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Special Sessions for ASLO 2005 Summer Meeting
SS01 Ecosystem Engineers in the Benthic
Boundary Layer
Organizers: Luca A. van Duren, Netherlands Institute of Ecology,
(l.vanduren@nioo.knaw.nl)
and Joseph D. Ackerman, University of Guelph, (ackerman@uoguelph.ca)
Benthic plants and animals influence their hydrodynamic environment
by extracting horizontal momentum from the flow and introducing
turbulence into the near-bed region. This occurs either passively,
when biogenic structures act as roughness elements, or actively,
through the action of the suspension feeders (e.g., pumping, exhalant
siphons). In the former, biomechanical properties, especially stiffness,
have a large impact on the interaction of the biogenic structures
with flow and sediments. In the latter, changes in behaviour (e.g.
pumping rates of bivalves) have an impact on the exchange processes
near the sediment-water interface. Collectively, these relatively
small-scale hydrodynamic processes can affect ecosystems. This
session therefore encourages papers that examine the role of organisms
as ecosystem engineers in the benthic environment. Papers that
couple the physical and biological environments in freshwater and
marine systems are encouraged at the level of individual organisms,
small aggregates of organisms, as well as the larger scale of ecosystems.
SS02 Ecology of Gelatinous Zooplankton
Organizers: Francesc Pages, Institut de Ciencies del Mar (CSIC),
(fpages@cmima.csic.es)
and Jennifer E. Purcell, Western Washington University, (purcelj@cc.wwu.edu)
The gelatinous zooplankton have received increased attention from
the global scientific community in recent years, in part due to
dramatic blooms of native and introduced species, and their obvious
importance in the plankton food web. This group includes filter-feeding
pelagic tunicates (e.g., appendicularians, salps), and predators
that feed with tentacles (scyphomedusae, hydromedusae, siphonophores,
ctenophores) or lobes (some ctenophores). We seek to bring together
scientists from many countries to explore recent advances in our
understanding of the importance of these abundant consumers. Topics
of special focus in this session will be their importance in the
food web, population dynamics, and relationships to environmental
change.
SS03 Trace Metal Cycling in Aquatic
Environments
Organizers: Antonio Tovar-Sanchez, CSIC- Univ. Illes Balears, SPAIN,
(antonio.tovar@uib.es)
and Sergio A. Sañudo-Wilhelmy, Stony Brook University, NY,
USA, (ssanudo@notes.cc.sunysb.edu)
While trace metals are ubiquitous in aquatic systems, we are still
learning how external and internal forcing functions influence
their biogeochemical cycling. This session will provide a forum
for presentations that contribute to the understanding of the biotic
and abiotic processes regulating these cycles. Participation is
encouraged by scientists investigating natural and anthropogenic
sources, fate and transport of trace metals in rivers, lakes, coastal
and oceanic waters. Both empirical and modeling studies are welcome.
This session will also aim to identify critical research needs
for better understanding of metal cycles in aquatic systems.
SS04 Climate Change in Ocean and Marginal
Sea Ecosystems: Observation, Modeling, and Experiments
Organizers: Evaristo Vázquez-Domínguez, ICM-CMIMA
(CSIC), (evazquez@icm.csic.es)
and Victoria Coles, University of Maryland Center for Environmental
Science, Horn Point Laboratory, (vcoles@hpl.umces.edu)
We propose a special session for the 2005 ASLO summer meeting highlighting
the effects of anthropogenic climate change on open ocean and marginal
sea ecosystems. Discriminating between the ecological effects of
anthropogenically induced climate variability, natural decadal
climate variability, and global changes associated with anthropogenic
influences distinct from climate, remains a challenge. However,
it seems clear that most IPCC models predict a global surface air
temperature warming of between 2 and 5ºC for this century
if the concentration of CO2 is doubled. These effects are spatially
heterogeneous, and regionally, particularly in the northern hemisphere,
the increases may be even greater. Observations of glacial retreat,
reductions in sea ice cover, and increasing sea level all corroborate
an increase in the warming trend. There is greater uncertainty
about changes to rainfall, frequency of storm events, surface ocean
pH, and other factors that influence the physical conditions of
the upper ocean, however these effects are likely to also influence
ecosystem response. Because these studies are largely projected
into the next century using numerical models with well-known deficiencies,
which generally do not include potential ecosystem feedbacks, the
challenge for the coming decade is to generate observations, experiments,
and model refinements to improve these forecasts, and ultimately
to guide mitigation efforts.
Our biosphere is composed of a complex network of systems, and
to understand the effects of climate change on this network, we
must understand not only the changes in the interacting components,
but also, the new pathways which may be formed under conditions
different from those observed today. Indeed, this is especially
important for the aquatic systems that cover 71% of the earth surface
and are the main reservoir of easily available inorganic carbon.
Beyond this study of passive response to external change, we must
also improve our understanding of the feedbacks between ocean ecosystems,
the carbon system, and climate. We propose that this session include;
the study of recent climate variability to understand its effects
on biogeochemical cycles and on the ecosystem; model studies of
the effects of climate change and variability on ecosystems and
potential feedbacks to the climate system; and mechanistic experiments
focused on food web response to climate changes under controlled
conditions. This diverse range of studies will provide a mechanism
for cross-fertilization of different branches of investigation.
SS05 Biogeochemistry of Tropical Rivers
Organizers: Michael McClain, Florida International University,
(michael.mcclain@fiu.edu)
and Jay Brandes, The University of Texas at Austin, (brandes@utmsi.utexas.edu)
We would like to hold a special session focusing on the biogeochemistry
of tropical river systems. There are a wide variety of ongoing
studies on these rivers, covering a diversity of subjects from
basic examinations of carbon and inorganic matter inputs and transport,
nutrient cycling, to more complex studies of deforestation and
global change impacts, pollution and water use issues. This session
provide a much-needed opportunity for researchers to discuss the
current state of tropical river studies.
SS06 Fate and Effects of
Terrestrial DOM in Aquatic Ecosystems
Organizers: Jan Karlsson, Climate Impact Research Centre, Umeå University,
(jan.karlsson@eg.umu.se)
and Morten Søndergaard, Freshwater Biological Laboratory,
University of Copenhagen, (msondergaard@bi.ku.dk)
Rivers, lakes and coastal ecosystems receive large quantities of
allochthonous DOM with consequences for ecosystem function and
activity. Important properties of DOM are its specific absorption
of UV- and PAR radiation and its function as a carrier of nutrients
and chemical energy. Due to the absorption properties of DOM, and
specifically the absorption by coloured compounds, it competes
with primary producers for light and at the same time protects
aquatic communities against high UV radiation. The bound nutrients
are made available by interactions between photochemical reactions
and direct microbial utilisation. The chemical energy is utilized
by heterotrophic bacteria and may support a substantial portion
of secondary production. Research over the past decade has dramatically
increased our understanding of the quantity of terrestrial DOM
export and how it can affect the biota. However, much is still
to be learned about the effects and behaviour of specific DOM compounds,
e.g. differences in quality and quantity linked to climate gradients
and land use, competition between heterotrophic bacteria and primary
producers for the bound nutrients, degradation kinetics, and the
importance for ecosystem energy support and metabolism. We invite
you to contribute to this special session with focus on the fate
of terrestrial DOM (DOC, DON and DOP) in rivers, lakes and coastal
waters, and how the physical and chemical properties affect these
ecosystems and their biota. Results presenting new methods and
approaches are also welcome.
SS07 Applied Ecosystem-level Research
to Reverse Coral Reef Degradation
Organizers: Michael J. Dowgiallo, NOAA/Center for Sponsored Coastal
Ocean Research, (michael.dowgiallo@noaa.gov)
and Felix A. Martinez, NOAA/Center for Sponsored Coastal Ocean
Research, (felix.martinez@noaa.gov)
Coral reefs, one of the most complex marine ecosystems, remain
poorly understood and are under intense pressure from anthropogenic
disturbance against the background of environmental variability.
This has influenced scientists and resource managers to focus on
addressing the suite of stressors that affect coral reef ecosystem
health. However, the need to devise management strategies has been
hampered by the lack of understanding of how coral reef ecosystems
function under pristine conditions much less when disturbed. The
approach of combining basic research with applied objectives presents
an alternative for providing insight on coral reef ecosystem function
that also informs resource managers when designing and evaluating
management strategies to stop and ultimately reverse coral reef
degradation due to human impact. The purpose of this special session
is to provide an international forum for scientists and resource
managers to 1) provide examples of basic and applied research activities
that have management implications; and, 2) share views and evaluate
the success of such an approach.
SS08 Carbon and Carbonate Fluxes in
the Coastal Ocean
Organizers: Fred T. Mackenzie, Department of Oceanography University
of Hawai'i at Manoa, USA, (fredm@soest.hawaii.edu)
and Jean-Pierre Gattuso, Laboratoire d'Oceanographie de Villefranche,
CNRS-Université de Paris 6, Fr, (gattuso@obs-vlfr.fr)
The role of the coastal ocean in the global carbon and carbonate
cycles is disproportionately high considering its relatively small
surface area (7% of the surface of the ocean). For example, it
contributes 14-30% of the oceanic primary production and about
50% of the marine calcification. The aim of this session is to
examine the factors explaining such high rates of activity and
update global estimates of processes such as primary, production,
respiration, calcification, air-sea CO2 fluxes, inputs from land
and atmosphere, and outputs to the open ocean. Presentations based
on process studies, modelling and data synthesis are welcome. This
session is a tribute to the late Professor Roland Wollast, a leader
and visionary, one of the leading scientists who helped to recognize
the critical importance of the coastal ocean in the global biogeochemical
cycles.
SS09 Interactive Effects of Multiple
Stressors on Aquatic Ecosystems
Organizer: Rolf Vinebrooke, University of Alberta, (rolf@ualberta.ca)
Additive and non-additive interactions among anthropogenic stressors
are the key drivers of current changes in aquatic ecosystem functioning.
However, our understanding of the ecological impacts on stressors
is largely derived from findings of single- stressor studies, which
cannot be used to predict the effects of non-additive antagonistic
or synergistic interactions among stressors. Nevertheless, most
stressors do not operate independently, but rather in combination
with other stressors to adversely affect aquatic biodiversity and
ecosystem function. The purpose of this session is to bring together
aquatic ecologists who are developing and testing hypotheses that
examine how major human stressors, such as climate warming, chemical
pollution, invasive species, and land-use, interact to affect freshwater
and marine ecosystems at the levels of physiology, population,
community, and function.
SS10 Coastal Pollution: From Molecular
Biology Based Genome Sensing to Real Time Ocean Sensing
Organizers: Sunny Jiang, University of California, Irvine, (sjiang@uci.edu)
and Stanley Grant, University of California, Irvine, (sbgrant@uci.edu)
Rapid human development in the coastal region has put tremendous
pressure on coastal water quality and nearshore ecosystems with
consequent impacts on human health and the coastal economy. To
characterize and mitigate this problem, tools are necessary for
rapid identification of the source, severity, fate and transport
of pollutants in coastal regions. Recently, multi-dimensional tools,
from molecular biology based genome sensing to large-scale real-time
ocean sensing programs, have been developed and applied to investigate
coastal pollution issues. This session calls for research papers
on all aspects of coastal pollution investigation. The topics include,
but are not limited to, microbial pathogen and indicator dynamics,
pollution source identification, fate and transport (governed by
microbial ecological and oceanographical processes), real-time
sensing programs, ocean observing programs, computational modeling
of pollutants and health effects, and integration of biology, physics
and ocean/atmosphere science for coastal pollution investigation.”
SS11 Biodiversity, Biogeochemistry
and Trophic Interactions: The Braid of Pelagic Microbial Ecology
Organizers: Farooq Azam, Scripps Institution of Oceanoraphy, (fazam@ucsd.edu)
and Fereidoun Rassoulzadegan, Laboratoire d'Oceanographie de Villefranche
(LOV), Université de Paris VI (, (rassoul@obs-vlfr.fr)
While research into the pelagic ecosystem often focus on system
properties such as biodiversity, biogeochemistry, and food web
structure, these phenomena are presumably closely linked and emerge
from a common set of basic mechanisms. Insight into the linkages
between biodiversity, biogeochemistry and trophic networks should
bring us closer to a deeper understanding of these underlying principles,
as well as how they link to the different emergent properties at
the system level. Contributions to this session may range from
adaptive mechanisms at the gene and organism levels optimizing
competitive or defense strategies, on specific sets of trophic
interactions, to responses at the food web level to changes in
environmental conditions.
SS12
Quantifying Bioturbation and Bio-irrigation: A ‘Camino’ Beneath
the Sediment-water Interface
Organizers: Filip J. R. Meysman, Netherlands Institute of Ecology,
(f.meysman@nioo.knaw.nl)
and Jack J. Middelburg, Netherlands Institute of Ecology, (j.middelburg@nioo.knaw.nl)
Individual organisms as well as their concerted action have a major
impact on sediment texture, heterogeneity and particle and solute
transport. Solute transport is enhanced in and near tubes, burrows
and burrow networks through passive or active flushing. Particle
mixing occurs due to animal movement as well as due to feeding
and defecation. A quantitative understanding of bio-irrigation
and bioturbation depends on development of theory and models, detailed
combined tracer-animal data sets and new, improved experimental
approaches. This session welcomes contributions addressing all
aspects of bio-irrigation and bioturbation whether observational,
theoretical or experimental. Papers integrating field or experimental
data with models are in particular welcome.
SS13 Stable Isotopes in Ecology and
Biogeochemistry
Organizers: Eric Boschker, Netherlands Institute of Ecology, (e.boschker@nioo.knaw.nl)
and Jack J. Middelburg, Netherlands Institute of Ecology, (j.middelburg@nioo.knaw.nl)
Stable isotopes have shown to be powerful tools in a wide range
of applications in aquatic sciences. Natural abundance isotope
ratios have proven to be useful in unraveling food-webs and tracing
organic matter and nutrient sources. Stable isotopes have also
been used extensively as tracers for rate measurements (e.g., primary
production, nitrogen cycling). More recent applications involve
the use of stable isotopes in unconfined, field experiments and
combination of stable isotope with biomarkers to link microbial
identity with activity or to integrate microbial components in
food web studies. This session welcomes contributions from systems
along the aquatic continuum. Natural abundance, tracer application
as well deliberate in situ addition studies are invited.
SS14 Nutrient Return Pathways to the
Upper Ocean and Their Climate Sensitivity on Decadal to Centennial
Time Scales
Organizers: Andreas Oschlies, School of Ocean and Earth Science,
University of Southampton, (andreas.oschlies@soc.soton.ac.uk)
and Jorge L Sarmiento, AOS Program, Princeton University, (jls@princeton.edu)
Data from large-scale surveys and process studies as well as results
from ecosystem-circulation models now begin to reveal details of
the complex three-dimensional pathways that return nutrients from
thermocline and deeper waters back to the ocean surface. Recent
studies have revealed the potential of various mode and intermediate
water masses to modulate nutrient supply on decadal to centennial
time scales. However, the mechanisms that control the nutrient
and associated carbon fluxes and their climate sensitivity are
not yet well understood. Processes that may be relevant range from
upwelling and subsequent modification of nutrient-rich deep water
masses, large-scale balances of mode-water formation and destruction,
and eddy-mediated transports, to local enhancements of diapycnal
mixing. We invite contributions from both data and model based
studies that help to identify the relevant pathways along which
nutrients are carried back to the ocean surface, to quantify the
associated transport rates and transition times, and to determine
their sensitivity to climate change.
SS15 Food Webs End-to-end, Including
the Ecosystem Approach to Living Marine Resources
Organizers: Richard B. Rivkin, Memorial University of Newfoundland,
Canada, (rrivkin@mun.ca)
and Louis Legendre, Villefranche Oceanography Laboratory, France,
(legendre@obs-vlfr.fr)
The management and sustainable use of living marine resources
depends on the quantitative understanding of (a) the recruitment,
growth
and mortality of species, (b) the channelling of energy and organic
matter through the autotrophic and heterotrophic components of
the food web to the marine resources and (c) the flux and recycling
of elements from the food web back to primary producers and downward
to the deep ocean. The ecosystem-scale consideration of living
marine resources is necessary to developing quantitative approaches
to complex ecosystems. The characterization, analysis and modelling
of marine pelagic ecosystems is generally conducted along three
distinct approaches, i.e. pelagic ecosystems, biogeochemistry
and ecosystem approach to marine resources. This Special Session
will
bring together the three communities, to compare and exchange
concepts and results from field work, laboratory experiments
and modelling
exercises, with the goal of fostering integrative approaches
to marine pelagic ecosystems and living resources.
SS16 Environmental Effects on Reproduction
of Marine Invertebrates
Organizers: Catharina J.M. Philippart, Royal Netherlands Institute
for Sea Research, (katja@nioz.nl),
Peter M. J. Herman, Netherlands Institute of Ecology, (P.Herman@nioo.knaw.nl),
and Steve J. Hawkins, Marine Biological Association of the UK,
(sjha@mba.ac.uk)
The recruitment of sessile marine benthic invertebrates with pelagic
larvae is the end result of a complex reproductive cycle, which
starts with gametogenesis and spawning in adults, and continues
with fertilization, growth and development in the pelagic larval
phase, followed by settlement, post-settlement growth and development
(and sometimes resettlement), to eventually deliver juveniles with
a reasonable probability to recruit into the adult population.
Density-dependent and density-independent mortality during these
complex recruitment processes critically influence such population
phenomena as age-class strength, population fluctuations correlated
with life history, and uncorrelated densities of recruits and adults.
As an example, settlement rate is influenced by the number of propagules
arriving, the site-specific hydrodynamic conditions, behavioral
factors and activities of the resident benthic assemblage.
During the previous century, marine systems have experienced drastic
changes in external forcing, such as in the rates of supply of
organic matter and nutrients, and in climatic conditions. When
environmental conditions change, a transformation in behavior,
physiology or morphology of marine organisms during early development
might incur a selective advantage. New environmental conditions
may not only affect the intensity, timing and temporal extent of
spawning and settlement, but also the morphology of the larvae
and settlers. Shell shape, for example, can be structured by the
degree of wave-exposure, the overcrowding posing physical compression
on individuals, food availability and the nature of substrate.
Morphological flexibility of feeding structures has been proved
to exist in the larvae of distantly related phyla, such as molluscs
and echinoderms. However, the relatively high connectivity of marine
systems facilitates dispersal of pelagic propagules of sessile
benthic marine organisms and may counteract evolutionary adaptation
to changed conditions.
The aim of this symposium session is to further and fuller understand
the effects of changing environmental conditions on the recruitment
of marine invertebrates. Contributions covering the research on
the direct and indirect effects of environmental conditions on
the reproductive cycle of marine invertebrates and the consequences
for their dispersal, settlement success and survival are welcomed.
Understanding factors that affect the reproduction of marine organisms
is necessary to better resolve questions with regard to spatio-temporal
patterns in biodiversity and ecosystem functioning, and to potential
effects of eutrophication and global warming on marine ecosystems.
SS17 Viruses, Microbial Diversity and
Ecosystem Function
Organizers: Steven W Wilhelm, University of Tennessee, (wilhelm@utk.edu),
Markus G. Weinbauer, Laboratoire d'Océanographie de Villefranche,
(Markus.Weinbauer@obs-vlfr.fr),
and Curtis A. Suttle, University of British Columbia, (csuttle.eos.ubc.ca)
Viruses are major players that shape the diversity of planktonic
communities and influence biogeochemical cycles through horizontal
gene transfer (including virus genes) and selective mortality of
hosts. Molecular techniques including clone libraries, community
fingerprinting approaches and large-scale shot-gun sequencing (meta-genomics)
have demonstrated the enormous diversity of virus communities.
Through cell mortality and the release of lysis products (the viral
shunt), these communities strongly affect ecosystem functions such
as carbon and nutrient cycling, primary and secondary production
and respiration. This session invites papers that address virus
infection and diversity (including virus host systems), and how
they influence the linkage(s) between microbial diversity and ecosystem
functioning. Papers on the effect(s) of viruses on functional diversity
and activity are also encouraged. Such studies are essential to
develop an understanding of the role of virus infection on ecosystem
stability and efficiency.
SS18 The Consequences of
Biodiversity in Aquatic Habitats
Organizers: Per Jonsson, Tjärnö Marine Biological Laboratory,
Gothenburg University, Sweden, (per.jonsson@tmbl.gu.se)
and Helmut Hillebrand, University of Cologne, Institute for Botany,
Aquatic Ecology, Cologne, Germ, (helmut.hillebrand@uni-koeln.de)
Understanding the consequences of biodiversity for the functioning
of ecosystems has become a major task in the face of the recent
global decline in biodiversity. Does biodiversity affect the rates
of processes in aquatic ecosystems such as production rates or
consumption rates? Does biodiversity increase or weaken the stability
of aquatic communities? What are the mechanisms underlying biodiversity
effects? These questions have raised considerable interest and
transformed into a highly successful research agenda. However,
the main evidence in this context comes from terrestrial communities.
The special features of aquatic habitats inhibit the direct transfer
of these results, and warrant a strong aquatic research initiative
on the role of diversity in aquatic habitats. Recently, a variety
of projects have been started in North America and Europe extending
the knowledge on biodiversity consequences. These projects address
a variety of novel questions: 1) how does genetic versus morphological
diversity affect ecosystem functioning? 2) does diversity present
an insurance against the multitude of stressors potentially affecting
aquatic communities? 3) does the openness of aquatic communities
to dispersal affect the relation between diversity and ecosystem
functioning? 4) how does the diversity of one trophic level propagate
through other compartments of aquatic food webs. These highly relevant
topics will attract a large group of potential contributors and
a large audience. The special session will therefore unite experimental
ecologists from both freshwater and marine sciences, and theoretical
ecologists.
SS19 Ecosystem Level Approach in Environmental
Assessments of Maricultures
Organizers: Kenny Black, Scottish Association of Marine Sciences,
(Kenny.Black@sams.ac.uk)
and Marianne Holmer, Institute of Biology, University of Southern
Denmark, (holmer@biology.sdu.dk)
Due to the on-going declines of natural fish stocks and the growing
demand for marine products aquaculture is expected to maintain
or even increase the rate of expansion in the coastal zones throughout
the world. Although the industry is beneficial for the society,
the environmental issues are often of concern to the public. The
issues raised have been extending from the effects of waste products,
such as particulates, chemicals and medicines on the environment,
to transmission of genes and interactions with local fisheries.
The knowledge on environmental issues has grown significantly during
the past decade in many regions, but there are still gaps, in particular
in the tropics and in countries where the industry has been introduced
recently. Most environmental studies have been done at single farm
level, whereas an integrated approach on ecosystem level has only
seldom been applied. The local effects are thus well-documented
whereas positive or negative effects on ecosystem level remain
unexplored despite the fact that there is a large difference in
sensitivity and assimilations capacity in different ecosystems.
It is therefore difficult to transfer knowledge between different
global regions, such as from temperate to tropical or from eutrophic
to oligotrophic sites. The aim of this special session is to bring
together groups working within the area of environmental issues
of maricultures and to fill the gaps of knowledge and to provide
ideas towards an integrated ecosystem approach for environmental
assessments of maricultures in the future.
SS20 Diazotrophy in the Ocean: Rates,
Causes and Consequences
Organizers: Aubert Le Bouteiller, IRD, (Aubert.Le-Bouteiller@noumea.ird.nc)
and Cecile Dupouy, IRD, (dupouy@noumea.ird.nc)
Over the past decade, data of dinitrogen-fixation rates by diazotrophs
have produced greatly increased estimates of N2-fixation in oceanic
waters, implying that nitrogen fixation is quantitatively significant
in the global nitrogen cycle. Moreover, biogeochemical studies
and modelling have demonstrated the important role of N2-fixing
organisms in the biological pump, ocean/atmosphere CO2 exchanges
and climate regulation. Recently, an intensive multidisciplinary
research program comprising nine cruises in the SW Pacific produced
new data of cyanobacteria pigments, in situ C and N2-fixation rates,
phosphate uptake, sedimentation and bacterial production. The evidence
of Trichodesmium influence on satellite radiances allows a better
understanding of spatial and temporal distributions of these organisms.
This session is devoted to a presentation of last results dealing
with the importance of diazotrophy in the ocean, including remote
sensing approach and modelling, and to a discussion about the different
biogeochemical processes linked to N2-fixation in the oligotrophic
ocean, with a special focus on its fate.
SS21 Functional Diversity of the Microzooplankton
Organizers: Albert Calbet, Institut de Ciències del Mar-CMIMA
(CSIC), (acalbet@icm.csic.es)
and Michael R. Landry, Scripps Institution of Oceanography, (mlandry@ucsd.edu)
Recent research has revealed that microzooplankton (principally
heterotrophic protists) play a pivotal role in shaping the structure
of marine ecosystems, as primary grazers of marine phytoplankton,
as major secondary producers, and as important contributors to
bulk respiration and remineralization in the ocean’s euphotic
zones. These insights come primarily from techniques that measure
microzooplankton-associated processes and impacts at the integrated
or net community level. However, at a point in time where phytoplankton
ecologists and microbiologists are embracing the notion of ‘functional
groups’ and seeking to distinguish and depict their characteristics
in empirical and modeling studies, and where mesozooplankton ecologists
aim at incorporating the ontogenetic, behavioral and energetic
complexities of dominant species in individual-based models, we
have little information about the importance of functional biodiversity
and behaviorally driven interactions among microzooplankton or
the extent of their species or group- specific activities within
the food web. As a first step toward achieving a more robust and
useful realization of microzooplankton functional roles in the
dynamics of marine systems, we invite contributions that contemplate
the significance of their diversity and varying impacts in plankton
communities and ecosystems, as well as advanced techniques for
their study in ocean research programs.
SS22
Polar Shelf-basin Exchange: Physical Forcing, Biogeochemical
Fluxes and Food Web Dynamics
Organizers: Jackie Grebmeier, University of Tennessee, (jgrebmei@utk.edu)
and Louis Fortier, University of Quebec, Canada, (louis.fortier@bio.ulaval.ca)
Implementing the plans for the International Polar Year (2007-2008),
which is based on a suite of national and international initiatives
that bring together synoptic sets of multidisciplinary observations,
obtains key data sets necessary to understand factors controlling
change, establishes a legacy of observational networks and launches
internationally coordinated multidisciplinary expeditions into
new scientific frontiers, entails rigorous examination of the present
status quo of polar research. On our pilgrimage into some of last
unexplored regions of the ocean, the engirdling polar shelves have
to be crossed and knowledge obtained here used as a proxy for those
regions still to be investigated. Scenarios of future climatic
development, in essence based upon global circulation models, predict
significant warming in the Arctic, but far less so in Antarctica.
Changes in the marginal ice zone extent, ice thickness and changes
in the extent and eventual disappearance of polynyas (or establishment
of new ones), will result in significant alterations of the C flux,
biodiversity and changes of mans live conditions. How these changes
will influence the polar shelf-basin exchange of biogenic matter
is the main focus of this session. Based on these considerations,
we pose three comprehensive questions: (1) How will physical forcing
and biological alterations affect the dissolution and biological
C pump on and off the shelves fringing the Polar Ocean and Antarctica?
(2) What are the food web dynamics and the C flux in the various
polar shelf regions? (3) How do the shelves 'work' to produce and
concentrate food, and how will such mechanisms be altered under
scenarios of climate variability?
To address these questions we invite contributions focusing on
the physical oceanography, ice cover, primary production, pelagic
food web dynamics, pelagic-benthic coupling and benthic mineralization
of Polar shelf regions, with the aim to sum up the present state-of-the
art, contribute to a pan-polar understanding of C cycling and climate
change and get ready for the implementation of one of the greatest
challenges in oceanographic research, i.e. the IPY.
SS23 The Urban Coast: A Growing World-Wide
Trend
Organizers: Russell Moll, California Sea Grant, (rmoll@ucsd.edu)
and Linda Duguay, University of Southern California Sea Grant,
(duguay@usc.edu)
The human population of the world is increasingly becoming urban
and drawn to coastal cities. As of 1998, about 3.2 billion people,
or more than half of the population of the planet inhabit a thin
strip along the coast just 120 miles wide. The juxtaposition of
large population centers to the coast is posing new and challenging
problems with regard to maintaining high quality coastal aquatic
environments. The rate of human migration to already crowded coasts
is ever increasing and the associated issues of this continued
demographic shift are becoming more urgent. By 2050, 80% of the
human population is expected to live in urban centers and anticipated
growth will add another 4 billion residents to the more than 3
billion already in such settings. An additional factor in the impact
of major cities on coastal environments is the level of development
and the increasing size of the world's major cities. The focus
of this session is on the suite of problems that are unique to
the urban coast. Topics such as urban water quality, non-point
pollution from runoff, aquatic invasive species, increasing size
and concentrations of large ports and harbors, and the overall
effect of urbanization on human health are among the issues that
will be addressed in this session. Contributions are sought that
highlight problems in the coastal aquatic environment that are
unique to or accentuated by the urban setting.
SS24 Biodiversity and Ecosystem Function,
Contrasting Human-altered With Pristine Streams
Organizers: Francesc Sabater, Department of Ecology, Universitat
de Barcelona, (fsabater@ub.edu),
Tom J. Battin, Department of Limnology, IECB, University of Vienna,
(tomba@pflaphy.pph.univie.ac.at),
and Eugenia Marti, Centre d'Estudis Avançats de Blanes (CSIC),
(eugenia@ceab.cisc.es)
While most of our knowledge on stream ecology originates from pristine
ecosystems, society cannot ignore that streams have experienced
multiple alterations from human activity over the past decades.
Humans have reduced habitat structure, altered hydrological regime
and increased nutrient inputs through diffuse and point pathways.
Ultimately, this has resulted in reduced stream ecosystem integrity
and services. Recently growing societal awareness (EC Water Framework
Directive, USA Water Act) has significantly promoted research on
human altered streams. However, most of this research is devoted
to biotic indexes and less to ecosystem function. This session
will bring together research on biodiversity and ecosystem function
from human altered stream and contrast this with knowledge from
pristine streams. Researchers studying human impacts on organic
matter processing, nutrient dynamics, metabolism, community structure,
and trophic interactions are welcome to participate. The session
aims at establishing the state-of-the-art of human altered stream
ecology, transferring knowledge from pristine streams, identifying
major gaps and future needs. Ultimately this should enhance exchange
of perspectives on a transnational environmental issue and strengthen
collaboration among scientific communities.
SS25 Identification and Quantification
of Major Feed-backs of Ocean Biology to Climate Change
Organizers: Dieter Wolf-Gladrow, AWI, (dwolf@awi-bremerhaven.de)
and Marion Gehlen, LSCE, (gehlen@cea.fr)
Anthropogenic driven climate change implies a change in forcing
to which ocean biology will respond. The response of ocean biology
will in turn feed back on the initial forcing to either reinforce
(positive feed-back) or dampen it (negative feed-back). Climate
forcing includes global warming, changing atmospheric composition
(CO2), changing inputs of nutrients, modifications in hydrological
cycle etc. These changes will impact on ocean physics (circulation,
stratification), chemistry (acidification, nutrient availability,
water column oxygenation) and ocean biology. The response of ocean
biology will operate through changes in ecosystem structure (for
instance, reduction of calcifiers under high pCO2). Effects on
marine biota will translate to changes in the strength of the biological
C pumps and modifications in air-ea exchanges of climatically active
gases (CO2, DMS, N2O), thereby closing the feed-back loop. We invite
contributions from field, laboratory and integrative modeling studies
aiming at the identification and quantification of major feed-backs
between ocean biology and ongoing/future climate change. While
field observations and laboratory studies might address parts of
a feed-back loop, modeling studies should aim at a complete integration
of the latter.
SS26 Respiration in Aquatic Ecosystems:
Current Understanding and Future Directions
Organizers: Peter J. Le B. Williams, University of Bangor, UK,
(pljw@bangor.ac.uk) and
Paul A. del Giorgio, Dépt des sciences biologiques, Université du
Québec à Montréal, Canada, (del_giorgio.paul@uqam.ca)
Respiration in aquatic ecosystems remains perhaps the largest gap
in our understanding of the global carbon cycle, and as such, has
received increasing attention in recent years. The increased focus
on aquatic respiration has led in some case to the questioning
of current paradigms, and more generally to a change in our conceptual
and practical approach to assessing carbon dynamics and metabolism
in aquatic ecosystems. This session aims at promoting a synthesis
and discussion of the major accomplishments in the field in recent
years, as well as of the major unresolved discrepancies and gaps
in our current understanding of aquatic respiration. We would like
to encourage presentations that focus on large-scale patterns and
processes related to respiration in the major aquatic ecosystems
of the biosphere, covering freshwater and marine wetlands, oceans,
estuaries, lakes and rivers and through the net productivity of
individual systems, the connections between them. Research that
specifically attempts to incorporate respiration into models of
carbon and energy flow is also encouraged.
SS27 Biomineralized Tissues in Marine
and Freshwater Organisms
Organizers: Beatriz Morales-Nin, CSIC/UIB-IMEDEA, (beatriz.morales@uib.es)
and Erlend Moksness, Institute of Marine Research, Flødevigen
Marine Research Station, (moksness@imr.no)
The biomineralized tissues are key players in the organisms as
structural components as well as ionic reservoirs of fundamental
elements such as Calcium. Moreover, calcified structures such as
otoliths and statoliths form part of the sensorial system and represent
a part of the organisms interaction with the environment. The formation
of these tissues is related to the environmental conditions as
well as to the organism metabolism. Certain biominerals are not
reabsorved during the organism life and can last for a long time
after the death, thus having the potential to act as registers
of both the organism and the environmental conditions. In molluscs,
corals and fish the biomineralized tissues have been extensively
studied for age determination. Recently their microchemical composition
has been employed for paleostudies, to identify natal habitats,
and to explore ecological traits. However, many questions remain
unresolved concerning the present situation (biomineral fluxes,
growth rates) and the future in the context of global change. How
is the increase acidification going to affect the calcium budget
at the sea? How is this going to affect the organisms? The developments
in several research fields such as stoichhiometry, modelling, environmental
and biological studies, make a session on biomineralization in
the context of global change a timely issue.
SS28 Copper: A Micronutrient or Toxic
Element in the Environment?
Organizers: Maria T. Maldonado, University of British Columbia,
(mmaldonado@eos.ubc.ca)
and James W. Moffett, Woods Hole Oceanographic Institution, (jmoffett@whoi.edu)
Copper has long been recognized as an important contaminant in
natural waters and is the focus of increasing regulatory scrutiny.
Yet, it is also a critical element required for many metalloenzymes
that catalyze biogeochemically important reactions such as denitrification.
Given that its bioavailability is governed by its complexation
chemistry in natural waters, which is highly variable, it is important
to determine the conditions when it is beneficial versus harmful.
We seek to bring together researchers studying copper from biogeochemical,
physiological, toxicological and molecular perspectives, since
the processes involved in toxicity and micronutrient limitation
share many common
characteristics.
SS29 Atmospheric Deposition of Nutrients,
Organic Carbon and Pollutants as a Driver of Marine and Limnic
Ecosystems
Organizers: Steven J. Eisenreich, Joint Research Centre, Ispra,
(steven.eisenreich@jrc.it)
and Jordi Dachs, IIQAB-CSIC, (jdmqam@cid.csic.es)
Atmospheric deposition can contribute important inputs of nutrients,
carbon and pollutants to aquatic ecosystems. During the last decades,
research has shown the importance of atmospheric inputs of N, P
and Fe in oligotrophic regions and in areas with high aerosol concentrations.
However, much effort is needed to clearly determine the role of
these inputs in ecosystems dynamics and productivity. On the other
hand, atmospheric deposition is a key entry route of stressors,
such as pollutants, to marine and limnic ecosystems. In fact, atmosphere-water
exchange controls the dynamics of most pollutants (organic and
inorganic) in aquatic ecosystems, and thus their potential impact.
Recently, it has also been suggested that atmospheric inputs of
organic carbon may be important to balance the marine carbon cycle
and for the aquatic metabolic balance. Besides all these lines
of evidence of the important role that atmospheric drivers have
on aquatic ecosystems, the field is in its infancy. The proposed
special session aims to address the multiple interactions between
atmospheric inputs of materials (carbon, nutrients, pollutants,
etc) and the functioning of marine and limnic ecosystems.
SS30 Nitrate Uptake By Phytoplankton
in Nutrient-rich Areas
Organizers: Patricia Glibert, University of Maryland, (glibert@hpl.umces.edu)
and Yves Collos, University of Montpellier, France, (collos@univ-montp2.fr)
Many earlier studies of nitrate uptake by phytoplankton considered
that uptake was saturated near 10-20 µmol N/liter. A few
recent studies have shown that this is not always the case and
multiphasic uptake systems do exist in some unicellular algae and
operate in a range of concentrations that are important in the
cureent context of eutrophication in coastal waters. This introduces
serious bases that are not taken into account by present models
of new production. Other phenomena that are related to nitrate
uptake are nitrite and ammonium excretion during nitrate assimilation.
We invite contributions on these topics as an effort to reach more
accurate estimates of net nitrate uptake in eutrophic areas.
SS31 Coupled Oceanographic Processes
in Estuaries and River Dominated Margins
Organizers: Pere Puig, Institut de Ciències del Mar, CSIC
and Miguel A. Goñi, Department of Geological Sciences, University
of South Carolina, (goni@geol.sc.edu)
Estuaries and river dominated ocean margins are extremely dynamic
environments that are especially sensitive to anthropogenic activities
and climate change. New multidisciplinary research initiatives
are exploring the interconnections between physical forcing (e.g.,
waves and currents) and geological (e.g., sediment transport and
deposition), chemical (e.g., carbon turnover and burial), and biological
processes (e.g., primary and secondary production, species compositions)
in these environments. This session invites presentations investigating
the coupling of physical, geological, biogeochemical and ecological
processes in estuaries and river dominated margins. Interdisciplinary
research from both field studies and modeling efforts will be considered
and are appropriate for this session.
SS32 Diversity Among Components
of the Microbial Loop
Organizer: John Dolan, Marine Microbial Ecology Group, Lab Oceanogr
Villefranche, (dolan@obs-vlfr.fr)
This session will be devoted to exploring patterns of diversity
in planktonic microbes with the goal of establishing commonalities
and differences. Free-living microbes have been described as having
global distributions. The amount of genetic diversity among both
prokaryotic and eukaryotic planktonic microbes (femto, pico and
nano- sized organisms) presently being described should then soon
reach a plateau? This is far from clear. Distinct patterns may
exist for autotrophic prokaryotes compared to autotrophic eukaryotes.
Contributions will ideally involve a variety of microbes from viruses
(relations between bacterial and viral diversity) to Pico-autotrophs
(prokaryotes & eukaryotes) to bacteriovores and herbivores.
SS33 Estuaries as Biogeochemical Reactors
Organizers: Kenneth Mopper, Old Dominion University, (kmopper@odu.edu)
and Elizabeth C. Minor, Old Dominion University, (eminor@odu.edu)
Estuaries, in addition to being sites of significant autochthonous
production, are also sites of significant reworking of nitrogen,
phosphorous, trace metal, and organic carbon moieties ultimately
derived from terrestrial and anthropogenic sources. The combination
of these processes leads to considerable alteration of riverine
inputs before export to the coastal ocean. This special session
focuses upon processes within the estuarine “biogeochemical
reactor” including microbial and photochemical reactions,
and physicochemical processes such as flocculation, aggregation
and disaggregation.
SS34 Plate Tectonics and Chemotrophy
at Deep-sea Vents
Organizers: F. Grant Ferris, University of Toronto, Ontario, Canada,
(grant.ferris@utoronto.ca)
and Danielle Fortin, University of Ottawa, Ontario, Canada, (dfortin@uottawa.ca)
Plate tectonics give rise to tens of thousands of kilometers of
mid-ocean ridges and back-arc basins around the world. The intense
hydrothermal activity present in such areas sustains a rich geochemical
supply of nutrients that nourish some of the most unique ecosystems
on Earth. Primary production arises solely from microbial chemotrophy,
which not only represents possibly one of the earliest metabolic
pathway on the planet, but also contributes significantly to global
cycling of mineral forming elements. This special symposium will
address new inter-disciplinary cutting-edge research in microbial
geochemistry of mid-ocean ridges and back-arc basins. It will specifically
focus on the role of microorganisms in metal cycling resulting
from mineral dissolution, precipitation and sorption reactions,
and on reactions kinetics and microbial diversity.
SS35 Alternative Pathways of Nitrogen
Removal From the Sea
Organizers: Stefan Hulth, Department of Chemistry, Göteborg
University, (stefan.hulth@chem.gu.se),
Nils Risgaard-Petersen, National Environmental Research Institute,
(nri@dmu.dk), and Tage Dalsgaard,
National Environmental Research Institute, (tda@dmu.dk)
The biologically mediated reduction of NO3- or NO2- (NOx-) to N2
through denitrification is generally considered to be the major
process responsible for removal of nitrogen from the sea. Until
recently, it was believed that denitrification was based solely
on the reduction of NOx- to N2 in an oxygen-free environment by
facultatively aerobic bacteria with an organotrophic metabolism.
This classical view has recently been challenged by the discovery
of alternative pathways of combined nitrogen transformations. These
alternative pathways include the anaerobic oxidation of NH4+ to
NO3- or N2 with manganese oxides and the ANAMMOX process i.e. the
anaerobic oxidation of NH4+ to N2 with NO2-. Both ANAMMOX and the
anaerobic oxidation of NH4+ with manganese oxides have long been
overlooked in biogeochemical N-cycling. However, especially within
the last few years, field studies have shown that for instance
the ANAMMOX process is a significant alternative to conventional
denitrification in both sediments and anoxic water columns. Yet
we are only beginning to understand the quantitative importance
of these processes, their regulation and their underlying microbiology
in aquatic systems. This session will focus on ANAMMOX and anaerobic
NH4+ oxidation with manganese oxides. State-of-the-art knowledge
about the biogeography of these processes, their regulation and
microbiology plus their impact on our ability to measure aquatic
N2 production will be addressed.
SS36 Non-extremophilic Archaea in Aquatic
Environments
Organizers: Lydie Herfort, Royal Netherlands Institute for Sea
Research (NIOZ), (Herfort@nioz.nl)
and Randall E. Hicks, University of Minnesota-Duluth, (rhicks@imap.d.umn.edu)
For decades Archaea were thought to only dwell in extreme environments
inhospitable for Eukarya and Bacteria, but new approaches such
as ribosomal RNA surveys or archaeal lipid analysis have clearly
established that they are abundant in the water column of both
marine and freshwater environments. Yet very little is known about
these pelagic Archaea, mainly because so far cultivation has been
unsuccessful. Recently, however, important results have emerged
from studies that use cultivation-independent approaches and from
work carried out on the only cultured non-extremophyle Archaea,
Cenarchaeum symbiosum, a symbiont of the marine sponge Axinella
mexicana. This session encourages the presentation of results from
studies in the marine and freshwater environments that will further
our understanding of the physiology, biochemistry and ecology of
non-extremophilic Archaea.
SS37 Size Structure of Plankton Communities
Organizers: Xabier Irigoien, AZTI, (xirigoien@pas.azti.es),
Roger Harris, Plymouth Marine Laboratory, (r.harris@pml.ac.uk),
and Angel Lopez-Urrutia, Instituto Español de Oceanografía,
(alop@gi.ieo.es)
Size plays a major role in ecology at most scales. Size effects
range from those of body size on biological rates and times to
the effects of community size spectra on energy flow in aquatic
ecosystems. Important new findings concerning the basis of allometric
relationships have been published recently These provide the theoretical
foundation for practical applications and the establishment of
a metabolic theory of ecology. Since the first descriptions of
plankton size spectra by Sheldon et al, the slope of the log-log
relation between individual biomass and abundance in aquatic ecosystems
has been shown to be around -1. Sheldon himself suggested an allometric
explanation for this pattern. Hence, size spectra distribution
and allometry share many common aspects. In this session we invite
contributions on theoretical and practical aspects of both size
spectra distribution and allometric relationships. Papers on the
widest range of aquatic ecosystems, including size structured modelling
as well as possible connections between both theories are particularly
encouraged.
SS38 Microbial Plankton Ecology and
Biogeochemical Fluxes in the Subtropical Gyres
Organizers: Emilio Marañón, Universidad de Vigo,
(em@uvigo.es) and Ricardo Letelier,
Oregon State University, (letelier@coas.oregonstate.edu)
The oligotrophic subtropical regions of the open ocean support
extensive ecosystems which, due to their vast size, are of global
biogeochemical importance. Once termed 'marine deserts', these
regions are now known to account for a significant fraction of
global marine primary production and carbon export into the deep
ocean. Over the past 15 years, on-going programs that look at the
temporal and spatial variability of upper ocean biogeochemistry
and ecology (e.g. HOT, BATS, AMT) have greatly advanced our understanding
on the composition, structure and functioning of the microbial
community in these subtropical gyres. Recent advances in molecular
tools have been used to determine the high diversity in both prokaryotic
and eukaryotic assemblages, and to detect novel metabolic pathways
in the upper layers of these regions. Far from being steady-state
systems, marine ecosystems in subtropical oligotrophic environments
display a considerable amount of variability in biological rates
over a wide range of temporal and spatial scales. At the local
scale, episodes of enhanced primary and export production can be
caused by several mechanisms, including eddy- or internal-wave
induced nutrient pumping, summer water-column stratification, and
atmospheric dust deposition. During these events, complex interactions
within the food web, including trophic cascades, can alter significantly
biogeochemical fluxes and the fate of organic matter. Interannual
and long-term variability in upper ocean biogeochemistry of the
subtropical gyres has been linked to climate-related changes of
the coupled ocean-atmosphere system. In the context of climate
change, there is a pressing need to understand how these vast marine
ecosystems will respond to long-term changes in the frequency and
intensity of physical perturbations. Thanks to the sustained progress
of different observational programs, it is already possible to
attempt comparative studies of the composition and activity of
pelagic microbial assemblages in different subtropical provinces,
which should be more revealing than the detailed study of a particular
environment. The proposed session will invite contributions reporting
on the results of observational, experimental and modelling studies
on the microbial ecology and biogeochemistry of the subtropical
gyres. Addressed topics will include, among others, plankton diversity,
trophic interactions, physical-biological coupling, nutrient control
of biological rates, community metabolism, biological coupling
of elemental fluxes, and the role of atmospheric inputs and climate-induced
variability in modulating the biogeochemical role of the microbial
pelagic assemblage. The ultimate aim will be to integrate different
perspectives and approaches into a coherent view of the structure
and functioning of the planktonic compartment in the subtropical
gyres, as a previous step to address the response of these ecosystems
to on-going and predicted processes of global change.
SS39 Ecological Thresholds of Sustainability
in Aquatic Ecosystems
Organizers: Michael F. Piehler, University of North Carolina at
Chapel Hill, (mpiehler@email.unc.edu),
Hans Paerl, University of North Carolina at Chapel Hill, (hans_paerl@unc.edu),
and Daniel Conley, National Environmental Research Institute, Denmark,
(dco@dmu.dk)
It is becoming increasingly clear that ecosystems do not always
respond to gradual changes in forcing variables in a smooth way,
but can respond with abrupt, discontinuous shifts to an alternative
state as the ecosystem exceeds a threshold in one or more of its
key variables or processes. Identification of ecological thresholds
of sustainability could clearly assist in the management of aquatic
ecosystems by identifying the level of pressure imposed on a given
resource while maintaining acceptable levels of environmental quality
or ecological condition. Whenever these thresholds are exceeded,
the resources, services or functions affected may suddenly shift
status, adopting attributes that cannot be easily reverted to levels
below the thresholds. The levels of the indicators at which such
state shifts occur are termed points of no return. These changes
in ecological thresholds and points of no return invokes the existence
of non-linear behavior such that alternative mathematical formulations
must be used to address the changes that occur in the quality,
property or functioning of the ecosystem. This session will focus
on ecological thresholds in aquatic ecosystems and will explore
some of the various aspects of thresholds research including the
development of links between pressures and thresholds to achieve
sustainability in aquatic ecosystems.
SS40 Nutrient Transformations Along
the Land-ocean Continuum in the Context of Global Change
Organizers: Caroline Slomp, Faculty of Geosciences, Utrecht University,
the Netherlands, (slomp@geo.uu.nl),
Ragueneau Olivier, UMR CNRS 6539, Institut Universitaire Européen
de la Mer, France, (olivier.ragueneau@univ-brest.fr),
and Phillip Ford, CSIRO, Australia, (Phillip.Ford@csiro.au)
Nutrient cycles in the coastal ocean over the past century are
profoundly being affected by human-induced changes. These are occurring
worldwide and include modified river inputs of nutrients through
river manipulation, fertilizer application, waste water discharge
or biological invasions. On a short-term, this can greatly affect
the ecology of the coastal ocean. On the long-term, this may impact
the marine carbon cycle in the open ocean. This session welcomes
all contributions focussing on changes in nutrient cycling at the
land-ocean interface and the consequences for the ecology and biogeochemistry
of the coastal ocean. Both experimental and modeling studies are
welcome. Contributions focusing on the links between terrestrial
processes and deliveries, and marine nutrient cycling are particularly
encouraged, as well as those dealing with the cycling of several
biogenic elements (e.g. Si, N, P) or those studying the responses
of the coastal zone to more than one anthropogenic perturbation.
SS41 Lipids in Trophic Interactions
Organizers: Michael Arts, National Water Research Institute Environment
Canada, (Michael.Arts@ec.gc.ca)
and Eric von Elert, University of Konstanz, (eric.vonelert@uni-konstanz.de)
The flow of energy and material in aquatic food webs is substantially
determined by the quality of the dietary carbon. There is increasing
evidence of a requirement for specific lipids, (e.g. particular
fatty acids or sterols), of different functional groups in food
webs ranging from protozoan to herbivorous invertebrates to fish.
Such requirements are becoming more and more obvious for planktonic
and benthic species in both marine and freshwater systems. Changing
abiotic factors (e.g. temperature and UV) and biotic factors (e.g.
exotic invaders) may greatly affect the availability and/or composition
of dietary lipids thereby influencing trophic interactions. The
purpose of this session is to bring together researchers interested
in the role that dietary lipids have on growth, production, energy
transfer efficiency and competition within and amongst trophic
levels.
SS42 Hydrology-related Downstream-effects
on Lakes
Organizers: Alfred Wüest, Limnological Research Center, Switzerland,
(Wuest@eawag.ch), S. Geoffrey
Schladow, Director, Tahoe Environmental Research Center, (Gschladow@ucdavis.edu),
and Kenneth I. Ashley, Aquatic Ecosystem Science Section, Fisheries
Centre, University of British , (Ken.Ashley@gems5.gov.bc.ca)
Many lakes and reservoirs are situated downstream of major hydrological
disturbances. Examples include upstream reservoirs and dams, large-scale
river diversions and flow alterations, clear-felled watersheds,
or encroaching urbanization. Alterations of the stream, groundwater
and direct runoff regimes and specifically timing and magnitude
of hydro-peaking discharges not only affect the habitats for fish
and macro-zoobenthos, but have also physical and biogeochemical
effects. Water temperature changes, as a result of reservoir and
dam operations, can negatively affect downstream fish diversity
(cool/warm water fishery) and habitat suitability. Dam-induced
nutrient retention results in downstream “cultural” oligotrophication.
Changes in the sediment discharge patterns alter the light regime,
and hence primary productivity. Presentations that focus on downstream
effects, particularly resulting from the altered hydrology, hydraulics,
biogeochemical cycling and resulting trophic interactions in the
modified catchment, are specifically welcomed.
SS43 Eutrophication and Harmful Algal
Blooms
Organizers: Edna Graneli, University of Kalmar, (Edna.Graneli@hik.se)
and Patricia M. Glibert, Univ. of Maryland Center for Environmental
Science, (glibert@hpl.umces.edu)
Eutrophication is now recognized as one of the factors contributing
to the proliferation of harmful algal blooms (HABs). In the past
decade several advances have been made in our understanding of
the relationship between nutrients and HABs. For example, much
has been learned about the global extent of eutrophication and
about the diverse physiological mechanisms that HABs employ to
obtain their nutrients. In this session contributions that highlight
progress in our understanding of global eutrophication, physiological
ecology of HABs with respect to nutrients, new methodologies and
approaches for measuring nutrients and their relationship to HABs,
studies on HABs in comparative eutrophic systems, and models that
address the relationship between nutrients and HABs are encouraged.
SS44 Interactive Effects of DOM Properties
and Mineral Nutrients on Bacterial Composition and Activity
Organizers: Isabel Reche, Universidad de Granada, (IRECHE@UGR.es)
and Stuart Findlay, Inst. of Ecosystem Studies, Millbrook, NY USA,
(findlays@ecostudies.org)
Microbial ecology has undergone technological advances allowing
description of community composition in diverse aquatic ecosystems.
Given the information on taxonomic distribution and diverse measures
of metabolic activity, the field is now poised to ask questions
about what system characteristics or processes control diversity,
activity or the abundance of particular taxa. We propose a special
session focussed on the capacity for organic substrates and inorganic
nutrients to act as predictors of community structure and metabolism.
Invited speakers representing particular ecosystem types (e.g.
streams, lakes, estuaries, coastal waters) will address the potential
ability of these solutes to cause changes in which taxa are present,
similarity among communities, metabolic processes and capacity
for growth. This broad view should reveal whether attributes of
solute dynamics, composition or quantities can organize the rapidly
increasing data available on bacterial community structure and
function in aquatic ecosystems.
SS45 Understanding the Plumbing of
the Biosphere: Theory and Observations in Aquatic Systems (Homage
to Ramon Margalef)
Organizers: Marta Estrada, Institut de Ciències del Mar,
CMIMA (CSIC), Barcelona, Spain, (marta@icm.csic.es)
and Dolors Planas, Université de Québec à Montreal,
Montreal, Canada, (planas.dolores@uqam.ca)
Ramon Margalef was one of the great ecologists of our time and
a world expert in both limnology and oceanography. He had the ability
to integrate concepts and ideas from different fields with insight
from his naturalistic knowledge, to propose a coherent framework
of unifying principles for the interpretation of ecological observations.
Before modern sensors and computing power helped to highlight the
importance of physical-biological interactions, Margalef saw the
aquatic medium as an environment structured by turbulent motions
at different scales (a manifestation of the external or auxiliary
energy introduced by wind and currents), which interacted with
organism adaptations. One of the most inspiring conceptual models
in phytoplankton ecology has been his classification of phytoplankton
life-forms as a function of available nutrients and external energy.
In one of his early publications, Margalef proposed the use of
expressions derived from information theory to quantify ecological
diversity. The significance of diversity in planktonic systems
and its relationships with connectivity and ecosystem structure
and function were a recurring topic throughout his scientific career.
Other subjects in which he made outstanding contributions were
the characterization of ecological succession on the basis of global
parameters of the ecosystem such as the production to biomass ratio,
the role of external energy in biological production, and the contacts
between ecological succession and evolution. He was also a pioneer
in adopting an integrative view of biogeochemistry. Margalef insisted
on considering man as an integral part of the biosphere, rather
than as a bystander, and emphasized the need of interpreting the
relationships among human societies within a general ecological
context. Margalef combined his intellectual capacity with a high
human quality. He was generous in sharing ideas and had a fine
sense of humour. He was also an enthusiastic teacher that communicated
his love for nature to students and coworkers.
This special session is a tribute to the scientific legacy of Ramon
Margalef and aims to feature contributions that will emphasize
integration of theory and observation or provide opportunity for
discussion on subjects that had been Margalef’s favorites,
such as (but not limited to) the relationships between diversity
and ecosystem structure and function, the interactions between
physics and biology and how these shape succession and selection
of life forms, and the ecological role of boundaries and spatial
organization in general.
SS46 Allelopathy in Aquatic Systems
Organizers: Catherine Legrand, Marine Science division, Dept. of
Biology and Environmental Science, Univer, (catherine.legrand@hik.se)
and Karin Rengefors, Limnology, Dept. of Ecology, Lund University,
Sweden, (Karin.Rengefors@limnol.lu.se)
It is well established that chemical interactions are a component
of competition in terrestrial systems, but they are still largely
unknown in aquatic systems. In recent years, there has been increasing
evidence that allelochemicals are produced by aquatic plants, algae,
bacteria, and fungi. These allelochemicals influence algal growth,
water chemical characteristics, nutrient dynamics, life cycles,
and microbial ecology. Allelopathy is also part of plant and microbial
interactions, may structure plant and microbial communities, changes
competition patterns, and leads to co-evolution of organisms. The
understanding of and knowledge about allelopathy in aquatic systems
is still limited and this session will bring together a diverse
group of biologists, ecologists, and chemists who have used various
approaches to examine the role/importance of allelopathy in aquatic
systems. Submissions are encouraged that examines the role, the
chemical nature, and the mode of action of allelochemicals in aquatic
ecology, as well as evolutionary aspects of the chemical warfare
among aquatic plants and microbes.
SS47 Autotrophic and Heterotrophic
Relationships in Streams and Rivers
Organizers: Bill Sobczak, College of the Holy Cross, (wsobczak@holycross.edu)
and Sergi Sabater, University of Girona, (sergi.sabater@udg.es)
Algal biomass and productivity in fluvial ecosystems affects the
relevance of heterotrophic components coexisting in fluvial and
downstream ecosystems. At the same time, bacterial processing of
organic matter may influence rates of primary production. These
mutual bacterial and algal relationships affect the efficiency
of river ecosystems in transforming organic matter, and are likely
influenced by the terrestrial-aquatic linkages existing in the
ecosystem. The trophic significance of these interactions may be
different in streams and rivers with watersheds of varying size,
land-use and hydrological modifications. This symposium will aim
to define the relevance of algal and bacterial interactions at
a wide range of spatial scales and watershed disturbances.
SS48 Biogeochemistry, Ecology, and
Hydrodynamics of Tidal Flat Systems
Organizers: Jack Middelburg, Netherlands Institute of Ecology (NIOO-KNAW),
(j.middelburg@nioo.knaw.nl)
and Meinhard Simon, ICBM, University of Oldenburg, (m.simon@icbm.de)
Tidal flat regions at the land sea interface are one of the most
productive aquatic ecosystems and significant sinks of organic
matter in coastal regions. They are affected by terrestrial as
well as marine inputs of dissolved and particulate inorganic and
organic matter. They exhibit pronounced tidal currents and the
specific hydrodynamic properties lead to rhythmic settling and
resuspension of particulate inorganic as well as organic matter.
The sediment is characterized by biofilms of autotrophic and heterotrophic
microbes and anoxic processes govern the system already closely
below the surface. Usually, particulate organic matter is accumulated
and microbial processes dominate cycling of matter and elements
and energy fluxes. During the recent past tidal flat systems have
been investigated by quite a few research groups with respect to
various aspects of biogeochemical and microbial processes in the
sediment and water column and hydrodynamics, including modelling
approaches. We would like to bring together the interesting results
of these recent studies in a session to assess state of the art
knowledge and to identify aspects for future work. Therefore we
encourage active researchers in this field to submit contributions.
SS49 An Ocean Literacy Campaign
Organizers: Michiko Martin, National Oceanic and Atmospheric Administration,
(michiko.martin@noaa.gov)
and Francesca Cava, National Geographic Society, (francesca.cava@noaa.gov)
It was most recently recognized by the Preliminary Report of the
U.S.Commission on Ocean Policy that “to successfully address
complex ocean- and coastal-related issues, balance the use and
conservation of marine resources, and realize future benefits from
the ocean, an interested, engaged public will be needed.” The
Commission identified ocean education as a key component of the
strategy to promote lifelong learning that leads to an informed
public. A technologically advanced world requires scientifically
and environmentally literate public. An educated public can keep
pace with technological advances as well as environmental issues
of great complexity and scale. This special session will bring
together researchers leading the effort to increase ocean literacy
through ocean education. Presentations that focus on efforts that
integrate K-12 teachers and students in scientific research are
especially encouraged. Papers will also be encouraged that identify
new scientific discoveries that have not made it into text books
and how to make this information and data available to teachers
and classrooms.
SS50 Ecology of Aquatic Pathogens in
a Changing Environment
Organizers: Alexandra Z Worden, Marine Biology and Fisheries Division,
Rosenstiel School of Marine and Atmo, (aworden@rsmas.miami.edu)
and Stefan Bertilsson, Department of Limnology, Evolutionary Biology
Centre, Uppsala University, S, (stebe@ebc.uu.se)
Microbial pathogens represent a severe threat to the sustainable
use of aquatic resources for drinking water, food and recreation.
Recently, several studies have shown that global change and local
environmental disturbances can alter the spread and persistence
of such aquatic health hazards. However to date the underlying
mechanisms and the magnitude of these impacts are poorly known
for most pathogens. This session focuses on the impact of biotic
and abiotic environmental factors on dynamics of pathogenic microorganisms
in freshwaters and coastal ecosystems. The overall goal is to provide
a forum for integrating different approaches to understanding persistence,
growth and spread of such microbes in aquatic environments. Thus
a range of topics are welcomed, including both experimental studies
and field-surveys of how pathogenic bacteria, microeukaryotes and
viruses respond to diverse environmental factors. Mechanisms of
population control, such as predation, dispersal and growth requirements
for both organic substrates and nutrients are appropriate to the
session, Studies of in situ dynamics and physiological responses
to environmental parameters are also appropriate Furthermore, we
encourage submission of contributions in which predictive population
models and novel molecular tools for parallel detection and quantification
of microbial pathogens are used as “early warning systems.” Thus
critical areas of research necessary for understanding pathogens
in the aquatic environment will be brought together: research on
the mechanisms by which they are controlled or proliferate and
modelling as well as detection efforts for safer and more efficient
management of risks factors associated with microbial pathogens
and in natural aquatic systems.
SS51 Exchange Processes in Upwelling
Systems
Organizers: M. Kosro, Oregon State University, (kosro@coas.oregonstate.edu)
and E. D. Barton, IIM, CSIC, (e.d.barton@iim.csic.es)
Upwelling sytems exchange water, biota, particles, and dissolved
material vertically between sub-surface and surface layers, and
horizontally between continental shelf and open ocean. Some exchanges
are widespread and general, like Ekman transport; others are localised
and specific, like subduction at fronts or upwelling around capes.
All have profound implications for biogeochemical and biological
processes, whether these refer, for example, to nutrient cycling,
carbon budget, or dispersion or retention of larvae and eggs. Recent
advances in numerical modelling down to the mesoscale, in direct
observations of vertical exchanges through tracer studies, in study
of bottom boundary exchanges, and in the biogeochemistry of the
water column justify a general session on upwelling systems. Studies
in the different upwelling zones around the oceans (including of
course the Iberian system) merit exposure in a common meeting where
progress may be assessed and ideas for future developments propounded.
Leading players in the various disciplines and regions will be
able to present their vision of the state of the art.
SS52 Comparative Ecosystem Studies
of Harmful Algal Blooms
Organizers: Grant C Pitcher, Marine and Coastal Management, Cape
Town, South Africa, (gpitcher@deat.gov.za),
Patrick Gentien, CREMA, L'Houmeau, France, (Patrick.Gentien@ifremer.fr),
and Alan Cembella, Alfred Wegener Institute for Polar and Marine
Research, Bremerhaven, German, (acembella@awi-bremerhaven.de)
Harmful Algal Blooms (HABs) cause world-wide problems with significant
economic, social and human health consequences. A present challenge
is to improve the prediction of HABs by determining the ecological
and oceanographic mechanisms underlying their population dynamics
through integration of biological, chemical and physical studies
supported by enhanced observation and modeling techniques. The
international programme Global Ecology and Oceanography of Harmful
Algal Blooms (GEOHAB) has been established to foster international
co-operative research on HABs in ecosystem types sharing common
features, comparing the key species involved and the oceanic processes
that influence their population dynamics. Comparative studies of
this nature allow patterns of correspondence, consistency and reproducibility
to be resolved; harmful species from similar habitat types may
be grouped, and the extent to which these species respond in a
similar way, in systems that share similar characteristics, allow
the oceanographic processes that influence HAB population dynamics
and community interactions to be established. Equally important
will be the identification of similar systems that do not have
the same functional HAB species or groupings; or do not respond
in a consistent way to the processes that characterize these systems.
Understanding the response of harmful algae to perturbations within
similar systems also assists in prediction, and identification
of divergences from predicted responses will also be informative.
Invited speakers will address comparative studies of HABs in upwelling
systems, fjords and coastal embayments, and stratified systems.
SS53 Polar Aquatic Ecosystems and Environmental
Change
Organizers: Warwick F. Vincent, Laval University, (warwick.vincent@bio.ulaval.ca),
Carles Pedrós-Alió, Institut de Ciències del
Mar, (cpedros@cmima.csic.es),
and John C. Priscu, Montana State University, (jpriscu@montana.edu)
Global circulation models predict that the Arctic and Antarctic
regions will experience accelerated climate change over the course
of this century. This session will focus on new insights into the
structure and functioning of marine and freshwater ecosystems in
the north and south polar regions, and their sentinel roles as
early indicators of global change. Contributions are welcome on
high latitude lakes, ponds, rivers, ice habitats and polar seas,
with emphasis on microbial community structure, biodiversity, ecosystem
processes and responses to environmental forcing.
SS54 Production of the Odours Geosmin
and MIB in Freshwater
Organizers: Niels O. G. Jorgensen, Dept. of Ecology, Royal Veterinary & Agricultural
University, Copenhagen, D, (nogj@kvl.dk)
and Michele Burford, Centre for Riverine Landscapes, Griffith University,
Brisbane, Australia, (m.burford@griffith.edu.au)
The taste and odour compounds geosmin and methylisoborneol (MIB)
reduce the quality of surface water as a source of drinking water.
Due to the increasing global water consumption, the odours constitute
a growing problem to the water supply in many cities. In addition,
the odours cause damage to fish in freshwater aquacultures as the
compounds accumulate in fish and lower their value as consumer
food. Geosmin and MIB are produced by several species of cyanobacteria,
but recent studies indicate that actinomycete bacteria may also
be responsible for the odour production in freshwater. The present
knowledge on mechanisms controlling the production of geosmin and
MIB in cyanobacteria and actinomycetes is limited and sporadic.
Therefore, The taste and odour compounds geosmin and methylisoborneol
(MIB) reduce the quality of surface water as a source of drinking
water. Due to the increasing global water consumption, the odours
constitute a growing problem to the water supply in many cities.
In addition, the odours cause damage to fish in freshwater aquacultures
as the compounds accumulate in fish and lower their value as consumer
food. Geosmin and MIB are produced by several species of cyanobacteria,
but recent studies indicate that actinomycete bacteria may also
be responsible for the odour production in freshwater. The present
knowledge on mechanisms controlling the production of geosmin and
MIB in cyanobacteria and actinomycetes is limited and sporadic.
Therefore, in this symposium we wish to focus on ecological, physiological
and molecular tools for characterizing odour production in freshwater
cyanobacteria and actinomycetes.
SS55 Parasitism in the Plankton
Organizers: Alf Skovgaard, Institut de Ciènces del Mar,
Barcelona, Spain, (skovgaard@icm.csic.es)
and D. Wayne Coats, Smithsonian Environmental Research Center,
MD, (coatsw@si.edu)
Organisms in plankton communities, i.e. phytoplankton, microzooplankton
and mesozooplankton, are hosts for a wide variety of parasites.
Most recent research has considered marine, parasitic dinoflagellates,
freshwater microsporidians, and freshwater fungi, suggesting that
these types of parasites may be most common and ecologically important.
However, several other taxonomic groups, including ciliates, myxosporidians,
perkinsids, apicomplexans, and ellobiopsids, are known to infect
phyto- or zooplankton. In general, the functional biology, pathology,
and epizootiology of these parasite/host associations are not well
understood, but examples show that parasites are sometimes important
in regulating populations of planktonic organisms. Parasitism must,
thus, be taken into account as a regulating factor in concert with
food supply, grazing, food quality, behavioural interactions, etc.
The fact that planktonic parasites, or their hosts, are often difficult
or impossible to culture sets certain limits for experimental and
morphological studies. Recent molecular methods have, however,
proven valuable for resolving the taxonomy and phylogeny of several
groups of planktonic parasites that were not well resolved using
traditional morphological studies.
This session will encourage contributions on ecology, distribution,
and functional biology of planktonic parasites in marine and freshwater
environments, including papers addressing taxonomy and phylogeny
of hosts and parasites. One of our goals is to bring together scientific
expertise freshwater and marine parasites to stimulate cross-fertilization
of ideas.
SS56 Coastal Sand Ecosystem Dynamics
Organizers: Perran Cook, Max Planck Institute, (pcook@mpi-bremen.de)
and Markus
Huettel, Florida State University, (mhuettel@ocean.fsu.edu)
Sediment transport, low concentrations of organic matter and nutrients,
and deep oxygen penetration characterize the sands that blanket
a large fraction of the shallow continental shelf. Despite the
mechanical stress caused by bed load transport and the low standing
stock of organic substrates, these sediments often exhibit high
mineralization rates and benthic primary production rates that
can match those of the overlying water column. The relatively high
permeability of the sands permits rapid pore water and particle
exchange. Thus, the dynamics of uptake, metabolism, and release
of organic matter are fundamentally different from those in fine-grained
cohesive marine deposits. The biological and biogeochemical dynamics
of this ecosystem are further complicated by the fluctuating inputs
of nutrients through atmosphere, rivers, groundwater and anthropogenic
activities. In the shallow coastal zone, variations in temperature,
fresh water, nutrient and contaminant input are not buffered very
well and cause dramatic changes in the ecosystem over short time
periods. Coastal resource exploitation affects the sandy shelf
ecosystem on different spatial and temporal scales, and a rapid
increase of these activities can be expected. The consequences
of global climate change will be most pronounced in the shallow
coastal zone affecting, amongst others, water level, currents and
waves, sediment transport, and primary production and, thus, profoundly
influence this ecosystem. In this session we will focus on processes
and observations in coastal sandy ecosystems with emphasis on the
biogeochemical cycling of matter, water column and benthic biology/microbiology,
processes and dynamics of the sedimentary environment, and the
influences of hydrodynamics, external input and anthropogenic activities.
SS57 Eutrophication, Macroalgal Blooms
and Coastal Ecosystem Services
Organizers: Just Cebrian, Dulphin Island Sea Lab, (jcebrian@disl.org)
and Nuria Marba, Consejo Superior de Investigaciones Científicas,
Spain, (nuria.marba@uib.es)
Increased anthropogenic nutrient and carbon loading into coastal
ecosystems is often conducive to the appearance of extensive and
pervasive macroalgal blooms in the receiving systems. Consequently,
much attention has been devoted recently to evaluating the effects
of eutrophication-induced macroalgal blooms on the structure, metabolism
and dynamics of coastal ecosystems. Nevertheless, our understanding
of how macroalgal blooms alter the services and benefits offered
by these ecosystems, such as, for instance, the trophic support
of fisheries, the provision of habitat for organisms, and the filtering
of land-derived nutrients, is little developed. Results to date
suggest opposing trends, with some studies pointing to increased,
but others indicating decreased, secondary production and nutrient
accumulation with macroalgal blooms. This session seeks papers
that investigate how macroalgal blooms influence the critical components
and processes that determine the services and benefits that coastal
ecosystems offer to the biosphere and humankind. The goals are
twofold: (1) to increase our knowledge of the diversity of impacts
that macroalgal blooms may have on these services, and (2) to improve
our understanding of the mechanisms that regulate those impacts.
SS58 Global or Coastal Observations
with Ships of Opportunity
Organizers: Friedhelm Schroeder, GKSS Research Centre, (friedhelm.schroeder@gkss.de),
David Hydes, SOC, (dhj@soc.soton.ac.uk),
and Franciscus Colin, GKSS Research Centre, Inst. f. Coastal Research,
(franciscus.colijn@gkss.de)
Within GOOS (Global Ocean Observation System) ships of opportunity
are used to do regular observations. These can have the character
of regular observations on oceanic transects to observe long term
changes or the measurement of water quality parameters in coastal
and shelf seas. In the latter case these observations maybe part
of regular monitoring tasks by governmental or environmental agencies.
The development of a wide variety of sensors has enbaled us to
measure many parameters at a high temporal and spatial scale. An
extension of the spatial scale can be reached by coupling these
shipborne observations with remotes sensing. Data gathered are
available for operational services, for environmental assessments
and modelling. Specific problems such as coastal eutrophication
can be used to show the power of the observational strategy. In
the symposium different technical developments for measuring systems
of ships of opportunity and applications to different problems
(oceanography, eutrophication, water quality etc.) will be discussed.
In addition, a link to remote sensing and modelling will be established.
SS59 Seamount and Island Oceanography
Organizers: Rui Miguel A. Caldeira, Center for Macaronesian Studies,
University of Madeira, (rui.caldeira@uma.pt)
and Manfred Kaufman, Center for Macaronesian Studies, University
of Madeira, (mkbiomar@uma.pt)
Small islands and seamounts often rise 4000m above the seafloor
with diverse bathymetry; their influence to the prevailing currents
creates unique distribution patterns of biogeochemical variables,
including plankton and nekton organisms. The sustainability of
high biomass levels often depends upon an enhanced primary production
supported by upwelling of deep nutrient-rich water; this effect
also known as “island-mass-effect” has had some attention
from the scientific community, and yet the full scope of its dynamics
are not completely understood. In recent years however, small islands
and seamounts received carefull attention in light of an increase
in the fishery activities diverting from overexploited continental
coastal areas. In this symposium we propose to discuss research
themes relevant to small island and seamount oceanography,particularly
those focusing on multidisciplinary studies i.e. biological-physical-chemical
interactions of marine ecosystems.
SS60 Hydrology, Geochemistry and Ecology
of Monsoonal Catchments
Organizers: Robert Wasson, Charles Darwin University (Darwin, Northern
Territory, Australia), (Robert.Wasson@cdu.edu.au)
and Miles Furnas, Australian Institute of Marine Science, (mfurnas@aims.gov.au)
The catchments and associated freshwater systems of eastern Africa,
southern Asia, southeast Asia, east Asia and northern Australia
are profoundly influenced by the monsoonal climatology of the region.
Rainfall and flow regimes in monsoonal catchments and river systems
are strongly seasonal, usually without the large temperature fluctuations
characteristic of high-latitude river systems. The broad monsoonal
region supports a large proportion (ca. 40%) of the world’s
human population and associated agricultural land use, and delivers
a significant proportion of the freshwater, sediment and solutes
(including nutrients) from land sources to the ocean. Monsoonal
catchments are geographically and ecologically diverse, varying
widely in the extent of human modification. All are characterised
by seasonal, often episodic flow regimes that present significant
challenges for measurement of key fluxes and processes, and for
the management of water, fishery and other resources. A considerable
amount of work has been undertaken in recent years on watersheds
and rivers of the monsoonal region. Contributions will illustrate
the diversity of characteristics and dynamics of monsoonal catchments
and river , emphasizing common features of and approaches to dealing
with monsoonal river systems, particularly in how knowledge gained
in better studied systems can be used to better understand the
many poorly or unstudied rivers and catchments of the region.
SS61 Linkage Between Pico, Nano-plankton
and Biogeochemical Cycle in the Ocean
Organizers: Yoshimi Suzuki, Department of Biology and Geosciences,
Shizuoka University, (seysuzu@ipc.shizuoka.ac.jp),
Loic Charpy, IRD, (lcharpy@com.univ-mrs.fr),
and Beatriz E. Casareto, Laboratory of Aquatic Science, (casaretobe@aol.com)
For a long time, oceanographers have studied the likage between
foodweb and biogeochemical cycles in the ocean. Until now main
species of phytoplankton were diatom and coccolithophorids in the
organic matter and nutrient dynamics. However, pico, nano-plankton
plays more important role than previously thought in biomass production
and biogeochemical cycles. In this session, we would like to discuss
recent results including topics about temporal and spacial variation
of pico, nano- plankton, interaction between pico- nanoplankton
and organic carbon, nutrients consumption, new production throuhout
N2 fixation, export fluxes. Studies on field observations, laboratory
experiments, and model in the open ocean, coastal ocean, coral
reef, mangrove and seagrass communites will be discussed.
SS62 Pelagic Infochemistry
Organizers: Susan B. Watson, National Water Research Institute,
Environment Canada, (swatson@ucalgary.ca),
Georg Pohnert, Max Planck Institute for Chemical Ecology, Department
of Bioorganic Chemist, (pohnert@ice.mpg.de),
and Michael Steinke, School of Environmental Sciences, University
of East Anglia, (M.Steinke@uea.ac.uk)
Infochemicals are important signalling compounds in terrestrial
and benthic ecosystems. Aside from a few examples, relatively little
is known about the chemical ecology of pelagic organisms. This
special session will explore the relevance of infochemicals in
the pelagic ecology of freshwater and marine habitats. The role
of chemical signalling in aquatic environments is likely to be
important and studies in this area may provide information on species
competition, bloom development seasonal succession and the structuring
of food-webs. Submissions are encouraged on topics such as the
pelagic infochemistry of trophic interactions and sexual reproduction,
intra- and interspecific cell-to-cell signalling, biosynthesis
and signalling pathways of infochemicals, evolution of pelagic
signalling and the chemical “arms race”. Due to the
multi-disciplinary nature of infochemistry research, this session
will be of interest to investigators in aquatic biochemistry, molecular
biology, ecology, biogeochemistry, limnology and oceanography.
SS63 Chemical Characterization of Dissolved
Organic Matter in Aquatic Systems
Organizers: Georgina Spyres, Institute of Marine & Coastal
Sciences, Rutgers University, USA, (spyres@imcs.rutgers.edu)
and Alexandra Gogou, Hellenic Centre for Marine Research, Athens,
Greece, (agogou@ath.hcmr.gr)
Dissolved Organic Matter is composed of a great variety of molecules
ranging from simple hydrocarbons to complex polymers that are exchanged
and transformed biogeochemically in aquatic systems. The cycling
of these components plays a key role in global carbon and nitrogen
fluxes and is intrinsically linked to the cycling of nutrients
and trace metals. In the last decade, there has been increasing
evidence linking the chemical character of DOM and its production,
transformation and removal in aquatic ecosystems. However, to date,
less than 20% of the DOM pool has been chemically characterized
at the compound level. The chemical analysis of isolated fractions
from the DOM pool is currently the most commonly adopted approach
for compound class and specific compound information. Methodologies
such as gas and liquid chromatography combined with mass spectrometry
(MS) and other spectroscopic techniques are used for compound class
and specific compound information. Furthermore, novel applications
of other state-of-the-art techniques (e.g., electrospray ionization
mass spectrometry) have significantly enhanced our ability to detect
and identify specific organic compounds in water samples. This
session invites presentations of analytical studies that examine
the chemical composition of DOM and help to demonstrate its role
in biogeochemical cycling in both freshwater and marine environments.
SS65 Human Incentives and Valuation
of Aquatic Ecosystems and Their Services
Organizers: Niels Vestergaard, University of Southern Denmark,
(nv@sam.sdu.dk) and Eva Roth,
University of Southern Denmark, (er@sam.sdu.dk)
What is the economical value of aquatic ecosystems and how can
it be found? How does people react to different management regimes?
Is the value needed to perform proper management? Understanding
of aquatic ecosystems and their services has become an important
contemporary problem in science and policy making. The purpose
of this special session is to explore the main contemporary themes.
Several new topics and approaches will be discussed.
SS66
Ocean & Ice - Atmosphere Interactions
Through the Emission of Trace Gases
Organizers: Patricia A. Matrai, Bigelow Laboratory for Ocean Sciences,
(PMatrai@bigelow.org)
and Rafel Simó, Institut de Ciències del Mar, CSIC,
(rsimo@icm.csic.es)
The oceanic biosphere plays a crucial role in the regulation of
the composition of the atmosphere through the exhalation and uptake
of volatile substances. Marine biota is not only a major agent
for carbon dioxide sequestration in the long term, but it is also
the source of many trace gases that balance the global cycle of
a number of major elements, and contribute to the performance of
the atmosphere as a reactor, transporter, radiation reflector and
heat accumulator. Biogenic trace gases are, therefore, essential
vectors in the biosphere-climate feedback gears that characterize
the functioning of the Earth System. In this session, we intend
to address all aspects of trace gas (DMS and other S gases, halocarbons,
N2O and other N gases, CH4, LMW hydrocarbons, etc.) science, from
the way they are produced and cycled in the water column to their
atmospheric effects, through air-sea exchange and their response
to physicochemical forcing. Emphasis will be given to the biological
and chemical controls of trace gas net production in the water
column, comprehensive modeling, and large-scale effects on biogeochemical
cycles and atmospheric chemistry. Contributions on trace gas emissions
from oceanic ice and its snow cover are encouraged.
SS67 Aquatic Pilgrimages: Non-Indigenous
Species Invasions in Aquatic Ecosystems
Organizers: Henry Vanderploeg, GLERL/NOAA, (Henry.Vanderploeg@noaa.gov),
Thomas Nalepa, GLERL/NOAA, (Thomas.Nalepa@noaa.gov),
and Beatrix Beisner, University of Quebec at Montreal, (beisner.beatrix@uqam.ca)
Long-range assisted migration of species is having a profound impact
in freshwater, estuarine, and marine ecosystems world-wide. Much
attention has been paid to invasions and impacts in the Great Lakes
region and North American estuarine waters, yet non-indigenous
species are also having important impacts elsewhere. In one sense,
invasions and impacts are a local phenomenon as species from outside
a particular region have major impacts on a focal ecosystem. On
the other hand, invasions are of global interest, both because
they may lead to a homogenization of community structure across
local systems, and because a number of local communities may be
invaded by species from different donor regions. In either case,
resulting impacts may be unique, cumulative, or broadly uniform.
It is towards a general theory of both potential local and cross-system
effects that this session will work. The responses of aquatic communities
to invasion can provide insight into not only specific invader
impacts but provide “natural” experiments that can
be used to uncover general ecological mechanisms. We propose to
examine invasion dynamics and impacts in diverse systems world-wide.
With this session, we hope to further work towards a set of global
generalizations on what constitutes a successful invader and an
invasible system, while also determining when peculiarities of
ecosystems or species must be taken into account. In order to accomplish
this, we welcome presentations of experimental and observational
studies from aquatic communities (e.g. plankton, benthos, fish),
but are also looking for presentations on new theoretical ideas
and modeling approaches.
SS68 Pharmaceuticals in the Aquatic
Environment
Organizers: Miquel Lurling, Wageningen University, Aquatic Ecology & Water
Quality Management Group, (miquel.lurling@wur.nl)
and Marieke de Lange, Wageningen University, Aquatic Ecology & Water
Quality Management Group, (marieke.delange@wur.nl)
The occurrence of pharmaceuticals and other personal care products
is investigated worldwide. However, little is known about fate
and dynamics of pharmaceuticals: do they break down easily, where
do they end up in the aquatic system, do they sorb to suspended
matter and sediment or do they remain soluble. Next big question
is what threat do these pharmaceuticals pose for biota? First results
show that even at low surface water concentrations pharmaceuticals
do have a negative effect on organisms, ranging from phytoplankton,
macrophytes to macroinvertebrates. These negative effects are expected
to have implications for ecosystem functioning. These effects occur
worldwide at low concentrations and chronic exposure. It is a hidden
threat to ecosystems, and should be of interest to limnologists,
not only to ecotoxicologists.
Contributions covering the following 4 themes would be welcome:
1) sources, occurrence and concentrations of pharmaceuticals and
other personal care products in surface waters, 2) fate and dynamics
in the aquatic system, 3) effects on biota (on all levels and processes:
e.g. individual, population, community, ecosystem, trophic interactions)
and 4) implications for policy makers.
SS69 Ecosystem Dynamics in Pulsing
Littoral Zones: Lakes and Rivers
Organizers: Karl-Otto Rothhaupt, University of Konstanz, Limnological
Institute, (Karl.Rothhaupt@uni-konstanz.de)
and Matthias Wantzen, University of Konstanz, Limnological Institute,
(wantzen@mpil-ploen.mpg.de)
Water level fluctuations are widely accepted as important drivers
for ecosystem dynamics in littoral zones of rivers, e.g. by shaping
the physical and chemical setting of the habitat, by intensifying
aquatic-terrestrial linkages and organic matter dynamics, and by
setting the stage for sequential use of littoral habitats during
the flood cycle. Hydraulic engineering has reduced these important
functions not only in rivers but also in lakes. Few lakes have
remained which still have a pulsing hydrology. For example, most
prealpine lakes have been regulated for several centuries and fixed
positions of the peri-, epi- and eulittoral zones are generally
taken as "normal" in most northern countries. On the
other hand, studies from systems that still undergo natural water
level fluctuations can provide insights into undisturbed processes
both for basic research and for ecosystem rehabilitation. This
special session aims to summarize the current state of the art
and to investigate how hydrological pulses influence the littoral
biota and ecosystem functions in lakes and rivers.
SS70 Advances in the Development of
Biological Indicators for Assessment of Aquatic Ecosystem Health
Organizers: Dorte Krause Jensen, National Environmental Research
Institute, Denmark, (dkj@dmu.dk),
Anna-Stiina Heiskanen, EC-Joint Research Centre, Institute for
Environment and Sustainability, (anna-stiina.heiskanen@jrc.it),
and Anne Lyche Solheim, Norwegian Institute for Water Research,
(anne.lyche@niva.no)
The sustainable management of aquatic environment requires ecological
status assessment based on monitoring of the structure and functioning
of aquatic ecosystems. Assessment of water quality has traditionally
been mainly based on chemical aspects but current legislation like
the European Water Framework Directive (WFD) and the U.S. Clean
Water Act set ecological quality objectives, and demand water quality
to be assessed using biological quality elements such as phytoplankton,
fish, and benthic flora and fauna. Currently intensive research
is being carried out to develop biological indicators that respond
in a predictable manner to human disturbances, and allow classification
of ecological quality based on functional relationships between
pressures and indicators. This session will present scientific
achievements in the recent developments of biological quality indicators
and metrics for the assessment of the inland and marine (coastal
and transitional) waters. The session seeks to identify promising
biological indicators through scientific work and to illustrate
how these may be used in monitoring and management of aquatic ecosystems.
SS71 Role of Algal Mortality in the
Dynamics of Harmful Blooms
Organizer: Ed Buskey, University of Texas at Austin, (buskey@utmsi.utexas.edu)
There has been considerable interest the the ecology of harmful
algal blooms in recent years. Much research has focused on the
factors regulating the growth rates of harmful algal species. This
session would focus on the role of cell mortality, through grazing
losses, disease (bacterial and viral) and physical loss processes
(sinking, dispersal) on the development of harmful algal blooms.
As a related consideration, the role of theshold bloom levels in
grazing suppression and losses to disease processes could also
be considered.
SS72 Assessing and Modelling Eutrophication
Organizer: Alice Newton, Universidade do Algarve, (anewton@ualg.pt)
Eutrophication is affecting all types of aquatic environments,
freshwater, estuarine and coastal. This problem has grown from
local to regional and is now global. Assessing the causes and evaluting
the extent of the eutrophication is a priority for the management
of these important resources. Modelling is useful for understanding
the scale and consequences of eutrophication and also for running
scenarios for predicting the response of the system. A range of
models will be considered: from complex descriptions of a particular
system to simpler approaches, which provide comparative indicators
for a range of systems. The ways in which information may be exchanged
between models and scaling issues will be addressed.
SS73 Coupling of Physical, Chemical
and Biological Processes in Plankton Dynamics: A Quantitative
Multidisciplinary Perspective
Organizers: Yvan Lagaduec, Caren, Umrs CNRS Ecobio, Université de
Rennes, (yvan.lagadeuc@univ-rennes1.fr),
Jef Huisman, Aquatic Microbiology, Institute for Biodiversity and
Ecosystem Dynamics, Un, (jef.huisman@science.uva.nl),
and Myriam Bormans, CSIRO Land and Water, (Myriam.Bormans@csiro.au)
Human induced changes in catchments combined with climate variability
have altered the structure and succession of plankton in fresh
and coastal waters in a way which is difficult to assess and predict
quantitatively. Over the past decades many of the signs of unhealthy
impacts of flow and land use changes (eutrophication, sediment
inputs, algal blooms) are becoming more apparent. Population increases,
mainly in coastal areas are likely to exacerbate these effects.
A combination of physical, chemical and biological approaches offers
the best chance to understand the complex interactions on a variety
of scales and to better manage these systems. This session welcomes
contributions, which explore aspects of these interactions. We
encourage presentations on experimental and modeling studies in
both freshwater and coastal systems to increase cross-fertilization
of techniques, models and approaches.
SS74 Biogeochemistry of Methane and
Carbon Dioxide at High Concentrations
Organizers: George W. Kling, University of Michigan, (gwk@umich.edu)
and Bernhard Wehrli, EAWAG / ETH, (wehrli@eawag.ch)
Research on methane in aquatic systems has recently focused on
topics such as the biogeochemical cycling of methane production
and oxidation in lakes, methane emissions from lakes and reservoirs
to the atmosphere and their contribution to the global radiative
forcing, and the fascinating occurrence of gas seeps and methane
hydrates in Lake Baikal, Black Sea and other continental and coastal
waters. Elevated concentrations of carbon dioxide are usually found
in lakes in volcanic regions, where CO2 is emitted from the subsurface.
In the case of Lakes Nyos and Monoun in Cameroon, accumulated CO2
was suddenly released from these lakes with catastrophic consequences.
Finally, in Lake Kivu both gases, methane and carbon dioxide, play
an important role, as the elevated methane concentrations could
potentially trigger a CO2 eruption from this lake. Presentations
which contribute to the understanding of the biogeochemical cycling
and physical transport of gases in lakes and coastal seas including
the sediment to water, water to atmosphere and bubble-related fluxes
as well as related transformation processes are encouraged.
SS75 Advances at the Interface of Theoretical
and Empirical Plankton Ecology
Organizers: Chris Klausmeier, Georgia Institute of Technology,
(christopher.klausmeier@biology.gatech.edu)
and Elena Litchman, Georgia Institute of Technology, (Elena.litchman@biology.gatech.edu)
Given their small size, short generation times, and relative simplicity,
plankton are ideal systems to test existing ecological theory in
the laboratory and the field. In turn, plankton have inspired a
large body of ecological theory. Recent advances at the interface
of theoretical and empirical plankton ecology include experimental
tests of predator-prey theory, field tests of resource-competition
theory, expansion of the theory of ecological stoichiometry, and
the discovery of chaos in resource-competition interactions. We
welcome empirical talks that address theoretical questions, theoretical
talks that are based in reality, or talks that combine theoretical
and empirical approaches. We also seek talks from all levels from
the physiological to the ecosystem, especially those that cross
these scales.
SS76 The Microbial World as an Effective
Model System in Ecology
Organizers: Thierry Bouvier, CNRS-University of Montpellier II,
(tbouvier@univ-montp2.fr)
and Thomas Pommier, Kalmar University, (thomas.pommier@hik.se)
Understanding the structure and functions of diversity in the ecosystem
is a common interest shared by general and microbial ecologists.
Although the microbial world provides an effective model system
to address fundamental ecological questions, general ecology and
microbial ecology grew into two parallel stems. However, studies
merging ecological theories, microbial laboratory-based model and/or
field experiments are becoming more common and start to bridge
the gap between the two disciplines. From this perspective, this
session encourages contributions unifying different approaches
from both disciplines through the study of the aquatic microbial
world and address questions relative to diversity (evolution, distribution
and variability) and the ecological mechanisms and theories that
govern their patterns.
SS77 Stoichiometric Aspects of Ecology
and Evolution in Aquatic Ecosystems
Organizers: Dag O. Hessen, Dept. Biology, University of Oslo, (d.o.hessen@bio.uio.no)
and Tom Andersen, Dept. Biology, University of Oslo, (tom.andersen@bio.uio.no)
Ecological stoichiometry (ES) is the study of the balance of energy
and multiple chemical elements in ecological interactions. This
field has many intellectual roots like the seminal works of Liebig,
Lotka and Redfield, but most proximally it has emerged from studies
of trophic interactions in freshwater plankton. It has in recent
years expanded it ranges, and appears to be a useful concept for
understanding effects at cellular level such regulation of growth
in response of elemental ratios, as well as providing additional
insights in the coupling of biogeochemical cycling of key elements
like C, N and P at the ecosystem level. At the individual level,
stoichiometric principles clearly have some important evolutionary
implications. The field of ES has been rapidly expanding field
with the aquatic sciences, and we thus find it timely to arrange
a special session to highlight recent advances within the topic
of ES, bringing together marine and freshwater scientists, theoretical
as well as empirical works and finally merging evolutionary aspects
and ecology.
SS78 Radionuclide Tracers: Contributions
to Our Understanding of Freshwater, Estuarine and Marine Processes
Organizers: Joseph Smoak, University of South Florida St. Petersburg
Environmental Science, Policy an, (smoak@stpt.usf.edu)
and Ashanti J. Pyrtle, University of South Florida College of Marine
Science, (apyrtle@marine.usf.edu)
Radionuclide tracers have been successfully applied in examining
processes within aquatic systems as well as aquatic system interactions
with other environments. This session will highlight recent advancements
in and applications of radiometric techniques used to investigate
a wide-range of aquatic processes. We invite contributions on both
natural and artificial tracer studies of complex aquatic systems
and surrounding environments. Such environments include surface,
subsurface, groundwater, estuarine, marine, and freshwater systems.
Presentations focused on interactions between these environments,
as well as those that consider exchanges at terrestrial, air and/or
particle interfaces, are particularly encouraged.
SS79 Algal and Bacterial Cell Death:
Incidence, Mechanisms and Consequences
Organizers: Ilana Berman-Frank, Bar Ilan University, (irfrank@mail.biu.ac.il),
Tom Berman, Kinneret Limnological Laboratory, (berman@amiad.org.il),
Kay Bidle, Institute of Marine and Coastal Sciences, Rutgers University,
(bidle@imcs.rutgers.edu),
and Susana Agusti, IMEDEA, CSIC-UIB, (sagusti@uib.es)
Microplankton evolved in the Archaen oceans more than 2.5 billion
years ago and, in time, came to have pivotal roles in regulating
aquatic food webs, biogeochemical cycles, and Earth’s climate.
In order to maintain biogeochemical cycles throughout billions
of years of Earth’s history, microplankton must not only
grow, but also die. Over the past century of discovery of aquatic
biogeochemical cycles, a misconception emerged that phytoplankton
are immortal: unless eaten by heterotrophic zooplankton, or sinking
irreversibly into the deep ocean, it has been assumed that the
cells grow indefinitely, primarily by binary fission. New discoveries
and growing empirical evidence on the rates and mechanisms of phytoplankton
and bacterial cell death illustrate key loss processes across aquatic
systems. It has become increasingly apparent that phytoplankton
are not immortal; upon encountering adverse environmental conditions,
they often die spontaneously. Indeed, substantial cell death by
lysis has been documented in field populations, with some estimates
exceeding 50% of phytoplankton growth. These observations highlight
important loss processes independent of grazing by heterotrophs
must exist and might explain how an average of ~50% of global primary
production is consumed by bacteria. In parallel, evidence of high
mortality has emerged as a consequence of an improved understanding
of the role of viruses and pathogens in aquatic ecosystems. It
is clear that the population dynamics of bacteria and phytoplankton,
the most abundant components of pelagic communities, are dependent
on the balance between growth and losses. Indeed, now recognized
as a key loss component of aquatic microorganisms, cell death processes
may explain their abundance and community structure equally as
well as resource availability. Yet, the environmental conditions
and cellular mechanisms that illicit and execute microplankton
cell death remain poorly investigated. This lack of understanding
precludes our capability to predict microplankton cell death in
nature and, thereby, to incorporate this important process in models
of ecosystem structure and nutrient fluxes in pelagic ecosystems.
This session provides a platform to present new findings on the
environmental and physiological triggers of cell death in bacteria
and phytoplankton, the cellular mechanisms responsible, and its
ecological consequences. This session aims to bring together phytoplankton
and microbial ecologists, physiologists, molecular biologists,
evolutionary biologists and biogeochemists in an imaginative, interdisciplinary
and vibrant area of science. We invite papers with field, lab and
theoretical backdrop in order to exhibit the spectrum of approaches
used in this field.
SS80 Impacts of Climate Change and
Other Drivers of Change on Freshwater Ecosystems
Organizers: Charles R. Goldman, University of California, (crgoldman@ucdavis.edu),
Martin Dokulil, Institute for Limnology, Austrian Academy of Sciences,
Austria, (martin.dokulil@oeaw.ac.at),
Martin Kernan, Environmental Change Research Centre, University
College London, (mkernan@geog.ucl.ac.uk),
and Rick Battarbee, Environmental Change Research Centre, University
College London, (rbattarb@geog.ucl.ac.uk)
Freshwater ecosystems, already under stress from land-use change
and pollution, now face additional pressures from climate change,
directly and through interaction with other drivers of change.
There is a pressing need to understand and manage the ecological
consequences of these interactions. The proposed special session
will focus on the key drivers of aquatic ecosystem change (land-use,
nutrients, acid deposition and toxic substances) and how these
interact with global, especially climate, change. We will consider
lakes, rivers, wetlands and groundwater. A tutorial session will
review the current state of research. It is anticipated that subsequent
papers will examine the effects of climate change and its interactions
with other drivers and methods for disentangling these across a
range of ecosystem types. We are keen to ensure that research on
climate change effects on aquatic ecosystems being undertaken across
the globe are represented through oral and poster presentations.
SS81 Single-cell Analyses in Aquatic
Microbes: Patterns, Controls, and Linkages Between Biogeochemical
Function and Microbial Diversity
Organizers: Josep M. Gasol, Institut de Ciéncias del Mar
- MCIMA, CSIC, (pepgasol@icm.csic.es),
Barry F. Sherr, Oregon State University, (sherrb@coas.oregonstate.edu),
and Gerhard J. Herndl, NIOZ, The Netherlands, (herndl@nioz.nl)
Identifying the role that particular microbes play in biogeochemical
cycles relies on the simultaneous assessment of their phylogenetic
identity and ecological function. Over the last few years various
single-cell techniques have been developed for the phylogenetic
identification of microbes and for the evaluation of their contribution
to the cycling of C, P, and S. Various combinations of these techniques
now allow us to open the microbial black boxes and to identify
groups of microbes that are functionally important components of
ecosystems. This enables us to gain insights into the dynamics
and regulation mechanisms in the microbial food web and thereby
advancing from a description of microbial processes to a mechanistic
understanding of the functioning of microbial communities, allowing
for the resolution of the spatial and temporal scales of in situ
cell-specific microbial activity, and for the differential response
of microbial groups to changing environmental conditions.
We invite contributions that make use of single-cell analyses,
such as flow cytometry cell sorting, microautoradiography, confocal
microscopy, bacterial enzyme activities and fluorescence in situ
hybridization, to answer ecological questions relevant to the identification,
physiological status and ecological function of important microbial
groups in aquatic systems.
Recognizing the land-to-ocean path of the medieval Santiago's Way
and the meeting's motto ‘A pilgrimage through global aquatic
sciences’, we encourage contributions from investigators
working in all aquatic environments, from lakes to the oceans and
from the benthos to the plankton.
SS82 Benthic Biofilms in Freshwater
and Marine Systems
Organizers: Anna M. Romaní, University of Girona, Institute
of Aquatic Ecology, (anna.romani@udg.es),
Helene Cyr, University of Toronto, (helene@zoo.utoronto.ca),
and Graham Underwood, University of Essex, (gjcu@essex.ac.uk)
Many aquatic microorganisms live in attached communities (biofilms)
embedded in a polysaccharide matrix and contribute substantially
to the energy flow (production and loss of organic matter) and
sediment-water interactions (e.g. stabilization of sediments, exchanges
of nutrients and contaminants, refuge for pathogens). Microbial
consortia living within benthic biofilms (algae, bacteria, fungi,
protozoa) are in close contact to each other and are organized
by antagonistic and/or synergistic relationships. These species-rich
communities also respond to human disturbances and are important
indicators in environmental assessment programs. The main goal
of this Special Session is to bring together researchers working
on benthic biofilm communities in streams, lakes and shallow marine
systems to compare approaches and contrast the structure and functioning
of biofilms in these different ecosystems.
SS83 Spatial Processes in Marine and
Freshwater Ecosystems
Organizers: W. Gary Sprules, University of Toronto at Mississauga,
(gsprules@utm.utoronto.ca),
Andre W. Visser, Danish Institute for Fisheries Research, (awv@dfu.min.dk),
and E. Agnes Blukacz, University of Toronto at Mississauga, (ablukacz@utm.utoronto.ca)
It has long been realized that distributions of aquatic organisms from
fish to plankton to bacteria are not uniform in space and
time. These distributions are often organised into patches and
aggregations with peak concentrations several times higher than
mean background levels, and at scales ranging from millimetres
to kilometres. How these patches are formed, maintained and exploited
is thought to be a key determinant in shaping pelagic ecosystems
and influencing processes from fisheries recruitment to the vertical
flux of detrital material. Oftentimes, the governing dynamics have
both physical (turbulence and stirring) and biological (growth,
grazing and motility) components, the relative contributions of
which may be strongly scale dependent. In the 50 years or so since
Morrison Cassie’s seminal work on plankton patchiness, interest
in spatial heterogeneity has endured, although emphasis on food
web consequences has received less attention than measurement and
origins of spatial pattern. A recent explosion in particle-counting
technologies and analytical techniques such as wavelets and multifractals
have stimulated this continuing interest. This session invites
contributions that through modelling, observation or experiment
examine spatial patterning in marine and freshwater ecosystems,
its effects on trophic processes and its governing dynamics.
SS84 Multi-tracer Approaches Toward
Understanding Particle Fluxes and Dynamics in the Sea
Organizers: Pere Masque, Institut de Ciécia I Tecnologia
Ambientals, Universitat Autónoma de Barcelo, (Pere.Masque@uab.es),
Stuart Wakeham, Skidaway Institute of Oceanography, (sutart@skio.peachnet.edu),
Robert Armstrong, Marine Sciences Research Center, (rarmstrong@notes.cc.sunysb.edu),
and Juan-Carlos Miquel, International Atomic Energy Agency - Marine
Environmental Laboratory (MEL), (j.c.miquel@iaea.org)
Particulate matter plays a major role in the redistribution of
carbon and other elements in the sea. Sinking particles export
organic matter from the sea surface into the interior of the ocean,
where it can provide energy and nutrition to heterotrophs, can
be remineralized, or can be sequestered in deep water and sediments.
The redistribution of organic carbon influences the depth distribution
of dissolved CO2 which in turn affects the exchange of CO2 between
ocean and atmosphere and the response of the ocean and global climate
to environmental change. It is thus critical to understand quantitatively
and mechanistically those processes involved in organic carbon
remineralization. Biogeochemical investigations into the behavior
of particulate matter now rely on multi-tracer approaches, combining
tools in organic geochemistry, inorganic and radioisotope geochemistry,
zooplankton ecology and microbiology, and statistical analysis
and modeling. Current studies include DYFAMED and MedFlux in the
Mediterranean; RODA and ESTOC near the Canary Islands in the Atlantic;
PAP in the North Atlantic; VERTIGO and BATS near Bermuda in the
Atlantic; and HOT, VERTIGO, and E-FLUX near Hawaii in the Pacific,
among others. This session encourages presentations that involve
multi-tracer approaches that are in use to shed new light on the
mechanisms responsible for POC profiles in the ocean and that will
lead to a predictive capability relating oceanic carbon cycling
and global climate change.
SS85 The Implementation of Observations
in the Coastal Zone: The Global Ocean Observing System
Organizers: Tom Malone, Ocean.US Office for Integrated and Sustained
Ocean Observations, (t.malone@ocean.us)
and Tony Knap, Bermuda Biological Station, (knap@bbsr.edu)
Coastal systems are experiencing unprecedented changes and becoming
more susceptible to natural hazards, more costly to live in, and
less able to support living resources. There are troubling trends
in the magnitude or frequency of a broad spectrum of phenomena
from global warming and sea level rise to harmful algal blooms
and habitat loss. Trends such as these are related to both natural
processes and increasing human demands on coastal ecosystems to
support commerce, living resources, recreation, and living space
and to receive, process, and dilute the effluents of human society.
Informed management for sustained use of these goods and services
requires the capacity to routinely and rapidly assess the state
and health of marine systems, detect changes on a broad spectrum
of time and space scales, and provide timely predictions of likely
future states. We do not have this capacity today. The coastal
module of GOOS is intended to develop this capacity through a more
integrated and holistic approach to achieving six societal goals:
1) improve the safety and efficiency of marine operations; 2) more
effectively control and mitigate the effects of natural hazards;
3) improve the capacity to detect and predict the effects of global
climate change on coastal ecosystems; 4) reduce public health risks;
5) more effectively protect and restore healthy ecosystems; and
6) more effectively restore and sustain living marine resources.
This session is designed to take advantage of the release of the
Implementation Plan for the Coastal Panel of GOOS in mid-2005.
Developing a fully integrated, multi-disciplinary global system
for the coastal module of GOOS is especially challenging for at
least two reasons: (1) monitoring and research activities in much
of the world’s coastal ocean are non-existent or primitive
at best; and (2) operational capabilities for detecting and predicting
changes in ecosystem health and the sustainability of living marine
resources are poorly developed relative to those for marine operations,
weather forecasting, and climate prediction. Meeting these challenges
will require major investments in capacity building and pilot projects
for the development of “end-to-end” observing capabilities,
for enabling implementation in the developing world, and improving
specific elements of system from observing capabilities to data
management and modeling.
This session will invite and call for papers on any of the topics
discussed above however they should specifically relate to implementation.
Presentations on Specific Pilot projects or ongoing operational
systems would be encouraged as well as presentations on data management
and modeling and analysis.
SS86 Brown Trout From the Old World
to the New World: Modification and Homogenization of Freshwater
Ecosystems Around the Globe
Organizers: Francis Juanes, Univ. of Massachusetts, (juanes@forwild.umass.edu)
and Doris Soto, Universidad Austral de Chile, Puerto Montt, Instituto
de Acuicultura, (dsoto@uach.cl)
The Brown trout, Salmo trutta, is native to Europe, north Africa
and Western Asia. It was introduced to North America in 1884, and
is now widely stocked throughout much of Canada and the US. The
species was also introduced to southern South America early in
1900, as well as to New Zealand. In most cases sport fishing was
one of the major objectives for introduction. Apparently its success
in the new habitats is due to its tolerance to poor-quality water.
Indeed, this species seems to tolerate warmer water temperatures
than other trout species. Brown trout (BT) is today one of the
most cosmopolitan freshwater fish, however, we do not have large
assessments on its impact, where introduced, particularly at the
ecosystemic level. It is quite possible that this species have
contributed to homogenization of freshwater habitats around the
world. This special session is attempting to bring together brown
trout studies around the world, which will allow us to compare
the species role in the ecosystem. Questions such as BT role as
top predator, BT modifying resource and energy allocation in streams
and lakes, BT having any effects on the relevance of allochtonous
vs. autochtonous resources for productivity, BT affecting biodiversity
etc. Other indirect effects such as the role of BT on mercury accumulation
in ecosystems could also be relevant around the globe. Therefore,
we invite scientists all over the world to send provocative abstracts
and to join us in this exciting special session.
SS87 The Biogeochemistry of the Tropical
Atlantic Ocean
Organizers: Ajit Subramaniam, LDEO, Columbia University, New York,
(ajit@ldeo.columbia.edu),
Douglas Capone, University of Southern California, Los Angeles,
(capone@usc.edu), and Douglas
Wallace, Leibniz-Institut für Meereswissenschaften, Kiel,
(dwallace@ifm-geomar.de)
The tropical Atlantic Ocean is a very dynamic system influenced
by intense seasonal riverine inputs and dust deposition. Biological
productivity exceeds what might otherwise be expected in an otherwise
oligotrophic environment. There have been several recent interdisciplinary
studies of the tropical Atlantic Ocean by European and American
investigators. These studies have included new measurements and
experimental studies of trace metal chemistry, diazotrophy, and
carbon drawdown. They are altering our understanding of the impact
of tropical rivers and aeolian dust on oceanic carbon and nitrogen
cycling. We invite presentations of results from field surveys
as well as modeling studies of the biogeochemistry of the tropical
Atlantic Ocean in order to promote the exchange of ideas and results
across disciplinary boundaries and among research groups.
SS88 Reservoirs: Limnology in the Making
Organizers: Fabio Roland, Universidade Federal de Juiz de Fora,
(fabio.roland@ufjf.edu.br)
and Joan Armengol, Univ. Barcelona, (jarmengol@ub.edu)
The growing number and size of reservoirs worldwide is re-shaping
the distribution and role of freshwater ecosystems at a global
scale. Reservoirs affect the hydrological balance of the biosphere,
as well as the sedimentary budget and the fluxes of materials from
land to aquatic ecosystems and, eventually, the ocean. Reservoirs
also preclude the free migration of organisms upstream in watersheds.
In summary, reservoirs are reshaping the distribution and role
of freshwater ecosystems and deserve, therefore, a dedicated examination
within the realm of aquatic sciences. Compared to the millenary
age of most freshwater bodies, reservoir life spans count in decades,
and the consequences of the removal of dams can be massive on the
processes mentioned above. This session provides a forum to present
results on the role of reservoirs on ecosystem processes at both
the local and, particularly, the regional and global scales.
SS89 Global Limnology
Organizers: Yves Prairie, Université du Québec à Montréal,
(prairie.yves@uqam.ca) and Jonathan Cole, Institute of Ecosystem
Studies (cole@ecostudies.org)
Limnology has traditionally been dominated by research at the single
ecosystem (lake, reservoir, pond, stream) level, with the occasional
comparative analyses at regional scales. As a consequence, the
role of freshwater aquatic ecosystems have largely remained within
the boundaries of those offered by these local ecosystems, such
as recreation, fishing, and local water supply. Not surprisingly
then, the global role of freshwater ecosystems in the functioning
of the biosphere is seldom addressed in spite of the mounting evidence
that it may play a quantitatively important role in the processing
of materials they receive from land.
The purpose of this special session is to bring together current
estimates of the extent of freshwater resources (streams, rivers,
lakes, reservoirs) and the biogeochemical role they play at the
global scale.
SS90
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