First record of the non-indigenous Melita nitida Smith, 1873 (Crustacea: Amphipoda: Melitidae) in the Bay of Biscay (NE Atlantic)
The non-native amphipod Melita nitida Smith, 1873 was collected between 2013 and 2016 in Arcachon Bay, Hossegor Lake and the Gironde Estuary (SW France) in intertidal oyster reefs and under stones. This species, native to the Atlantic coast of North America, is considered as a non-indigenous species on the Pacific coast of North America. Recently, the presence of M. nitida was reported in Europe, both in The Netherlands and in Germany. This species may have been accidentally introduced to Arcachon Bay with oyster transfers. An identification key for species belonging to the genus Melita and closely related species in European waters is also provided.
(BioInvasions Records. vol. 5, n° 2242-1300, pp. 85-92, 01/01/2016)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Using recent high-frequency surveys to reconstitute 35 years of organic carbon variations in a eutrophic lowland river
Concentrations of dissolved and particulate organic carbon (DOC and POC), total suspended solids (TSS), were measured daily, and phytoplankton pigments (chlorophyll-a and pheopigments) were measured every 3 days at three strategic stations along the eutrophic Loire River between November 2011 and November 2013 marked by a high annual and seasonal variability in hydrological regimes. This unique high-frequency dataset allowed to determine the POC origin (autochthonous or allochthonous). Some strong relationships were evidenced between POC, total pigments and TSS and were tested on a long-term database with a lower frequency (monthly data) to reconstitute unmeasured algal and detrital POC concentrations and estimate annual total organic carbon (TOC) fluxes from 1980 onwards. The results were subjected to only ≈25 % uncertainty and showed that the annual TOC fluxes at the outlet of the Loire River decreased from 520 103 tC year−1 (i.e. 4.7 t km−2 year−1) in the early 1990s to 150 103 tC year−1 (i.e. 1.4 t km−2 year−1) in 2012. Although DOC always dominates, the autochthonous POC represented 35 % of the TOC load at the basin outlet by the end of the 1980s and declined to finally represent 15 % only of the TOC. The control of phosphorus direct inputs and the invasion by Corbicula clams spp. which both occurred since the early 1990s probably highly reduced the development of phytoplankton. Consequently, the autochthonous POC contribution declined and TSS concentrations in summertime significantly decreased as well as a result of both less phytoplankton and less calcite precipitation. At the present time, at least 75 % of the POC has allochthonous origins in the upper Middle Loire but downstream, autochthonous POC dominates during summer phytoplanktonic blooms when total pigments concentrations reach up to 70 μg L−1 (equivalent to 75 % of the total POC).
(Environmental Monitoring and Assessment. vol. 188, n° 0167-6369, pp. 41, 01/01/2016)
GéHCO, UT, NEOLAiA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Structure of Manila Clam (Ruditapes philippinarum) Microbiota at the Organ Scale in Contrasting Sets of Individuals
Marine invertebrate microbiota has a key function in host physiology and health. To date, knowledge about bivalve microbiota is poorly documented except public health concerns. This study used a molecular approach to characterize the microbiota associated with the bivalve Manila clam (Ruditapes philippinarum) by determining (1) the difference among organs either or not under the influence of host habitat, (2) small-scale variability of microbiota, and (3) the experimental response of the Manila clam microbiota submitted to different lateral transmissions. These questions were investigated by sampling two groups of individuals living in contrasting habitats and carrying out a transplant experiment. Manila clam microbiota (i.e., bacterial community structure) was determined at organ-scale (gills, gut, and a pool of remaining tissues) by capillary electrophoresis DNA fingerprinting (CE fingerprinting). The Manila clam microbiota structure differed among organs indicating a selection of Manila clam microbiota at organ scale. Habitat strongly influenced gill and gut microbiota. In contrast, microbiota associated with remaining tissues was similar between group individuals suggesting that these communities are mostly autochthonous, i.e., Manila clam specific. Transplant experiment showed that improving living condition did not induce any change in microbiota associated with remaining tissues. In contrast, the reduction in individual habitat quality led to individuals in declining health as strongly suggested by the increase in phagocytosis activity and decrease in condition index together with the change in internal organ microbiota. This study provides a first description of the Manila clam holobiont which can withstand disturbance and respond opportunistically to improved environmental conditions.
(Microbial ecology. vol. 71, n° 0095-3628, pp. 194-206, 01/01/2016)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, DFO-MPO, LEMAR, IRD, IFREMER, UBO EPE, CNRS
Danio rerio ABC transporter genes abcb3 and abcb7 play a protecting role against metal contamination
ATP‐binding cassette (ABC) proteins are efflux transporters and some of them are involved in xenobiotic detoxification. The involvement of four zebrafish ABC transporters in cadmium, zinc and mercury detoxification was characterized in a metal hypersensitive mutant of Escherichia coli. The E. coli tolC mutant expressing ABCB3 or ABCB7 transporters exhibited higher survival ratios and lower metal accumulation under a metal exposure condition than the controls. For instance, in the presence of 8 and 10 μM of HgCl2, the survival ratios of bacteria expressing ABCB3 were four and six‐times higher than the control whereas the mercury concentrations were 2.5 and 2‐times lower than in the control. This work provides new data on the function of zebrafish ABCB3 and ABCB7 transporters and highlights their significance in metal detoxification
(Journal of Applied Toxicology. vol. 36, n° 0260-437X, pp. 1551-1557, 01/01/2016)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Validation and uncertainties evaluation of an isotope dilution-SPE-LC–MS/MS for the quantification of drug residues in surface waters
The present work describes the development and validation of a reference method conducted at the French National Institute of Metrology (LNE) for the quantitative determination of psychoactive compounds in the dissolved fraction of surface waters. More specifically an isotope dilution-SPE-LC-MS/MS based method has been implemented for the characterization of a broad range of analytes belonging to different classes of psychotropic drugs such as benzodiazepines, antidepressants, stimulants, opiates and opioids, anticonvulsants, anti-dementia drugs, analgesics as well as the anti-inflammatory drug diclofenac in the low ng L(-1) range of concentration. Full validation of the method was performed following procedures described by the French standard NF T90-210. Limits of quantification between 0.14 and 3.54 ng L(-1) were obtained. Method recoveries from 71 to 123% were observed with standard deviation below 10% in intermediate precision conditions. Accuracy was determined for every compound: measurement errors were between -4 and +1% and standard deviations in intermediate precision conditions were included within a 1-9% interval. Finally, measurement uncertainties were evaluated following the Guide to the expression of uncertainty in measurement (GUM). Expanded uncertainties (k=2) ranged from 2% for carbamazepine, EDDP (2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine) and venlafaxine to 17% for diazepam. The validated method was implemented to Seine river surface waters demonstrating its fitness for purpose. All compounds were detected and 22 out of 25 analytes were quantified. More specifically, measured concentration ranged from 0.39 ng L(-1) for MDMA (3,4-methylene-dioxy-N-methylamphetamine) to 182 ng L(-1) for gabapentine.
(Talanta. vol. 146, n° 0039-9140, pp. 138-147, 01/01/2016)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Long-term (1998-2010) large-scale comparison of the ecological quality status of gulf of lions (NW Mediterranean) benthic habitats
A comprehensive Mediterranean data set has been used to address 3 questions associated with the use of sensitivity/tolerance based biotic indices to infer the Ecological Quality status (EcoQs) of benthic habitats. Our results showed: (1) a significant effect of the reference database on derived sensitivity/tolerance measure (ES500.05) as well as associated Benthic Quality Index values and derived EcoQs; (2) a lack of correlation neither between BQI and AZTI Marine Biotic Index values nor between BQI and Multivariate-AZTI Marine Biotic Index values; (3) a lack of correlation between the values of the Benthic Habitat Quality Index (index derived from Sediment Profile Imagery) and those of either of the 3 tested biotic indices; and (4) a general agreement between the 3 tested biotic indices in describing the lack of global trend for the EcoQs of the Gulf of Lions despite the occurrence of significant changes in benthic macrofauna composition between 1998 and 2010. (C) 2015 Elsevier Ltd. All rights reserved.
(Marine Pollution Bulletin. vol. 102, n° 0025-326X, pp. 102--113, 01/01/2016)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LECOB, OOB, UPMC, CNRS, UPMC, CNRS, CEAB, CSIC, IMBE, AU, AMU, CNRS, DIMAR, CNRS
Indicator-based assessment of marine biological diversity – lessons from 10 case studies across the European Seas
The Marine Strategy Framework Directive requires the environmental status of European marine waters to be assessed using biodiversity as one out of 11 descriptors, but the complexity of marine biodiversity and its large span across latitudinal and salinity gradients have been a challenge to the scientific community aiming to produce approaches for integrating information from a broad range of indicators. The Nested Environmental status Assessment Tool (NEAT), developed for the integrated assessment of the status of marine waters, was applied to ten marine ecosystems to test its applicability and compare biodiversity assessments across the four European regional seas. We evaluate the assessment results as well as the assessment designs of the ten cases, and how the assessment design, particularly the choices made regarding the area and indicator selection, affected the results. The results show that only 2 out of the 10 case study areas show more than 50 % probability of being in good status in respect of biodiversity. No strong pattern among the ecosystem components across the case study areas could be detected, but marine mammals, birds, and benthic vegetation indicators tended to indicate poor status while zooplankton indicators indicated good status when included into the assessment. The analysis shows that the assessment design, including the selection of indicators, their target values, geographical resolution and habitats to be assessed, has potentially a high impact on the result, and the assessment structure needs to be understood in order to make an informed assessment. Moreover, recommendations are provided for the best practice of using NEAT for marine status assessments.
(Frontiers in Marine Science. vol. 3, n° 2296-7745, pp. 159, 31/08/2026)
SYKE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, NIVA, NIOZ
Seasonal and long-term changes in elemental concentrations and ratios of marine particulate organic matter
What is the temporal variability of the elemental stoichiometry of marine microbial communities across ocean regions? To answer this question, we present an analysis of environmental conditions, particulate organic carbon, nitrogen, and phosphorus concentrations and their ratios across 20 time series (3-25 years duration) representing estuarine, coastal, and open ocean environments. The majority of stations showed significant seasonal oscillations in particulate organic elemental concentrations and ratios. However, shorter-term changes contributed most to overall variance in particulate organic matter concentrations and ratios. We found a correlation between the seasonal oscillations of environmental conditions and elemental ratios at many coastal but not open ocean and estuarine stations. C:N peaked near the seasonal temperature minimum and nutrient maximum, but some stations showed other seasonal links. C:N ratios declined with time over the respective observation periods at all open ocean and estuarine stations as well as at five coastal station but increased at the nine other coastal stations. C:P (but not N:P) declined slightly at Bermuda Atlantic Time-series Study but showed large significant increases at Hawaii Ocean Time-series and Arendal stations. The relationships between long-term changes in environmental conditions and particulate organic matter concentrations or ratios were ambiguous, but interactions between changes in temperature and nutrient availability were important. Overall, our analysis demonstrates significant changes in elemental ratios at long-term and seasonal time scales across regions, but the underlying mechanisms are currently unclear. Thus, we need to better understand the detailed mechanisms driving the elemental composition of marine microbial ecosystems in order to predict how oceans will respond to environmental changes.
(Global Biogeochemical Cycles. vol. 30, n° 0886-6236, pp. 1699-1711, 31/08/2026)
UPMC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Gene transcription profiling in wild and laboratory-exposed eels: Effect of captivity and in situ chronic exposure to pollution
Aquatic ecosystems are subjected to a variety ofman-induced stressors but also vary spatially and temporally due to variation in natural factors. In such complex environments, it remains difficult to detect, dissociate and evaluate the effects of contaminants in wild organisms. In this context, the aim of this study was to test whether the hepatic transcriptome profile of fish may be used to detect in situ exposure to a particular contaminant. Transcriptomic profiles from laboratory-exposed and wild eels sampled along a contamination gradient were compared. During laboratory experiments, fish were exposed during 45 days to different pollutants (Hg, PCBs, OCPs or Cd) or natural factors (temperature, salinity or lowfood supply) at levels close to those found in the sampling sites. A strong differencewas observed between the transcriptomic profiles obtained fromwild and laboratory-exposed animals (whatever the sites or experimental conditions), Suggesting a general stress induced by captivity in the laboratory. Among the biological functions that were up-regulated in laboratory eels in comparison to wild eels, histonemodification was the most represented. This finding suggests that laboratory conditions could affect the epigenome of fish and thus modulate the transcriptional responses developed by fish in response to pollutant exposure. Among experimental conditions, only the transcription profiles of laboratory animals exposed to cold temperature were correlated with those obtained from wild fish, and more significantly with fish from contaminated sites. Common regulated genes were mainly involved in cell differentiation and liver.
(Science of the Total Environment. vol. 571, n° 0048-9697, pp. 92-102, 31/08/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IRSTEA, ULaval, UR EABX, IRSTEA
Study of benthic foraminiferal faunas along the French Mediterranean coasts: a new biotic index in the EU Water Framework Directive
(31/08/2026)
LPG-ANGERS, LPG, UA, UN UFR ST, UN, INSU - CNRS, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS