BSSC 2011 Abstracts

8th Baltic Sea Science Congress 2011 8th Baltic Sea Science Congress 22 – 26, August 2011 St. Petersburg, Russia BOOK OF ABSTRACTS St. Petersburg 2011 1 8th Baltic Sea Science Congress 2011 Table of Contents Invited lectures IL1-IL6 ......................................................................................................... 3 Plenary lectures L1-L20 ......................................................................................................... 12 Oral presentations O1-O204................................................................................................... 32 Poster presentations P1-P133 ................................................................................................. 236 2 8th Baltic Sea Science Congress 2011 IL1. Knowledge generation vs. decision processes - the issue of regional climate service Hans von Storch1 Institute for Coastal Research, Helmholtz-Zentrum Geesthacht and KlimaCampus, Hamburg Climate science, the process of generating knowledge about the state and dynamics of climate, climate change and climate impact, is motivated not only by the traditional curiosity for better understanding of an otherwise complex world, but more and more so by the application-driven need for information and insight, which constrains the various public and economic decision processes. The latter takes place in a “postnormal” environment, where “facts are uncertain, values are in dispute, stakes are high and decisions are urgent”. In such an environment, competing knowledge claims compete for the public recognition of providing “right” insights, with considerable political and/or economic implications. Climate science has to acknowledge this challenging situation, by reflecting upon the consequences of the presence of competing knowledge claims (e.g., alarmists, skeptics) and by providing a “regional climate service”. Such a service comprises different elements. One element is data sets describing possible futures as well as recent and ongoing changes, and the consistency of past and futures. Another element is the assessment of the scientifically legitimate knowledge about climate, climate change and climate impact in the region of interest. An important issue is the determination of the degree of consensus and of disagreement within the scientific community. Finally, a dialogue has to be built between scientific actors and the public and decision makers. At the Institute of Coastal Research of Helmholtz-Zentrum Geesthacht, such a regional climate service has been established, involving the International BALTEX Secretariat and the “Norddeutsches Klimabüro”, who have prepared reports about the available climate knowledge in the Baltic Sea Region (BACC) and in the metropolitan region of Hamburg, have assembled data sets of ongoing and possible future climate change in the data set “CoastDat” and “Klimaatlas”, and have established a dialogue with public and decision makers. Personal profile Prof. von Storch ([email protected]) is director of Institute of Coastal Research of the Helmholtz Zentrum Geesthacht and professor at the Meteorological Institute of the University of Hamburg. His research interests are climate diagnostics and statistical climatology, regional climate change and its transdisciplinary context. He has published seventeen books and numerous articles. He is involved in the Fifth Assessment of the IPCC as a lead author in Working Group II, and as a contributing author in Working Group I. He supervised the assessments of scientific knowledge about climate, climate change and impact in the Baltic Sea Region (BACC) and the metropolitan region of Hamburg. In 2008 he was awarded a honorary doctorate by the University of Göteborg, and in 2010 he received the award of the International Meeting of Statistical Climatology. When a photo is needed, refer to http://fotos.web.de/hvonstorch/hans-public 1 This key-note lecture is sponsored by BONUS Joint Baltic Sea Research and Development Programme 3 8th Baltic Sea Science Congress 2011 IL2. Bioavailability of dissolved organic nitrogen and its contribution to eutrophication in aquatic systems Deborah Bronk1 Department of Physical Sciences, Virginia Institute of Marine Science, College of William and Mary Relative to inorganic nitrogen, concentrations of dissolved organic nitrogen (DON) are often high, even in regions believed to be nitrogen limited. The persistence of these high concentrations led to the view that the DON pool was largely refractory and therefore unimportant to plankton nutrition. What DON was utilized was believed to fuel bacterial production. However, more recent work in my laboratory indicates that rates into and out of the DON pool can be large, and that the constancy in concentration is a function of tightly coupled production and consumption processes. For the last decade my lab group has measured uptake of organic nitrogen by plankton in a wide variety of systems, including a number of harmful algal species. Our most recent work has focused on developing ways to discriminate between autotrophic and heterotrophic utilization, including stable isotope probing and flow cytometric sorting merged with 15N tracer techniques. We have also been investigating a number of mechanisms that could facilitate phytoplankton use of DON components such as cell surface enzymes and photochemical decomposition. We have also been applying what we have learned through our basic research to the applied question of whether organic nitrogen in wastewater treatment plant effluent is available to plankton. Evidence to date indicates that effluent organic nitrogen is available to cells and can contribute to coastal eutrophication via direct uptake, photochemical release and salinity-mediated release. Personal profile Deborah Bronk ([email protected]), is professor of marine science at Virginia Institute of Marine Science. Her research interests involve the fluxes of nitrogen in open-ocean, coastal, and estuarine environments with emphasis on the role of dissolved organic nitrogen (DON) in microbial food webs. She has developed 15N tracer techniques for quantifying in situ rates of DON release and uptake. Recently she has investigated photochemical processes as a mechanism that facilitates the uptake of organic nitrogen by phytoplankton and bacteria. D. Bronk has successfully linked the flow cytometry with 15N-tracer techniques to quantify nitrogen flow into autotrophs vs. heterotrophs. Currently she is president of American Society of Limnology and Oceanography. 4 8th Baltic Sea Science Congress 2011 IL3. Some aspects of biogeochemistry of oxygen-deficient marine systems Wajih Naqvi1 National Institute of Oceanography, Goa, India and Max-Planck Institute of Marine Microbiology, Bremen, Germany Oxygen-deficient conditions including complete anoxia develop naturally below the pycnocline in several semi-enclosed basins and at intermediate depths in a few areas of the open-ocean, particularly along the productive eastern boundaries of the Pacific Ocean and in the northern Indian Ocean. The open-ocean oxygen deficient zones (ODZs) appear to be expanding currently, presumably due to global warming. In addition, hundreds of ODZs have also been formed in coastal areas around the world as a result of human activities (mainly eutrophication). Oxygen removal from water brings about large ecological changes including exclusion of fish and mortality of benthos. However, these “dead zones” are inhabited by anaerobic micro-organisms that carry out redox transformations of a number of biologically and climatically important elements and thus play important roles in global biogeochemical cycles as well as modulation of the Earth’s climate. Under anaerobic conditions heterotrophic microbes sequentially utilize various electron acceptors - 2- in the order of declining energy yield (e.g., NO3 , Mn(IV), Fe(III), and SO4 ), but anaerobic biogeochemistry is dominated by the nitrogen and sulphur cycles. Conversion of combined nitrogen - (mostly NO3 ) to N2, and to a smaller extent N2O, in anaerobic environments is the main loss term in the nitrogen budget. This term is poorly constrained vis-ŕ-vis N2-fixation – the principal source term. Moreover, it is still not clear whether nitrogen loss in water occurs dominantly through - - heterotrophic denitrification (reduction of NO3 to N2O/N2 via NO2 and NO) or anaerobic ammonium - + oxidation (anammox, reaction of NO2 with NH4 mediated by autotrophic bacteria). In addition, processes such as dissimilatory nitrate reduction to ammonium (DNRA), previously not considered to be important in the water column, now seem to contribute significantly to nitrogen cycling in 2- ODZs. Evidence is also emerging for a “cryptic sulphur cycle” in which SO4 reduction may occur in reducing waters before the oxidized nitrogen species are completely exhausted. Thus, several important questions concerning inter-linked cycles of major biogenic elements in ODZs still remain to be answered. Anaerobic processes play a key role in controlling atmospheric chemical composition on a variety of time scales. Denitrification is not only responsible for keeping the atmospheric N2 content constant over geological times, it also controls – along with N2-fixation with which it may be coupled – the oceanic combined nitrogen inventory. Changes in this inventory could modulate export production and thereby climate on the geological time scale. In addition, the ocean is an important contributor to the atmospheric budget of N2O, the cycling of which is

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