Program and abstracts V2 - Euromarine Network...Nakov Teofil University of Arkansas, USA [email protected] Not Fabrice CNRS, Roscoff, France [email protected] Olivier Marion UPMC,

EuroMarine Foresight Workshop

PlankDiv Impact of climate change on the distribution of plankton functional and phylogenetic diversity

14-17 March 2016

Observatoire Océanologique de Villefranche sur mer (OOV) Sorbonne Universités, UPMC/CNRS

Station Zoologique, 181 chemin du Lazaret France

PROGRAM AND BOOK OF ABSTRACT http://plankdiv.obs-vlfr.fr/

Sponsors: EuroMarine Consortium

Laboratoire d'Océanographie de Villefranche (LOV, UMR 7093, UPMC/CNRS) PlankMed action of the WP5 MERMEX MISTRALS INSU/CNRS

FunOmics project of LEFE-EC2CO of INSU/CNRS

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Name Firstname Institution (EuroMarine in bold) Mail

Aubert Anaïs MIO, Marseille [email protected]

Ayata Sakina-Dorothée UPMC, Villefranche, France [email protected]

Basconi Laura CONISMA, Italy [email protected]

Beaugrand Grégory CNRS, Wimereux, France [email protected]

Benedetti Fabio UPMC, Villefranche, France [email protected]

Benoiston Anne-Sophie UPMC, Paris, France [email protected]

Biard Tristan UPMC, Roscoff, France [email protected]

Bittner Lucie UPMC, Paris, France [email protected]

Blanco-Bercial Leocadio BIOS, Bermudes [email protected]

Brun Philipp DTU-Aqua, Denmark [email protected]

Buttay Lucie IEO, Spain [email protected]

Chapelle Annie Ifremer, Brest, France [email protected]

Chiarello Marlene Marbec, CNRS, Montpellier, France [email protected]

Chust Guillem AZTI, Spain [email protected]

Cornils Astrid AWI, Germany [email protected]

Cotté Cédric MHNH, Paris, France [email protected]

Da Silva Ophélie UPMC, master Paris [email protected]

de Vargas Colomban CNRS, Roscoff, France [email protected]

Dudeck Tim IHF, Hamburg, Germany [email protected]

Gaborit Charlie CSIC-ICM, Spain [email protected]

Guidi Lionel CNRS, Villefranche, France [email protected]

Guilhaumon François IRD, Montpellier, France [email protected]

Irisson Jean-Olivier UPMC, Villefranche, France [email protected]

Kiørboe Thomas DTU-Aqua, Denmark [email protected]

Lezama-Ochoa Ainhoa Ifremer, Montpellier, France [email protected]

Nakov Teofil University of Arkansas, USA [email protected]

Not Fabrice CNRS, Roscoff, France [email protected]

Olivier Marion UPMC, master Villefranche [email protected]

Righetti Damiano ETHZ, Switzerland [email protected]

Sourisseau Marc Ifremer, Brest, France [email protected]

Stemmann Lars UPMC, Villefranche, France [email protected]

Vallim Lima Alessandra Julio de Mesquita Filho Univ., Brazil [email protected]

Vallina Sergio CSIC, Barcelona, Spain [email protected]

Villarino Ernesto AZTI-Technalia, Spain [email protected]

Villéger Sébastien CNRS, Montpellier, France [email protected]

Vogt Meike ETHZ, Switzerland [email protected]

PlankDiv - EuroMarine Foresight workshop - Villefranche sur mer - 14-17 March 2016

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General Program

Monday 14 March - Room Trégouboff (1st floor main building)

• 13h00-14h00: Lunch at the Observatoire Océanographique de Villefranche sur mer, for those who have already arrived (please inform us before March 1 if you want to have lunch at the Observatoire the first day)

• 14h00-14h15: Introduction to the workshop (Ayata Sakina-Dorothée) • 14h15-17h30: Oral session 1: Functional diversity

Gathering of early career researchers for a Pizza Party. Other participants may join them. Tuesday 15 March - Room Trégouboff (1st floor main building)

• 9h00-12h30: Oral session 2: Phylogenetic diversity • 12h30-13h00: Side event: discovering the Observatoire: visit of the zooplankton

collection/visit of the library and its old books on plankton • 13h00: Lunch at the Observatoire • 14h00-17h00: Oral session 3: Ecological niche modelling • 17h00-18h30: Poster session

Wednesday 16 March - Room Trégouboff (1st floor main building)

• 9h00-12h30: Working group 1: Ecological niche modelling for plankton • 13h00: Lunch at the Observatoire • 14h00-17h30: Working group 2: Practical tutorial with R on Functional and

phylogenetic diversity of plankton (please bring you personal laptop) • 17h30: Questionnaire for the participants: what do they expect as following of the

workshop (for preparing the general discussion)? Conference dinner in a restaurant in Villefranche Thursday 17 March - Room Jean Maetz (1st floor Jean Maetz Building)

• 9h00-09h45: Invited presentation by Louis Legendre “Some of the "secrets" of successful researchers”

• 9h45-10h30: Outputs of the workshops and General discussion: how to combine plankton niche modelling with functional and phylogenetic diversity estimates?

• 10h30-11h00: COFFEE BREAK • 11h00-12h30: General discussion on how to plan and organizing the following of the

workshop (writing a synthesis, future proposal, plan future actions) • 13h00: Lunch at the Observatoire (please inform us before March 1 if you want to

have lunch at the Observatoire the last day of the workshop)

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Detailed organization of the Oral Sessions

Oral Session 1: Functional diversity Room Trégouboff (1st floor main building) • 14h15 - 15h00: Invited talk: Kiørboe Thomas: How to identify the key traits of

zooplankton • 15h00-15h15: Benedetti Fabio: Trait and functional groups biogeography • 15h15-15h30: Brun Philipp: A trait biogeography of marine pelagic copepods • 15h30-15h45: Vallina Sergio: Phytoplankton functional diversity increases ecosystem

productivity and stability. • 15h45-16h15: COFFEE BREAK • 16h15-17h00: Invited talk: Villéger Sébastien: Assessing the complementary facets of

functional diversity • 17h00-17h15: Vogt Meike: Phytoplankton biomass: Patterns, drivers & uncertainties • 17h15-17h30: Villarino Ernesto: Large-scale oceanic connectivity and plankton body size Oral session 2: Phylogenetic diversity Room Trégouboff (1st floor main building) • 9h00-9h45: Invited talk: Bittner Lucie: Tara Oceans expedition: Revealing planktonic

networks who are driving carbon export in the oligotrophic ocean • 9h45-10h00: de Vargas Colomban: Assessing global plankton functional biodiversity

patterns with high-throughput sequencing and imaging technologies • 10h00-10h15: Nakov Teofil: Opportunities and constraints in diatom evolution • 10h15-10h30: Not Fabrice: Impact of environmental change on planktonic

photosymbioses • 10h30-11h00: COFFEE BREAK • 11h00-11h45: Invited talk: Guilhaumon François: Phylogenetic diversity: what is it?

Why is it important? How do we measure it? • 11h45-12h00: Chiarello Marlene: Evaluating new frameworks for measuring microbial

phylogenetic diversity • 12h00-12h15: Cornils Astrid: Hidden diversity in polar copepod species • 12h15-12h30: Blanco-Bercial Leocadio: Better, but not perfect yet: zooplankton

metabarcoding at BATS Oral session 3: Ecological niche modelling Room Trégouboff (1st floor main building) • 14h00-14h45: Invited talk: Chust Guillem: modelling for studying the impact of climate

change on pelagic species • 14h45-15h00: Righetti Damiano: Global patterns in marine phytoplankton diversity

inferred from species distribution modeling • 15h00-15h15: Benedetti Fabio: Quantifying relative sources of uncertainties in predictions

of species assemblages • 15h15-16h00: Invited talk: Beaugrand Grégory: Using niche modelling for plankton

biogeography • 16h-16h30: COFFEE BREAK • 16h30-16h45: Chapelle Annie: Ecological niche and phenology modeling of toxic

phytoplankton blooms linked to environmental parameters and phytoplankton diversity. • 16h45-17h00: Gaborit Charlie: Mechanisms underlying the long term temporal pattern in

phytoplankton community assembly


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Poster Session Posters should be in portrait A0-format 1. Aubert Anaïs: Development of plankton indicators in the frame of the European Marine

Strategy Framework Directive (MSFD) 2. Basconi Laura: Jellyfish's functional role in the plankton 3. Biard Tristan: Unravelling the ecological significance of Rhizaria in the California current

ecosystem (Project) 4. Buttay Lucie: Environmental multi-scale effects on zooplankton population dynamics 5. Cotté Cédric: Acoustic patterns and physical habitats of zooplankton in the Southern

Ocean 6. Da Silva Ophélie: Zooplankton of the Crozet Basin 7. Dudeck Tim: Size diversity: A suitable ecological indicator and easy-to-measure

biodiversity substitute for lower trophic levels 8. Lezama-Ochoa Ainhoa: Acoustic study of macrozooplankton in the Bay of Biscay: spatial

distribution, interactions and impact of environmental forcing 9. Sourisseau Marc: Spatial and temporal variability of phenotypic diversity in a tidal front

ecosystem: the Iroise Sea (N-E Atlantic). 10. Vallim Lima Alessandra: Predictive modelling in cnidaria: will jellyfishes dominate the

oceans and coral reefs parish?

Other events Side events will be organized Tuesday and Thursday mornings:

• Visit of the zooplankton collection of the Villefranche Observatoire (organized by Lars Stemmann, about 20 minutes for 7-8 persons): http://rade.obs-vlfr.fr/RadeZoo/RadZoo/Accueil.html

• Visit of the old library of the Villefranche Observatoire and discovery of its old books on planktonic organisms (the visit will be in French but translated in English)

• Invited presentation by Louis Legendre “Some of the "secrets" of successful researchers”

Invited participants • Kiørboe Thomas DTU-Aqua, Denmark. • Villéger Sébastien CNRS, Montpellier, France. • Bittner Lucie UPMC, Paris, France.

Workshop Co-organizers

• Ayata Sakina-Dorothée UPMC, Villefranche, France. • Guilhaumon François IRD, Montpellier, France. • Chust Guillem AZTI, Spain. • Cornils Astrid AWI, Germany. • Vogt Meike ETHZ, Switzerland. • Beaugrand Grégory CNRS, Wimereux, France. • Blanco-Bercial Leocadio BIOS, Bermuda. • Benedetti Fabio UPMC, Villefranche, France.

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Full list of participants (by alphabetical order) Aubert Anaïs, MIO, Marseille, France. Development of plankton indicators in the frame of the European

Marine Strategy Framework Directive (MSFD) Ayata Sakina-Dorothée, UPMC, Villefranche, France. Introduction to the workshop Basconi Laura, CONISMA, Italy. Jellyfish's functional role in the plankton Beaugrand Grégory, CNRS, Wimereux, France. Using niche modelling for plankton biogeography Benedetti Fabio UPMC, Villefranche, France. 1) Projected shifts in copepod surface communities in the

Mediterranean Sea under several climate change scenarios. 2) The biogeography of copepods functional groupsBenoiston Anne-Sophie, UPMC, Paris, France.

Biard Tristan, UPMC, Roscoff, France. Unravelling the ecological significance of Rhizaria in the California current ecosystem

Bittner Lucie, UPMC, Paris, France. Tara Oceans expedition: Revealing planktonic networks who are driving carbon export in the oligotrophic ocean

Blanco-Bercial Leocadio, BIOS, Bermuda. Better, but not perfect yet: zooplankton metabarcoding at BATS Brun Philipp, DTU-Aqua, Denmark. A trait biogeography of marine pelagic copepods Buttay Lucie, IEO (Instituto Español de Oceanografia), Gijón, Spain. Environmental multi-scale effects on

zooplankton population dynamics Chapelle Annie, IFREMER, France. Ecological niche and phenology modeling of toxic phytoplankton

blooms linked to environmental parameters and phytoplankton diversity. Chiarello Marlene, Marbec, CNRS, Montpellier, France. Evaluating new frameworks for measuring

microbial phylogenetic diversity Chust Guillem, AZTI, Spain. Using niche modelling for studying the impact of climate change on pelagic

species Cornils Astrid, AWI, Germany. Hidden diversity in polar copepod species Cotté Cédric, MHNH, Paris, France. Acoustic patterns and physical habitats of zooplankton in the Da Silva Ophélie, UPMC, France. Zooplankton of the Crozet Bassin de Vargas Colomban, CNRS, Roscoff, France. Assessing global plankton functional biodiversity patterns

with high-throughput sequencing and imaging technologies Dudeck Tim, IHF, Hamburg, Germany. Size diversity: A suitable ecological indicator and easy-to-measure

biodiversity substitute for lower trophic levels Gaborit Charlie, CSIC-ICM, Spain. Mechanisms underlying the long term temporal pattern in phytoplankton

community assembly Guidi Lionel, CNRS, Villefranche, France. Guilhaumon François, IRD, Montpellier, France. Phylogenetic diversity: what is it? Why is it important?

How do we measure it? Irisson Jean-Olivier, UPMC, Villefranche, France. Kiørboe Thomas, DTU-Aqua, Denmark. How to identify the key traits of zooplankton Lezama-Ochoa Ainhoa, IFREMER, Montpellier, France. Nakov Teofil, University of Arkansas, USA. Opportunities and constraints in diatom evolution Not Fabrice, CNRS, Roscoff, France. Impact of environmental change on planktonic photosymbioses Olivier Marion, UPMC, France. Righetti Damiano, ETHZ, Switzerland. Global patterns n marine phytoplankton diversity inferred from

species distribution modeling Sourisseau Marc, IFREMER, Brest, France. Spatial and temporal variability of phenotypic diversity in a

tidal front ecosystem: the Iroise Sea (N-E Atlantic). Stemmann Lars, UPMC, Villefranche, France. Vallim Lima Alessandra, Julio de Mesquita Filho University, Brazil. Predictive modelling in cnidaria: will

jellyfishes dominate the oceans and coral reefs parish? Vallina Sergio, CSIC, Barcelona, Spain. Phytoplankton functional diversity increases ecosystem productivity

and stability. Villarino Ernesto, AZTI-Technalia, Spain. Large-scale oceanic connectivity and plankton body size Villéger Sébastien, CNRS, Montpellier, France. Assessing the complementary facets of functional diversity Vogt Meike, ETHZ, Switzerland. Phytoplankton biomass in the global ocean: patterns, drivers, uncertaintiess


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LIST OF ABSTRACTS

(by alphabetical order of presenter) Aubert, Anaïs MIO, Marseille, France POSTER

The development of plankton indicators in the frame of the European Marine Strategy Framework Directive (MSFD)

Aubert A., Rombouts I., Thibault D., Artigas F., Guérin L.

Plankton organisms have a great potential as indicators of environmental changes, both natural and human induced, at variable temporal/spatial scales, from short-term/local to long-term/regional ones due to their dynamics which are largely determined by meteo-climatic and hydrographic drivers. As such, indicators based on plankton present a high interest as tools to monitor the good environmental status of marine waters, which are particularly needed for the European Marine Strategy Framework Directive (MSFD), adopted in June 2008 (2008/56/CE). In the frame of this directive, both local and large scale indicators are in development. Large-scale indicators which will be common within member states are mostly developed in the frame of the OSPAR convention and are based on life traits characteristics, key species group and diversity aspects. Some local indicators are also tested from stationary plankton time-series. By presenting the different indices so far in development, we stress the need for joint analysis of different ocean basins and shelf seas allowing comparative work among different marine ecosystems. Further testing is also required considering biogeography, phylogeny and functional traits of plankton. Basconi, Laura CONISMA, Italy POSTER

Jellyfish's functional role in the plankton Jellyfish are carnivorous, feeding on plankton, crustaceans, fish eggs, small fish and other jellyfish. On the other hand they are kept under control by top predators in the food chain like tuna, sharks, swordfish and sea turtles and other jellyfish which has been classified as the most important predator as interspecific competitors. In some locations jellyfish may be filling ecological niches occupied by now overfished creatures. Human activities together with climate change which is leading to the formation of more temperature stable water masses with less nutrients are forcing marine food webs toward the increase of jellyfish abundances. The shift from fish to jellyfish in the sea water world wide is occurring now and this may have serious effects on ecosystems and it could lead to a top-down control of marine food webs by gelatinous predators. It can ultimately have a possible subsequent de-evolution of the pelagic marine ecosystem back to a Medusozoan dominance. In this scenario, the understanding of ecological dynamics of gelatinous zooplankton becomes an impelling priority.

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Beaugrand, Grégory CNRS, Wimereux, France INVITED ORAL PRESENTATION

Using niche modelling for plankton biogeography Benedetti, Fabio UPMC, Villefranche, France ORAL PRESENTATION

The biogeography of copepods functional groups

Fabio Benedetti, Damiano Righetti, François Guilhaumon, Meike Vogt, Sakina-Dorothée Ayata Functional traits-based approaches are increasingly being used to study planktonic communities. Traits are species characteristics that can be used to understand how climate variability impacts plankton diversity and ecosystem functioning. As biogeochemical and ecosystem models are relying on compartments that are insufficiently diverse, they are over-simplifying the broad variety of taxa and processes that are controlling the functioning of pelagic food-webs and biogeochemical cycles. Using species traits can help scientists identify key functional groups and processes that may be used to improve models,and better capture marine biodiversity. However, many questions remain regarding the mechanistic processes driving the planktonic functional groups, or regarding their relationship with environmental gradients, i.e. their biogeography. In this study, we aim to test whether different zooplankton functional groups and traits exhibit different biogeographies. Statistical niche modeling is used to estimate the species environmental preferences (niche traits), which are combined with functional traits data in multivariate and variances analysis to explore the position of the functional groups in environmental space. Results support the view that copepod species present broad but different environmental preferences, but functional groups do not show very different biogeographies. Carnivores seem to be affiliated to more saline and less varying conditions, contrary to large and small filter-feeding herbivores, as well as small ambush-feeding omnivores.

Benedetti, Fabio UPMC, Villefranche, France ORAL PRESENTATION Projected shifts in copepod surface communities in the Mediterranean Sea

under several climate change scenarios

Fabio Benedetti, François Guilhaumon, Fanny Adloff, Sakina-Dorothée Ayata Although future increases in water temperature and future changes in regional circulation are expected to have great impacts on the pelagic food-web, estimates focusing on community-level shifts are still lacking for the planktonic compartment.


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By combining statistical niche models (or species distribution models) with projections from a regional circulation model, the impact of climate change on copepod epipelagic communities is assessed for the Mediterranean Sea. Habitat suitability maps are generated for 106 of the most abundant copepod species to analyze emerging patterns of diversity at the community level. Using variance analysis, we also quantified the uncertainties associated to our modeling strategy (niche model choice, CO2 emission scenario, boundary forcings of the circulation model). Comparing present and future projections, changes in species richness (alpha diversity) and in community composition (beta diversity, decomposed into turnover and nestedness component) are calculated. Average projections show that copepod communities will mainly experience turn-over processes, with little changes in species richness. Species gains are mainly located in the Gulf of Lions, the Northern Adriatic and the Northern Aegean seas. However, projections are highly variable, especially in the Eastern Mediterranean basin. We show that such variability is mainly driven by the choice of the niche model, through interactions with the CO2 emission scenario or the boundary forcing of the circulation model can be locally important. Finally, the possible impact of the estimated community changes on zooplanktonic functional and phylogenetic diversity is also assessed. We encourage the enlargement of this type of study to other components of the pelagic food-web, and argue that niche models’ outputs should always be given along with a measure of uncertainty, and explained in light of a strong theoretical background. Biard, Tristan UPMC, Roscoff, France POSTER Unravelling the ecological significance of Rhizaria in the California current

ecosystem Plankton diversity and community structure are key drivers of oceanic ecosystem functioning and are centrally important for the ecology and biogeochemistry of our planet. In these ecosystems, large zooplankton link primary production to higher trophic levels through the marine food web, impacting biogeochemical fluxes to the deep ocean. Most of our knowledge on larger zooplankton is based on emblematic taxa, such as copepods, that are abundant, robust and relatively easy to collect with standard sampling procedures. In contrast, the biology and ecology of planktonic Rhizaria, one of the main eukaryotic super-kingdoms, is still largely unexplored. A number of recent studies, ranging from sediment trap to environmental molecular surveys, provide hints as to the importance of Rhizaria in oceanic ecosystems. However, as plankton nets severely damage delicate rhizarians they are inconsistently sampled and their quantitative significance and role in pelagic ecosystems have long remained elusive. Using data from a worldwide in situ imaging survey of plankton larger than 600 µm, we showed that the Rhizaria were a major component of zooplankton communities, constituting on average 33% of zooplankton abundance and 4.5% of the global carbon standing stock in the upper 200 m of the world oceans. More specifically, in diverse regions of the California Current Ecosystem (CCE), the Rhizaria represent 81% of zooplankton observed in situ and clearly appear to be a key component of this upwelling ecosystem. Yet, their abundances in different sub-regions of the CCE, vertical distributions, and processes controlling their distributions, have so far been poorly documented and this component still remains elusive. In this context, the core of the research I plan to conduct at Scripps Institution of Oceanography as postdoctoral scholar, involves three main issues: 1) characterize the rhizarian community in Californian Current Ecosystem, by assessing its structure and diversity (i.e., species composition based on light microscopy, metagenomics,

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and in situ imaging), 2) estimate the impact of rhizarian on ecosystem functioning with particular attention to their contribution to the vertical flux of silica and 3) investigate the ecological impacts of the strong El Niño of 2015-2016 on the rhizarian community and the consequences of these expected changes on Si fluxes in this pelagic ecosystem. Overall, my postdoctoral research project will lead to a more comprehensive view of the structure and the functioning of the California Current Ecosystem. The expected results will provide novel insights into our understanding of rhizarian communities and the interactions between climate change, community structure and ecosystem dynamics in a major coastal upwelling biome.

Bittner, Lucie UPMC, Paris, France INVITED ORAL PRESENTATION

Tara Oceans expedition: Revealing planktonic networks who are driving carbon export in the oligotrophic ocean

Guidi L* , Chaffron S*, Bittner L *, Eveillard D*, Jeroen Raes, Eric Karsenti, Chris Bowler, Gabriel

Gorsky and the Tara Oceans consortium The biological carbon pump is the process by which CO2 is transformed to organic carbon via photosynthesis that sinks to the deep ocean as particles where it is sequestered. While the intensity of the pump correlates with plankton community composition, the underlying ecosystem structure and interactions driving the process remain largely uncharacterised. Environmental and metagenomic data gathered during the Tara Oceans expedition were used to improve our understanding of the underlying processes. Our results help elucidate ecosystem drivers of the biological carbon pump and present a case study for scaling from genes-to-ecosystems. Blanco-Bercial, Leocadio BIOS, Bermuda ORAL

Better, but not perfect yet: zooplankton metabarcoding at BATS Metabarcoding analysis of planktonic communities allows for a fast and detailed description of the taxonomic composition. Compared to morphological-based identification approaches, metabarcoding presents a series of pros and cons. Molecular IDs will depend on the extant reference library linking species to sequences, and the discriminating power of the marker. At the same time, those markers carrying strong phylogenetic signal (e.g., ribosomal genes), allow for molecular-based analyses (e.g., phylogenetic diversity) based on the reconstructed phylogenetic tree or matrix without the need of taxonomic IDs. This represents a clear advantage when analyzing groups where taxonomy is not yet settled, or when morphological analyses are too challenging or time-consuming to be carried out. On the other hand, with current technology, those phylogenetic signal-rich markers often fail to discriminate among close (and often not that close) species. The lack of taxonomic resolution could have undesired consequences if the identifications are used for other analyses, like functional diversity. In this talk, the example of the Sargasso Sea zooplankton community will be used to explain some of these advantages and associated problems, with the aim of providing “food for thought” during the workshop. The marker chosen to analyze the community was the V9 region of the 18S ribosomal gene.


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Brun, Philipp DTU-Aqua, Denmark ORAL PRESENTATION

A trait biogeography of marine pelagic copepods Pelagic copepods are ubiquitous from icy polar oceans to stratified tropical seas, dominating the mesozooplankton biomass across large areas. The success of this homogeneous group of crustaceans is only possible through efficient adaptations to contrasting environments, and these adaptations should be visible in their traits. We combined extensive datasets of copepod traits and distributions, and environmental variables to investigate how the key traits of copepod communities vary across the world’s oceans. In a first step, we identified four key traits based on ecological relevance and a variance analysis: body size, feeding activity, relative offspring size, and respiration rate. Then, we joined information on these key traits with global observational data and produced trait distribution maps. Furthermore, we identified key environmental drivers of the distributions. While the sparse data coverage in the Pacific Ocean may limit the accuracy of our analysis in this area, we find high correlations between global presence-only data based trait estimates and abundance weighted estimates from the North Atlantic. Besides improving our understanding of trait-environment relationships for copepods, our maps represent a new baseline against which hypotheses and model predictions can be tested. Buttay, Lucie IEO (Instituto Español de Oceanografia), Gijón, Spain POSTER

Environmental multi-scale effects on zooplankton population dynamics In the present work we focused on an area subjected to strong seasonality which corresponds to the northern limit of the canary upwelling system. Using wavelet methods we describe the periodic component on a 17 years time-series (monthly sampling) of zooplankton total biomass, abundance and taxonomic composition and their relation with upwelling index and river outflow periodicities. The main mode of variation in all series corresponds to annual periodicity. It was intermittent in all cases and zooplankton aggregates (total biomass and total abundance) showed as expected a strong association with upwelling index and river outflow. Amplitude of annual component of zooplankton total biomass and abundance increased in 2000 concomitant with the highest amplitude (at the annual scale also) of upwelling index and river outflow and also to a shortening of the upwelling event duration (2000-2004). The extraction of the annual component revealed that during this period of perturbance, the main taxa and copepod species fluctuated suddently in stronger synchronicity. Fluctuations in the degree of synchronicity have been quantified as the phase angle variance which appear to be highly correlated with the duration of the upwelling events. Indeed when upwelling event shorten the degree of synchronicity increase suggesting that the small scale variation of environmental drivers can lead to effect at a bigger scale in zooplankton population.

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Chapelle, Annie IFREMER, France ORAL PRESENTATION

Ecological niche and phenology modeling of toxic phytoplankton blooms linked to environmental parameters and phytoplankton diversity.

Annie Chapelle, Carles Guallar-Morillo, Cédric Bacher, Martin Plus, Marc Sourisseau,

Valérie le Guennec Due to their toxicity and monitoring, harmful algae are ideal models to study ecological niches. We investigate it for two keys species, the dinoflagellate Alexandrium minutum and the diatom Pseudo-nitzschia (both responsible for toxic outbreaks), through statistical analysis combining the definition of environmental niche and bloom phenology and through numerical modelling based on physiological traits parameterization for generating emergent properties among phytoplankton functional types. Results showed that environment parameters influence differently the bloom phases (growth, maximum, and decline) and that if general schema could be highlighted as for temperature, local controls may modify the bloom dynamic. Chiarello, Marlene Marbec, CNRS, Montpellier, France ORAL PRESENTATION Evaluating new frameworks for measuring microbial phylogenetic diversity

Chiarello M, Villéger S, Bouvier T. To understand the assembly rules that shaped communities, it is necessary to accurately assess facets of biodiversity and especially phylogenetic diversity. A huge variety of phylogenetic diversity indices accounting for composition or structure of communities as well as for alpha and beta levels of diversity have been published for the last decades. Recently, frameworks to unify some of these indices have been proposed to allow comparing biodiversity facets and their components. These methods were designed for macrobial communities, and their application on microbial communities was only recently and partially tested. However, microbial communities have features that distinguish them from macrobial ones, e.g. a low evenness and a very high richness. Here we propose to test the properties of these different frameworks using simulated microbial communities. We demonstrate that the different existing frameworks have contrasted properties and that their application may depend on intrinsic features of the communities studied, and on the objectives of the study.


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Chust, Guillem AZTI, Spain INVITED ORAL PRESENTATION Using niche modelling for studying the impact of climate change on pelagic

species Improving models of the future ocean and disentangling climate change from other drivers affecting species distribution shifts and phenology are some of the main challenges in marine research. I present a general approach to address these issues using species distribution modelling (in particular with Generalized Additive Models (GAMs) algorithm) to define the n-dimensional species ecological niche, and applications to zooplankton and fish species. In order to analyse trends using historic data and test whether changes in distribution and phenology is caused by climate change or not, first sampling effort should be analysed. In general, sampling effort is not random through time and space, which may trigger bias in distribution and therefore in estimated trends. Hence, the approach consists on performing and comparing simulation experiments of different spatio-temporal models. In essence, two models are needed: 1) A model using temporal and spatial terms to reconstruct the population distribution, hence to avoid bias in sampling effort; 2) A model using only climate factors (i.e. niche-based model) to simulate species habitat suitability for which hypothesis we want to test; for instance, if our goal is to test if sea warming triggers species poleward shifts, hence, only sea temperature should be considered to build the model allowing the thermal habitat to be defined. The distribution shift rates from these two models are then analysed and compared. When the trends of these two models are similar, then we are in the case of niche tracking. In order to address future projections of species distribution and phenology, a third model using different environmental factors should then be used. Cornils, Astrid AWI, Germany ORAL PRESENTATION

Hidden diversity in polar copepod species The existence of widespread or even cosmopolitan species has been widely accepted in marine plankton due to high dispersal potentials and the lack of apparent geographic barriers. During the past years molecular studies have however, revealed that cryptic diversity plays an important role within widespread species. Although the mode of speciation in the pelagic is largely unknown several features have been suggested as possible barriers to gene flow: e.g. landmasses or continents, oceanic gyres, frontal systems or temperature or salinity ranges. Also vertical partitioning of cryptic species has been observed. An understanding of the present environmental factors and historical events that shape the biogeography of widespread zooplankton organisms is critical to analyze the impact of climate change on their future distribution. To identify possible barriers that shape the biogeography of polar copepod species three abundant polar copepods species-groups were chosen. They are all circumglobally distributed, but live in different vertical habitats (e.g. Oithona similis (epipelagic), Microcalanus spp. (mesopelagic) Spinocalanus abyssalis/longicornis (meso-bathypelagic)). Specimens were analysed from different climate zones (Southern Ocean and its boundaries, Arctic Ocean, North Atlantic, North Sea, Mediterranean Sea, North Pacific Ocean, tropical Atlantic) and from various depths. Phylogeographic analyses were carried out based on nuclear and mitochondrial genetic markers (e.g. 28S, ITS1, COI). The global assessment of the

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evolutionary lineages revealed that the epipelagic O. similis “species” is a conglomerate of putative cryptic species with restrictions to polar, subpolar or temperate environments. Behavioral, ecological or physiological differences between the lineages are probably, but cannot be evaluated at this stage. The meso- and bathypelagic cryptic species within Microcalanus and Spinocalanus may have a wider distribution range. Cotté, Cédric MHNH, Paris, France POSTER

Acoustic patterns and physical habitats of zooplankton in the South-Western Indian Ocean

Cotté C.1, Behagle N.1,2, d'Ovidio F.1, Guinet C.3, Bost CA.3, Roudaut G.2, Josse E.2, Bremher

P.2,& Cherel Y.3

1 Sorbonne Universités (UPMC, Univ Paris 06)-CNRS-IRD-MNHN, LOCEAN Laboratory, Paris, France 2 Institut de Recherche pour le Développement (IRD), UMR LEMAR 195, Campus Ifremer, BP 70, 29280 Plouzané, France

3 UMR CEBC 7372 (CNRS-Université de La Rochelle), 79360 Villiers-en-Bois, France Despite its ecological importance, zooplankton remains largely under-investigated in the open-ocean ecosystems of south Indian Ocean. Using the hydroacoustic methodology through multi-frequency echosounder, we employed adapted analytical tool to discriminate groups of scatterers in the top (sub-)surface waters (300m). Acoustic data were collected during fishing and research voyages along 18 linear transects totaling about 50 000 km to investigate the large-scale distribution of zooplankton over a large latitudinal gradient (20-50°S) and two different seasons (summer and winter) in the South-Western Indian Ocean. We also investigated the distribution of these organisms at a regional scale in the productive oceanic zone east of Kerguelen Islands (southern Indian Ocean). Using both satellite remote sensing data and in situ measurements, we described a complex multiscale patterns according varying oceanographic conditions. Despite uncertainties with species identification, acoustic data provides an essential baseline to examine the distribution of zooplankton and their physical habitats, the trophic interactions with predators and the functioning of the open-ocean ecosystems at various scales. Da Silva, Ophélie UPMC, France POSTER

Zooplankton of the Crozet Bassin The Crozet area is a productive region although it is still largely undersampled in the Indian part of the Southern Ocean. This area is characterized by the presence of the sub-antarctic and the sub- tropical fronts and the circulation around the Plateau is forced by the bathymetry and controlled the annual bloom. The Continuous Plankton Recorder is a useful tool to study the distribution of the zooplanktonic communities. Using this monitoring in the surface waters, the aim of this study was to characterize the variations of abundances of several taxa and to associate them with oceanographic features and geography. Their distribution varied in time and space. Highest abundances were found close to the Plateau, where the primary production is higher likely due to iron-enrichment, and in the frontal area. Zooplankton temporal patterns were also affected by diel migrations.


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de Vargas, Colomban CNRS, Roscoff, France ORAL PRESENTATION

Assessing global plankton functional biodiversity patterns with high-throughput sequencing and imaging technologies

De Vargas C.1, 2, Audic S.1, 2, Colin S.1, 2, the EPEP team1, 2 & Tara-Oceans consortium.

1 CNRS, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France. 2 Sorbonne Universités, UPMC Univ Paris 06, UMR 7144, Station Biologique de Roscoff, Place Georges

Teissier, 29680 Roscoff, France. Automated, high-throughput DNA sequencing and imaging technologies are revolutionizing ecology, allowing to dramatically increase spatio-temporal sampling granularity while erasing the boundaries between organismal size fractions and taxonomic divisions. In Tara Oceans, we used massive DNA metabarcoding to assess the entire diversity of eukaryotic organisms from the smallest unicell (or protist) to small animals across a planetary biome. The sequencing of ~800 million metabarcodes from >300 size-fractionated plankton communities allowed biodiversity assessment close to saturation, both locally and globally. We estimated that sunlit marine plankton contain ~150 000 genetic types of eukaryotes, which is much greater than the ~11 000 described species of eukaryotic plankton. The large majority of this biodiversity belongs to protists, and most of it comes from unknown and uncultured organisms. This eukaryotic biodiversity is significantly greater than the bacterial one, and ~2/3 of it belongs to poorly known groups of heterotrophic protists, including a huge variety of parasites and species known to live in symbiosis. We assigned broad ecological functions to the metabarcodes and used OTUs abundance profiles to better understand the ecological behavior of this unveiled majority of plankton life, and reconstruct a global photic plankton interactome including viruses, prokaryotes, eukaryotes, and environmental parameters. Eukaryotes appear to play a fundamental role in structuring the plankton network, and, overall, biotic and positive interactions -in particular through parasites- are significantly more prevalent than abiotic and/or negative interactions. We finally developed a new automated confocal fluorescent imaging process (eHCFM) to validate network-generated hypotheses, unveil and quantify the complexity of novel plankton symbioses, and provide the needed tool to link genetic and morpho-functional diversity for future holistic studies of plankton systems. Dudeck, Tim IHF, Hamburg, Germany POSTER

Size diversity: A suitable ecological indicator and easy-to-measure biodiversity substitute for lower trophic levels

Dudeck, Tim, Hufnagl, Marc, Rohlf, Norbert and Möllmann, Christian

Biodiversity is a key aspect of the good environmental status (GES) of an ecosystem. Higher diversity is assumed to be related to a number of ecosystem functions such as a higher stability of the system and a stronger resilience to external perturbations. Since often determination of taxonomic diversity of lower trophic level species is time consuming - whereas size can be sampled automatically with optical devices - size diversity in a

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community may serve as a suitable statistic to detect changes that can be evaluated against GES. Here we present a unique time-series on winter zooplankton size, abundance and taxonomic composition sampled on the ICES International herring larvae survey station grid in the Eastern English Channel using modified GULF III samplers with 300µm mesh size. Covering the period 1988 to 2014, we analysed zooplankton with an automatic system, i.e. ZooScan, and followed patterns in taxonomic and size diversity over time and space. Results suggest that size diversity can substitute biodiversity as an indicator and also serve to detect regime shifts. It may further serve as indicator for zooplanktonic prey biomass available to fish larvae and thus shows potential to be included in ecosystem models to simplify the energy flow through trophic levels using size only. For future holistic modelling approaches to examine the effect of climate change on the zooplankton diversity in this region, ecosystem relevant parameters were also analyzed in conjunction with size diversity. In conclusion, even though taxonomic diversity is crucial to describe GES, size diversity can serve as more than an additional descriptor for ecosystem functioning and thus may be integrated into a GES approach. Gaborit, Charlie CSIC-ICM, Spain ORAL PRESENTATION Mechanisms underlying the long term temporal pattern in phytoplankton

community assembly The rules that govern the seasonal assembly of phytoplankton communities is one of the major question of marine ecology. Several ecological theories have been proposed to explain some of the observed large-scale spatial patterns of marine phytoplankton community assembly. The two major competing conceptual frameworks are the niche theory and the neutral theory. However there is a clear lack of studies addressing the long-term temporal patterns of phytoplankton community assembly. Here we study the seasonal dynamics of phytoplankton community assembly over a 9 year period (2006 to 2014) using the Blanes Bay Observatory plankton time-series of species taxonomic diversity. We combine the analysis of real data with simulated theoretical scenarios to provide a coherent picture of the mechanisms underlying the observed temporal patterns in community similarity (Jaccard and Bray Curtis indices). Standing diversity is generally a small fraction of total integrated diversity over time and does not show a clear seasonal cycle. However the communities display fast species turnover, with a clear seasonal cycle in community composition. The seasonal pattern in community similarity is mostly due to the subset of common species, overimposed over a constant background of community similarity due to rare species (i.e. less than 1% of biomass contribution). Our results suggest that marine phytoplankton follow a non-random (niche-based) temporal community assembly driven by changes in environmental conditions.


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Guilhaumon, François IRD, Montpellier, France INVITED ORAL PRESENTATION

Phylogenetic diversity: what is it? Why is it important? How do we measure it?

Once upon a time ecologists thought that measuring biodiversity collapses to measuring species numbers and abundances. However, it is today acknowledged that all species are not equal and that some are more equal than others. Particularly, species differ in the amount of evolutionary history they share. Those differences are important. Indeed, there is increasing evidence that assemblages gathering species with divergent evolutionary history are more productive, realize more ecological functions and may be more resilient to environmental perturbations than assemblages constituted of closely related species. Furthermore, from a conservation point of view, recent evaluations of the amount of evolutionary history represented by protected area networks highlight new perspectives on the endangerment status of the Tree Of Life. In the context of climate change, projecting species distributions under future climate conditions (via Ecological Niche Modeling) allows to make projections on the ongoing erosion of the evolutionary history accumulated on the earth and in the oceans across geological times. In this talk I will briefly recall the general theories linked to the concept of phylogenetic diversity, I will discuss examples of key or recent studies putting phylogenetic diversity into perspective, and review key methods to estimate phylogenetic diversity. Exemplifications and applications of the phylogenetic diversity concept across the literature focusing on plankton ecology are scarce, and the global phylogeny of planktonic organisms is not yet assembled, however the concept and it's applications should provide new perspectives on the past (evolution), the present (ecology) and the future (in the context of climate change) of the fundamental compartment of marine food webs that plankton represent. Kiørboe, Thomas DTU-Aqua, Denmark INVITED ORAL PRESENTATION

How to identify the key traits of zooplankton Currently, many fields use the traits that can be easily measured without necessarily knowing what functions the used traits serve, but not all traits are equally useful and informative. What are the key traits for zooplankton? How to identify them?

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Lezama-Ochoa, Ainhoa IFREMER, Montpellier, France POSTER

Acoustic study of macrozooplankton in the Bay of Biscay: spatial distribution, interactions and impact of environmental forcing

In the Bay of Biscay, fisheries play an important economic and social role. Unfortunately, up to now, most data collection pertaining to the marine ecosystem mainly focused on exploited fish populations. This led to a lack of knowledge about the actual functioning of the system and the role of other key components. It is particularly the case for the macrozooplankton, which plays a key role in pelagic ecosystems as a link between lower trophic levels and fish. The objective of this work was to study the spatiotemporal distribution of macrozooplankton and then to asses the influence of diverse environmental parameters including fish predators on macrozooplankton dynamics during the spring stratification. In order to obtain comprehensive information on the macrozooplankton distribution in the Bay of Biscay we adapted a bi-frequency acoustic method developed for the Humboldt Current system. This method allows extracting continuous and simultaneous high-resolution information on the spatiotemporal patterns of acoustic biomass distributions of macrozooplankton and pelagic fish throughout the diel cycle. We showed that macrozooplankton was generally more abundant and formed larger aggregation offshore than inshore, whereas fish showed an opposite trend. Finally, we found that the correlation between fish and macrozooplankton was positive on a small scale and negative on a large scale. One of the most noticeable result was the observation of a 'biocline' during the day i.e. a thin layer where zooplankton biomass changes more rapidly with depth than it does in the layers above or below. The biocline separated the surface layer almost depleted in macrozooplankton from the macrozooplankton rich deeper layers. Macrozooplankton biocline could be seen as a tradeoff between avoiding size-selective visually hunting predators and maximizing energy gain. We also investigated the biogeography of macrozooplankton and fish distribution. Hydrodynamic spatial structures together with coastal influence and the vertical structuring of the ecosystem appeared as the main factors determining macrozooplankton and fish distributions. The high-‐resolution biological data obtained in this study opens new perspective to perform integrated multiscale ecological studies and to calibrate biogeochemical, trophic and End-‐to-‐End models. Nakov, Teofil University of Arkansas, USA ORAL PRESENTATION

Opportunities and constraints in diatom evolution The benthos-plankton divide and marine-freshwater salinity gradient are key factors partitioning aquatic microbial diversity. Diatoms – a lineage of photoautotrophic eukaryotes that play critical roles in the global cycling of carbon, oxygen, and silica – are common, abundant, and diverse at both ends of the benthos-plankton divide and across the salinity gradient. Yet, the principal opportunities and constraints that have shaped their evolution are poorly understood. We constructed the most comprehensive diatom phylogeny to date and used it to address a set of questions related to diatom evolution in the plankton and benthos of marine and freshwaters. What were the dominant pathways of historical colonization of alternate environments? How these evolutionary routes interact with each other and with diatom growth form (colonial vs. solitary)? What type of changes, if any, in the frequency and direction of transitions can be associated with diatoms’ developmental shifts to axial


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symmetry (pennate diatoms) and active motility (raphid diatoms)? Our analyses reveal that transitions between marine and freshwaters had different probabilities in planktonic and benthic lineages, and vice versa, supporting broad sense between-character interactions throughout diatom evolution. Traversals between environments were also linked to species’ growth form; some types of transitions were more likely in colonial vs. solitary growing diatoms. Life as a suspended particle was inferred to be a derived and absorbing state, established by irreversible recruitment from the benthos, followed by in situ diversification and conservation. Centric diatoms can colonize the plankton as solitary or colonial, however, in pennate diatoms invasions of the plankton occurred only in colonial lineages. Overall, our findings suggest that the developmental shifts to axial symmetry and active motility, and other life history changes coincident with these, opened new opportunities, but were also followed by new constraints altering the principal evolutionary pathways in diatom evolution. Not Fabrice CNRS, Roscoff, France ORAL PRESENTATION

Impact of environmental change on planktonic photosymbioses

Oceanic environments are sensitive to climate change. The most emblematic example is the bleaching of coral reefs due to the breakdown of the symbiosis between the coral and its dinoflagellate microalgal symbionts in response to temperature rise. Such mutualistic photosymbioses are not only a highly significant process for evolution, but also a key ecological interaction supporting the functioning of whole ecosystems. While corals are highly symbolic and attract most of the research attention, they represent only a small fraction of photosymbioses in the global ocean. In the plankton, arguably one of the least explored compartments of the biosphere, photosymbiotic relationships with dinoflagellates are frequently observed and hold a key position in pelagic ecosystems. Considering the obvious significance of plankton on the one hand and photosymbiosis on the other, coral bleaching could just be the tip of the iceberg of a more global unnoticed phenomenon occurring at the surface of all oceans. “Plankton bleaching”, which has been reported from fossil records to have already occurred in the middle Eocene (40 Million years ago), could have a considerable impact on oceanic ecosystem structure and function. We hypothesize that fundamental biological processes underlying benthic and planktonic photosymbioses are based on common molecular pathways and have been selected to respond to similar environmental settings. In this context, in the IMPEKAB project we will seek i- to evaluate the sensibility of planktonic photosymbiosis to environmental changes, ii- to unveil fundamental biological processes involved in the response of photosymbiosis to thermal stress across eukaryotic lineages by comparing outcomes of similar experiments performed on marine benthic and planktonic host models. Finally, based on our comprehensive understanding of photosymbiosis stress processes and considering that plankton bleaching could impact the whole pelagic ecosystem, we will iii- apply an original eco-systems biology approach to evaluate the thermal stress response of planktonic photosymbiosis in the environment. The research strategy we propose in order to attain our objectives is based on promising preliminary results obtained on the sea anemone and the Radiolaria, our ecologically relevant benthic and planktonic biological models, respectively. Taking advantage of the strong expertise of the partners on their respective biological models, we have developed a carefully planned experimental strategy. Briefly, once the physiological characteristics of the models with respect to temperature variation have been defined, we will use this framework to conduct experiments to decipher the genetic and metabolic responses associated to thermal stress. Data acquired and outcomes of comparative analysis between experimental conditions

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and biological models will be used to implement innovative modelling approaches to integrate all results into an environmental context. Ultimately we aim to achieve a detailed physio-genomic understanding of how marine photosymbiosis responds to environmental stressors in order to develop tools that will facilitate in situ monitoring of the potentially critical bleaching phenomenon. This joint initiative, ambitious and highly original in the national and international research landscape, will involve recognized scientists from the fields of biology, ecology, chemistry, bioinformatics, and computational modelling, promoting strong exchanges of concepts and technical expertise and contributing to the development of the novel “eco-systems biology” field. As a consortium, we will implement a carefully organized strategy for scientific dissemination, outreach, and valorization of the results obtained in IMPEKAB. Righetti Damiano ETHZ, Switzerland ORAL PRESENTATION

Global patterns n marine phytoplankton diversity inferred from species distribution modeling

Phytoplankton comprise a phylogenetically diverse array of taxa, but their diversity patterns on the global scale are currently poorly understood. Global diversity patterns of oceanic phytoplankton are depicted by means of quantifying species richness as a function of environmental parameters using species distribution models (GAMs) and occurrence data from the Global Biodiversity Information Facility (GBIF), the Ocean Biogeographic Information System (OBIS) and the MARine Ecosystem DATa (MAREDAT). Models are being tested for sensitivity regarding spatial data-thinning, variable-choice and pseudoabsence-selection strategy and used to characterise the richness of functional (e.g., silicifiers, calcifiers) and taxonomic plankton groups (e.g., diatoms, coccolithophores, or cyanobacteria). Results show that the ecological super-niches of phytoplankton classes are widespread and sequentially shifted along the ocean's temperature range. Latitudinal species richness gradients and the relative importance of underpinning environmental drivers differ between diatoms and coccolithophores. Total integrated phytoplankton diversity varies as a function of ocean basin, latitude and season, highlighting that possible links between diversity and ecosystem function warrant investigation across a range of different spatio-temporal scales.


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Sourisseau Marc IFREMER, Brest, France POSTER

Spatial and temporal variability of phenotypic diversity in a tidal front ecosystem: the Iroise Sea (N-E Atlantic).

Cadier M.(1) , Memery L. (1), Sourisseau M. (2) , Gorgues T. (3)

(1) UMR-CNRS-IRD 6539,LEMAR,IUEM, Place Nicolas Copernic, 29280 Plouzané,France (2) Département dynamique de l'environnement côtier, Pelagos,IFREMER Brest, Plouzané (3) IRD, LPO, Institut Universitaire Européen de la Mer – 29280 Plouzané The efficiency of the carbon pump depends on the quality of primary producers and their composition is assumed as directly driven by environmental factors through selection process. In this context, mechanisms that promote coexistence, such as the variability of the environmental factors in coastal waters, are of center of interest in this topic. This study thus aims to evaluate the impact of hydrodynamic conditions variability on phenotypic diversity of phytoplankton through an exclusive competition process in coastal waters. Some realistic hydrodynamic simulations coupled with a modeling approach that integrates a phenotypic diversity and selection processes were done. Our results show a seasonal succession as well as a link between phytoplankton diversity and physical processes. The potential relationship between diversity patterns and the advection however appears modulated by sensitivity of the phenotypes fitness to the “top-down” control.

Vallim Lima Alessandra

Julio de Mesquita Filho University, Brazil POSTER

Predictive modelling in cnidaria: will jellyfishes dominate the oceans and coral reefs parish?

One of the biggest problems related to cnidarian is the massive appearance of jellyfish in some areas of the world. They are the major plankton consumers and feed on microorganisms to fish larvae, strongly acting in the ocean’s trophic chain, influencing directly on the quantity of fish. Coral reefs are the most diverse and productive marine ecosystems, however in the absence of zooxantellae heterotrophy becomes the only food source, increasing the plankton competition that results in the death or reallocation of numerous animals such as fishes. Extremely important therefore is the modelling of these organisms niche, aiming to recognize patterns and estimate future sceneries. The present project’s objective is to ascertain the factors that cause significant alteration in the population of Scyphozoa, Cubozoa e Anthozoa, using abiotic data (climate, topography, pH, salinity and precipitation); and biotic ones (characterized by algorithms such as GARP, SVM, MAXET that uses presence data and (when existent) pseudo-absence). The major part of these data have already been gathered and available to use, and the mathematical results obtained by the algorithms will be the foundation of the entire project, once they are vital to plot the graphics for the predictive model, and check the data by dividing the animals into calibration and test groups, making the model highly reliable. It will then be possible to analyse the population’s decrease or increase on short and long term of these highly resistant animals, due to decades of intense anthropogenic actions like greenhouse effect that triggers varied negative reactions on Earth’s natural cycles affecting the entire oceanic trophic chain.

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Vallina Sergio CSIC, Barcelona, Spain ORAL PRESENTATION

Phytoplankton functional diversity increases ecosystem productivity and stability

The effect of biodiversity on ecosystem functioning is one the major questions of ecology. However, the role of phytoplankton functional diversity in ecosystem productivity and stability under fluctuating (i.e. non-equilibrium) environments remains largely unknown. Here we use a marine ecosystem model to study the effect of phytoplankton functional diversity on both ecosystem productivity and its stability for seasonally variable nutrient supply and temperature. Functional diversity ranges from low to high along these two environmental axes independently. Changes in diversity are obtained by varying the range of uptake strategies and thermal tolerances of the species present in the community. Species can range from resource gleaners to opportunists, and from cold to warm thermal tolerances. The phytoplankton communities self-assemble as a result of species selection by resource competition (nutrients) and environmental filtering (temperature). Both processes lead to species asynchrony but their effect on productivity and stability differ. While the diversity of temperature niches has a strong and direct positive effect on productivity and stability, the diversity of uptake strategies has a weak and indirect positive effect. These results show that more diverse communities lead to higher and more stable ecosystem productivity than less diverse communities. However, the strength of the biodiversity effect on ecosystem functioning for microbial communities depends critically on the type of environmental gradient. Villarino Ernesto AZTI-Technalia, Spain ORAL PRESENTATION

Large-scale oceanic connectivity and plankton body size

Ernesto Villarino*, Guillem Chust, James Watson, Josep M Gasol, Guillem Salazar, Marta Estrada, Massimo Pernice, Pilar Olivar, Naiara Rodriguez-Ezpeleta, Jon Corell, José L. Acuña, Axayacatl

Molina, Ignacio Gonzalez-Gordillo, Susana Agusti, Eugenio Fraile-Nuez, Jesus Mari Arrieta, Carlos Duarte, Xabier Irigoien

The degree to which marine communities are connected depends on the dispersal capacity of the organisms. In order to better understand the role of dispersal in structuring marine communities, we analyzed connectivity patterns of a broad range of planktonic groups (from bacteria to macro-zooplankton), atmospheric aero-bacteria and small mesopelagic fishes (myctophids). The analysis was carried out as a function of the organism body size and at different depths (from surface to 4000m depth), based upon β-diversity metrics. Our samples are globally distributed across the world oceans and have been obtained under the same conditions during the Malaspina circumnavigation expedition. Results reveal size-driven significant differences in the organisms’ dispersal capacities. Large-bodied groups show shorter dispersal scales and stronger spatial patterning compared to small-bodied groups. On the other hand, results reveal no depth driven dispersal scale differences between surface and deep communities. We also found that dispersal limitation explains organism community assembly more than environmental factors. These findings suggest organism body size linked to dispersal capacity as an important factor to explain global connectivity patterns of marine plankton.


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Villéger Sébastien CNRS, Montpellier, France INVITED ORAL PRESENTATION

Assessing the complementary facets of functional diversity Trait-based approaches are increasingly applied in community ecology to assess spatial patterns and temporal trends of functional diversity to ultimately understand how human impacts affect ecosystem functioning. Several methodological frameworks have been proposed to compute the diversity of traits values present in a species assemblage and the similarity of traits values between several assemblages. However, methodological choices could have deep implications on the results since some approaches have biases (e.g. functional dendrogram) and because indices have different properties (e.g. accounting for relative biomass of species or only for their traits values). Here I will present user-oriented guidelines for each of the three steps to compute functional diversity: (1) selecting a set of traits and measuring them in a set of species assemblages, (2) building a multidimensional space of high quality to place all the species according to their respective traits values, (3a) computing complementary indices describing the facets of the distributions of species and of their biomass in this space and/or (3b) computing complementary indices of functional dissimilarity between assemblages. Vogt Meike ETHZ, Switzerland ORAL PRESENTATION

Phytoplankton biomass: Patterns, drivers & uncertainties Phytoplankton biomass in the global ocean: patterns, drivers, uncertainties The relative contribution of different phytoplankton taxa to global plankton biomass is likely crucial for ecosystem services related to biogeochemical cycling, ecosystem productivity and the dynamics of higher trophic levels. Yet, the drivers of phytoplankton biomass dynamics are currently not particularly well understood, as bottom-up, top-down and competition effects influence global phytoplankton biogeography. Here, we attempt to understand the drivers of phytoplankton community composition in the pelagic ocean on the monthly, seasonal and annual scale. We extrapolate phytoplankton biomass estimates from the MARine Ecosystem DATa (MAREDAT) project to the global scale using statistical relationships between taxon-specific biomass and environmental predictor variables such as nutrient concentrations, light levels, sea surface temperature, or other plankton taxa. We discuss the spatiotemporal variability of global open ocean phytoplankton biomass for several major phytoplankton taxa, with a particular focus on diatoms and coccolithophores. Competition between diatoms and coccolithophores is an important driver for coccolithophore biomass dynamics, as indicated by the high diagnostic power of silicate in the coccolithophore model, and an inverse relationship between diatom and coccolithophore biomass. We estimate diatoms to contribute roughly 10-15%, and coccolithophores 0.3-0.6% to global carbon biomass within the mixed layer. The comparison of abundance-based with pigment-derived biomass estimates can serve as an indicator for the current uncertainty associated with these new estimates of the relative contribution of different phytoplankton taxa to total phytoplankton biomass.

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Venue information

Coming to Villefranche Travelling by plane The nearest airport is Nice; it then takes about 1 h to get to Villefranche via public transport or 40 min by cab. To come by bus from the Airport, take the bus 98 (6€) till "Promenade des Arts" then bus 81 (1,50€) from "Promenade des Arts" or bus 100 (1,50€) from "Nice Port" and go off at "Saint-Estève" in Villefranche. You can also take the airport shuttle and walk to Nice Saint-Augustin train station. Then take a train to Villefranche sur mer (you may need to change at Nice-Ville train station). The train ticket from Nice-Saint-Augustin to Villefranche-sur-mer costs 2,80€. By cab, the fare should be around 50€. Travelling by train The TGV stops in Nice. Travel by local train to Villefranche-sur-Mer takes ~15 min. Walking from the Villefranche train station to OOV takes 25 min, on a small path along the sea (from the train station, go down to the sea, then turn right and follow the water until you reach the Observatory). From Nice Two bus lines (81 and 100) connect Nice to Villefranche each 15 min and this takes ~15 min. Your can also join Villefranche from Nice by train. Observatoire Océanologique de Villefranche sur mer (UPMC/CNRS) The meeting will be held at the Observatoire Océanologique de Villefranche sur mer (OOV), 181 chemin du Lazaret, 06230 Villefranche sur mer, France.

• Oral sessions and working groups will take place in the "Galériens" building (main building, see #2 on map) in the Trégouboff room (1st floor).

• Final discussions of the last day of the workshop will take place in the "Jean Maetz" building (see #3 on map) in the Jean Maetz conference room (1st floor).

• The cantine hall for lunch is located in the "Corderine building" (see #1 on map). • The early career researchers who have obtained a travel grant will be accommodated

in the Galériens building. Map of the campus of the Observatoire Océanologique de Villefranche sur mer (UPMC/CNRS), at the Darse harbor.

Locate the Observatoire Google Maps from the workshop web page: plankdiv.obs-vlfr.fr

3: Jean Maetz

1: Corderie 2: Galériens

Documents

Program and abstracts V2 - Euromarine Network...Nakov Teofil University of Arkansas, USA [email protected] Not Fabrice CNRS, Roscoff, France [email protected] Olivier Marion UPMC,