References of "Lepoint, Gilles"
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See detail15th Benelux Congress of Zoology abstract book
Colleye, Orphal ULg; Dauby, Patrick ULg; Fabri, Gregory et al

Book published by Editions de l'université de Liège (2008)

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See detailCarbon dioxide dynamics in lake Kivu during the dry and wet seasons
Borges, Alberto ULg; Delille, Bruno ULg; Descy, J.-P. et al

Poster (2008, April)

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See detailDistribution of trace elements in organs of six species of cetaceans from the Ligurian Sea (Mediterranean), and the relationship with stable carbon and nitrogen ratios
Capelli, R.; Das, Krishna ULg; De Pellegrini, R. et al

in Science of the Total Environment (2008), 390

Mercury (total and organic), cadmium, lead, copper, iron, manganese, selenium and zinc concentrations were measured in different organs of 6 different cetacean species stranded in an area of extraordinary ... [more ▼]

Mercury (total and organic), cadmium, lead, copper, iron, manganese, selenium and zinc concentrations were measured in different organs of 6 different cetacean species stranded in an area of extraordinary ecological interest (Cetaceans’ Sanctuary of the Mediterranean Sea) along the coast of the Ligurian Sea (North-West Mediterranean). Stable-isotopes ratios of carbon (13C/12C) and nitrogen (15N/14N) were also measured in the muscle. A significant relationship exists between 15N/14N, mercury concentration and the trophic level. The distribution of essential and non-essential trace elements was studied on several organs, and a significant relationship between selenium and mercury, with a molar ratio close to 1, was found in the cetaceans’ kidney, liver and spleen, regardless of their species. High selenium concentrations are generally associated with a low organic to total mercury ratio. While narrow ranges of concentrations were observed for essential elements in most organs, mercury and selenium concentrations are characterised by a wide range of variation. Bio-accumulation and bio-amplification processes in cetaceans can be better understood by comparing trace element concentrations with the stable-isotopes data. [less ▲]

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See detailIsotopic ratios and elemental contents as indicators of seagrass C processing and sewage influence in a tropical macrotidal ecosystem (Madagascar, Mozambic channel)
Lepoint, Gilles ULg; Frederich, Bruno ULg; Gobert, Sylvie ULg et al

in Scientia Marina (2008), 72(1), 109-117

Isotopic ratios and elemental concentrations of carbon and nitrogen were measured in seven seagrass species colonising different tidal flats near Toliara (SW Madagascar) in order to determine the ... [more ▼]

Isotopic ratios and elemental concentrations of carbon and nitrogen were measured in seven seagrass species colonising different tidal flats near Toliara (SW Madagascar) in order to determine the potential use of these parameters for assessing C processing and sewage use by tropical seagrasses. Nitrogen concentrations measured in upper intertidal seagrasses near Toliara were almost twice those measured on the tidal flat near a healthy mangrove situated 20 km away from Toliara town. At Toliara Beach, δ15N values were correlated with the N concentrations of Halodule sp., one of the dominant species on the tidal flat. This correlation did not exist for Halophila ovalis, the other dominant species. An increase in N concentrations and δ15N values demonstrates the influence of sewage coming directly onto Toliara Beach on the N cycles of intertidal seagrasses. Nevertheless, this influence seems restricted to the upper littoral zone and was not the main cause of seagrass die-off. On the other hand, at the mangrove site, δ15N values were not correlated with the N concentrations of Halodule sp. or Thalassia hemprichii, showing that natural δ15N variability is driven by other factors than the δ15N of N sources. Moreover, inter-individual variability of δ15N values was greater than inter-specific or inter-site variability, making the δ15N difficult to interpret in the context of human-disturbance influence on the N cycle of tropical seagrasses. δ13C values were close to -9‰, indicating the use of HCO 3– as an inorganic carbon source by the seven investigated species. Contrary to our hypothesis, variation between sites and location on the tidal flat was limited, suggesting limited impact on δ13C values of sewage, emersion duration and mechanisms for HCO 3– incorporation. [less ▲]

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See detailDiet and foraging ecology of Roseate terns and lesser noddies breeding sympatrically on Aride Island, Seychelles
Monticelli, David; Ramos, J. A.; Tavares, P. C. et al

in Waterbirds (2008), 31(239), 248

Inferences on seabird ecology from stable isotopes ratios (δ13C, δ15N) and mercury concentrations analysis of feathers have been made for temperate and polar species but are far more rare for tropical ... [more ▼]

Inferences on seabird ecology from stable isotopes ratios (δ13C, δ15N) and mercury concentrations analysis of feathers have been made for temperate and polar species but are far more rare for tropical species. In this paper, we used this approach combined with analysis of regurgitations and feeding observations at colonies to examine diet segregation between Roseate Terns (Sterna dougallii) and Lesser Noddies (Anous tenuirostris) breeding sympatrically on Aride Island (Seychelles), western Indian Ocean. Our results indicated extensive overlap between the two species in trophic level and foraging area during the breeding season. Goatfish predominated (93-97%) in all diet samples of adults and chicks collected in the colonies, except in prey fed to mates by Roseate Terns, of which scad and tuna comprised 20%. The isotopic analyses of feathers replaced by adults during molt (primary and body feathers) suggested, however, that the two species differ in foraging ecology during the nonbreeding period. Roseate Tern adults had consistently lower δ15N values than Lesser Noddies which, in turn, had δ15N values comparable to those of chick feathers grown on Aride. Moreover, low but similar mercury levels were found in body feathers of Lesser Noddy adults and Roseate Tern chicks, whereas Roseate Tern adults were significantly more contaminated. Overall, these results support the hypothesis that the Lesser Noddy is largely sedentary, being associated with the same food web in the vicinity of the colonies year-round. In contrast, Roseate Terns rely on distinct prey during the molting (nonbreeding) season which may be also consistent with a change in food web (i.e., a migratory regime) although the assignment of potential wintering areas remain difficult without isotopic basemaps currently available for the Indian Ocean. [less ▲]

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See detailPCDD, PCDF AND PCB DETERMINATION IN DOLPHINS REVEALS A WORLD HOTSPOT FOR PCBS IN GUANABARA BAY, BRAZIL
Dorneles, Paulo; Lailson-Brito, José; Eppe, Gauthier ULg et al

in Organohalogen Compounds (2008), 70

The main objective of the present study was to determine the current concentrations of PCDDs, PCDFs and PCBs in dolphins from a region of high industrialization and urbanization in the Southern Hemisphere ... [more ▼]

The main objective of the present study was to determine the current concentrations of PCDDs, PCDFs and PCBs in dolphins from a region of high industrialization and urbanization in the Southern Hemisphere. Since most of these compounds biomagnify in food chains and changes in ratios of stable isotopes of nitrogen (15N/14N) have been used to elucidate trophic relationships 7, measurements of these isotopes have been carried out in marine tucuxi dolphins and their prey in Guanabara Bay. Stable isotopes were measured, firstly, to quantitatively assess the trophic level of the dolphin, and, secondly, to provide information for future human risk assessment investigations related to fish consumption [less ▲]

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See detailLINK BETWEEN MARINE MAMMAL EXPOSURE TO PERFLUOROOCTANE SULFONATE (PFOS) AND STABLE-CARBON ISOTOPE RATIOS IN NERITIC AND OCEANIC WATERS OFF BRAZIL
Dorneles, Paulo; Lailson-Brito, José; Meyer, Johan et al

in Organohalogen Compounds (2008), 70

The main objective of the present study was to determine the current concentrations of PFOS in dolphins from neritic and oceanic waters of a region of high industrialization and urbanization in the ... [more ▼]

The main objective of the present study was to determine the current concentrations of PFOS in dolphins from neritic and oceanic waters of a region of high industrialization and urbanization in the Southern Hemisphere. Since stable carbon isotopes can be used to point out relative contributions to the diet of different potential primary sources in trophic networks, indicating for example the inshore versus offshore contribution to food intake 7,8, stable carbon isotope measurements were carried out in the same dolphins in order to clarify inter-species differences. [less ▲]

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See detailLactation effect on the trace element dynamics in northern elephant seals (Mirounga angustirostris)
Habran, Sarah ULg; Debier, Cathy; Lepoint, Gilles ULg et al

Conference (2007, November 30)

Northern elephant seals, Mirounga angustirostris, are exceptional mammals: females fast entirely during nursing while their pups may quadruple in weight over the 25-day suckling period. Females thus lose ... [more ▼]

Northern elephant seals, Mirounga angustirostris, are exceptional mammals: females fast entirely during nursing while their pups may quadruple in weight over the 25-day suckling period. Females thus lose approximately a third of body mass and produce energy-rich milk with a high fat content. Stable carbon and nitrogen isotope ratios (d13C and d15N used as diet markers) and total mercury concentrations (Hg) were measured in tissues (blood cells, serum, full blood, milk and blubber) from 20 mother-pup pairs on days 4 and 21 of lactation. A systematic difference was observed between isotopic values in blood cells and serum of the mothers, linked to diet and distinct biochemical composition between blood components. d13C differed between inner and outer blubber layers and were similar between inner blubber and milk. High Hg concentrations (up to 350 ng.g-1ww at the beginning of lactation) were found in the blood of mother elephant seals linked to their high d15N values in blood cells. Hg transfer through placenta and milk was observed between mothers and pups. A significant increase of blood Hg concentration in mothers (+285 ng.g-1ww) and a decrease in pups (-93 ng.g-1ww) were observed between days 4 and 21 of lactation. Both processes were explained by a remobilization of proteins and lipids during fasting and milk production in mothers and by a dilution of Hg in pups due to their high mass increase during this period. This study confirms that lactation modifies stable nitrogen isotope ratios in tissues, as well as mercury levels in blood from mothers and pups, and highlights the existence of a transplacental and transmammary transfer of mercury in northern elephant seals. Therefore, physiological processes and body condition should be considered carefully when interpreting stable isotope ratios and Hg concentrations in the framework of biomonitoring. [less ▲]

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See detailNocturnal vertical migrations by amphipods of the Posidonia oceanica (L.) Delile foliar stratum : Importance of the litter cover
Michel, Loïc ULg; Sturaro, Nicolas ULg; Lepoint, Gilles ULg et al

Poster (2007, November)

In seagrass meadows, several groups of vagile invertebrates are well known to perform a nocturnal rise from the lower layers of the meadow to the foliar stratum. This vertical migration is generally ... [more ▼]

In seagrass meadows, several groups of vagile invertebrates are well known to perform a nocturnal rise from the lower layers of the meadow to the foliar stratum. This vertical migration is generally regarded as a defense mechanism against predation by diurnal fishes, as well as a mean to maximize the exploitation of trophic resources offered by the meadow. Here, we focused on the amphipods from a Mediterranean Posidonia oceanica meadow. We sampled the community present in the meadows of Calvi Bay (NW Corsica) using two different techniques (hand-towed net and litter collecting). Samples were taken at two seasons, during both night and daytime. Our results confirm the nocturnal rise to the foliar stratum. Combined to an analysis of the recent literature, they also tend to show that amphipods spend the daytime not in the matte itself, as it has been proposed in the past, but in the thin layer of Posidonia litter present at the interface between the foliar stratum and the root/rhizome system. This would emphasize the role of the litter cover in the complexity of the habitat within the meadow, and therefore in the vagile invertebrate community structure and the functioning of the whole meadow as an ecosystem. [less ▲]

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See detailField measurements of inorganic nitrogen uptake by epiflora components of the seagrass Posidonia oceanica (Monocotyledons, Posidoniaceae)
Lepoint, Gilles ULg; Jacquemart, Julien; Bouquegneau, Jean-Marie ULg et al

in Journal of Phycology (2007), 43(2), 208-218

Crustose corallines, crustose and erect brown algae, and sessile animals are major components of the epiphytic community of the Mediterranean seagrass Posidonia oceanica (L.) Delile. Production, biomass ... [more ▼]

Crustose corallines, crustose and erect brown algae, and sessile animals are major components of the epiphytic community of the Mediterranean seagrass Posidonia oceanica (L.) Delile. Production, biomass, and specific composition of this epiphyte-seagrass association are impacted by anthropogenic increase of nutrient load in this oligotrophic area. In this context, nitrogen uptake by P. oceanica and its epiflora was measured using the isotope N-15 at a 10 m depth in the Revellata Bay (Corsica, Mediterranean Sea). Epiflora components showed various seasonal patterns of biomass and abundance. The epiphytic brown algae appeared at the end of spring, later than the crustose corallines, and after the nitrate peak in the bay. Because of their later development in the season, epiphytic brown algae mostly rely on ammonium for their N needs. We hypothesize that the temporal succession of epiphytic organisms plays a crucial role in the N dynamics of this community under natural conditions. The epiphytic brown algae, which have a growth rate one order of magnitude greater than that of crustose corallines, showed lower N-uptake rates. The greater N-uptake rates of crustose corallines probably reflect the greater N requirements (i.e., lower C/N ratios) of red algae. We determined that the epiflora incorporated ammonium and nitrate more rapidly than their host. Nevertheless, when biomass was taken into account, P. oceanica was the most important contributor to N uptake from the water column by benthic macrophytes in this seagrass bed. [less ▲]

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See detailEvaluation of the usefulness of bird feathers as a non-destructive biomonitoring tool for organic pollutants: A comparative and meta-analytical approach
Jaspers, V. L. B.; Voorspoels, S.; Covaci, Adrian et al

in Environment International (2007), 33(3), 328-337

In this study, we investigated whether bird feathers can be used as a non-destructive biomonitor for organic pollutants. We analysed the outermost tail feathers of 8 terrestrial and aquatic bird species ... [more ▼]

In this study, we investigated whether bird feathers can be used as a non-destructive biomonitor for organic pollutants. We analysed the outermost tail feathers of 8 terrestrial and aquatic bird species from Belgium (8 species, n = 108) for polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs). Every compound class could be quantified in one single tail feather of the birds under study (sum PCBs ranging from 5.5 to 5 10 ng/g feather, sum PBDEs from 0.33 to 53 ng/g feather, sum DDTs from 1.5 to 730 ng/g feather), except for PBDEs in feathers of the common moorhen (Gallinula chloropus). Further, we calculated Pearson correlations between concentrations of organic pollutants in feathers and concentrations in corresponding muscle or liver tissue from the birds. Correlations were found significant in half of the cases of the terrestrial species, but were found not significant for the aquatic species, with the exception of a significant correlation of sum PCBs in the common moorhen. Only for the common buzzard (Buteo buteo) (n=43) all correlations were found significant (0.32 < r < 0.77). In order to cope for low statistical power, we performed a meta-analysis on all bird species together. This led to significant correlations between levels in feathers and corresponding levels in muscle or liver for all terrestrial birds (p < 0.05 in all cases, effect size 0.59 (p,p'-DDE) to 0.71 (Sigma PCB) for levels in feather and muscle). When correlations were recalculated excluding the birds that had died due to starvation, correlation coefficients for the terrestrial birds were found even higher (effect size up to 0.83 (Sigma PCB)). These results have important implications for non-destructive and retrospective biomonitoring. Although our results suggest that exact concentrations in the body cannot be predicted using feathers, bird feathers can give a good estimate of contamination levels in a population and as such are a potential non-destructive biomonitoring tool for organic pollutants. Outermost tail feathers and muscle tissue were also examined for nitrogen (delta N-15) and carbon (delta C-13) stable isotope content in the different bird species. However, delta N-15/delta C-13 signatures in feather or muscle were not significantly correlated with the corresponding levels of organic pollutants in these tissues. Various confounding factors (such as habitat, condition, age, sex) may have masked a relationship between delta N-15 values and organic pollutant levels in the birds under study. (c) 2006 Elsevier Ltd. All rights reserved. [less ▲]

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See detailEarly colonization of Posidonia oceanica (L.) Delile by epiphytes: Comparison between natural and artificial seagrass leaves
Pete, Dorothée ULg; Gobert, Sylvie ULg; Lepoint, Gilles ULg et al

in Pergent-Martini, Christine; El Asmi, Souha; Le Ravallec, Célia (Eds.) Proceedings of the third Mediterranean symposium on marine vegetation (2007, March)

Posidonia oceanica is an important marine Magnoliophyta of the Mediterranean coastal zone that can form dense meadows. The leaves of this seagrass are colonized by a lot of organisms, from bacteria to ... [more ▼]

Posidonia oceanica is an important marine Magnoliophyta of the Mediterranean coastal zone that can form dense meadows. The leaves of this seagrass are colonized by a lot of organisms, from bacteria to polychaetes and algae. However, the early stages of colonization are not well known. A preliminary is proposed to examine the nine first days of colonization by epiphytes on natural leaves and on Artificial Seagrass Units (ASUs). Aims of this work were to understand which species are the first to set up, to compare colonization on both leaves and to determine the interest of ASUs in ecological studies. It was shown that the setting up of epiphytes on the bases of both leaves is rapid (first algae on the second day) but the number of organisms increases quicker on ASUs than on natural leaves and on the smooth faces than the rough ones. Shannon-Wiener diversity and evenness were higher for the P. oceanica leaves and the use of Bray-Curtis similarity index showed that colonisation is not similar (between 20 and 30 % similarity) on both leaves for the same day. It can be explained by the lower colonization rate of natural leaves. This lower rate is probably due to a less developed biofilm on natural leaves than on ASUs, to a difficult access to the bases of P. oceanica leaves for epiphytes and microoganisms, and the production of phenol compounds by the plant. Even if ASUs used here do not seem to be similar to natural leaves in early stages of colonization, they could be used in ecological studies thanks to their rapid covering by epiphytes. [less ▲]

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See detailLong-Term Feeding Ecology and Habitat Use in Harbour Porpoises Phocoena Phocoena from Scandinavian Waters Inferred from Trace Elements and Stable Isotopes
Fontaine, Michael ULg; Tolley, K. A.; Siebert, U. et al

in BMC Ecology (2007), 7

BACKGROUND: We investigated the feeding ecology and habitat use of 32 harbour porpoises by-caught in 4 localities along the Scandinavian coast from the North Sea to the Barents Sea using time-integrative ... [more ▼]

BACKGROUND: We investigated the feeding ecology and habitat use of 32 harbour porpoises by-caught in 4 localities along the Scandinavian coast from the North Sea to the Barents Sea using time-integrative markers: stable isotopes (delta13C, delta15N) and trace elements (Zn, Cu, Fe, Se, total Hg and Cd), in relation to habitat characteristics (bathymetry) and geographic position (latitude). RESULTS: Among the trace elements analysed, only Cd, with an oceanic specific food origin, was found to be useful as an ecological tracer. All other trace elements studied were not useful, most likely because of physiological regulation and/or few specific sources in the food web. The delta13C, delta15N signatures and Cd levels were highly correlated with each other, as well as with local bathymetry and geographic position (latitude). Variation in the isotopic ratios indicated a shift in harbour porpoise's feeding habits from pelagic prey species in deep northern waters to more coastal and/or demersal prey in the relatively shallow North Sea and Skagerrak waters. This result is consistent with stomach content analyses found in the literature. This shift was associated with a northward Cd-enrichment which provides further support to the Cd 'anomaly' previously reported in polar waters and suggests that porpoises in deep northern waters include Cd-contaminated prey in their diet, such as oceanic cephalopods. CONCLUSION: As stable isotopes and Cd provide information in the medium and the long term respectively, the spatial variation found, shows that harbour porpoises experience different ecological regimes during the year along the Scandinavian coasts, adapting their feeding habits to local oceanographic conditions, without performing extensive migration. [less ▲]

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See detailFatty acids and stable isotopes in fish and harbour porpoises (Phocoena phocoena) from the North Sea: further insights in their trophic relationships
Drouguet, Olivier; Caut, Stéphane; Haelters, Jan et al

Poster (2007)

Recent observations revealed an increased abundance of the harbour porpoise in the southern part of the North Sea. Concomitant to sightings of living individuals, the number of stranded porpoises ... [more ▼]

Recent observations revealed an increased abundance of the harbour porpoise in the southern part of the North Sea. Concomitant to sightings of living individuals, the number of stranded porpoises displaying lesions linked to fishing nets has also increased this last decade. The increased abundance of porpoises together with the increase in numbers of bycaught animals raised the question of possible competition between porpoises and fishermen in the North Sea. Therefore, a detailed view on harbour porpoise trophic ecology in this region is crucial for their conservation. Stomachs of the washed ashore porpoises were often empty and provided limited information on their recent diet. Another way of looking into the diet of marine mammals is the analysis of blubber. Stable isotopes ratio (d13C and d15N, SI) and fatty acid composition (20 fatty acids, FA) were analyzed in muscle and blubber of 10 freshly stranded harbour porpoises and in 60 potential prey fish from 10 species collected in the North Sea. The SI ratio and FA composition of these fish enabled a clear classification in different trophic levels and different trophic niches. The FA composition was very similar between harbour porpoise blubber and demersal fish, underlining a preferential predation on that resource for the porpoises investigated. A bias might exist for the porpoises: most of the animals were juveniles, and washed ashore during spring. Porpoises might display other feeding habits in other life stages, other periods of the year. These preliminary results however indicate the enhanced accuracy of crossing these biomarker approaches. [less ▲]

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See detailAssessment of trophic relationships between symbiotic tropical ophiuroids using C and N stable isotope analysis
Fourgon, Didier; Lepoint, Gilles ULg; Eeckhaut, Igor

in Journal of the Marine Biological Association of the United Kingdom (2006), 86(6), 1443-1447

Analyses of the natural abundance of carbon and nitrogen stable isotopes were performed to investigate the feeding habits of two ophiurolds, Ophiomastix venosa and Ophiocoma scolopendrina, and to assess ... [more ▼]

Analyses of the natural abundance of carbon and nitrogen stable isotopes were performed to investigate the feeding habits of two ophiurolds, Ophiomastix venosa and Ophiocoma scolopendrina, and to assess the potential benefit obtained by the symbiotic Ophiomastix venosa juveniles. A tracer experiment was also carried Out to clarify the contribution of algae to the nitrogen uptake amongst the tested ophiurolds. Our results suggest that Ophiocoma scolopendrina adults occupy a higher position in the food web than Ophiomastix venosa and mainly feed on neuston. In contrast, O. venosa adults feed on the alga Sargassum densifolium, and on organic matter associated with sediment. Free juveniles and symbiotic juveniles of O. venosa have intermediate PC values between both adult species. The high proportion of C-13 in the symbiotic juveniles compared to the one in their conspecific adults indicates that their diet slightly differs from the latter and is closer to that of Ophiocoma scolopendrina. This raises the hypothesis that symbiotic juveniles steal neuston front their associated host, O. scolopendrina. [less ▲]

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See detailLactation effect on stable isotope ratios and mercury levels in the blood of northern elephant seals
Habran, Sarah ULg; Debier, Cathy; Lepoint, Gilles ULg et al

Poster (2006, October 27)

Female northern elephant seals, Mirounga angustirostris, fast entirely during nursing while their pups may quadruple in weight over the 25-day suckling period. Stable carbon and nitrogen isotope ratios ... [more ▼]

Female northern elephant seals, Mirounga angustirostris, fast entirely during nursing while their pups may quadruple in weight over the 25-day suckling period. Stable carbon and nitrogen isotope ratios (d13C and d15N used as diet markers) and total mercury concentrations (Hg) were measured in tissues (blood cells, serum, full blood, milk and blubber) from 20 mother-pup pairs on day 4 and 21 of lactation. A systematic difference was observed between isotopic values in blood cells and serum of the mothers, linked to diet and distinct biochemical composition between blood components. d13C differed between inner and outer blubber layers and were similar between inner blubber and milk. High Hg concentrations (up to 350 ng.g-1 ww at the beginning of lactation) were found in the blood of mother elephant seals linked to their high d15N values in blood cells. Hg transfer through placenta and milk was observed between mothers and pups. A significant increase of blood Hg concentration in mothers (+285 ng.g-1ww) and a decrease in pups (-93 ng.g-1ww) were observed between days 4 and 21 of lactation. Both processes were explained by a remobilization of proteins and lipids during fasting and milk production in mothers and by a dilution of Hg in pups due to their high mass increase during this period. To conclude, physiological processes and body condition should be considered carefully when interpreting stable isotope ratios and Hg concentrations in the framework of biomonitoring. [less ▲]

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See detailDiet of Damselfishes (Pomacentridae): a multidisciplinary approach
Fabri, Grégory ULg; Parmentier, Eric ULg; Lepoint, Gilles ULg et al

Poster (2006, October)

Coral reefs are the marine ecosystem showing the greatest fish diversity. Damselfishes (Pomacentridae) represent, with more than 340 species, one of the most important families in the coral reef ... [more ▼]

Coral reefs are the marine ecosystem showing the greatest fish diversity. Damselfishes (Pomacentridae) represent, with more than 340 species, one of the most important families in the coral reef environment. Currently their diet is understudied. This work has 2 aims: (i) to characterize the diet of 13 pomacentrid species of the reef of Toliara (Madagascar) and (ii) to investigate if the specific diversity of this family would result from a strong trophic segregation. A multidisciplinary approach including morphological data (teeth, lower jaw-lever mechanics and intestine length), stomach contents and stable isotope analysis were used. The morphological approach and the stomach contents show that each studied species is able to capture small planktonic preys (e.g. copepods). However, the 13 species can be divided into two trophic guilds: alguivores and planktivores (respectively species where the filamentous algae and the planktonic preys count for more than 60% of their diet). Within these two principal classes, the analysis of the stomach contents and stable isotopes permit to define sub-groups : (1) the species having a food behaviour exclusively alguivore or planktivore (> 90% of their diet) (2) species showing a more varied diet by also eating other types of preys such as vagiles and/or sessiles invertebrates. The diet would contribute but could not explain all diversity in Pomacentridae. Some species show a very similar diet. Consequently other ecological factors should be responsible for the reduction of interspecific competitions and for the existence of such diversity. [less ▲]

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