Consulta: creatorFacets:"Thebault, Julien"
Registros recuperados: 12
Data/hora: 19/05/2024 10:35:38

An evaluation of Mg/Ca, Sr/Ca, and Ba/Ca ratios as environmental proxies in aragonite bivalve shells
Provedor de dados: 5
Autores: Poulain, C.; Gillikin, D. P.; Thebault, Julien; Munaron, Jean-marie; Bohn, M; Robert, Rene; Paulet, Yves-marie; Lorrain, Anne.
The influence of salinity and water chemistry on Mg/Ca, Sr/Ca and Ba/Ca ratios in the aragonitic shells of the Manila clam were investigated. Clams were reared at constant temperature (20 °C) under different controlled conditions of salinity, commonly encountered in their natural habitat. Clams were held in three tanks with a constant salinity of 35 for the first 35 days and then two tanks were changed to lower salinities (20 and 28) for the next 29 days. Individual shell Mg/Ca, Sr/Ca and Ba/Ca ratios were studied through time. Despite stable conditions (temperature, salinity, and Mg/Cawater) for clams reared at salinity 35 during the experiment, Mg/Ca shell ratios increased through the time. Moreover the salinity decrease at t35 slowed the increase of...
Tipo: Text
Palavras-chave: Ruditapes philippinarum; Aragonite; Sclerochronology; Bivalved mollusk; Trace element; Proxy.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00245/35649/34158.pdf

Bivalve trophic ecology in the Mediterranean: Spatio-temporal variations and feeding behavior
Provedor de dados: 5
Autores: Purroy, Ariadna; Najdek, Mirjana; Isla, Enrique; Zupan, Ivan; Thebault, Julien; Peharda, Melita.
The trophic ecology of two bivalves, the clam Callista chione and the cockle Glycymeris bimaculata was studied using environmental and biochemical variables of the suspended particulate matter and the sediment. Samples were collected from two shallow sites, Pag and Cetina, in the coastal oligotrophic Mediterranean Sea, during a 17 month period. The temporal variation of the particulate matter reflected a mixture between marine and terrestrial sources throughout the year, with a clear marine influence during summer and fall, and predominance of terrestrial inputs during spring and winter. The digestive gland was a useful rapid turnover tissue, where the carbon isotope signal was species-specific and the nitrogen isotope one was site-specific. FA markers in...
Tipo: Text
Palavras-chave: Feeding ecology; Bivalves; Suspension feeder; Biochemical variables; Stable isotopes; Fatty acids; Adriatic sea; Niche partitioning; Coastal ecosystems.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00463/57478/59596.pdf

Circadian behaviour of Tectus (Trochus) niloticus in the southwest Pacific inferred from accelerometry
Provedor de dados: 5
Autores: Jolivet, Aurelie; Chauvaud, Laurent; Thebault, Julien; Robson, Anthony A.; Dumas, Pascal; Amos, George; Lorrain, Anne.
Background : Behaviour and time spent active and inactive are key factors in animal ecology, with important consequences for bioenergetics. For the first time, here, we equipped the gastropod Tectus (= Trochus) niloticus with accelerometers to describe activity rhythms at two sites in the Southwest Pacific with different temperature regimes: New Caledonia and Vanuatu. Results : Based on a 24-hour cycle, T. niloticus activity began at dusk and gradually stopped during the night, before sunrise. This nocturnal behaviour was characterised by short (duration &lt;30 s), low intensity (acceleration &lt; 0.12 ɡ) movements and was probably associated with foraging behaviour. We assumed that activity ceased once the animal was satiated. Our analysis of two size...
Tipo: Text
Palavras-chave: Activity; Accelerometry; 24-hour periodicity; Tectus niloticus; Foraging; Migration.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00295/40658/39640.pdf

Combined Use of Morphological and Molecular Tools to Resolve Species Mis-Identifications in the Bivalvia The Case of Glycymeris glycymeris and G. pilosa
Provedor de dados: 5
Autores: Purroy, Ariadna; Segvic-bubic, Tanja; Holmes, Anna; Buselic, Ivana; Thebault, Julien; Featherstone, Amy; Peharda, Melita.
Morphological and molecular tools were combined to resolve the misidentification between Glycymeris glycymeris and Glycymeris pilosa from Atlantic and Mediterranean populations. The ambiguous literature on the taxonomic status of these species requires this confirmation as a baseline to studies on their ecology and sclerochronology. We used classical and landmark-based morphometric approaches and performed bivariate and multivariate analyses to test for shell character interactions at the individual and population level. Both approaches generated complementary information. The former showed the shell width to length ratio and the valve asymmetry to be the main discriminant characters between Atlantic and Mediterranean populations. Additionally, the...
Tipo: Text
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00354/46566/72953.pdf

Contrasting shell growth strategies in two Mediterranean bivalves revealed by oxygen-isotope ratio geochemistry: The case of Pecten jacobaeus and Glycymeris pilosa
Provedor de dados: 5
Autores: Peharda, Melita; Thebault, Julien; Markulin, Kresimir; Schone, Bernd R.; Janekovic, Ivica; Chauvaud, Laurent.
High-resolution stable-isotope ratio data (delta O-18, delta O-18) were used to study growth strategies of two bivalve species, Pecten jacobaeus (calcitic shell) and Glycymeris pilosa (aragonitic shell) from the North Adriatic Sea. The principal objectives of this study were to identify the period of the year when the growth line is formed in the shell of two target species, to identify the main growing season of these two species, to identify the environmental drivers of shell growth, and to evaluate the potential applicability of delta O-18 and delta O-18 values for the reconstruction of environmental variability. Samples were collected from the North Adriatic Sea by commercial bean trawl (P. jacobaeus, December 2013 and January 2014, N = 4) and SCUBA...
Tipo: Text
Palavras-chave: Sclerochronology; Mediterranean; Adriatic; Stable-isotope ratio geochemistry; Bivalve shells.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00615/72753/74907.pdf

Does trace element composition of bivalve shells record utra-high frequency environmental variations?
Provedor de dados: 5
Autores: Poitevin, Pierre; Chauvaud, Laurent; Pecheyran, Christophe; Lazure, Pascal; Jolivet, Aurélie; Thebault, Julien.
Saint-Pierre and Miquelon (SPM) is a small archipelago where instrumental measures based on water column velocity and temperature profiles compiled comprehensive evidence for strong near-diurnal (25.8h) current and bottom temperature oscillations (up to 11.5 °C) which is possibly the largest ever observed — at any frequency — on a stratified mid-latitude continental shelf. The main objective of our study was to identify if Placopecten magellanicus can record on its shell these high frequency environmental variations. To this end, we have tried to identify proxies for water temperature and food availability through development of a new ultra-high resolution LA-ICPMS analyses method capable of resolving shell surface elemental composition with a 10 μm...
Tipo: Text
Palavras-chave: Ultra-high resolution LA-ICPMS; Placopecten magellanicus; Shell chemistry; Trace elements; Environmental change; Bivalve; Environmental proxies; North Atlantic; Saint-Pierre and Miquelon; Coastal trapped wave.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00612/72400/71345.pdf

Influence of riverine input on the growth of Glycymeris glycymeris in the Bay of Brest, North-West France
Provedor de dados: 5
Autores: Featherstone, Amy M.; Butler, Paul G.; Peharda, Melita; Chauvaud, Laurent; Thebault, Julien.
A crossdated, replicated, chronology of 114 years (1901-2014) was developed from internal growth increments in the shells of Glycymeris glycymeris samples collected monthly from the Bay of Brest, France. Bivalve sampling was undertaken between 2014 and 2015 using a dredge. In total 401 live specimens and 243 articulated paired valves from dead specimens were collected, of which 38 individuals were used to build the chronology. Chronology strength, assessed as the Expressed Population Signal, was above 0.7 throughout, falling below the generally accepted threshold of 0.85 before 1975 because of reduced sample depth. Significant positive correlations were identified between the shell growth and the annual averages of rainfall (1975-2008; r = 0.34) and inflow...
Tipo: Text
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00420/53103/61588.pdf

Is the meiofauna a good indicator for climate change and anthropogenic impacts?
Provedor de dados: 5
Autores: Zeppilli, Daniela; Sarrazin, Jozee; Leduc, Daniel; Arbizu, Pedro Martinez; Fontaneto, Diego; Fontanier, Christophe; Gooday, Andrew J.; Kristensen, Reinhardt Mobjerg; Ivanenko, Viatcheslav N.; Sorensen, Martin V.; Vanreusel, Ann; Thebault, Julien; Mea, Marianna; Allio, Noemie; Andro, Thomas; Arvigo, Alexandre; Castrec, Justine; Danielo, Morgan; Foulon, Valentin; Fumeron, Raphaelle; Hermabessiere, Ludovic; Hulot, Vivien; James, Tristan; Langonne-augen, Roxanne; Le Bot, Tangi; Long, Marc; Mahabror, Dendy; Morel, Quentin; Pantalos, Michael; Pouplard, Etienne; Raimondeau, Laura; Rio-cabello, Antoine; Seite, Sarah; Traisnel, Gwendoline; Urvoy, Kevin; Van Der Stegen, Thomas; Weyand, Mariam; Fernandes, David.
Our planet is changing, and one of the most pressing challenges facing the scientific community revolves around understanding how ecological communities respond to global changes. From coastal to deep-sea ecosystems, ecologists are exploring new areas of research to find model organisms that help predict the future of life on our planet. Among the different categories of organisms, meiofauna offer several advantages for the study of marine benthic ecosystems. This paper reviews the advances in the study of meiofauna with regard to climate change and anthropogenic impacts. Four taxonomic groups are valuable for predicting global changes: foraminifers (especially calcareous forms), nematodes, copepods and ostracods. Environmental variables are fundamental in...
Tipo: Text
Palavras-chave: Meiofauna; Climate change; Anthropogenic impacts; Biomonitoring; Natural observations and experimental studies.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00278/38938/37521.pdf

Ligament, hinge, and shell cross-sections of the Atlantic surfclam (Spisula solidissima): Promising marine environmental archives in NE North America
Provedor de dados: 5
Autores: Poitevin, Pierre; Thebault, Julien; Schoene, Bernd R.; Jolivet, Aurelie; Lazure, Pascal; Chauvaud, Laurent.
The Atlantic surfclam (Spisula solidissima) is a commercially important species in North American waters, undergoing biological and ecological shifts. These are attributed, in part, to environmental modifications in its habitat and driven by climate change. Investigation of shell growth patterns, trace elements, and isotopic compositions require an examination of growth lines and increments preserved in biogenic carbonates. However, growth pattern analysis of S. solidissima is challenging due to multiple disturbance lines caused by environmental stress, erosion in umbonal shell regions, and constraints related to sample size and preparation techniques. The present study proposes an alternative method for describing chronology. First, we analyzed growth...
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00444/55597/57229.pdf

Responses of Two Scleractinian Corals to Cobalt Pollution and Ocean Acidification
Provedor de dados: 5
Autores: Biscere, Tom; Rodolfo-metalpa, Riccardo; Lorrain, Anne; Chauvaud, Laurent; Thebault, Julien; Clavier, Jacques; Houlbreque, Fanny.
The effects of ocean acidification alone or in combination with warming on coral metabolism have been extensively investigated, whereas none of these studies consider that most coral reefs near shore are already impacted by other natural anthropogenic inputs such as metal pollution. It is likely that projected ocean acidification levels will aggravate coral reef health. We first investigated how ocean acidification interacts with one near shore locally abundant metal on the physiology of two major reef-building corals: Stylophora pistillata and Acropora muricata. Two pH levels (pH(T) 8.02; pCO(2) 366 mu atm and pH(T) 7.75; pCO(2) 1140 mu atm) and two cobalt concentrations (natural, 0.03 mu g L-1 and polluted, 0.2 mu g L-1) were tested during five weeks in...
Tipo: Text
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00266/37758/35807.pdf

Shells of the bivalve Astarte moerchi give new evidence of a strong pelagic-benthic coupling shift occurring since the late 1970s in the North Water polynya
Provedor de dados: 5
Autores: Olivier, Frederic; Gaillard, Blandine; Thebault, Julien; Meziane, Tarik; Tremblay, Rejean; Dumont, Dany; Belanger, Simon; Gosselin, Michel; Jolivet, Aurelie; Chauvaud, Laurent; Martel, Andre L.; Rysgaard, Soren; Olivier, Anne-helene; Pettre, Julien; Mars, Jerome; Gerber, Silvain; Archambault, Philippe.
Climate changes in the Arctic may weaken the currently tight pelagic-benthic coupling. In response to decreasing sea ice cover, arctic marine systems are expected to shift from a 'sea-ice algae-benthos' to a 'phytoplankton-zooplankton' dominance. We used mollusc shells as bioarchives and fatty acid trophic markers to estimate the effects of the reduction of sea ice cover on the food exported to the seafloor. Bathyal bivalve Astarte moerchi living at 600m depth in northern Baffin Bay reveals a clear shift in growth variations and Ba/Ca ratios since the late 1970s, which we relate to a change in food availability. Tissue fatty acid compositions show that this species feeds mainly on microalgae exported from the euphotic zone to the seabed. We, therefore,...
Tipo: Text
Palavras-chave: Arctic; Climate change; Sclerochronology; Pelagic-benthic coupling; Match; Mismatch hypothesis; Bivalve growth.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00686/79854/82695.pdf

Variation in Size and Growth of the Great Scallop Pecten maximus along a Latitudinal Gradient
Provedor de dados: 5
Autores: Chauvaud, Laurent; Patry, Yann; Jolivet, Aurelie; Cam, Emmanuelle; Le Goff, Clement; Strand, Oivind; Charrier, Gregory; Thebault, Julien; Lazure, Pascal; Gotthard, Karl; Clavier, Jacques.
Understanding the relationship between growth and temperature will aid in the evaluation of thermal stress and threats to ectotherms in the context of anticipated climate changes. Most Pecten maximus scallops living at high latitudes in the northern hemisphere have a larger maximum body size than individuals further south, a common pattern among many ectotherms. We investigated differences in daily shell growth among scallop populations along the Northeast Atlantic coast from Spain to Norway. This study design allowed us to address precisely whether the asymptotic size observed along a latitudinal gradient, mainly defined by a temperature gradient, results from differences in annual or daily growth rates, or a difference in the length of the growing...
Tipo: Text
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00087/19861/17506.pdf