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| Registros recuperados: 32 | |
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| Ragueneau, Olivier; Raimonet, Melanie; Maze, Camille; Coston-guarini, Jennifer; Chauvaud, Laurent; Danto, Anatole; Grall, Jacques; Jean, Frederic; Paulet, Yves-marie; Thouzeau, Gerard. |
| In this contribution, the study of the Bay of Brest ecosystem changes over the past 50 years is used to explore the construction of interdisciplinary knowledge and raise key questions that now need to be tackled at the science-policy-communities interface. The Bay of Brest is subject to a combination of several aspects of global change, including excessive nutrient inputs from watersheds and the proliferation of invasive species. These perturbations strongly interact, affecting positively or negatively the ecosystem functioning, with important impacts on human activities. We first relate a cascade of events over these five decades, linking farming activities, nitrogen, and silicon biogeochemical cycles, hydrodynamics of the Bay, the proliferation of an... |
| Tipo: Text |
Palavras-chave: Sustainability; Land-ocean continuum; Bay of Brest; Interdisciplinarity; Science-policy-community interface. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00616/72792/72272.pdf |
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| 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 |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00420/53103/61588.pdf |
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| Lorrain, Anne; Paulet, Yves-marie; Chauvaud, Laurent; Savoye, Nicolas; Nezan, Elisabeth; Guerin, Laurent. |
| The aim of this study was to characterize the daily shell growth of Pecten maximus from early 1998 to late spring 1999 in the Bay of Brest with a careful qualitative and quantitative description of the pelagic primary production. Our results, in accordance with previous studies, demonstrate that there are episodic declines in the growth rate. Concurrent events of low growth rate and large bottom-concentrations of algae following diatom blooms (Cerataulina pelagica or Rhizosolenia delicatula), suggests that this high concentration of phytoplankton on the bottom layer may affect food intake or respiratory activity of the scallops by gill clogging or oxygen depletion. In this study, silicic acid or phosphorus are inferred to be limiting factors responsible... |
| Tipo: Text |
Palavras-chave: Biscay bay; Limiting factors; Primary production; Phytoplankton cnoncentration; Pecten maximus; Growth rate. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-612.pdf |
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| Suquet, Marc; Billard, Roland; Cosson, Jacky; Dorange, Germaine; Chauvaud, Laurent; Mugnier, Chantal; Fauvel, Christian. |
| This paper presents some features of turbot sperm and compares them with data reported in the literature on other freshwater and marine fish. In captivity, turbot spermiation period lasts 6 months. When compared to other fish species, turbot males are characterized by low values of maximum gonadosomatic index (0.6-0.8%) and are poor sperm producers in terms of volume (0.2-2.2 ml), concentration (0.7-11.0 x 10(9) spermatozoa/ml) and total sperm number released per stripping (0.2-12.0 x 10(9) spermatozoa). Compared to most freshwater species, the duration of cell movement is long (1-17 min). The spermatozoon of turbot can be considered to be of a primitive type. A very high protein content (8.8 mg/ml) is found in the seminal fluid of turbot. Increasing... |
| Tipo: Text |
Palavras-chave: Scophthalmus maximus; Turbot; Biologie du sperme; Liquide séminal; Mobilité du spermatozoïde; Morphologie du spermatozoïde; Poisson marin; Scophthalmus maximus; Turbot; Sperm biology; Seminal fluid; Sperm motility; Sperm morphology; Marine fish. |
| Ano: 1994 |
URL: http://archimer.ifremer.fr/doc/00188/29893/28334.pdf |
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| Albert, Luana; Deschamps, François; Jolivet, Aurélie; Olivier, Frédéric; Chauvaud, Laurent; Chauvaud, Sylvain. |
| The goal of clean renewable energy production has promoted the large-scale deployment of marine renewable energy devices, and their associated submarine cable network. Power cables produce both electric and magnetic fields that raise environmental concerns as many marine organisms have magneto and electroreception abilities used for vital purposes. Magnetic and electric fields' intensities decrease with distance away from the cable. Accordingly, the benthic and the sedimentary compartments are exposed to the highest field values. Although marine invertebrate species are the major fauna of these potentially exposed areas, they have so far received little attention. We provide extensive background knowledge on natural and anthropogenic marine sources of... |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00617/72944/71974.pdf |
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| Le Goff, Samuel; Barrat, Jean-alix; Chauvaud, Laurent; Paulet, Yves-marie; Gueguen, Bleuenn; Ben Salem, Douraied. |
| Gadolinium-based contrast agents (GBCAs), routinely used in magnetic resonance imaging (MRI), end up directly in coastal seawaters where gadolinium concentrations are now increasing. Because many aquatic species could be sensitive to this new pollution, we have evaluated the possibility of using shellfish to assess its importance. Gadolinium excesses recorded by scallop shells collected in Bay of Brest (Brittany, France) for more than 30 years do not reflect the overall consumption in GBCAs, but are largely controlled by one of them, the gadopentetate dimeglumine. Although its use has been greatly reduced in Europe over the last ten years, gadolinium excesses are still measured in shells. Thus, some gadolinium derived from other GBCAs is bioavailable and... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00615/72758/72029.pdf |
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| Lambert, Clément; Penaud, A.; Vidal, Marie-odile; Gandini, C.; Labeyrie, L.; Chauvaud, Laurent; Ehrhold, Axel. |
| The Holocene period (last 11,700 years BP) has been marked by significant climate variability over decadal to millennial timescales. The underlying mechanisms are still being debated, despite ocean–atmosphere–land connections put forward in many paleo-studies. Among the main drivers, involving a cluster of spectral signatures and shaping the climate of north-western Europe, are solar activity, the North Atlantic Oscillation (NAO) varying atmospheric regimes and North Atlantic oceanic gyre dynamics. Over the last 2500 years BP, paleo-environmental signals have been strongly affected by anthropogenic activities through deforestation and land use for crops, grazing, habitations, or access to resources. Palynological proxies (especially pollen grains and... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00665/77715/79803.pdf |
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| 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 |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00087/19861/17506.pdf |
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| Morvezen, Romain; Charrier, Gregory; Boudry, Pierre; Chauvaud, Laurent; Breton, Florian; Strand, Oivind; Laroche, Jean. |
| The great scallop Pecten maximus is harvested in several European countries and fisheries targeting this species are severely regulated by fishing quotas. In addition, hatchery-based population enhancement has been developed in some countries to provide alternative or complementary production. The genetic structure of wild populations of P. maximus and the potential impact of aquaculture on the genetic diversity of this species remains poorly documented. In this study, we explored the genetic structure of P. maximus using 12 microsatellite markers, considering 14 populations sampled from Galicia (Spain) to the North of Norway, and one population of Pecten jacobaeus (L., 1758) from the Lion Gulf (Mediterranean Sea). Results indicated a clear differentiation... |
| Tipo: Text |
Palavras-chave: Great scallop; Pecten maximus; Microsatellites; Population genetics; Aquaculture. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00311/42251/41692.pdf |
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| 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 <30 s), low intensity (acceleration < 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 |
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| Jézéquel, Youenn; Chauvaud, Laurent; Bonnel, Julien. |
| The detection ranges of broadband sounds produced by marine invertebrates are not known. To address this deficiency, a linear array of hydrophones was built in a shallow water area to experimentally investigate the propagation features of the sounds from various sizes of European spiny lobsters (Palinurus elephas), recorded between 0.5 and 100 m from the animals. The peak-to-peak source levels (SL, measured at one meter from the animals) varied significantly with body size, the largest spiny lobsters producing SL up to 167 dB re 1 µPa2. The sound propagation and its attenuation with the distance were quantified using the array. This permitted estimation of the detection ranges of spiny lobster sounds. Under the high ambient noise conditions recorded in... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00630/74201/73827.pdf |
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| Carlier, Antoine; Chauvaud, Laurent; Van Der Geest, Matthijs; Le Loc'H, Francois; Le Duff, Michel; Vernet, Marc; Raffray, Jean; Diakhate, Djibril; Labrosse, Pierre; Wague, Abdoulaye; Le Goff, Clement; Gohin, Francis; Chapron, Bertrand; Clavier, Jacques. |
| Banc d’Arguin (BA), Mauritania, is a nationally protected shallow gulf > 10,000 km2 between the Sahara desert and the upwelling system off the Mauritanian coast. In the southeast, BA consists of a 500 km2 tidal flat, the most important wintering site for shorebirds using the East Atlantic Flyway. The Mauritanian upwelling-driven phytoplankton production supports the most productive fisheries worldwide, but little is known about its trophic role in the functioning of the inshore BA food web. Using stable isotopes as trophic tracers to distinguish between upwelling-driven phytoplankton, open ocean phytoplankton, and benthic primary producers, we assessed the spatial extent to which the inshore BA food web is fuelled by upwelling-driven phytoplankton... |
| Tipo: Text |
Palavras-chave: Banc d'Arguin; West Africa; Food web structure; Remote sensing; Stable isotope; Upwelling. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00269/37999/36078.pdf |
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| Coquereau, Laura; Jolivet, Aurelie; Hegaret, Helene; Chauvaud, Laurent. |
| Harmful algal blooms produced by toxic dinoflagellates have increased worldwide, impacting human health, the environment, and fisheries. Due to their potential sensitivity (e.g., environmental changes), bivalves through their valve movements can be monitored to detect harmful algal blooms. Methods that measure valve activity require bivalve-attached sensors and usually connected cables to data transfers, leading to stress animals and limit the use to sessile species. As a non-intrusive and continuously deployable tool, passive acoustics could be an effective approach to detecting harmful algal blooms in real time based on animal sound production. This study aimed to detect reaction changes in the valve movements of adult Pecten maximus exposed to the toxic... |
| Tipo: Text |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00616/72846/72899.pdf |
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| Robson, Anthony A.; Halsey, Lewis G.; Chauvaud, Laurent. |
| The effects of unnatural disturbances on the behaviour and energetics of animals are an important issue for conservation and commercial animal production. Biologging enables estimation of the energy costs of these disturbances, but not specifically the effect these costs have on growth; a key outcome measure for animal farming enterprises. We looked at how natural and anthropogenically induced activity and energy expenditure of king scallops Pecten maximus varies with temperature. These data were then used to model growth time of king scallops reared in an aquaculture facility under different temperatures and anthropogenic disturbance levels. The scallops exhibited a typical total metabolic rate (MR)-temperature curve, with a peak reached at a middling... |
| Tipo: Text |
Palavras-chave: Growth; Temperature; Anthropogenic disturbance; Activity; Metabolic rate; Energy expenditure. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00344/45561/72893.pdf |
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| 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 |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00266/37758/35807.pdf |
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| Wang, X.; Barrat, Jean-alix; Bayon, Germain; Chauvaud, Laurent; Feng, D.. |
| Methane is an important greenhouse gas whose emissions into the oceans and atmosphere are regulated by relatively unconstrained anaerobic and aerobic microbial processes. The aerobic pathway for methane oxidation is thought to be largely dependent upon the use of rare earth elements (REE), but to date the effects of this process on their abundances in bacteria or in organisms living in symbiosis with methanotrophs remain to be evaluated. Here we show that deep sea chemosynthetic mussels prospering at methane seeps display distinctive lanthanum enrichments linked to the enzymatic activities of their symbionts. These results demonstrate that methanotrophy is able to fractionate efficiently REE distributions in organisms and possibly in the environment.... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75532/76427.pdf |
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| Clavier, Jacques; Chauvaud, Laurent; Amice, Erwan; Lazure, Pascal; Van Der Geest, Matthijs; Labrosse, Pierre; Diagne, Ahmed; Carlier, Antoine; Chauvaud, Sylvain. |
| Benthic primary production and respiration were investigated at 4 sites representative of the major coastal communities bordering the Sahara Desert in the Banc d'Arguin, Mauritania, Western Africa. These sites correspond to intertidal Zostera noltii beds (270 km(2)), intertidal bare sediments (88 km(2)), subtidal Cymodocea nodosa beds (374 km(2)), and subtidal bare sediments (311 km(2)). At each site, production-irradiance relationships were established in situ in November 2008 and January 2010, and used to calculate daily carbon fluxes for these communities. In intertidal areas, compared to emersion, the gross maximal photosynthetic rates for Z. noltii bed and bare sediment communities were on average 8-and 7-fold higher during immersion, respectively;... |
| Tipo: Text |
Palavras-chave: Seagrass; Carbon metabolism; Intertidal; Subtidal; Respiration; Primary; Production; Western Africa. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00189/29987/28460.pdf |
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| 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 |
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| Registros recuperados: 32 | |
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