, analysis and/or solution of important environmental problems. The award is given to aquatic scientists who have made either sustained contributions or a single, but critical contribution towards solving an environmental problem.

2015 John Martin Award presented to Stephen Carpenter, Director of the Center for Limnology and Stephen Alfred Forbes, Professor of Zoology, University of Wisconsin, Madison, Wisconsin, USA for

  • S. R. Carpenter, J.F. Kitchell, and J.R. Hodgson for transforming our view of food web regulation and making a compelling case for "top-down" regulation of primary productivity. The paper was published in BioScience.1985. 35:634-639.

The Award: The John Martin Award recognizes a paper in aquatic sciences that is judged to have had a high impact on subsequent research in the field. The model for such a paper is Martin et al (1991), which laid out the case for iron limitation of phytoplankton productivity in the ocean. The Martin Award is for papers at least 10 years old.

Plenary Presentations

Tim Lenton, University of Exeter, College of Life and Environmental Sciences, Exeter, United Kingdom

An evolutionary ecology approach to modelling the marine ecosystem and its response to global change

Presentation description: How should we model the response of ecosystems to global change? Current approaches typically treat organisms as black boxes with no adaptive capacity, yet organisms are continually acclimating to changing environmental conditions and populations are evolving – nowhere more so than in the marine microbial ecosystem. To try and better understand and simulate this we have developed an evolutionary ecosystem model (‘EVE’), which resolves the allocation of resources within individual phytoplankton cells that in turn form populations within the grid cells of a global ocean model. Phytoplankton traits and the crucial trade-offs between them are grounded in laboratory physiological measurements. The simulated physical environment then selects for successful phytoplankton growth strategies. This produces familiar patterns of phytoplankton cell size, and makes predictions of, for example, their N:P composition (the Redfield ratio). Using the model we have been able to test the ‘growth rate hypothesis’ for variations in phytoplankton cellular N:P composition and identify locations where it is falsified. The approach also enables a closer link between models and ‘omics’ (molecular genetics) datasets.

Biographical Information: Tim Lenton is Professor of Climate Change and Earth System Science at the University of Exeter. His research focuses on understanding the behavior of the Earth as a whole system, especially through the development and use of Earth system models. He is interested in how life has reshaped the planet in the past, and what lessons we can draw from this as we proceed to reshape the planet now – as detailed in his book with Andrew Watson on the ‘Revolutions that made the Earth’ (OUP, 2011). Tim’s work identifying the tipping elements in the climate system won the Times Higher Education Award for Research Project of the Year 2008. He has also received a Philip Leverhulme Prize 2004, a European Geosciences Union Outstanding Young Scientist Award 2006, the British Association Charles Lyell Award Lecture 2006, the Geological Society of London William Smith Fund 2008, and a Royal Society Wolfson Research Merit Award 2013.

Amanda Vincent, University of British Columbia, Vancouver, BC, Canada

Imperfect advice or none at all

Presentation description: There is no chance of perfect advice in ocean conservation and management. The choice is between imperfect advice and none at all. This realization should free ocean scientists to engage meaningfully in the development and implementation of public policy. My talk will address the uncomfortable but pressing need for us to apply existing knowledge immediately, rather than simply calling for more research. My story draws from the journey to develop and implement pioneering global export controls on marine fishes under the Convention on International Trade in Endangered Species (CITES). Along the way, we plunged forward with trade evaluation, establishment of marine protected areas, management recommendations, and policy change. We were often at the very edge of our technical understanding. In the best spirit of adaptive management, however, rapid application of existing knowledge helped both to effect societal change and to guide further research.

Biographical Information: Amanda Vincent (@amandavincent1) suffers from aqualust and needs to spend more time underwater. She is now Professor in the Fisheries Centre at the University of British Columbia, after previous stints at Cambridge, Oxford and McGill. She directs Project Seahorse, a marine conservation team committed to conservation and sustainable use of the world’s shallow coastal marine ecosystems. Its work includes ecological and social research, establishment of marine protected areas, fisheries and trade management, and development of integrated policy. Amanda holds a Pew Fellowship in Marine Conservation, a Rolex Award for Enterprise and a Whitley Award, among other honors. She has many international roles with the IUCN and CITES, spends lots of time in Southeast Asia, and tries to take quick and effective action for the ocean.

Thursday Plenary Session and Awards

Thursday, 26 February 2015 - Auditorium Federico Garcia Lorca (Floor 0)
12:00 - 13:30

Award Presentations

2015 Raymond L. Lindeman Award presented to Hilary G. Close, Assistant Researcher, Department of Geology and Geophysics, University of Hawai'i, Honolulu, Hawaii, USA

For important and novel insights about the export of submicron particulate organic matter into the deep ocean, presented in her paper entitled, “Export of submicron particulate organic matter to mesopelagic depth in an oligotrophic gyre.”

- Proceedings of the National Academy of Sciences (2013)

The Award: This annual award in honor of Raymond L. Lindeman (1915-1942) was first presented in 1987 to recognize an outstanding paper written by a young aquatic scientist age written by a scientist 35 years of age or less.

2015 Ramón Margalef Award for Excellence in Education to Marianne V. Moore, Frost Professor in Environmental Science and Professor of Biological Sciences, Wellesley College, Wellesley, Massachusetts, USA

The Award: This award is targeted toward ASLO members at any stage in their careers and is presented to the ASLO member who best exemplifies the highest standards of excellence in education. The Ramón Margalef Award for Excellence in Education was first presented in 2009 and is presented annually.

Plenary Presentations

Thorsten Dittmar, University of Oldenburg, Institute for Chemistry and Biology of the Marine Environment, Oldenburg, Germany

Fire in the ocean: black carbon in aquatic environments

Description: Fire has been an integral part of global biogeochemical cycles ever since vascular plants evolved on the continents. In the more recent history of Earth, humans have used fire extensively as a tool to shape Earth’s vegetation. Wildfires produce a wide suite of black carbon moieties ranging from slightly altered biopolymers, that quickly decompose in soils and waters, to charcoal. Today, global biomass burning generates an approximated 40-250 million tons of charcoal every year. Due to its particular chemical and physical properties, charcoal can be preserved over centuries and millennia in soils and sediments. After years of microbial attack in soils, however, charcoal becomes partially soluble, is lost from soils by leaching, and eventually enters the aquatic environment. The global flux of soluble charcoal to the oceans accounts to about 25-28 million tonnes carbon per year, which is ~10% of the global riverine flux of dissolved organic carbon (DOC). At the ocean’s surface, dissolved black carbon is susceptible to photo-bleaching, but a fraction survives transport into the dark deep ocean. In the dark ocean, dissolved black carbon is the chemically most stable form of DOC known. It is stable over tens of thousands of years, and has accumulated there to >12,000 million tonnes of carbon. Fire is now recognized as an important player in global biogeochemical cycles, impacting even the most remote regions of the abyssal ocean.

Biographical Information: Marine dissolved organic matter (DOM) is one of the largest carbon pools on Earth’s surface. The stability of DOM over millennia is enigmatic and has fascinated Thorsten Dittmar from early on in his research career. Dittmar’s research has revealed an unparalleled molecular diversity of DOM, and he uses this rich molecular archive in the ocean to gain novel insights into marine biogeochemical and microbiological processes. Dittmar is professor at the University of Oldenburg (Germany) and leads the Research Group for Marine Geochemistry that bridges between his home institute (Institute for Chemistry and Biology of the Marine Environment, ICBM) and the Max Planck Institute for Marine Microbiology (MPI Bremen, Germany). Dittmar gained his PhD in Marine Chemistry from the University of Bremen in 1999. Prior to being an Assistant Professor at Florida State University (2003-2008), he was a postdoctoral researcher at the Alfred Wegener Institute for Polar and Marine Research (AWI, Germany), at the Federal University of Pará (Belém, Brazil) and at the University of Washington (Seattle, USA). He returned to Germany in 2008 to lead the Max Planck Research Group for Marine Geochemistry, and became professor at the University of Oldenburg in 2013.

Tamara Galloway, University of Exeter, College of Life and Environmental Sciences, Exeter, United Kingdom

Microscopic plastic debris in aquatic ecosystems

Description: Global plastic production has risen rapidly over the past sixty years, and 10% of all discarded plastic waste is thought to end up in the oceans. There it can fragment, but takes centuries to fully degrade. As a result, microplastics (small plastic detritus <1 mm diameter) have become a widespread pollutant, and are increasingly present in aquatic ecosystems (both freshwater and marine) across the globe.

This talk will bring together the latest research documenting the distribution of microplastics in the oceans, on shorelines and in coastal sediments, and provide evidence for bioaccumulation and the biological effects of microplastics ingestion on organisms from across the food web. Finally, it will discuss the potential ecological impacts of predicted increases in marine litter on different aspects of ecosystem function and biogeochemical processes, and how these effects may be influenced by interactions between plastics and biota.

Biographical Information: Tamara Galloway is professor of ecotoxicology at the University of Exeter and also holds an honorary chair at University of Exeter Medical School. Tamara's research focus is in understanding how organisms adapt and survive in polluted environments and she studies the health effects of some of the most pressing priority and emerging pollutants: including complex organics, plastics and their additives, metals and nanoparticles. She receives funding from a wide range of competitive sources including NERC, BBSRC, Wellcome Trust, medical charities and industry groups both in the UK and internationally. She is an expert member of several (inter)/national committees charged with environmental protection and the promotion of translational research.

Friday Plenary Session and Awards

Friday, 27 February 2015 - Auditorium Federico Garcia Lorca (Floor 0)
12:00 - 13:30

Award Presentation

2015 Yentsch-Schindler Early Career Award presented to Matthew Church, Associate Professor, Department of Oceanography, University of Hawaii at Manoa, Honolulu, Hawaii, USA

About the Award: In 2012, the ASLO Board initiated a new annual award in honor of early career scientists. The Yentsch-Schindler Early Career Award honors an aquatic scientist within 12 years of the completion of their terminal degree, for outstanding and balanced contributions to research, science training, and broader societal issues such as resource management, conservation, policy, and public education. The award was presented for the first time in 2013.

Plenary Presentations

Bess Ward, Princeton University, Department of Geosciences, Princeton, NJ, USA

Cryptic pathways of microbial nitrogen transformations in the ocean

Presentation Description: The major pathways of microbial N transformations have been known for more than a century. But in recent years, recognition of important new pathways and modifications of known pathways have changed our understanding of N cycling in the ocean. And these lead to new mysteries and new angles on longstanding questions. For example, nitrate is recognized as the major inorganic N source for phytoplankton, but how phytoplankton manage to obtain and utilize nitrate at the very low concentrations at which it occurs in surface waters is unclear. Using natural abundance stable isotope methods and isotope tracer incubations, we are able to trace the differential utilization of nitrate and ammonium into different fractions of the natural phytoplankton assemblage. We find that the small eukaryotic phytoplankton appear to be nitrate specialists although the mechanisms they use to obtain nitrate are unknown. Another example of a lingering mystery is the distributions of nitrite and nitrous oxide in the oxygen minimum zones of the world oceans. While the processes that produce and consume these intermediate components of the nitrogen cycle are well known, just how they operate to maintain the maxima and minima features that characterize the OMZ water column is unknown. We find using tracer incubations and simple models that even these apparently static distributions are the result of rapid, nearly cryptic, cycling by microbial transformations.

Biographical Information: Bess Ward is a biological oceanographer who works on the microbial biogeochemistry of the marine nitrogen cycle. Her Ph.D. work at the University of Washington was on nitrification, at the time a little studied part of the N cycle. As a post doc and research scientist at Scripps Institution of Oceanography, she measured nitrification rates in many regions of the ocean and began working in oxygen minimum zones. She also investigated the oxidation of methane in seawater associated with the subsurface methane maximum in oxygenated seawater, and detected anoxic methane oxidation in the Cariaco Trench and the Black Sea. At the University of California at Santa Cruz, Ward began working on the molecular ecology of denitrification and established the interdisciplinary approach of molecular biology and isotope tracer biogeochemistry that she continues to this day. In the Department of Geosciences at Princeton University since 1998, she has focused on nitrogen cycling in oxygen gradient environments (oceans, lakes, sediments) and nitrogen utilization by phytoplankton. In both endeavors, she measures rates and distributions of N transformations and links those rates to the community composition and dynamics of the microbes responsible for the rates.

Peter Raymond, Yale School of Forestry & Environmental Studies, CT, USA

Drainage Networks as Reactors

Presentation Description: Inland waters are part of a global circulatory system, delivering terrestrial elements and water to the ocean. As early as the 15th century, da Vinci noted that this delivery system has components that are predictable and provide an opportunity for scaling. Precipitation and discharge events have frequency and distribution curves. Drainage networks have self-similar properties that can be simplified using mathematical expressions. Streams have a hydraulic geometry that can be quantified and are similar across landscapes. These relationships will be presented in the context of drainage network biogeochemistry. Specifically, utilization of these relationships will be developed to demonstrate approaches to model DOM dynamics within a basin, including DOC fluxes off the landscape, reactions during transport and coastal export.

Biographical Information: Pete Raymond started studying carbon in the Hudson River as an undergrad with scientists at the Cary Institute of Ecosystem Studies. He earned a PhD from the Virginia Institute of Marine Science in 1999. He was awarded the CERF Cronin award for young scientists and a NSF CAREER grant. He has been a professor at the Yale School of Forestry and Environmental Studies for the last 12 years, where he is also the director of the Yale Analytical and Stable Isotope Center. His work focuses mainly on the controls of carbon chemistry of inland waters and estuaries. Most recently he is the lead PI on a NSF MacroSystems grant studying DOM dynamics in the Connecticut River.