References of "Bouquegneau, Jean-Marie"
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See detailRecent threats on coastal ecosystems by new pollutants: a multiple trace element study
Richir, Jonathan ULg; Gobert, Sylvie ULg; Bouquegneau, Jean-Marie ULg

Poster (2009, January)

The Mediterranean Sea is an enclosed basin, highly submitted to anthropogenic pressures. Chemical pollution from coastal urban centres and industries, or carried by air and rivers, primarily affects its ... [more ▼]

The Mediterranean Sea is an enclosed basin, highly submitted to anthropogenic pressures. Chemical pollution from coastal urban centres and industries, or carried by air and rivers, primarily affects its coastal ecosystems. Pollution by trace elements is rapidly evolving further to the recent modifications of their production and industrial uses by men. As a result, certain trace elements can now be considered as new environmental pollutants. Appropriate bioindicators are useful tools for the early warning of marine pollution. We presently investigate the use of the purple sea urchin Paracentrotus lividus and the marine phanerogam Posidonia oceanica as bioindicators to monitor the Mediterranean coastal pollution by new trace pollutants (Be, V, Mo, Mn, PGEs, Ag, Al, As, Se, Sb and Bi). Classic trace metals (Cd, Cr, Cu, Zn, Ni, Sn, Pb, Co and Fe) are also studied. Organisms were seasonally collected in 2008 in a reference site and a polluted one, respectively Calvi bay (Corsica) and Marseille (France). Their tissular trace element concentrations were determined by ICP-MS. All the investigated trace elements were chosen for their potential toxic effects. [less ▲]

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See detailFish farm impacts on Posidonia oceanica meadows: interest of the microbenthic loop.
Pete, Dorothée ULg; Velimirov, Branko; Bouquegneau, Jean-Marie ULg et al

Poster (2009, January)

Posidonia oceanica, the seagrass endemic to the Mediterranean Sea, is a valuable tool to assess the environmental quality in coastal zones. However, only few studies have attempted to use characteristics ... [more ▼]

Posidonia oceanica, the seagrass endemic to the Mediterranean Sea, is a valuable tool to assess the environmental quality in coastal zones. However, only few studies have attempted to use characteristics of its sediment compartment as an indicator of environmental perturbations. In this study, the impact of a fish farm on the microbenthic loop (organic matter, bacteria, microphytobenthos and meiofauna) of P. oceanica meadows will be described. Samples were taken under an aquaculture situated in Calvi Bay (Corsica, France) at a depth of 22 m, in March and June 2008. The control site was the meadow situated in front of the research station STARESO (Calvi Bay, Corsica, France), sampled at the same periods and depth. Results concerning bacteria, microphytobenthos and organic matter will be presented here. For both seasons, differences between sites exist. For example, biomasses of organic matter, microphytobenthos and bacteria are higher in the fish farm than in the control site, indicating that the microbenthic loop has potential to be a good early indicator of pollution in this sea. [less ▲]

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See detailDevelopment of a strategy to study toxicodynamic of pollutants in spawning sea turtles
Dyc, Christelle ULg; Bouquegneau, Jean-Marie ULg; Gillet, Marie-Claire ULg et al

in Proceedings of the 29th Annual Symposium on Sea Turtle Biology and Conservation (2009)

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See detailDevelopment of a strategy to study toxicodynamic of pollutants in spawning sea turtles from French West Indies (Guadeloupe and Martinique)
Dyc, Christelle ULg; Debier, Cathy; Thomé, Jean-Pierre ULg et al

Conference (2008, November)

Sea turtles including the green turtle Chelonia mydas and the hawksbill turtle Eretmochelys imbricata are critically endangered species, facing different factors as marine pollution. There is a blatant ... [more ▼]

Sea turtles including the green turtle Chelonia mydas and the hawksbill turtle Eretmochelys imbricata are critically endangered species, facing different factors as marine pollution. There is a blatant lack of data dealing with toxicants such as metals and persistent organic pollutants (POPs) in sea turtles. We developed a strategy to apprehend levels, effects and transfer to offspring of several pollutants in sea turtles. Sampling of blood, subcutaneous tissue and eggs of 15 gravid C. mydas and E. imbricata was carried out between July and September 2008 in Martinique (Diamant’s beach) and Guadeloupe (Petite Terre and Marie-Galante). Blood was collected from the dorso-cervical sinus and subcutaneous tissue was sampled in shoulder of the spawning females using a 5 mm biopsy punch (Kai Europe GmbH, Germany). Total blood and serum were successfully taken for metal, POP and biomarker investigations. T-mercury was analyzed by DMA milestones while PCBs, DDT and chlordecone were analyzed by EDC Ni63 high performance gas chromatography HPLC. Samples of serum were analyzed for vitamins (A and E) by HPLC and for thyroid hormones (triiodothyronine and thyroxine) by radioimmunoassay. In parallel to this field study, a cell model using 3T3-L1 cell line was built up to test in vitro effects of PCBs and mercury as well as the relationship between in vitro exposure and fat mobilization. Preliminary results showed a dose-response relationship between increased Aroclor 1234 and 1252 concentrations (0.5 ppb, 1 ppb and 1.5 ppb) and adipocyte mortality (Nucleocounter). The strategy we propose here will bring further insights on levels and potential impact of pollutants on female sea turtles and their offspring. [less ▲]

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See detailPotential use of Paracentrotus lividus as bioindicator for recent trace element pollution monitoring
Richir, Jonathan ULg; Gobert, Sylvie ULg; Bouquegneau, Jean-Marie ULg

Poster (2008, October)

The Mediterranean Sea is an enclosed basin, highly submitted to anthropogenic pressures. Chemical pollution originating from coastal urban centres and industries, or carried by air and rivers, will ... [more ▼]

The Mediterranean Sea is an enclosed basin, highly submitted to anthropogenic pressures. Chemical pollution originating from coastal urban centres and industries, or carried by air and rivers, will primarily affect its coastal ecosystems. The pollution by trace elements into the marine environment is rapidly evolving further to the recent modifications of their production and industrial uses by men. As a result, some trace elements that were previously poorly studied can be considered now as environmental pollutants, whose concentrations can sometimes be way above their natural baseline levels. The purple sea urchin Paracentrotus lividus is a well know bioindicator used for metal pollution monitoring (Fe, Cd, Cr, Pb, Zn and Cu) along the Mediterranean and Atlantic coasts. This sedentary organism successfully concentrates the pollutants diluted in its environment, and the measured concentrations reflect properly the health status of the ecosystem. This study is a first approach on the use of P. lividus as bioindicator for some less investigated trace elements (Al, V, Mn, Co, Ni, Se, Mo and Ag), chosen for their potential toxic effects. We have compared the element concentrations of the digestive tract tissues and gonads of female and male sea urchins. The organisms were frozen prior to dissection, or they were dissected alive, the two experimental procedures being compared afterwards. The existence of an eventual relationship between their gonadic index or their test diameter and the measured pollutant concentrations was also investigated. [less ▲]

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See detailHarbour porpoise thyroids: Histological investigations and potential interactions with environmental factors
Schnitzler, Joseph ULg; Siebert, Ursula; Jepson, Paul et al

in Journal of Wildlife Diseases (2008), 44

The thyroid plays an important role in development and is of primary importance in metabolism and heat loss for cetaceans, including the harbor porpoise (Phocoena phocoena). Several studies have ... [more ▼]

The thyroid plays an important role in development and is of primary importance in metabolism and heat loss for cetaceans, including the harbor porpoise (Phocoena phocoena). Several studies have demonstrated that environmental contaminants can alter various aspects of thyroid function in mammals and may contribute to various histologic changes. The present study completes the data set of a 2006 study by Das et al., by performing histological and immunohistologic investigations on thyroids of 36 harbor porpoises from Belgian and United Kingdom waters. The number and mean diameter of follicles (µm) and the relative proportion of follicular, connective, and vascular tissue (%) were quantified in the thyroid gland of each individual. Interfollicular fibrosis has been observed in these thyroid glands, and the collective findings support the hypothesis of an endocrine disruption of thyroid function through organochlorinated compounds. Our study aimed also to reveal potential relationships between thyroid morphometric data and metal levels (Cd, Fe, Zn, Cu, Se, and Hg) using multivariate statistical analysis. The multiple regressions revealed statistically significant relationships between trace elements (cadmium, selenium, and copper) and thyroid fibrosis. The largely negative relationships are interesting findings but do not support the hypothesis that these elements have an adverse effect on thyroid morphometry. Further research is needed to understand the nature of any relationship between organochlorine and trace element exposure and thyroid gland morphology and function in harbor porpoises. [less ▲]

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See detailSpatial heterogeneity at small scale in the microbenthic loop of Posidonia oceanica meadows
Pete, Dorothée ULg; Lenartz, Fabian ULg; Velimirov, Branko et al

Conference (2008, October)

In the Mediterranean coastal zone, one the most important ecosystem is the Posidonia oceanica meadow. This seagrass is endemic of the Mediterranean Sea and plays many important ecological roles like ... [more ▼]

In the Mediterranean coastal zone, one the most important ecosystem is the Posidonia oceanica meadow. This seagrass is endemic of the Mediterranean Sea and plays many important ecological roles like oxygen production, nursery for numerous commercial species of fishes and protection of coastal zones by reducing the impact of waves. However, there is a severe lack of informations on small scale variations in its sediment compartment. In an attempt to understand spatial variations in the microbenthic loop (bacteria, organic matter, microphytobenthos and meiofauna) of this ecosystem, an experiment was led in Calvi Bay (Corsica, France), in March 2008, at 10 m depth. Twelve points were sampled randomly in a 125 x 125 cm grid, divided into twenty-five 25 x 25 cm squares, to assess and describe the spatial distribution and variations of different parameters of the sediment. Those parameters are granulometry, density of the P. oceanica meadow, nutrients concentration in pore water, bacteria (biomass, abundance, morphotypes), organic matter (biomass), microphytobenthos (biomass), roots and rhizomes (biomass) and meiofauna (biomass). Distribution maps were produced using the DIVA (Data-Interpolating Variational Analysis) method. Our results prove that the sediment compartment is highly heterogeneous at small scale, especially for bacteria and in the first centimeter of sediment cores. Moreover, a correlation has been established between microphytobenhtos variations and phosphate concentration in pore water. For the first time, such small scale variations are depicted in a P. oceanica meadow, which underlines the importance to take them into account in sampling strategies. [less ▲]

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See detailDevelopment of a strategy to study toxicodynamic of pollutants in spawning sea turtles from the French West Indies
Dyc, Christelle ULg; Bouquegneau, Jean-Marie ULg; Gillet, Marie-Claire ULg et al

Poster (2008, October)

Sea turtles including the green turtle Chelonia mydas and the hawksbill turtle Eretmochelys imbricata are critically endangered species, facing different factors as marine pollution. There is a blatant ... [more ▼]

Sea turtles including the green turtle Chelonia mydas and the hawksbill turtle Eretmochelys imbricata are critically endangered species, facing different factors as marine pollution. There is a blatant lack of data dealing with toxicants such as metals and persistent organic pollutants (POPs) in sea turtles. We developed a strategy to apprehend levels, effects and transfer to offspring of several pollutants in sea turtles. Sampling of blood, subcutaneous tissue and eggs of 15 gravid C. mydas and E. imbricata was carried out between July and September 2008 in Martinique (Diamant’s beach) and Guadeloupe (Petite Terre and Marie-Galante). Blood was collected from the dorso-cervical sinus and subcutaneous tissue was sampled in shoulder of the spawning females using a 5 mm biopsy punch (Kai Europe GmbH, Germany). Total blood and serum were successfully taken for metal, POP and biomarker investigations. T-mercury was analyzed by DMA milestones while PCBs, DDT and chlordecone were analyzed by EDC Ni63 high performance gas chromatography HPLC. Samples of serum were analyzed for vitamins (A and E) by HPLC and for thyroid hormones (triiodothyronine and thyroxine) by radioimmunoassay. In parallel to this field study, a cell model using 3T3-L1 cell line was built up to test in vitro effects of PCBs and mercury as well as the relationship between in vitro exposure and fat mobilization. Preliminary results showed a dose-response relationship between increased Aroclor 1234 and 1252 concentrations (0.5 ppb, 1 ppb and 1.5 ppb) and adipocyte mortality (Nucleocounter). The strategy we propose here will bring further insights on levels and potential impact of pollutants on female sea turtles and their offspring. [less ▲]

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See detailUnderwater Imagery, a Measuring Tool to Extend the Spatio-Temporal Understanding of Benthic Organisms Dynamics: Case Study of Codium elisabethae in the Azores.
Sirjacobs, Damien ULg; Tempera, Fernando; Cardigos, Frederico et al

Poster (2008, October)

Benthic habitat mapping studies have been increasingly exploiting the use of underwater images to collect information on substrate nature and biological coverage. Concurrently, research has been ongoing ... [more ▼]

Benthic habitat mapping studies have been increasingly exploiting the use of underwater images to collect information on substrate nature and biological coverage. Concurrently, research has been ongoing to develop methods that use the imagery collected to conduct regular quantitative monitoring studies of biological resources distributed over large areas. This study provides the first multi-annual monitoring information on the dynamics of a benthic macroalgae population derived from underwater imagery collected by scuba divers in the Monte da Guia Site of Community Importance /Natura 2000 network (Faial isl. Azores, NE Atlantic). The green alga Codium elisabethae - a long-living green alga that represents a potential good indicator of coastal environmental change - was chosen for the study. The analyses focus on using the underwater imagery to quantify seasonal fluctuations of density, percentage cover, biomass, growth rate and primary production of the species. Two study sites were investigated: one was located in a sheltered no-go reserve exhibiting a dense C. elisabethae population, and the other in a location experiencing more exposed conditions and holding a sparser population. Between August 2003 and November 2005, fifteen (15) photo coverages were collected by scuba-divers. Subsequent processing consisted of producing image mosaics and using automated and interactive change detection methods that recognized, measured and counted individuals present in photos of fixed quadrats and yielded dynamical parameters such as population structures, growth, recruitment, and mortality. Chi-square tests of image-derived estimates and in situ measurements confirmed the validity of a centimeter precision estimation of population structure for individuals above 4 cm diameter. Important variability of population structure and density were observed at small spatial scales. Population density showed a sharp reduction in autumn 2003 and did not show a full recovery in spring and summer 2004. During the following year, population of the protected site maintained density and biomass, while at the exposed site population density dropped. The production of information based on observations of thousands of individuals is mandatory in biological population statistics. The presented imagery approach made it possible, avoiding the need to collect all the measurements and quantitative information during time-constrained SCUBA diving operations. [less ▲]

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See detailImportance of the microbenthic loop of Posidonia oceanica meadows to detect anthropogenic perturbations early: first results
Pete, Dorothée ULg; Velimirov, Branko; Bouquegneau, Jean-Marie ULg et al

Conference (2008, August)

It was demonstrated that Posidonia oceanica, the marine magnoliophyte endemic to the Mediterranean Sea, is a valuable tool to assess environmental qualities of the coastal zones. However, only few studies ... [more ▼]

It was demonstrated that Posidonia oceanica, the marine magnoliophyte endemic to the Mediterranean Sea, is a valuable tool to assess environmental qualities of the coastal zones. However, only few studies have attempted to use characteristics of its sediment compartment as an indicator of the environment state of health. Yet, organisms living in this compartment have a turnover which is faster than for canopy-organisms which makes them useful as valid early descriptors of pollution. The study described here takes place in a project which aims to find an early holistic indicator of anthropogenic perturbations in the Mediterranean coastal zones. The investigation is based on the microbenthic loop (organic matter, bacteria, microphytobenthos and meiofauna) and was led in two different sites of Calvi Bay (Corsica, France), at 10 m depth, in March and June 2007. Only results about bacteria (abundance, biomass, morphotypes), microphytobenthos (biomass) and organic matter (biomass) will be presented. For both seasons, significant differences between sites are found, irrespective on whether variables are treated separately or together, thus indicating that the microbenthic loop has potential to be a good early indicator of pollution. [less ▲]

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See detailSmall scale variations in the microbenthic loop of Posidonia oceanica meadows: an experimental interpolation design.
Pete, Dorothée ULg; Lenartz, Fabian ULg; Velimirov, Branko et al

Poster (2008, August)

In the sediment compartment of Posidonia oceanica meadows, there is a severe lack of information on small scale variations. In an attempt to understand spatial variations of the microbenthic loop ... [more ▼]

In the sediment compartment of Posidonia oceanica meadows, there is a severe lack of information on small scale variations. In an attempt to understand spatial variations of the microbenthic loop (bacteria, organic matter, microphytobenthos and meiofauna), an experiment based on interpolation methods was led in Calvi Bay (Corsica, France), in March 2008, at 10 m depth. Twelve points were sampled randomly in a 125 x 125 cm square, divided into twenty-five 25 x 25 cm squares, to assess and describe the spatial distribution and variations of different parameters of the sediment. Those parameters are granulometry, density of P. oceanica, concentration in nutrients in the pore water, bacteria (biomass, abundance, morphotypes), organic matter (biomass), microphytobenthos (biomass), roots and rhizomes (biomass) and meiofauna (biomass). Results and distribution maps of the respective sediment parameters will be presented for the first time. [less ▲]

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See detailDioxin-like compounds in porpoises and seals from the southern North Sea: relationship with biological and ecological factors
Das, Krishna ULg; De Pauw, Edwin ULg; Eppe, Gauthier ULg et al

in Organohalogen Compounds (2008), 70

The North Sea represents a major ecosystem for the harbour porpoise (Phocoena phocoena) and the harbour seal (Phoca vitulina). The grey seal (Halichoerus grypus) occurs more occasionally in the southern ... [more ▼]

The North Sea represents a major ecosystem for the harbour porpoise (Phocoena phocoena) and the harbour seal (Phoca vitulina). The grey seal (Halichoerus grypus) occurs more occasionally in the southern part of the North Sea. Their population over this last decade has experienced major fluctuations likely linked to prey availability and seal epizootics. Despite being banned more than 30 years ago, levels of polychlorinated biphenyls (PCBs) in marine mammals are still of concern due to historical contamination of the North Sea. [less ▲]

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See detailDevelopment of an in vitro model for mercury exposure in marine mammals
Dupont, Aurélie ULg; Bouquegneau, Jean-Marie ULg; Siebert, Ursula et al

Poster (2007, November 01)

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See detailRise of oceanographic barriers in continuous populations of a cetacean: the genetic structure of harbour porpoises in Old World waters
Fontaine, Michaël C. ULg; Baird, Stuart J. E.; Piry, Sylvain et al

in BMC Biology (2007), 5

BACKGROUND: Understanding the role of seascape in shaping genetic and demographic population structure is highly challenging for marine pelagic species such as cetaceans for which there is generally ... [more ▼]

BACKGROUND: Understanding the role of seascape in shaping genetic and demographic population structure is highly challenging for marine pelagic species such as cetaceans for which there is generally little evidence of what could effectively restrict their dispersal. In the present work, we applied a combination of recent individual-based landscape genetic approaches to investigate the population genetic structure of a highly mobile extensive range cetacean, the harbour porpoise in the eastern North Atlantic, with regards to oceanographic characteristics that could constrain its dispersal. RESULTS: Analyses of 10 microsatellite loci for 752 individuals revealed that most of the sampled range in the eastern North Atlantic behaves as a 'continuous' population that widely extends over thousands of kilometres with significant isolation by distance (IBD). However, strong barriers to gene flow were detected in the south-eastern part of the range. These barriers coincided with profound changes in environmental characteristics and isolated, on a relatively small scale, porpoises from Iberian waters and on a larger scale porpoises from the Black Sea. CONCLUSION: The presence of these barriers to gene flow that coincide with profound changes in oceanographic features, together with the spatial variation in IBD strength, provide for the first time strong evidence that physical processes have a major impact on the demographic and genetic structure of a cetacean. This genetic pattern further suggests habitat-related fragmentation of the porpoise range that is likely to intensify with predicted surface ocean warming. [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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