Yves-Marie Paulet

University of Brest · Biologie

Résumé / Abstract Des spécimens de palourdes européennes Ruditapes decussatus provenant des fouilles de l’amas coquillier mésolithique (6e millénaire avant J.-C.) de Beg-an-Dorchenn (Bretagne, France) ont été étudiés afin d'évaluer leur période de collecte et de fournir un aperçu des reconstructions des paléo-températures. Les coquilles sectionnée...

Isotopic investigations performed on carbonated shells from anthropogenic middens provide information about past environ- ments and cultural practices of the human populations who left these vestiges. Patella vulgata, an intertidal gastropod that inhabits northwest Atlantic rocky shores, is commonly occurring as shells in European shell middens, co...

“Maritime spaces, temporalities & global changes” Born in the 1970s (Lovelock & Margulies: 1974; Lovelock: 1999), the concept of global change refers to the study of short-, medium- and long-term interactions between the climate, the biosphere, the ocean, the land surface and, of course, human activities (Goudie, 2017). As a systemic conceptual fra...

Sclerochronological data from archaeological shell middens provides crucial information about past environments and subsistence practices of coastal human populations. These studies rely on a strong knowledge of species-specific growth patterns, as it is the main driver of the quantity and quality of information recorded in biogenic carbonates. The...

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 excess...

The present study aimed to improve understanding of the environmental conditions influencing the reproductive cycle of the great scallop Pecten maximus in two locations in Brittany (France). We also evaluated potential consequences of future climate change for reproductive success in each site. We simulated reproductive traits (spawning occurrences...

Identifying the drivers that control the reproductive success of a population is vital to forecasting the consequences of climate change in terms of distribution shift and population dynamics. In the present study, we aimed to improve our understanding of the environmental conditions that allowed the colonization of the Pacific oyster, Crassostrea...

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 e...

This study considers how to reconcile different spatial scales to find the best common denominator to be used as an ecosystem-based management unit. For this, two fishery production zones differing ecologically, economically, legally and institutionally were investigated. The first case study is located within French territorial waters, in a MPA cr...

During the winter 2013-2014, severe storm events caused a coastal erosion in the southern part of the Beniguet Island (Brittany, France). The associated shoreline retreat had uncovered three layers of shell middens interbedded into an aeolian sand dune deposit. From several radiocarbon dating crossed with the study of ceramic and lithic contents, t...

Although stable isotope ratios are increasingly used to investigate the trophic ecology of marine organisms, their spatial variations are still poorly understood in the coastal environment. In this study, we measured the stable isotope composition (δ13C, δ15N) of suspended particulate organic matter (SPOM) (primary producer), a suspension feeder, t...

This research investigated how the carbon isotopic composition of food source (d13Cfood) and dissolved inorganic carbon (d13CDIC) influences the carbon isotopic composition of Pecten maximus shells (d13Cshell) under both experimental and natural conditions. The objectives are to better understand the relationship between P. maximus and its environm...

Tréguier A.M., Floc’H-Laizet C., 22 others, Paulet Y.M. and V. Pichereau, 2015.- LabexMER, A changing Ocean; 2012-2014 report. 90 p. available at http://www.labexmer.eu/fr/en/labexmer-2012-2014-report.pdf. Abstract: The cluster of excellence LabexMER was created in November 2011 in the framework of the French “investments for the future” program....

Sandy beaches, forming the most widespread coastal habitat in the world, are threatened by the effects of increasing anthropogenic pressure in the context of global change, including the increased occurrence of green tides composed of free-living Ulva spp. Sandy beaches are also highly dynamic ecosystems that support numerous essential ecological f...

Sandy beaches, forming the most widespread coastal habitat in the world, are threatened by the effects of increasing anthropogenic pressure in the context of global change, including the increased occurrence of green tides composed of free-living Ulva spp. Sandy beaches are also highly dynamic ecosystems that support numerous essential ecological f...

Biological invasions in wetlands by Water Primroses (Ludwigia grandiflora ssp. hexapetala and L. peploides ssp. montevidensis) are an increasing problem especially in wet meadows. The aim of this paper is to quantify differences between species and the adaptation of these amphibious plants in order to establish the consequences for site managers. T...

Cover illustration and graphic design : Sébastien Hervé / UBO-IUEM ;Coord : Dominique Simon

We estimate the magnesium stable isotopic composition (δ26Mg) of the major compartments involved in the biomineralisation process of euryhaline bivalve, the manila clam Ruditapes philippinarum. Our aim is to identify the fractionation processes associated with Mg uptake and its cycling/transport in the bivalve organism, in order to better assess th...

We investigated the relationships between the opacity and the physico-chemical characteristics of fish otoliths and more specifically their aragonite and organic fractions. The analysis of these two fractions on otolith macrostructures was performed using Raman micro-spectrometry on both translucent and opaque zones of otoliths of pollock (Pollachi...

Comparing aquatic and terrestrial forms of Ludwigia in western France: biomass and morphology. http://prodinra.inra.fr/record/200159

Sandy beaches, forming the most widespread coastal habitat in the world, are threatened by the effects of increasing anthropogenic pressure in the context of global change, including the increased occurrence of green tides composed of free-living Ulva spp. Sandy beaches are also highly dynamic ecosystems that support numerous essential ecological f...

Etude des formes terrestres de Jussie à grandes fleurs (Ludwigia grandiflora) dans le marais de Mazerolles en Loire Atlantique, Mise en place d’une expérience de lutte et de restauration prairiale. http://prodinra.inra.fr/record/295454

Plantes invasives dans les Marais Nord-Loire : bilan et analyse des expérimentations 2011

Expérimentation de gestion raisonnée de la Renouée du Japon (Reynoutria japonica). Site du «Moulin à papier», à Saint Calais du Désert (53). Synthèse d'intervention 2011 et rappel des résultats 2010. http://prodinra.inra.fr/record/295459

The periodicity of increment formation in the shell of the Manila clam Ruditapes philippinarum was investigated in the subtidal zone of the Auray River estuary (South Brittany, France). Calcein markings were performed at different periods between May and October 2007 using in situ benthic chambers tented by scuba divers. This study shows that shell...

Stable carbon isotopes of dissolved inorganic carbon (delta13C-DIC) often vary with salinity in estuarine settings. Variations of salinity in estuaries also complicate temperature reconstructions based on oxygen isotope values in biological carbonates. Therefore having a salinity proxy could assist in estuarine temperature reconstruction as well as...

To determine the potential of Antarctic bivalve shells as biomonitors for environmental and climatic variations in polar marine areas, we developed a growth model for juvenile Adamussium colbecki Smith, 1902 based on the use of in situ temporal calcein markings to calibrate growth patterns in the external striae formation. To minimize scallop stres...

The influences of diet and seawater dissolved inorganic carbon (DIC) on the carbon isotope composition of shell aragonite (δ13Cshell) in the Manila clam Ruditapes philippinarum reared under laboratory conditions were investigated. Clams were exposed to two successive negative carbon isotope shifts: a first shift in diet (δ13Cphytoplankton) and a se...

Here we present a novel approach for the interpretation of stable isotope signatures recorded in benthic foraminifera from subtidal estuarine environments. The stable isotopic composition (δ18O and δ13C) of living Ammonia tepida and Haynesina germanica is examined in four stations in the Auray River estuary (Gulf of Morbihan, France) sampled in two...

Mollusc shells are used as an archive of climate variability in polar areas. The geochemistry (isotope and trace element) of the mineralized tissues is sensitive to the seawater physico-chemical changes (temperature, salinity, primary production …) and the accretionary growth of the shells provide intra-annual to centennial information. However, a...

We examined d13Ccalcite variations along scallop shells (Pecten maximus) sampled in Norway, France and Spain. Time series of shell calcite d13C show a consistent pattern of decreasing d13C with age. This almost linear d13C trend reflects an increasing contribution of metabolic CO2 to skeletal carbonate throughout ontogeny. We have removed this onto...

It is generally accepted that the formation of otolith microstructures (L- and D-zones) and in particular the organic and mineral fractions vary on a daily basis. Raman microspectrometry provides a nondestructive technique that can be used to provide structural information on organic and mineral compounds. We applied it to thin otolith sections of...

Barium/calcium profiles of bivalve shells are characterized by flat background signals periodically interrupted by sharp peaks, with the background signals correlated with water Ba/Ca. To test if the peaks are an environmental signal related to productivity, we analyzed high-resolution Ba/Ca profiles in bivalve shells that grew adjacent to one anot...

Mg isotopes can be helpful tracers to reveal the fundamental pathways of Mg incorporation during biomineralisation. We report in this study a detailed characterisation of the Mg isotopic signatures of different biominerals: high magnesium calcitic skeletons of selected echinoderms (sea urchins and starfish) and low magnesium aragonitic shells of a...

To test the potential of diet switching experiments in ecophysiological studies of marine invertebrates, stable carbon isotope ratios were measured at different seasons in the gonad, adductor muscle, digestive gland and gills of scallops (Pecten maximus) and oysters (Crassostrea gigas) held for 15 days on a constant diet of phytoplankton depleted i...

According to the size-advantage hypothesis, protandric sequential hermaphroditism is expected when the increase in reproductive success with age or size is small for males but large for females. Interestingly, some protandrous molluscs have developed gregarious strategies that might enhance male reproductive success but at the cost of intraspecific...

The reproduction of Crepidula fornicata was studied in the Bay of Brest in order to characterise the first step of the reproductive cycle of this invasive species. The survey was carried out from 2000 to 2003 and different parameters were measured, namely, the percentage of the different sexual stages, the straight length of the shell and the perce...

Although Sr/Ca ratios in abiogenic calcite are strongly controlled by precipitation rates, such a kinetic effect has never been demonstrated in calcitic bivalve shells. Therefore, we report Sr/Ca ratios together with daily growth rates in the calcitic shells of four individuals of the bivalve Pecten maximus (age class I). Ratios of Sr/Ca were found...

We investigate the environmental and biological controls on oxygen isotope ratios in the shells of modern Pecten maximus bivalves collected alive in the Bay of Brest (France). Seasonal δ18O profiles, obtained by drilling the daily calcite ridges deposited at the surface of the left valve, were compared with in situ measurements of temperature and s...

We examined δ13C values of shallow and deep-water scallop shells as well as δ13C of dissolved inorganic carbon (DIC) from the Bay of Brest in western Brittany. Time series of shell calcite δ13C do not reflect seasonal variation in seawater δ13C, but rather show a consistent pattern of decreasing δ13C with age, suggesting a metabolic effect rather t...

Tributyltin (TBT) pollution has been assessed in NW Brittany since 1992 using the bioindicator imposex in Nucella lapillus. The Bay of Brest is highly polluted by TBT and the outgoing water mass has contaminated the adjacent NW coasts. However environmental conditions have been improving in NW Brittany. The decrease in TBT pollution is most likely...

The aim of this study was to determine a simple routine procedure to preserve, decarbonate and analyse low-carbonated filters of suspended particulate organic matter (POM) for particulate organic carbon and nitrogen content, and . Our goal was to analyse these four parameters from a single and entire filter of POM without altering the organic mater...

Bivalves skeletons are able to produce great geochemical proxies. But general calibration of those proxies are based on approximate time basis because of misunderstanding of growth rhythm. In this context, the Great scallop, Pecten maximus, appears to be a powerful tool as a daily growth deposit has been clearly identified for this species (Chauvau...

As scallop shells grow incrementally at a rate of one line per day, environmental changes could then be evidenced on a daily basis. As an example for trace element incorporation studies, barium is a geochemical tracer that can be directly related to oceanic primary productivity. Hence, monitoring Ba/Ca variations in a scallop shell should give info...

Ecological shifts from diatoms to other phytoplankton species have been related to decreasing Si :N and Si : P nutrient ratios. The Bay of Brest is such a perturbated ecosystem where Si has become limiting but where diatoms continue to dominate the phytoplankton throughout the productive period. Several hypothesis have been invoked to account for t...

There have been several studies where the isotopic composition of organisms has been determined seasonally, but fewer have examined separate organs. In this context, separate organs (e.g. gonad, digestive gland and muscle) of a suspension-feeder, the scallop Pecten maximus, were used to assess seasonal changes of both stable isotopes and biochemica...

Previous studies carried out in the bay of Brest on daily shell growth of Pecten maximus have demonstrated that temperature is a major control on daily shell growth in contrast to food supply. However, repeated events of slow growth have been observed during diatom and dinoflagellate blooms. The aim of this study was to determine how fluctuations i...

Vitamins B1(thiamin) and B2 (riboflavin) in eggs of the scallop Pecten maximus are highly utilized during larval development. Possible storage of these vitamins, for later transfer to gonads and eggs, was studied over the natural reproductive cycle of the scallop. Vitamin concentrations were measured during hatchery conditioning at three periods of...

A 45 days experiment was conducted by exposing adult scallops with empty gonads to three different photoperiod regimes under constant food and temperature conditions: Simulated natural/decreasing photoperiod (N), constant photoperiod (C) and increasing photoperiod (I). At the end of the experiment the I and C groups had significantly higher gonad i...

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. Concu...

The influence of environmental factors on reproduction and energy partitioning was investigated in scallops (Pecten maximus) maintained in a hatchery under `winter' and `spring' conditions of changing temperature and day-length. Biometric measurements revealed that `spring' conditions favoured gonad growth whereas `winter' conditions were associate...

The study of the effects of environmental factors on the daily growth of Pecten maximus juveniles (one- and two-year olds) in the Bay of Brest was prompted by the decline of the scallop fishery in the Bay. Scallops over 30 mm in shell length were collected monthly from October 1994 to November 1995. Daily shell growth rings were counted using image...

This work is part of the program 'crecruitment determinism in scallops' initiated in 1992 by the 'Contrat de Baie'. The aim of his research was to explain interannual abundance fluctuations obserbed for Pecten maximus, in the Bay of Brest. To this end an analytical approah to the life cycle of the species was undertaken to determine its critical ph...

Tributyltin (TBT) pollution in west Brittany coastal waters was assessed in 1992, 1993 and 1994 using the bioindicator of imposex (superimposition of male sexual characters on females) in the neogastropod Nucella lapillus. Imposex was detected at all 75 stations sampled, from Kerfissien on the north coast to Ile de Sein in the south-west, indicatin...

A male genital defect was reported in a Nucella lapillus (L.) population at Dumpton Gap (England). This defect was termed Dumpton syndrome (DS) and appears to be a genetic feature. Its main characteristic is the absence of penis (aphally) in males and in females. In 1992, such a phenomenon was discovered in populations in the vicinity of Brest (Bri...

The structural and functional aspects of the digestive gland in the endosymbiont-bearing bivalve Loripes lucinalis were examined. Specimens were collected over a one year period (September 1991 to September 1992) from the Moulin Blanc beach, Bay of Brest, (Brittany, France). The two apertures leading from the stomach into the digestive diverticula...

The distributions of Pecten maximus and its potential benthic competitors and predators in the Bay of Brest were studied from dredge samples to define best areas for seeding of scallop juveniles produced in hatcheries. Negative associations would occur between scallops and their main competitors (segregated distributions), reflecting negative densi...

The baie de Seme, the baie de St-Brieuc and the rade de Brest are the three main fisheries in France. Measurements made on spawners issues from these areas allow now to consider two separate reproductive strategies, in these populations. Scallops from the baie de St-Brieuc spawn during a short period (july-august), a sexual rest stage being observe...

Since the introduction of the Manila clam Ruditapes philippinarum (Mollusca: Bivalvia) to aquaculture clam beds, this species has spread to several sites. As a result, an extensive fishery has developed around this species. Its reproductive cycle and that of a native clam species, Ruditapes decussatus (Mollusca: Bivalvia) from two Brittany sites ar...

The distribution of serotonin-like immunoreactivity was studied in the central nervous system and the gonad of Pecten maximus. Cerebral and pedal ganglia contain a well developed serotonin-immunoreactive neuronal subpopulation, whereas positive neurons are scarce in the visceral ganglion. The distribution pattern of immunoreactive elements in the g...