References of "Michel, Loïc"
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See detailOccurrence of legacy and emerging organic pollutants in whitemouth croakers from Southeastern Brazil
Pizzochero da Costa, Ana Carolina ULiege; de la Torre, Adrian; Sanz, Paloma et al

in Science of the Total Environment (in press)

The whitemouth croaker (Micropogonias furnieri) is one of the most commercially important species along the Atlantic coast of South America. Moreover, some of its biological traits (long life span ... [more ▼]

The whitemouth croaker (Micropogonias furnieri) is one of the most commercially important species along the Atlantic coast of South America. Moreover, some of its biological traits (long life span, inshore feeding, high trophic position) make this species a suitable sentinel of coastal pollution. Here, we investigated contamination by multiple legacy and emerging organic pollutants, such as brominated and chlorinated flame retardants, polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), in whitemouth croakers from two estuaries (Guanabara and Sepetiba Bays) located in industrialized and urbanized areas in Rio de Janeiro State, Southeastern Brazil. Furthermore, we assessed how biological and ecological features could explain the observed contamination patterns. Regarding brominated flame retardants, concentrations of polybrominated diphenyl ethers (PBDEs) varied from 7.6 to 879.7 pg g-1 wet weight (w.w.), with high contribution of tetra-, penta-, hexa- and deca-BDEs. The sum of chlorinated flame retardants (dechlorane-related compounds, ΣDRC) ranged from <LOD to 41.1 pg g-1 w.w., mostly represented by Dechlorane 603 and Dechlorane Plus (DP). Concentrations of PCDDs and PCDFs varied from <LOD to 1.7 pg g-1 w.w., while the Toxic Equivalent (TEQ-PCDD/Fs) levels ranged from 0.1 to 0.2 pg g-1 w.w. Positive correlations between δ15N and concentrations of tri-, tetra- and penta-BDEs, as well as ΣDRC, DP and anti-DP isomers suggested that ecological factors (namely biomagnification along the food web) influence contamination of whitemouth croakers in the estuaries studied. Moreover, the sum of PBDEs (ΣPBDE), tri- and tetra-BDEs concentrations were negatively correlated with fish size, suggesting that depuration by fishes and/or habitat shift throughout the whitemouth croaker’s life cycle might also influence concentrations. Overall, our study emphasized the need for further investigations to help understand the complex patterns of bioaccumulation and biomagnification that seem to exist in Southeastern Brazil. [less ▲]

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See detailModelling species response to climate change in sub-Antarctic islands: echinoids as a case study for the Kerguelen Plateau
Saucède, Thomas; Guillaumot, Charlène; Michel, Loïc ULiege et al

in CCAMLR Science (in press)

In the Kerguelen Islands, the multiple effects of climate change are expected to impact coastal marine habitats. Species distribution models (SDM) can represent a convenient tool to predict the ... [more ▼]

In the Kerguelen Islands, the multiple effects of climate change are expected to impact coastal marine habitats. Species distribution models (SDM) can represent a convenient tool to predict the biogeographic response of species to climate change but biotic interactions are not considered in these models. Nevertheless, new species interactions can emerge in communities exposed to environmental changes and the structure of biotic interactions is directly related to the potential resilience of ecosystems. Trophic interaction studies can help predict species vulnerability to environmental changes using carbon (δ13C) and nitrogen (δ15N) stable isotope ratios to generate trophic models. Using new available data inputs, we generated robust SDM and trophic interaction models to assess the potential response and sensitivity of three echinoid species to future worst-case scenarios of environmental change in the Kerguelen Plateau region. The two modelling approaches provide contrasting insights into the potential responses of each species to future environmental changes with both approaches identifying Abatus cordatus to be particularly vulnerable due to its narrow ecological niche and endemism to near-shore areas. Coupling insights gained from trophic niche ecology with species distribution modelling represents a promising approach that can improve our understanding and ability to predict the potential responses of species to future habitat changes. [less ▲]

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See detailIs the trophic diversity of marine benthic consumers decoupled from taxonomic and functional trait diversity? Isotopic niches of Arctic communities
Włodarska-Kowalczuk, Maria; Aune, Magnus; Michel, Loïc ULiege et al

in Limnology and Oceanography (in press)

It is predicted that a diverse array of functional traits in species‐rich assemblages can lead to strong resource partitioning among coexisting species and moderate a wider spectrum of resource use. We ... [more ▼]

It is predicted that a diverse array of functional traits in species‐rich assemblages can lead to strong resource partitioning among coexisting species and moderate a wider spectrum of resource use. We compared two benthic communities in an Arctic fjord: a species‐rich community (in an outer basin) and an impoverished community (in a glacially impacted bay) and explored (1) if high species richness was translated into high functional trait richness and (2) if high taxonomic and functional diversity promoted high trophic diversity in terms of resource use (indicated by isotopic niche measures). We documented higher functional trait richness in the outer basin (computed based on traits describing feeding mode, mobility, food source, body size and life habit), but the area occupied by consumers in the δ15N vs. δ13C iso‐space (a proxy for total trophic resource use) did not differ between the two sites. A wide array of functional traits used to acquire food may extend the benthic community trophic niche spatially (where and how animals forage) without impacting the isotopic niche breadth (in this system, mostly reflecting “what animals feed on”) due to the relatively homogenous distribution of isotopic characteristics of detritus pool across vertical scales in marine sediments. Moreover, this trend could indicate that a species‐poor community tends to exploit all the available food items, possibly due to the low food availability for primary consumers in a glacially impacted environment. Communities in glacial bays could therefore be particularly sensitive to future changes in glacial inputs and associated organic matter fluxes. [less ▲]

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See detailIncreased sea ice cover alters food web structure in East Antarctica
Michel, Loïc ULiege; Danis, Bruno; Dubois, Philippe et al

in Scientific Reports (2019), 9

In recent years, sea ice cover along coasts of East Antarctica has tended to increase. To understand ecological implications of these environmental changes, we studied benthic food web structure on the ... [more ▼]

In recent years, sea ice cover along coasts of East Antarctica has tended to increase. To understand ecological implications of these environmental changes, we studied benthic food web structure on the coasts of Adélie Land during an event of unusually high sea ice cover (i.e. two successive austral summers without seasonal breakup). We used integrative trophic markers (stable isotope ratios of carbon, nitrogen and sulfur) to build ecological models and explored feeding habits of macroinvertebrates. In total, 28 taxa spanning most present animal groups and functional guilds were investigated. Our results indicate that the absence of seasonal sea ice breakup deeply influenced benthic food webs. Sympagic algae dominated the diet of many key consumers, and the trophic levels of invertebrates were low, suggesting omnivore consumers did not rely much on predation and/or scavenging. Our results provide insights about how Antarctic benthic consumers, which typically live in an extremely stable environment, might adapt their feeding habits in response to sudden changes in environmental conditions and trophic resource availability. They also show that local and/or global trends of sea ice increase in Antarctica have the potential to cause drastic changes in food web structure, and therefore to impact benthic communities. [less ▲]

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See detailEnvironmental drivers of sea stars feeding ecology in the Southern Ocean
Le Bourg, Baptiste ULiege; Blanchard, Alice; Danis, Bruno et al

Conference (2019, May 06)

The Antarctic continent and the surrounding Southern Ocean undergo strong and contrasted impacts of climate change. In the Western Antarctic Peninsula, sea ice cover and ice season duration are decreasing ... [more ▼]

The Antarctic continent and the surrounding Southern Ocean undergo strong and contrasted impacts of climate change. In the Western Antarctic Peninsula, sea ice cover and ice season duration are decreasing, presumably in relation with increased air and water temperature and northwesterly winds originating from the also warming subtropical Pacific. In contrast, despite increased air and deep water temperatures, sea ice cover and ice season duration are increasing in other Antarctic regions. This is possibly linked with ocean stratification due to freshwater inputs from the melting continental ice. These changes are likely to impact marine communities and food webs of the Southern Ocean. Sea stars (Echinoderms: Asteroidea) are an important group of the Southern Ocean benthos. Compared to other organisms, they seem to have relatively high physiological tolerance to warming. However, they could be indirectly affected by climate change, notably through quantitative and qualitative modifications of food availability. In this context, the aim of this study was to infer the trophic diversity of sea stars of the Southern Ocean to assess their potential trophic plasticity regarding food web changes. Thanks to collaborative networking and valorization of museum samples, Sea stars samples taken in summer in various regions around the Antarctic continent with different types of environment (Antarctic or Subantarctic, deep-sea or coastal, presence of sea ice or not) were obtained. Stable isotopes ratios of C (denoted δ13C) and N (denoted δ15N) were then analysed in the tegument of sea stars in order to investigate their trophic ecology. Isotopic niches metrics were also computed to assess differences of trophic diversity between regions. Variability in stable isotope ratios and isotopic niche metrics revealed strong differences in sea star feeding ecology between and within locations, possibly in relation with differences in environmental conditions, notably sea ice coverage and dynamics. For example, on the continental shelf of Antarctic South Shetland Islands, small isotopic niches could indicate that sea stars exploit a food web based on a common basal food source and exhibit a "trophic continuum". In this context, absence of sea ice before and during the sampling period could have limited the number of available food sources. By contrast, on the continental shelf of the Antarctic Marguerite Bay or in the Subantarctic South Georgia Island, sea stars had large isotopic niches that suggest that they could exploit one or several food webs based on more than one food source, and exhibited strong trophic segregation. In Marguerite Bay, this could be linked with progressive sea ice melting, which allows export of both sea ice materials and blooming phytoplankton to the benthic compartment. In South Georgia, on the other hand, oligotrophic conditions and thus reduced availability of phytoplankton are more likely to explain this pattern. Ultimately, this project helps us understanding which ecological processes determine how an ecologically important animal group copes with environmental modifications linked to climate change. This research was funded by the Belgian Federal Science Policy Office (BELSPO) in the framework of the vERSO  and RECTO project (rectoversoprojects.be). [less ▲]

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See detailRiver habitat homogenisation enhances trophic competition and promotes individual specialisation among young of the year fish
Latli, Adrien; Michel, Loïc ULiege; Lepoint, Gilles ULiege et al

in Freshwater Biology (2019), 64(3), 520-531

In large rivers, the success of ontogenic development of fish is mainly influenced by resource availability and by the possibility of species to adapt their diet (i.e. trophic niche). Human have ... [more ▼]

In large rivers, the success of ontogenic development of fish is mainly influenced by resource availability and by the possibility of species to adapt their diet (i.e. trophic niche). Human have drastically modified freshwater habitats, notably for navigation purposes. Such modifications may drastically affect food availability for young of the year (YOY) fish and, consequently, influence their ability to reach the adult age. In the River Meuse, a decrease of fish abundance is thought to be linked to a drastic decrease of phytoplankton biomass. In this context of lowering phytoplankton biomass, we quantified the trophic niches of three cyprinid species (common bleak Alburnus alburnus, chub Squalius cephalus, and roach Rutilus rutilus) and one percid species (European perch Perca fluviatilis) at various stages of development, in order to estimate the influence of river channelization in the intra and interspecific competitions. It was done using stable isotope analysis in two reaches of the River Meuse differing by their degree of regulation. We hypothesized that habitat heterogeneity increases YOY abundance over time by offering more alternative resources which reduce food competition, notably during the early period of life. Our study provides evidence that the River Meuse flow and depth regulation significantly impacted the abundance and taxonomic diversity of YOY. In the context of low planktonic biomass, most YOY relied on benthic food sources. In the heavily channelized reach, between-stages competition and low resource diversity increased the diet partition between cyprinid larvae and forced a part of individuals to consume non-optimal energetic food sources such as aquatic vegetation. On the other hand, in the less channelized reach, larvae displayed a generalist feeding habit focusing on energetic prey such as different taxa of macroinvertebrates, suggesting that the diversity of habitat reduces the food competition within and between stages and the predation risk. Developing a sustainable and integrated river management may be useful for protecting biodiversity and restoring ecosystem function, in order to improve the ecological potential of regulated rivers. [less ▲]

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See detailStabilizing effects of seagrass meadows on coastal water benthic food webs
Jankowska, Emilia; Michel, Loïc ULiege; Lepoint, Gilles ULiege et al

in Journal of Experimental Marine Biology and Ecology (2019), 510

Seagrass meadows ecosystem engineering effects are correlated to their density (which is in turn linked to seasonal cycles) and often cannot be perceived below a given threshold level of engineer density ... [more ▼]

Seagrass meadows ecosystem engineering effects are correlated to their density (which is in turn linked to seasonal cycles) and often cannot be perceived below a given threshold level of engineer density. The density and biomass of seagrass meadows (Z. marina) together with associated macrophytes undergo substantial seasonal changes, with clear declines in winter. The present study aims to test whether the seasonal changes in the density of recovering seagrass meadows affect the benthic food webs of the southern Baltic Sea (Puck Bay). It includes meiofauna, macrofauna and fish of vegetated and unvegetated habitats in summer and winter seasons. Two levels of organization have been tested – species-specific diet preferences using stable isotopes (δ13C, δ15N) in Bayesian mixing models (MixSIAR) and the community-scale food web characteristics by means of isotopic niches (SIBER). Between-habitat differences were observed for grazers, as a greater food source diversity in species from vegetated habitats was noted in both seasons. Larger between-habitat differences in winter were documented for suspension/detritus feeders. The community-wide approach showed that the differences between the habitats were greater in winter than in summer (as indicated by the lower overlap of the respective isotope niches). Overall, the presence of seagrass meadows increased ecological stability (in terms of the range of food sources utilized by consumers) in the faunal assemblage, while invertebrates from unvegetated areas shifted their diet to cope with winter conditions. Therefore, as a more complex system, not sensitive to seasonal changes, Z. marina meadows create a stable habitat with high resilience potential. [less ▲]

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See detailRefugia and ecosystem tolerance in the Southern Ocean
Schön, Isa; Christiansen, Henrik; Danis, Bruno et al

Poster (2018, December 15)

Confronted with fast-paced environmental changes, biota in Antarctic ecosystems are strongly challenged and face three possible outcomes: adaptation, migration or extinction. Past glaciation periods have ... [more ▼]

Confronted with fast-paced environmental changes, biota in Antarctic ecosystems are strongly challenged and face three possible outcomes: adaptation, migration or extinction. Past glaciation periods have already forced marine zoobenthos of the Southern Ocean (SO) into refugia, followed by recolonization when the ice retreated. The collaborative Belgian BRAIN project RECTO, “Refugia and ecosystem tolerance in the Southern Ocean”, will strive at understanding how such past events have driven diversification and adaptation in different animal groups and how these can be applied as proxies to understand the contemporary situation and predict future scenarios. With molecular approaches, RECTO will reconstruct population histories and spatio-temporal features of Pleistocene refugia. The RECTO target taxa include birds, fish, sea stars, bivalves, amphipods, and ostracods. For all RECTO target taxa, the following molecular data will be obtained: (1) mitochondrial COI barcodes, (2) ddRAD data, and (3) mitochondrial genomes. Mitochondrial genomes will be obtained by genome skimming, and long range PCRs. Mitogenomes can improve the unravelling of phylogeographic relationships and dating of evolutionary events and, through comparisons with non-Antarctic taxa, allow to detect cold adaptations. In fish and amphipods, RECTO will also study in a novel phylogenetic framework how morphological diversification and trophic adaptability (estimated by stable isotope data) are interacting with each other and whether ecotypes of selected species have faster modes of evolution. Geographic models on future species and trait distributions based on physiological and energy limits and present and future climate data will be refined and integrated with individual based models for the SO. Finally, scenarios of future dispersal abilities and possible habitat shifts of the RECTO target groups will be developed to infer how the RECTO target species will respond to future climate change. [less ▲]

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See detailRefugia and ecosystem tolerance in the Southern Ocean
Schön, Isa; Christiansen, Henrik; De Ridder, Chantal et al

Poster (2018, December 15)

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See detailFood web structure in deep-sea cold seeps: a case study from Western Africa
Michel, Loïc ULiege

Learning material (2018)

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See detailStable isotopes as descriptors of ecological niches
Michel, Loïc ULiege

Learning material (2018)

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See detailUsing stable isotopes to estimate trophic position
Michel, Loïc ULiege

Learning material (2018)

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See detailStable isotope mixing models
Michel, Loïc ULiege

Learning material (2018)

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See detailTowards a stable isotope database for deep-sea foundation species
Michel, Loïc ULiege; Dubois, Stanislas; Hayden, Brian et al

Poster (2018, November)

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See detailStable isotopes in marine lipid science
Schaal, Gauthier; Michel, Loïc ULiege

Conference (2018, November)

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See detailStructure of food webs supporting deep-sea cold seeps communities off West Africa is influenced by environmental parameters and biotic interactions
Michel, Loïc ULiege; Portail, Marie; Cowart, Dominique et al

Conference (2018, November)

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See detailEnvironmental conditions and biotic interactions influence hydrothermal fauna colonisation patterns at the Lucky Strike vent field (Mid-Atlantic Ridge)
Alfaro-Lucas, Joan; Foviaux, Martin; Michel, Loïc ULiege et al

Conference (2018, November)

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See detailTowards a stable isotope database for deep-sea foundation species
Michel, Loïc ULiege; Dubois, Stanislas; Hayden, Brian et al

Poster (2018, September)

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See detailNematode-prokaryote interactions in deep-sea hydrothermal vents
Zeppilli, Daniela; Bellec, Laure; Cueff-Gauchard, Valérie et al

Poster (2018, September)

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