@article {9245, title = {Physiological condition of the warty venus (Venus verrucosa L. 1758) larvae modulates response to pile driving and drilling underwater sounds}, journal = {Frontiers in Marine Science}, volume = {10}, year = {2023}, month = {Jul-06-2024}, abstract = {Noise is now recognized as a new form of pollution in marine coastal habitats. The development of marine renewable energies has introduced new sonorous perturbations, as the wind farm installation requires pile driving and drilling operations producing low frequency sounds at high sound pressure levels. Exponential expansion of offshore wind farms is occurring worldwide, making impact studies, particularly on benthic species highly abundant and diverse in the coastal area used for wind farming, a necessity. As larval recruitment is the basis for establishing a population, we conducted an experimental study to assess the interactive effects of pile driving or drilling sounds and larval rearing temperature on the endobenthic bivalve Venus verrucosa. In ectothermic animals, temperature modifies the organism{\textquoteright}s physiology, resulting in performance variability. We hypothesize that temperature modulation could change larval responses to noise and explore the potential interacting effects of temperature and noise. Using two distinct rearing temperatures, physiologically different batches of larvae were produced with contrasting fatty acid content and composition in the neutral and polar lipid fractions. Without defining any absolute audition threshold for the larvae, we demonstrate that the effects of temperature and noise were ontogenic-dependent and modulated larval performance at the peri-metamorphic stage, acting on the metamorphosis dynamic. At the pediveligers stage, a strong interaction between both factors indicated that the response to noise was highly related to the physiological condition of the larvae. Finally, we suggest that underwater noise reduces the compensatory mechanisms established to balance the temperature increase.}, keywords = {Anthropophony, energetic metabolism, fatty acids, larval recruitment, Metamorphosis trigger}, doi = {https://doi.org/10.3389/fmars.2023.1117431}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2023.1117431/full}, author = {Gigot, Mathilde and Tremblay, Rejean and Bonnel, Julien and Chauvaud, Laurent and Fr{\'e}d{\'e}ric Olivier} } @article {9473, title = {Seasonal lipid dynamics of four Arctic bivalves: Implications for their physiological capacities to cope with future changes in coastal ecosystemsAbstract}, journal = {Ecology and Evolution}, volume = {13}, year = {2023}, month = {Jan-11-2023}, abstract = {The Arctic is exposed to unprecedented warming, at least three times higher than the global average, which induces significant melting of the cryosphere. Freshwater inputs from melting glaciers will subsequently affect coastal primary production and organic matter quality. However, due to a lack of basic knowledge on the physiology of Arctic organisms, it remains difficult to understand how these future trophic changes will threaten the long-term survival of benthic species in coastal habitats. This study aimed to gain new insights into the seasonal lipid dynamics of four dominant benthic bivalves (Astarte moerchi, Hiatella arctica, Musculus discors, and Mya truncata) collected before and after sea ice break-up in a high-Arctic fjord (Young Sound, NE Greenland). Total lipid content and fatty acid composition of digestive gland neutral lipids were analyzed to assess bivalve energy reserves while the fatty acid composition of gill polar lipids was determined as a biochemical indicator of interspecies variations in metabolic activity and temperature acclimation. Results showed a decrease in lipid reserves between May and August, suggesting that bivalves have only limited access to fresh organic matter until sea ice break-up. The lack of seasonal variation in the fatty acid composition of neutral lipids, especially essential ω3 fatty acids, indicates that no fatty acid transfer from the digestive glands to the gonads occurs between May and August, and therefore, no reproductive investment takes place during this period. Large interspecies differences in gill fatty acid composition were observed, which appear to be related to differences in species life span and metabolic strategies. Such differences in gill fatty acid composition of polar lipids, which generally influence metabolic rates and energy needs, may imply that not all benthic species will be equally sensitive to future changes in primary production and organic matter quality in Arctic coastal habitats.}, keywords = {Arctic coastal ecosystems, Bivalve, Climate Change, energy reserves, fatty acids, homeoviscous adaptation, meltwater inputs, metabolic rate depression}, issn = {2045-7758}, doi = {10.1002/ece3.v13.1110.1002/ece3.10691}, url = {https://onlinelibrary.wiley.com/toc/20457758/13/11}, author = {Bridier, Guillaume and Fr{\'e}d{\'e}ric Olivier and Grall, Jacques and Chauvaud, Laurent and Sejr, Mikael K. and Tremblay, Rejean} } @article {8447, title = {Pull the trigger: interplay between benthic and pelagic cues driving the early recruitment of a natural bivalve assemblage}, journal = {Ecosphere}, volume = {13}, year = {2022}, month = {Jan-01-2022}, abstract = {Larval settlement and recruitment are crucial phases in the benthic-pelagic life cycle of marine benthic invertebrates that controls population dynamic and habitat connectivity. Our study investigated potential triggers driving the settlement of bivalve larvae in a highly dynamic intertidal coarse sand habitat. The early recruitment rate of five dominant bivalve families and abiotic conditions, particulate (\<20 {\textmu}m) organic matter and sediment organic matter, were monitored from May to October 2014. Pelagic particulate organic matter (\<20 {\textmu}m) was dominated by picoplankton throughout the sampling period, with a substantial diatom bloom in spring. Sediment was characterized by fresh organic matter in spring, as suggested by the dominant contribution of polyunsaturated fatty acids, and by a higher proportion of bacterial fatty acid markers during late summer. Different dynamics were also observed in early bivalve recruitment rates, with four different patterns observed over the sampling period. Multiple regression analysis on selected bivalve families showed species-specific responses to trophic settlement triggers. Indeed, the larva recruitment rate of Mytilidae paralleled pelagic concentration of picoeucaryotes, with the peak early recruitment rate occurring in spring. Surprisingly, the early recruitment rate of Mactridae larvae showed a significant relation to bacterial concentration in the surficial sediment at the end of summer. While the Mytilidae results in such a eutrophic system confirmed those of a previous study in oligotrophic lagoons, therefore supporting the trophic settlement trigger hypothesis, more work is needed to understand the potential role of bacteria in the early recruitment of Mactridae. These results highlight for the first-time inter-specific differences in trophic cues that potentially trigger primary settlement in natural bivalve assemblages.}, keywords = {bacteria, bivalves, Chausey Archipelago, early larval recruitment, fatty acids, picoeucaryotes, trophic settlement trigger}, issn = {2150-8925}, doi = {10.1002/ecs2.v13.110.1002/ecs2.3672}, url = {https://onlinelibrary.wiley.com/toc/21508925/13/1}, author = {Androuin, Thibault and Barbier, Pierrick and Foret, Martin and Tarik Meziane and Thomas, Mathilde and Archambault, Philippe and Winkler, Gesche and Tremblay, Rejean and Fr{\'e}d{\'e}ric Olivier} } @article {7185, title = {Food sources, digestive efficiency and resource allocation in the sea cucumber Holothuria forskali (Echinodermata: Holothuroidea): Insights from pigments and fatty acids}, journal = {Aquaculture Nutrition}, volume = {26}, year = {2020}, month = {Apr-08-2022}, pages = {1568-1583}, abstract = {Various research projects in Europe and North Africa have recently intended to breed temperate holothurians to alleviate fishing pressure on natural populations. However, to date little is known about the nutritional requirements of East Atlantic and Mediterranean species. In this study, we propose a {\textquotedblleft}natural population{\textquotedblright}-oriented approach to characterize food sources, digestive efficiency and resources allocation based on the composition of pigments and fatty acids (FA) in gut contents and tis- sues (muscles, gonads and digestive tract walls) of wild individuals of the species Holothuria (Panningothuria) forskali (Delle Chiaje, 1823) sampled in Brittany (France). Our study reveals that neither green nor red algae enter the diet of H. forskali in spring and that the only fresh vegetal material found in gut contents is brown algae (very likely diatoms). The high nutritional quality of gut contents however contrasts with the detrital nature of the ingested food sources, suggesting that a trophic up- grading of organic matter occurs before digestion. In addition, unusual FA (i.e. only present in a few groups of living species) such as long-chain monounsaturated FA (especially the FA 23:1ω9) were found in large proportions in muscles and gonad and their effect on sea cucumber fitness needs further investigation.}, keywords = {echinoderms, fatty acids, gut contents, Holothuria forskali, pigments, sea cucumbers}, issn = {1353-5773}, doi = {10.1111/anu.13103}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/anu.13103}, author = {Frank David and C{\'e}dric Hubas and Laguerre, Hel{\`e}ne and Badou, Aicha and Herault, Gwen and Bordelet, Th{\'e}o and Ameziane, Nadia} } @article {7122, title = {Laminariales Host Does Impact Lipid Temperature Trajectories of the Fungal Endophyte Paradendryphiella salina (Sutherland.)}, journal = {Marine Drugs}, volume = {18}, year = {2020}, pages = {379}, abstract = {Kelps are colonized by a wide range of microbial symbionts. Among them, endophytic fungi remain poorly studied, but recent studies evidenced yet their high diversity and their central role in algal defense against various pathogens. Thus, studying the metabolic expressions of kelp endophytes under different conditions is important to have a better understanding of their impacts on host performance. In this context, fatty acid composition is essential to a given algae fitness and of interest to food web studies either to measure its nutritional quality or to infer about its contribution to consumers diets. In the present study,\ Paradendryphiella salina, a fungal endophyte was isolated from\ Saccharina latissima\ (L.) and\ Laminaria digitata\ (Hudson.) and its fatty acid composition was assessed at increasing salinity and temperature conditions. Results showed that fungal composition in terms of fatty acids displayed algal-dependent trajectories in response to temperature increase. This highlights that C18 unsaturated fatty acids are key components in the host-dependant acclimation of\ P. salina\ to salinity and temperature changes}, keywords = {fatty acids, fungal endophytes, laminariales, Paradendryphiella salina}, doi = {10.3390/md18080379}, url = {https://www.mdpi.com/1660-3397/18/8/379}, author = {Vallet, Marine and Tarik Meziane and Najet Thiney and Prado, Soizic and C{\'e}dric Hubas} } @article {5315, title = {Cultured eastern oysters (Crassostrea virginica): retention and assimilation of picophytoplankton using a multi-biomarker approach}, journal = {Aquatic Living Resources}, volume = {30}, year = {2018}, month = {08/2018}, type = {Article}, abstract = {

{In this study, we investigated the food sources of eastern oysters Crassostrea virginica cultivated in Atlantic Canada. Stable isotopes (C-13 and N-15) and fatty acid biomarkers were used to identify these sources under in situ conditions for suspended (similar to 0.5 m below surface) and bottom(similar to 2 m) culture stocks. It was found that particulate organic matter represented the main food source, with major contributions from live phytoplankton. Higher lipid contents were detected in the digestive glands of suspended oysters compared to bottom oysters (p \< 0.05). Bottom oysters did not show significant preference for detrital or bacterial organic matter. Near-surface waters contained an elevated picophytoplankton biomass (PPP, 0.2-2 mu m, 1.93 +/- 0.16mg l(-1), mean +/- SEM) compared to nanophytoplankton biomass (NPP, \> 2 mu m, 1.05 +/- 0.15 mu g l(-1), mean +/- SEM). To determine whether the small size PPP was captured and assimilated by C. virginica, feeding trials were conducted in the laboratory using three PPP/NPP diets (20\%, 50\%, and 80\% PPP), consisting of isotopically-labelled (delta C-13) PPP cells (Nannochloropsis oculata) and non-labelled NPP cells (Tisochrysis lutea). An isotopically-labelled fatty acids analysis indicated PPP assimilation in various tissues (digestive gland, gills, mantle, and abductor muscle), including from oysters fed the reduced (20\%) PPP diet. Isotopic enrichment (C-13) in the FA 22:2 (non-methylene-interrupted or NMI) showed that precursors of NMIs utilized PPP carbon in its biosynthesis process. In conclusion, C. virginica assimilated primarily particulate organic matter (POM), including PPP, which dominated the phytoplankton community in near surface waters. C. virginica can exploit PPP carbon during fatty acid production and further biosynthesis.}

}, keywords = {Aquaculture, fatty acids, Picophytoplankton, Shellfish}, Stable isotopes, {Crassostrea virginica}, issn = {{0990-7440}}, doi = {{10.1051/alr/2017031}}, author = {R{\'e}mi Sonier and R{\'e}jean Tremblay and Fr{\'e}d{\'e}ric Olivier and Tarik Meziane and Comeau, Luc Andre} } @article {4340, title = {The fate of C4 and C3 macrophyte carbon in central Amazon floodplain waters: Insights from a batch experiment}, journal = {Limnologica - Ecology and Management of Inland Waters}, volume = {59}, year = {2016}, pages = {90-98}, abstract = {

The central Amazon floodplains are particularly productive ecosystems, where a large diversity of organic carbon sources are available for aquatic organisms. Despite the fact that C4 macrophytes generally produce larger biomasses than C3 macrophytes, food webs in the central Amazon floodplains appear dominantly based on a C3 carbon source.

In order to investigate the respective fate and degradation patterns of C4 and C3 aquatic plant-derived material in central Amazon floodplains, we developed a 23-days batch experiment. Fatty acid and carbon concentrations as well as stable isotope compositions were monitored over time in 60\ L tanks. These tanks contained Amazon water, with different biomasses of C3 and C4 macrophyte, representative of in situ densities occurring in central Amazon floodplains.

In the C4Paspalum repens treatments, organic (POC, DOC) and inorganic carbon (DIC) got rapidly enriched in 13C, whereas in the C3Salvinia auriculata treatments, POC and DOC showed little change in concentration and isotopic composition, and DIC got depleted in 13C. The contribution of P. repens to POC and DOC was estimated to reach up to 94.2 and 70.7\%, respectively. In contrast, no differences were reported between the C3S. auriculata and control treatments, an observation attributed to the lower C3 biomass encountered in the field, to a slower degradation rate of C3 compared to C4 compounds, and to similar isotopic compositions for river POC and DOC, and C3 compounds.

The 13C enrichments of POC, DOC, and DIC from P. repens treatments were attributed to an enhanced bacterially-mediated hydrolysis and mineralization of C4 material. Evolutions of bacterial abundance and branched fatty acid concentrations confirmed the role of heterotrophic microbial communities in the high P. repens decomposition rate. Our experiment highlights the predominant role of C4 aquatic plants, as a large source of almost entirely biodegradable organic matter available for heterotrophic activity and CO2 outgassing to the atmosphere.

}, keywords = {Central amazon, Degradation, fatty acids, Floodplains, Macrophytes, Stables isotopes}, doi = {doi:10.1016/j.limno.2016.03.008}, author = {Jean-Michel Mortillaro and Passarelli, C and Gwena{\"e}l Abril and C{\'e}dric Hubas and Luis Felipe Artigas and Marc F Benedetti and Najet Thiney and Moreira-Turcq, P and P{\'e}rez, M A and Vidal, L and Tarik Meziane} } @article {3663, title = {Foraminiferal assemblages as bioindicators to assess potential pollution in mangroves used as a natural biofilter for shrimp farm effluents (New Caledonia)}, journal = {Marine Pollution Bulletin}, volume = {93}, year = {2015}, month = {15 April 2015}, pages = {103-120}, type = {Research}, abstract = {

In New Caledonia, semi-intensive shrimp farms release untreated effluents into the mangrove. Foraminiferal assemblages were analyzed for assessing the impact of effluent release on the benthic compartment. Comparison was made between samples collected (1) in an effluent receiving mangrove before and after the rearing cycle, and (2) for one-year monitoring an effluent receiving and a control mangrove. The distribution of foraminiferal assemblages was primarily driven by the gradient between\ Rhizophora\ stands and salt-flats, related to salinity and tidal elevation, and by seasonal cycles. The potential impact of effluent release was due to the combined effects of normal-saline effluents on surface salinity, and of nutrient input and microbial stimulation on food availability. Foraminiferal assemblages did not indicate a substantial impact of farm effluents and suggest that semi-intensive shrimp farming using mangrove for effluent discharge may appear as a sustainable solution in New Caledonia, when considering only the impact on the mangrove itself.

}, keywords = {Effluents, fatty acids, Foraminifera, Mangrove, Shrimp farming, SW Pacific}, doi = {10.1016/j.marpolbul.2015.02.009}, author = {Debenay, J-P and Cyril Marchand and Nathalie Molnar and Ad{\'e}laide Aschenbroich and Tarik Meziane} } @article {3383, title = {Seasonal variations of the composition of microbial biofilms in sandy tidal flats: Focus of fatty acids, pigments and exopolymers}, journal = {Estuarine, Coastal and Shelf Science}, volume = {153}, year = {2015}, pages = {29 - 37}, abstract = {

Abstract Biofilms, or microbial mats, are common associations of microorganisms in tidal flats; they generally consist of a large diversity of organisms embedded in a matrix of Extracellular Polymeric Substances (EPS). These molecules are mainly composed of carbohydrates and proteins, but their detailed monomer compositions and seasonal variations are currently unknown. Yet this composition determines the numerous roles of biofilms in these systems. This study investigated the changes in composition of carbohydrates in intertidal microbial mats over a year to decipher seasonal variations in biofilms and in varying hydrodynamic conditions. This work also aimed to assess how these compositions are related to microbial assemblages. In this context, natural biofilms whose development was influenced or not by artificial structures mimicking polychaete tubes were sampled monthly for over a year in intertidal flats of the Chausey archipelago. Biofilms were compared through the analysis of their fatty acid and pigment contents, and the monosaccharide composition of their \{EPS\} carbohydrates. Carbohydrates from both colloidal and bound \{EPS\} contained mainly glucose and, to a lower extent, galactose and mannose but they showed significant differences in their detailed monosaccharide compositions. These two fractions displayed different seasonal evolution, even if glucose accumulated in both fractions in summer; bound \{EPS\} only were affected by artificial biogenic structures. Sediment composition in fatty acids and pigments showed that microbial communities were dominated by diatoms and heterotrophic bacteria. Their relative proportions, as well as those of other groups like cryptophytes, changed between times and treatments. The changes in \{EPS\} composition were not fully explained by modifications of microbial assemblages but also depended on the processes taking place in sediments and on environmental conditions. These variations of \{EPS\} compositions are likely to alter different ecosystem processes such as biostabilisation or pollutants trapping.

}, keywords = {biofilms, biogenic structures, EPS, fatty acids, monosaccharide composition, pigments}, issn = {0272-7714}, doi = {http://dx.doi.org/10.1016/j.ecss.2014.11.013}, url = {http://www.sciencedirect.com/science/article/pii/S0272771414003412}, author = {Passarelli, C and Tarik Meziane and Najet Thiney and Dominique Boeuf and B Jesus and Mickael Ruivo and Christian Jeanthon and C{\'e}dric Hubas} } @article {3941, title = {Spatial changes in fatty acids signatures of the great scallop Pecten maximus across the Bay of Biscay continental shelf}, journal = {Continental Shelf Research}, volume = {109}, year = {2015}, month = {15/10/2015}, pages = {1-9}, abstract = {

The spatial variability of food resources along continental margins can strongly influence the physiology and ecology of benthic bivalves. We explored the variability of food sources of the great scallop Pecten maximus, by determining their fatty acid (FA) composition along an inshore{\textendash}offshore gradient in the Bay of Biscay (from 15 to 190\ m depth). The FA composition of the digestive gland showed strong differences between shallow and deep-water habitats. This trend was mainly driven by their content in diatom-characteristic fatty acids, which are abundant near the coast. Scallops collected from the middle of the continental shelf were characterized by higher contents of flagellate markers than scallops from shallow habitats. This could be related to a permanent vertical stratification in the water column, which reduced vertical mixing of waters, thereby enhancing organic matter recycling through the microbial loop. In the deeper water station (190\ m), FA compositions were close to the compositions found in scallops from shallow areas, which suggest that scallops could have access to the same resources (i.e. diatoms). Muscle FA composition was more indicative of the physiological state of scallops over this depth range, revealing contrasting reproductive strategies among the two coastal sites and metabolic or physiological adaptation at greater depth (e.g. structural and functional adjustments of membrane composition). This study therefore revealed contrasted patterns between shallow and deeper habitats for both P. maximus muscle and digestive gland tissues. This emphasizes the variability in the diet of this species along its distribution range, and stresses the importance of analyzing different tissues for their FA composition in order to better understand their physiology and ecology.

}, keywords = {Depth gradient, fatty acids, Metabolism, Pecten maximus, Trophic markers}, author = {Nerot, C and Tarik Meziane and Gauthier Schaal and Grall, J and Lorrain, A and Paullet, Y-M and Kraffe, E} } @article {3522, title = {Spatio-temporal variations in the composition of organic matter in surface sediments of a mangrove receiving shrimp farm effluents (New Caledonia)}, journal = {Science of The Total Environment}, volume = {512{\textendash}513}, year = {2015}, pages = {296 - 307}, abstract = {

In order to investigate spatio-temporal variations in the composition and origin of the benthic organic matter (OM) at the sediment surface in mangrove receiving shrimp farm effluents, fatty acid (FA) biomarkers, natural stable isotopes (δ13C and δ15N), C:N ratios and chlorophyll-a (chl-a) concentrations were determined during the active and the non-active period of the farm. Fatty acid compositions in surface sediments within the mangrove forest indicated that organic matter inputs varied along the year as a result of farm activity. Effluents were the source of fresh particulate organic matter for the mangrove, as evidenced by the unsaturated fatty acid (UFA) distribution. The anthropogenic \{MUFA\} 18:1ω9 was not only accumulated at the sediment surface in some parts of the mangrove, but was also exported to the seafront. Direct release of bacteria and enhanced in situ production of fungi, as revealed by specific FAs, stimulated mangrove litter decomposition under effluent runoff condition. Also, microalgae released from ponds contributed to maintain high benthic chl-a concentrations in mangrove sediments in winter and to a shift in microphytobenthic community assemblage. Primary production was high whether the farm released effluent or not which questioned the temporary effect of shrimp farm effluent on benthic microalgae dynamic. This study outlined that mangrove benthic organic matter was qualitatively and quantitatively affected by shrimp farm effluent release and that responses to environmental condition changes likely depended on mangrove stand characteristics.

}, keywords = {Chlorophyll-a, fatty acids, Mangrove, Organic matter, Shrimp farming, Stable isotopes}, issn = {0048-9697}, doi = {http://dx.doi.org/10.1016/j.scitotenv.2014.12.082}, url = {http://www.sciencedirect.com/science/article/pii/S0048969714017938}, author = {Ad{\'e}laide Aschenbroich and Cyril Marchand and Nathalie Molnar and Jonhatan Deborde and C{\'e}dric Hubas and Herv{\'e} Rybarczyk and Tarik Meziane} }