References of "Lepoint, Gilles"
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See detailFactors that influence trace element levels in blood and feathers of Pygoscelis penguins from South Shetland Islands, Antarctica
Padilha, J. A.; Carvalho, G. O.; Espejo, W. et al

in Environmental Pollution (2021), 284

Contaminant levels are lower in Antarctica than elsewhere in the world because of its low anthropogenic activities. However, the northern region of the Antarctic Peninsula, is close to South America and ... [more ▼]

Contaminant levels are lower in Antarctica than elsewhere in the world because of its low anthropogenic activities. However, the northern region of the Antarctic Peninsula, is close to South America and experiences the greatest anthropogenic pressure in Antarctica. Here, we investigated, in two Antarctic Peninsula islands, intra and interspecific factors that influence the concentrations of 17 trace elements (TEs) in blood and feathers of three penguin species breeding sympatrically in relation to their trophic ecology assessed via a stable isotopic approach (C, N and S). Geographical location, foraging zone (δ13C and δ34S) and diet influences the interspecific difference, and sex and maturity stage diet influence the intraspecific difference of Pygoscelis penguins. Penguins from Livingston showed higher values (mean, ng. g−1, dry weight - dw) of Zn (103), Mn (0.3), and Fe (95) than those from King George Island (Zn: 80, Mn: 1.9, and Fe: 11). Gender-related differences were observed, as males showed significantly higher values (mean, ng. g−1, dw) of Rb (3.4) and δ15N in blood of gentoo, and Ca (1344) in Adélie feathers. Chicks of gentoo and Adélie presented higher Zn, Mg, Ca, and Sr and lower 13C values in blood than adults. The highest concentrations (mean, ng. g−1, dw) of Cd (0.2) and Cu (26), and the lowest δ15N values were found in chinstrap. Geographical, intraspecific (i.e., ontogenetic and gender-related) and interspecific differences in feeding seemed to have influenced TE and stable isotope values in these animals. The TE bioaccumulation by penguins may have also been influenced by natural enrichment in environmental levels of these elements, which seems to be the case for Fe, Zn, and Mn. However, the high level of some of the TEs (Mn, Cd, and Cr) may reflect the increase of local and global human activities. [less ▲]

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See detailFactors affecting mercury concentrations in two oceanic cephalopods of commercial interest from the southern Caribbean
Barcia, Laura Garcia; Pinzone, Marianna ULiege; Lepoint, Gilles ULiege et al

in Marine Pollution Bulletin (2021), 168

Mercury (Hg) concentrations have significantly increased in oceans during the last century. This element accumulates in marine fauna and can reach toxic levels. Seafood consumption is the main pathway of ... [more ▼]

Mercury (Hg) concentrations have significantly increased in oceans during the last century. This element accumulates in marine fauna and can reach toxic levels. Seafood consumption is the main pathway of methylmercury (MeHg) toxicity in humans. Here, we analyzed total Hg (T-Hg) concentrations in two oceanic squid species (Ommastrephes bartramii and Thysanoteuthis rhombus) of an increasing commercial interest off Martinique, French West Indies. Stable isotope ratios reveal a negative linear relationship between δ15N or δ13C in diamondback squid samples. No significant trend was observed between δ34S values and T-Hg concentrations, contrasting with the sulfate availability and sulfide abundance hypotheses. This adds to a growing body of evidence suggesting Hg methylation via sulfate-reducing bacteria is not the main mechanism driving Hg bioavailability in mesopelagic organisms. All squid samples present T-Hg levels below the maximum safe consumption limit (0.5 ppm), deeming the establishment of a commercial squid fishery in the region safe for human consumption. [less ▲]

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See detailVariability of amphidromous organism isotopic niches in three Guadeloupe rivers affected by damming and water catchment
Frotté, Lou; Michel, Loïc ULiege; Lepoint, Gilles ULiege et al

in Belgian Journal of Zoology (2021), 151(1),

Native fauna of the tropical volcanic part of Guadeloupe is amphidromous: juveniles born in rivers but that grow in the sea need to migrate upstream to colonise their adult habitat in rivers. This ... [more ▼]

Native fauna of the tropical volcanic part of Guadeloupe is amphidromous: juveniles born in rivers but that grow in the sea need to migrate upstream to colonise their adult habitat in rivers. This migration is affected by any human-made obstacles placed in their way. Moreover, on volcanic tropical islands, streams are the main source of water catchment for the human population. This deeply affects river hydrology and characteristics. Both damming and water catchment potentially affect community diversity and species demography, but they may also alter the trophic ecology of the river fauna. Using stable isotopes and the stable isotope Bayesian ellipses approach in R (SIBER), this study aimed to assess the isotopic niche variability of riverine fauna of three persistent small rivers of Basse-Terre Island (Guadeloupe) affected by damming and water catchment. Using electrofishing, decapods and fishes (gobies) of three rivers were sampled upstream and downstream of dams. Our results demonstrated that the variability of the isotopic niches was extremely high between rivers but varied less between stations of the same river. Our results revealed complex and river-specific effects and a pattern merged with natural variability. Our two hypotheses (i.e., increase of resources upstream of dams and differential responses of trophic guilds to damming and water catchment) were only weakly supported and never in an unambiguous manner. Our study showed that it is necessary to consider the ‘noise’ generated by natural variability to observe and understand changes in the trophic ecology of associated fauna in relation to damming and water catchment. [less ▲]

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See detailFood web structure in a rapidly changing coastal environment: the West Antarctic Peninsula
Voisin, Anthony; Lepoint, Gilles ULiege; Danis, Bruno et al

Conference (2021, May 19)

The West Antarctic Peninsula (WAP) is one of the most rapidly changing regions in the world, in great part due to anthropogenic climate change. Steep environmental gradients in water temperature, sea ice ... [more ▼]

The West Antarctic Peninsula (WAP) is one of the most rapidly changing regions in the world, in great part due to anthropogenic climate change. Steep environmental gradients in water temperature, sea ice cover and glacier melting influence are observed, but much is left to document about significance of those shifts for biological communities and ecosystem processes. Here, we aimed to study how environmental changes impact trophic interactions and ecological habits of benthic communities along the WAP. During the Belgica 121 expedition, dominant benthic mega- and macrofauna, as well as primary producers, were sampled in multiple stations featuring contrasted environmental conditions around the Gerlache Strait. Stable isotope ratios of δ 13C, δ15N and δ34S were measured and combined in an isotope niche analysis (SIBER). Our results suggest that changes in environmental features, notably ice disturbance, could cause alteration of food sources availability and fluxes to benthic organisms. Isotopic compositions of abundant species were more variable in stations with stronger ice disturbance. Besides baseline variability, this could be linked with use of alternative resources (niche expansion) in stations influenced by glacier melting. Those results provide a first step towards understanding links between environmental change and ecological responses of benthic consumers along the WAP. [less ▲]

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See detailTrophic ecology of macrofauna inhabiting seagrass litter accumulations is related to the pulses of dead leaves
Remy, François ULiege; Michel, Loïc ULiege; Mascart, Thibaud ULiege et al

in Estuarine, Coastal and Shelf Science (2021), 252

Accumulation of exported macrophytodetritus (AEM) represent unique habitats formed by the dead material originating from macrophyte ecosystems (e.g., seagrass, kelp, other seaweeds). AEM can be found ... [more ▼]

Accumulation of exported macrophytodetritus (AEM) represent unique habitats formed by the dead material originating from macrophyte ecosystems (e.g., seagrass, kelp, other seaweeds). AEM can be found everywhere, from the littoral zone to the deepest canyons, and from high to low latitudes. Seagrass AEMs are among the most common detrital accumulations found in marine environments, and sometimes include macroalgae wrack that has been ripped from the substrate. In the Mediterranean Sea, Posidonia oceanica (L.) Delile litter accumulations undergo pulses of new necromass all year, particularly in autumn, when dead leaves are shed. Here, macrofauna inhabiting AEM of Calvi Bay (Corsica, France) was sampled troughout an annual cycle (four seasons). By combining gut content examination and stable isotope analysis, we aimed to assess the effect of seasonal litter pulses on the trophic ecology of the dominant macrofauna species. Litter composition showed drastic variations throughout the sampling period, with the highest leaf litter quantity and contribution to AEMs in November. Dominant detritivores, herbivores, and omnivores responded positively to this increase by ingesting more seagrass material. A Bayesian stable isotope mixing model showed that the assimilation of carbon originating from seagrasses also increased. Additionally, isotopic niche modelling showed that consumer niches shifted towards seagrass isotopic composition in November. Predators did not shift their diet, but their isotopic composition was affected by the isotopic shift of their prey, demonstrating the transfer of seagrass carbon to higher trophic levels and the shift towards dead leaf material in the entire community. This response was, therefore, a rapid (days to weeks) parallel to that of the slow (months to years) decomposition of detrital material via physical alteration and microbial decomposition. This seemingly underestimated transfer route should be better characterised to understand the role of these seagrass beds in carbon sequestration in the marine environment. [less ▲]

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See detailStable isotope ratios of C and N in diadromous fauna from Guadeloupe, French West Indies in 2017. Marine Data Archive.
Frotté, Lou; Michel, Loïc ULiege; Lepoint, Gilles ULiege et al

Textual, factual or bibliographical database (2021)

Measurements of trophic markers performed in diadromous fauna from Guadeloupe. more This dataset contains measurements of stable isotope ratios of carbon and nitrogen made in 580 samples of diadromous ... [more ▼]

Measurements of trophic markers performed in diadromous fauna from Guadeloupe. more This dataset contains measurements of stable isotope ratios of carbon and nitrogen made in 580 samples of diadromous fauna (459 individual specimens belonging to 14 taxa) and their food items (121 samples of drifting particulate organic matter, leaf litter or biofilm). Samples were taken in 3 rivers of Guadeloupe (French West Indies) between February and May 2017. In each river, 3 stations were sampled: one upstream from a water extraction dam, one downstream from each dam, and one at the mouth of the river. Analytical measurements were performed at University of Liège (Belgium)’s stable isotope facility (Laboratory of Oceanology, Stable Isotope in Environmental Sciences and Trophic Ecology workgroup, https://www.oceanobio.uliege.be/). More info about the studies and sample preparation can be found in the publication referenced below. The dataset consists of two files: one containing the data itself, and one describing all used terms (measurements or metadata, derived from Darwin Core standards, https://dwc.tdwg.org/terms/). [less ▲]

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See detailStable isotope ratios of C, N and S in Southern Ocean sea stars (1985-2017). v1.2. Antarctic Biodiversity Information Facility (ANTABIF). Dataset/Occurrence.
Le Bourg, Baptiste; Moreau, Camille; Danis, Bruno et al

Textual, factual or bibliographical database (2021)

This dataset is a compilation of stable isotope ratios of C, N and S in tissues of 2456 sea stars sampled from 1985 to 2017 in the Southern Ocean (Antarctica and Subantarctic Islands). Stable isotope ... [more ▼]

This dataset is a compilation of stable isotope ratios of C, N and S in tissues of 2456 sea stars sampled from 1985 to 2017 in the Southern Ocean (Antarctica and Subantarctic Islands). Stable isotope values were measured in the framework of Baptiste Le Bourg's PhD thesis at University of Liège, entitled “Trophic ecology of Southern Ocean sea stars: Influence of environmental drivers on trophic diversity”. Samples were provided by the University of Liège (Belgium), the Université Libre de Bruxelles (Belgium), the National Museum of Natural History (Paris, France) and the Institute of Oceanology of the Polish Academy of Sciences (Sopot, Poland). This work was supported by BELSPO through the vERSO and RECTO projects (contracts no. BR/132/A1/vERSO and BR/154/A1/RECTO). [less ▲]

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See detailStable isotope ratios of C and N in benthic macrofauna from Mediterranean seagrass litter accumulations from Calvi Bay in 2011-2012
Michel, Loïc ULiege; Remy, François ULiege; Mascart, Thibaud ULiege et al

Textual, factual or bibliographical database (2021)

Measurements of trophic markers performed in benthic macrofauna sampled in seagrass litter accumulations from Calvi Bay (Corsica, France) in 2011-2012. more This dataset contains measurements of stable ... [more ▼]

Measurements of trophic markers performed in benthic macrofauna sampled in seagrass litter accumulations from Calvi Bay (Corsica, France) in 2011-2012. more This dataset contains measurements of stable isotope ratios of carbon and nitrogen made in 568 individual specimens of 19 different taxa of benthic macrofauna (Nemertea, Mollusca, Polychaeta, Crustacea, Actinopterygii). Samples were taken in submerged seagrass litter accumulations, seasonally in 2011-2012, and at two sites of Calvi Bay (Corsica, France). Analytical measurements were performed at University of Liège (Belgium)’s stable isotope facility (Laboratory of Oceanology, Stable Isotope in Environmental Sciences and Trophic Ecology workgroup, https://www.oceanobio.uliege.be/). More info about the studies and sample preparation can be found in the publications referenced below. The dataset consists of two files: one containing the data itself, and one describing all used terms (measurements or metadata, derived from Darwin Core standards, https://dwc.tdwg.org/terms/). Publications based on this data set: Remy, F. (2016). Characterization, dynamics and trophic ecology of macrofauna associated to seagrass macrophytodetritus accumulations (Calvi Bay, Mediterranean Sea). PhD Thesis. University of Liège: Liège. xi, 285 pp. + Remy, F. et al. (2018). Seagrass organic matter transfer in Posidonia oceanica macrophytodetritus accumulations. Est., Coast. and Shelf Sci. 212: 73-79. https://hdl.handle.net/10.1016/j.ecss.2018.07.001 + Remy et al. 2021 Trophic ecology of macrofauna inhabiting seagrass litter accumulations is related to the pulses of dead leaves. ECSS in press [less ▲]

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See detailProgenesis as an intrinsic factor of ecological opportunity in a polyphenic amphibian
Lejeune, Benjamin ULiege; Bissey, Lucie; Didaskalou, Emilie et al

in Functional Ecology (2021), 35(2), 546-560

1. Paedomorphosis, a developmental heterochrony involving the retention of larval traits at the adult stage, is considered a major evolutionary process because it can generate phenotypic variation without ... [more ▼]

1. Paedomorphosis, a developmental heterochrony involving the retention of larval traits at the adult stage, is considered a major evolutionary process because it can generate phenotypic variation without requiring genetic modifications. Two main processes underlie paedomorphosis: neoteny, a slowdown of somatic development, and progenesis, a precocious maturation associated to body size reduction. Being essentially a truncation of ontogeny, progenesis has often been deemed an evolutionary dead-end with advantages attributed to precocious reproduction or small body size required in specific environmental contexts (e.g. parasitism, interstitial life), but there is a lack of studies on the immediate ecological consequences of progenesis. 2. Because body size is a key factor determining trophic ecology in animals, we hypothesized that progenesis might intrinsically promote ecological opportunity via body size reduction (i.e. ‘the trophic advantage of progenesis’ hypothesis). We tested this hypothesis in facultatively progenetic palmate newts (Lissotriton helveticus) using stable isotope niche modelling and diet reconstruction in conjunction with traditional stomach content analyses and body condition assessment. 3. We show that not only did progenetic individuals occupy a different trophic niche than metamorphic individuals in all populations, but the smaller they were compared to metamorphs due to progenesis, the more different they were in terms of trophic ecology, with no negative effect on their body condition. 4. Altogether, the results suggest that via body size reduction, progenesis may generally act as an intrinsic factor of ecological opportunity, allowing the use of existing but previously unavailable resources, even in habitats where seemingly little opportunity exists. We argue that beyond the classically recognized fitness advantages of progenetic development, this process may also generally bring an immediate trophic advantage via body size reduction, which would have important implications to understand the evolution and adaptiveness of this process in many different taxa, from marine meiofauna to primates. [less ▲]

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See detailLate Holocene Paleonvironmental Evolution of Two Coastal Lakes in Mediterranean Chile and Its Implications for Conservation Planning
Montes, Isis-Yelena; Banegas-Medina, Andy; Fagel, Nathalie ULiege et al

in Applied Sciences (2021), 11(8),

Paleolimnological reconstructions from the mid and high latitudes in the Southern Hemisphere are still relatively scarce. Anthropogenic impacts have evidenced trophic state changes and an increase in ... [more ▼]

Paleolimnological reconstructions from the mid and high latitudes in the Southern Hemisphere are still relatively scarce. Anthropogenic impacts have evidenced trophic state changes and an increase in cyanobacterial blooms in the lacustrine system of San Pedro de la Paz in the last decades. Here, we reconstructed primary production and sedimentological changes spanning the past 2500 years in two coastal lakes in Mediterranean Chile. A multiproxy approach including sedimentological, biogenic silica, carbon and nitrogen isotopes and fossil pigments analysis in sediment cores was performed in Laguna Grande (LGSP) and Laguna Chica de San Pedro (LCSP). A marked change in the sedimentology of the lakes, likely related to the terrigenous sediment inputs derived by a transition from an arid condition in the mid-Holocene to a more humid condition in the late Holocene that favoured arboreal forest establishment at 100 BC–AD 150. A period of low primary production was identified between 850 to 1050 AC for LCSP, suggesting moist and cold conditions that were possibly related to La Niña events. In recent decades, there have been increases in primary production, probably resulting from anthropogenic disturbances. These likely include the clearance of native vegetation, the introduction of exotic tree species, and urbanisation, which in turn, resulted in nutrient inputs and hence eutrophication. We conclude that an integrated management program for both lakes is urgently needed. [less ▲]

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See detailDiscriminating the impact of Na+ and Cl− in the deleterious effects of salt stress on the African rice species (Oryza glaberrima Steud.)
Prodjinoto, Hermann; Irakoze, Willy; Gandonou, Christophe et al

in Plant Growth Regulation (2021)

Salinity resistance of the African rice species (Oryza glaberrima) is poorly documented and the specific responses of the plant to Na+ and Cl− toxic ions remain unknown. Cultivars TOG5307 and TOG5949 were ... [more ▼]

Salinity resistance of the African rice species (Oryza glaberrima) is poorly documented and the specific responses of the plant to Na+ and Cl− toxic ions remain unknown. Cultivars TOG5307 and TOG5949 were maintained for 15 days on iso-osmotic nutrient solutions containing 50 mM NaCl, or a combination of Cl− salts (Cl−-dominant) or Na+ salts (Na+-dominant). Plant water status, ion accumulation, gas exchange, fluorescence related parameters, carbon (δ13C) and nitrogen (δ15N) isotope ratios were analyzed. TOG5307 accumulated lower amounts of Na+ and Cl− in the shoot (1.63 and 1.49 µmol g−1 DW, respectively) than TOG 5949 (2.5 and 2.2 µmol g−1 DW). At 50 mM NaCl, TOG5307 also exhibited a higher net carbon assimilation rate (2.51 µmol CO2 m−2 s−1) than TOG5949 (1.51 µmol m−2 s−1) and a higher water use efficiency. Most recorded physiological parameters were affected by both Na+ and Cl−. The pattern of modification induced by both types of toxicities was similar in the two studied cultivars which thus mainly differ for the quantitative aspects of the response rather than for the qualitative nature of the response. NaCl was the most detrimental treatment, followed by Na+-dominant treatment while Cl−-treatment had the lowest effect. The two considered cultivars mainly differ for their response to the ionic component of salt stress but not for their osmotic behaviour. The impact of Na+ and Cl− on considered parameters are additive, except for mineral nutrition where synergistic interactions were recorded for Na+ and S accumulation. [less ▲]

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See detailHabitat and resource segregation of two sympatric seals in the North Sea
Damseaux, France ULiege; Siebert, Ursula; Pomeroy, Patrick et al

in Science of the Total Environment (2021), 764

In the North Sea, sympatric grey and harbour seals may compete for food resources impacted by intense fishing activities and a recent increase of seal populations. In order to reduce inter-specific ... [more ▼]

In the North Sea, sympatric grey and harbour seals may compete for food resources impacted by intense fishing activities and a recent increase of seal populations. In order to reduce inter-specific competition, sympatric species must segregate at least one aspect of their ecological niches: temporal, spatial or resource segregation. Using isotopes and Se and Hg concentrations, the foraging resources of grey seals and harbour seals and the potential competition between these species in the North Sea was studied. δ13C, δ15N and δ34S values were combined with the concentrations of Hg and Se in blood samples of harbour and grey seals from the North Sea. Blood samples were collected on 45 grey seals and 37 harbour seals sampled along German and Scottish coasts. This multi-tracer approach showed spatial and resource partitioning within grey and harbour seals. Data indicated the offshore foraging distribution of grey seals as reflected by the lower δ15N values and T-Hg concentrations and higher Se concentrations, and the inshore foraging distribution of harbour seals because of higher δ15N values and T-Hg concentrations and lower Se concentrations. The SIAR mixing model revealed a more selective diet of grey seals compared to harbour seals, and the importance of sandeels in grey seal diet reflected by their high δ34S values. Lastly, diet ellipse overlaps between grey seals and harbour seals sampled along the German coasts suggested a potential sharing of food resources, possibly due to the increase number of grey seals number in this area during the foraging season - all year except breeding and moulting periods. The multi-tracer approach provided a more robust discrimination among diet resources and spatial foraging distributions of grey seals and harbour seals in the North Sea. [less ▲]

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See detailBioaccumulation of Per- and polyfluoroalkyl substances (PFASs) in a tropical estuarine food web
Miranda, Daniele A.; Benskin, Jonathan P.; Awad, Raed et al

in Science of The Total Environment (2021), 754

The biomagnification of per- and polyfluoroalkyl substances (PFASs) was investigated in a tropical mangrove food web from an estuary in Bahia, Brazil. Samples of 44 organisms (21 taxa), along with biofilm ... [more ▼]

The biomagnification of per- and polyfluoroalkyl substances (PFASs) was investigated in a tropical mangrove food web from an estuary in Bahia, Brazil. Samples of 44 organisms (21 taxa), along with biofilm, leaves, sediment and suspended particulate matter were analyzed. Sum (∑) PFAS concentrations in biota samples were dominated by perfluorooctane sulfonate (PFOS, 93% detection frequency in tissues; 0.05 to 1.97 ng g−1 ww whole-body (wb)), followed by perfluorotridecanoate (PFTrDA, 57%; 0.01 to 0.28 ng g−1 ww wb). PFOS precursors such as perfluorooctane sulfonamide (FOSA, 54%; 0.01 to 0.32 ng g−1 ww wb) and N-ethyl perfluorooctane sulfonamide (EtFOSA; 30%; 0.01 to 0.21 ng g−1 ww wb) were also detected. PFAS accumulation profiles revealed different routes of exposure among bivalve, crustacean and fish groups. Statistics for left-censored data were used in order to minimize bias on trophic magnification factors (TMFs) calculations. TMFs >1 were observed for PFOS (linear + branched isomers), EtFOSA (linear + branched isomers), and perfluorononanoate (PFNA), and in all cases, dissimilar accumulation patterns were observed among different trophic positions. The apparent biodilution of some long-chain PFCAs through the food chain (TMF < 1) may be due to exposure from multiple PFAS sources. This is the first study investigating bioaccumulation of PFASs in a tropical food web and provides new insight on the behavior of this ubiquitous class of contaminants. [less ▲]

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See detailDeepIso - a global open database of stable isotope ratios and elemental contents for deep-sea ecosystems.
Michel, Loïc ULiege; Bell, James; Dubois, Stanislas et al

Textual, factual or bibliographical database (2020)

The use of stable isotopes as ecological tracers in deep-sea ecosystems has a long history, dating back to the late 1970’s. Stable isotopes have been instrumental to many key-findings about ecosystem ... [more ▼]

The use of stable isotopes as ecological tracers in deep-sea ecosystems has a long history, dating back to the late 1970’s. Stable isotopes have been instrumental to many key-findings about ecosystem functioning, particularly in chemosynthesis-based habitats (hydrothermal vents, cold seeps). However, constraining sampling logistics commonly limit the scope, extent, and therefore insights drawn from isotope-based deep-sea studies. Overall, much is left to discover about factors globally influencing food web structure in deep-sea ecosystems. In this context, deep-sea ecologists have to ensure that no sample is left unexploited, and that all generated data are easily discoverable, available and reusable. DeepIso is a collaborative effort to produce a global compilation of stable isotope ratios and elemental contents in organisms from deep-sea ecosystems. In doing so, it aims to provide the deep-sea community with an open data analysis tool that can be used in the context of future ecological research, and to help deep-sea researchers to use stable isotope markers at their full efficiency. More info about the project can be found at https://loicnmichel.com/deepiso/ As of v1 (2020/10/22), the database contains 15 distinct datasets, for a total of 18677 fully documented measurements. Archived parameters currently include δ13C (n = 4587), δ15N (n = 4388), δ34S (n = 951), %C (n = 2740), %N (n = 2741), %S (n = 752) and C/N ratio (n = 2518). Those measurements pertain to 4378 distinct samples belonging to 493 taxa, plus sediments, suspended particulate organic matter, plankton and detritus. Samples were taken between 1989 and 2018 in multiple environments (hydrothermal vents, cold seeps, cold water coral reefs, and other benthic or pelagic environments) and at depths ranging up to 5209 meters. The database consists of three files: one containing the data itself, one describing all used terms (measurements or metadata, derived from Darwin Core standards, https://dwc.tdwg.org/terms/), and a changelog detailing changes made between successive versions. [less ▲]

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See detailHow the Genus Eusirus amphipods evolved and speciated in the Antarctic
Salabao, Louraine ULiege; Frederich, Michel ULiege; Lepoint, Gilles ULiege et al

Conference (2020, August)

Antarctica has been subjected to different climatic changes in the past requiring the marine fauna to either adapt to novel environmental conditions, migrate to better conditions or become extinct ... [more ▼]

Antarctica has been subjected to different climatic changes in the past requiring the marine fauna to either adapt to novel environmental conditions, migrate to better conditions or become extinct. Currently, warming of Antarctica is happening at an unprecedented rate. Understanding how these organisms have managed to survive in the past will thus allow us to predict their possible responses to future climate changes. Here, the amphipod Genus Eusirus will be used as model organisms since these amphipods are very diverse and knowledge on their ecology and biogeography is still very limited. In this study, molecular, morphological and ecological data of Eusirus will be collected. Because no reference genome exists for this group, we will use a Next generation sequencing approach to obtain the complete mitochondrial genome (mitogenome) of these amphipods. Draft mitogenomes have been assembled and annotated from skim sequencing for two Eusirus species. From these mitogenomes, we designed primers for long-range PCRs to amplify the entire mitogenome in several pieces. Complete mitogenomes will allow us to estimate genetic divergence amongst different species and check for specific temperature adaptations of mitochondrial genes. The obtained mitogenome data will also provide better supported phylogenies for reconstructing evolutionary history of Eusirus. In order to get a better understanding of adaptive and/or non-adaptive processes which led to the current diversity of Eusirus amphipods, we will explore how morphological and ecological diversity are partitioned along the resulting phylogeny, concurrently with potential changes in lineage diversification through time. [less ▲]

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See detailTemporal trends of legacy organochlorines in different white-tailed eagle (Haliaeetus albicilla) subpopulations: A retrospective investigation using archived feathers
Sun, Jiachen; Covaci, Adrian; Bustnes, Jan Ove et al

in Environment International (2020), 138

Understanding the spatiotemporal patterns of legacy organochlorines (OCs) is often difficult because monitoring practices differ among studies, fragmented study periods, and unaccounted confounding by ... [more ▼]

Understanding the spatiotemporal patterns of legacy organochlorines (OCs) is often difficult because monitoring practices differ among studies, fragmented study periods, and unaccounted confounding by ecological variables. We therefore reconstructed long-term (1939–2015) and large-scale (West Greenland, Norway, and central Sweden) trends of major legacy OCs using white-tailed eagle (Haliaeetus albicilla) body feathers, to understand the exposure dynamics in regions with different contamination sources and concentrations, as well as the effectiveness of legislations. We included dietary proxies (δ13C and δ15N) in temporal trend models to control for potential dietary plasticity. Consistent with the hypothesised high local pollution sources, levels of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethanes (DDTs) and hexachlorocyclohexanes (HCHs) in the Swedish subpopulation exceeded those in the other subpopulations. In contrast, chlordanes (CHLs) and hexachlorobenzene (HCB) showed higher concentrations in Greenland, suggesting the importance of long-range transport. The models showed significantly decreasing trends for all OCs in Sweden in 1968–2011 except for CHLs, which only decreased since the 1980s. Nevertheless, median concentrations of DDTs and PCBs remained elevated in the Swedish subpopulation throughout the 1970s, suggesting that the decreases only commenced after the implementation of regulations during the 1970s. We observed significant trends of increasing concentrations of PCBs, CHLs and HCB in Norway from the 1930s to the 1970s/1980s and decreasing concentrations thereafter. All OC concentrations, except those of PCBs were generally significantly decreasing in the Greenland subpopulation in 1985-2013. All three subpopulations showed generally increasing proportions of the more persistent compounds (CB 153, p.p′-DDE and β-HCH) and decreasing proportions of the less persistent ones (CB 52, p.p′-DDT, α- and γ-HCH). Declining trends of OC concentrations may imply the decreasing influence of legacy OCs in these subpopulations. Finally, our results demonstrate the usefulness of archived museum feathers in retrospective monitoring of spatiotemporal trends of legacy OCs using birds of prey as sentinels. [less ▲]

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See detailA 15-Month Survey of Dimethylsulfoniopropionate and Dimethylsulfoxide Content in Posidonia oceanica
Richir, Jonathan ULiege; Champenois, Willy ULiege; Engels, Guyliann et al

in Frontiers in Ecology and Evolution (2020), 7(510), 1-15

Posidonia oceanica is the only reported seagrass to produce significant amount of dimethylsulfoniopropionate (DMSP). It is also the largest known producer of DMSP among coastal and inter-tidal higher ... [more ▼]

Posidonia oceanica is the only reported seagrass to produce significant amount of dimethylsulfoniopropionate (DMSP). It is also the largest known producer of DMSP among coastal and inter-tidal higher plants. Here, we studied (i) the weekly to seasonal variability and the depth variability of DMSP and its related compound dimethylsulfoxide (DMSO) in P. oceanica leaves of a non-disturbed meadow in Corsica, France, (ii) the weekly to seasonal variability and the depth variability of DMSP to DMSO concentration to assess the potential of the DMSP:DMSO ratio as indicator of stress, and (iii) the relationships between DMSP, DMSO, and the DMSP:DMSO ratio with potential explanatory variables such as light, temperature, photosynthetic activity (effective quantum yield of photosystem II), and leaf size. The overall average concentrations of organosulfured compounds in P. oceanica leaves were 130 ± 39 μmol.g−1fw for DMSP and 4.9 ± 2.1 μmol.g−1fw for DMSO. Concentrations of DMSP and DMSO in P. oceanica were overall distinctly higher and exhibited a wider range of variations than other marine primary producers such as Spartina alterniflora, phytoplankton communities, epilithic Cyanobacteria and macroalgae. Concentrations of both DMSP and DMSO in P. oceanica leaves decreased from a maximum in autumn to a minimum in summer; they changed little with depth. Potential explanatory variables except the leaf size, i.e., the leaf age were little or not related to measured concentrations. To explain the seasonal pattern of decreasing concentrations with leaf aging, we hypothesized two putative protection functions of DMSP in young leaves: antioxidant against reactive oxygen species and predator-deterrent. The similar variation of the two molecule concentrations over time and with depth suggested that DMSO content in P. oceanica leaves results from oxidation of DMSP. The DMSP:DMSO ratio remained constant around a mean value of 29.2 ± 9.0 μmol:μmol for the non-disturbed harvested meadow regardless of the time of the year, the depth or the leaf size. As suggested for the salt march plant S. alterniflora, we hypothesized the DMSP:DMSO ratio could be considered as indicator of stress in seagrasses exposed to environmental or anthropogenic stressors. More research would now be needed to confirm the functions of DMSP and DMSO in seagrasses and how the DMSP:DMSO ratio will vary under various disturbances. [less ▲]

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See detailEffects of preservation methodology on stable isotope compositions of sea stars
Le Bourg, Baptiste ULiege; Lepoint, Gilles ULiege; Michel, Loïc ULiege

in Rapid Communications in Mass Spectrometry (2020), 34(2), 8589

Rationale:Stable isotope analysis is used to investigate the trophic ecology of organisms and, in order to use samples from archived collections, and it is important to know whether preservation methods ... [more ▼]

Rationale:Stable isotope analysis is used to investigate the trophic ecology of organisms and, in order to use samples from archived collections, and it is important to know whether preservation methods alter the results. This study investigates the long-term effects of four preservation methods on sea stars isotopic composition and isotopic niche parameters.Methods:We assessed effects of preservation method (freezing, drying, formaldehyde, ethanol) and duration (0, 1, 3, 6, 9, 12 and 24 months) on the stable isotope ratios of carbon, nitrogen and sulfur of sea star tissues. Isotopic ratios were measured using CF-EA-IRMS. We also monitored the evolution ofcommonly used ecological metrics (isotopic niche parameters) throughout the experiment. Results:Clear changes of δ13C values were observed for samples stored in formaldehyde and ethanol. None of the preservation methods had significant or consistent effects on δ15Nvalues. Formaldehydeinduced a decrease of δ34S values. All these changes could be mitigated using correction factors.Isotopic niches parameters slightly changed over time when computed with δ13C and δ15N values, but inconsistent variations occurred when computed with δ13C and δ34S values.Conclusions: Overall, these results show that preservation may affect the stable isotope ratios of sea stars. Correction factors can be used to mitigate the effects of the preservation method on stable isotope ratios. Isotopic niches parameters are overall unchanged. Consequently, in most cases, museum samples are suitable to calculate isotopic niche parameters. [less ▲]

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See detailDeep-water Zostera marina meadows in the Mediterranean
Boutahar, Loubna; Espinosa, Free; Richir, Jonathan ULiege et al

in Aquatic Botany (2020), 166

In Morocco, Zostera marina Linnaeus has disappeared from many localities where it was historically reported. The only known remaining meadows along Mediterranean coasts of Morocco, though in North Africa ... [more ▼]

In Morocco, Zostera marina Linnaeus has disappeared from many localities where it was historically reported. The only known remaining meadows along Mediterranean coasts of Morocco, though in North Africa, are those of Belyounech bay and Oued El Mersa bay, in the marine area of ‘Jbel Moussa’. An in-depth knowledge of these meadows is required for their effective conservation purpose. The Z. marina meadows of Jbel Moussa are deep, the lower limit being 17 m depth with patches extending down to 20 m depth. Seagrass cover of Belyounech bay meadow is continuous whereas that of Oued El Mersa is fragmented. Shoot density and aboveground biomass are higher in Belyounech meadow, with 745 ± 183 shoots.m−2 and 273 ± 40 gDW. m−2 of leaf biomass. During the survey, trawling scars and the invasive algae Caulerpa cylindracea Sonder were observed. Bioavailable Ni, As, Mo, Ag, Cd, Sn, Sb and U measured in the sediment are mainly accumulated in Z. marina roots. Nitrogen level is high in seagrass leaves and low in the sediment. Conversely, sediment is more enriched in phosphorus. Carbon levels and its isotopic ratio value are respectively higher and less negative in leaves when compared to the seagrass belowground compartments. All together, data collected during this survey allows defining the overall good health status of Z. marina meadows of Jbel Moussa. These Moroccan meadows, localized within the warm temperate-southern limit of the species, are well developed compared to many places worldwide. The exceptional presence of deep Z. marina meadows in the Mediterranean requires the implementation of measures as a major priority to ensure the conservation of these ecosystems, since seagrasses are being deeply threatened worldwide. [less ▲]

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See detailTemporal succession of a macrofaunal community associated with kelp fragment accumulations in an in situ experiment
de Bettignies, F.; Dauby, Patrick ULiege; Lepoint, Gilles ULiege et al

in Marine Ecology. Progress Series (2020), 656

ABSTRACT: A large part of the production of <i>Laminaria hyperborea</i> kelp forests is not directly consumed by grazers, but is exported during storm events or natural annual blade erosion. Drifting kelp ... [more ▼]

ABSTRACT: A large part of the production of <i>Laminaria hyperborea</i> kelp forests is not directly consumed by grazers, but is exported during storm events or natural annual blade erosion. Drifting kelp fragments are transported and can accumulate temporarily over subtidal benthic habitats. The decay process is particularly slow (>6 mo for complete decay during spring-summer) and <i>L. hyperborea</i> fragments are able to maintain their primary production function for several months. If they accumulate in low subtidal habitats, fragments can have a long residence time, thus modifying habitat structure. Based on a 6 mo cage experiment, we investigated macrofaunal colonization and community succession within accumulations of <i>L. hyperborea</i> fragments on a low subtidal (-10 m) sandy bottom ecosystem. Stable isotope (δ<sup>13</sup>C and δ<sup>15</sup>N) measurements were carried out to describe the structure and development of the trophic food web and the role of detritus as a food source. Kelp tissues were rapidly and abundantly colonized by macrofauna, and a classical ecological succession occurred, with changes in species dominance and increase in diversity during decay. The food web was based on 2 main sources: particulate organic matter from the water column and decaying kelp tissues. Kelp contributed significantly to the diet of numerous species that are commonly consumed by local predators (fish, shrimp). Following community succession, diets diversified and the food web became more complex during the decay process. Our results indicate that drift kelp accumulations structure their associated communities and food web during the whole decay process. [less ▲]

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