%0 Journal Article %J Science of The Total Environment %D 2022 %T Chlordecone-contaminated epilithic biofilms show increased adsorption capacities %A Cédric Hubas %A Monti, Dominique %A Jean-Michel Mortillaro %A Augagneur, Sylvie %A Carbon, Anne %A Duran, Robert %A Karama, Solange %A Tarik Meziane %A Pardon, Patrick %A Risser, Théo %A Tapie, Nathalie %A Najet Thiney %A Budzinski, Hélène %A Lauga, Béatrice %B Science of The Total Environment %V 825 %P 153942 %8 Jan-06-2022 %G eng %U https://linkinghub.elsevier.com/retrieve/pii/S0048969722010348 %! Science of The Total Environment %R 10.1016/j.scitotenv.2022.153942 %0 Journal Article %J Cybium %D 2018 %T Selectivity on epilithic diatom consumption for two tropical sympatric gobies: Sicydium punctatum (Perugia 1986) and Sicydium plumieri (Bloch 1786) %A Monti, Dominique %A Lefrançois, F %A Clara Lord %A Jean-Michel Mortillaro %A Pascal Jean Lopez %A Philippe Keith %K Biofilm %K Bioindication %K Caribbean Islands %K Gobiidae %K Tropical rivers %X

 

 Rivers of the Caribbean islands harbour a freshwater fauna mainly constituted of migrant diadromous species. In these hyperturbulent ecosystems, the primary producers are mostly represented by a thin epilithic biofilm, mainly composed of diatoms. Comparison of the diatoms available from the environment with the ones consumed and located in the digestive tracts of two gobiid fish, Sicydium punctatum Perugia, 1896 and Sicydium plumieri (Bloch, 1786) were made at twelve sampling locations, located upstream or downstream of six rivers, in Guadeloupe. One hundred and ninety-one epilithic diatom species were identified. A statistical approach was used to determine diatoms that best characterize the two species digestive tracts content (i.e. “diagnostic species”) and to evaluate the statistical relationship between species abundances and groups of sites or conditions. Eight taxa belonging to five families were considered as significant diagnostic species of digestive tracts from fish collected upstream (Achnanthidium subhudsonis, Achnanthes rupestoides, Diadesmis contenta, Diadesmis sp., Eolimna sp., Navicula (dicta) seminulum, Navicula difficillima and Nupela sp.), and five taxa belonging to three families were considered as significant diagnostic species for fish collected downstream (Gomphonema parvulum, Navicula arvensis, Navicula cruxmeridionalis, Nitzschia frustulum and Navicula incarum). Results indicate selective consumption of epilithic diatoms by the two major fish observed in the mid and upper stream of Caribbean rivers

%B Cybium %V 42 %P 365-373 %G eng %N 4 %0 Journal Article %J Limnologica - Ecology and Management of Inland Waters %D 2016 %T The fate of C4 and C3 macrophyte carbon in central Amazon floodplain waters: Insights from a batch experiment %A Jean-Michel Mortillaro %A Passarelli, C %A Gwenaël Abril %A Cédric Hubas %A Luis Felipe Artigas %A Marc F Benedetti %A Najet Thiney %A Moreira-Turcq, P %A Pérez, M A %A Vidal, L %A Tarik Meziane %K Central amazon %K Degradation %K fatty acids %K Floodplains %K Macrophytes %K Stables isotopes %X

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.

%B Limnologica - Ecology and Management of Inland Waters %V 59 %P 90-98 %G eng %R doi:10.1016/j.limno.2016.03.008 %0 Journal Article %J Marine Ecology and Progress Series %D 2016 %T Geographic variation in stable isotopic and fatty acid composition of anguilliform leptocephali and particulate organic matter in the South Pacific %A Liénart, Camilla %A Eric Feunteun %A Miller, M J %A Aoyama, J %A Jean-Michel Mortillaro %A Cédric Hubas %A Kuroki, M %A Watanabe, S %A Christine Dupuy %A Alexandre Carpentier %A Otake, T %A Tsukamoto, K %A Tarik Meziane %K Leptocephali · Fatty acids · Stable isotopes · Biomarkers · Trophic ecology · Oceanic currents %X

The feeding ecology of leptocephali has remained poorly understood because they apparently feed on particulate organic matter (POM), which varies in composition, and it is unclear which components of the POM they assimilate. The δ13C and δ15N stable isotope (SI) and fatty acid (FA) compositions of 3 families of leptocephali and POM were compared in 3 latitudinal current zones of the western South Pacific. The δ15N signatures of leptocephali and POM overlapped, with both having their lowest values in the southern current zone. POM in general (across all zones) contained 38 FAs and was rich in saturated FAs (SFA) (16:0, 18:0, 14:0), while leptocephali contained 50 FAs, with high proportions of 16:0, and higher contributions of 22:6ω3, 20:5ω3, 18:1ω9, 16:1ω7 and other FAs than found in the POM. Serrivomeridae leptocephali in the north had higher δ15N signatures and were also distinguished from Nemichthyidae and Muraenidae larvae by their FA compositions (higher SFAs, lower 22:6ω3 and 20:5ω3). Although SI signatures of the Serrivomeridae larvae did not clearly vary with size, 16:0 and 18:0 FA proportions decreased with increasing larval size, and 22:6ω3 and 16:1ω7 increased in larger larvae. Correspondences between the latitudinal variations in nitrogen SI signatures and FA compositions of POM with those of leptocephali and the presence of FA markers of both autotrophic and heterotrophic organisms were consistent with leptocephali feeding on POM. POM can contain various materials from primary producers and heterotrophic microorganisms, but differences in the SI signatures and FA compositions in leptocephali remain to be explained through further research.

%B Marine Ecology and Progress Series %V 544 %P 225-241 %@ doi:10.3354/meps11575 %G eng %0 Journal Article %J Biogeosciences %D 2016 %T Spatial and seasonal contrasts of sedimentary organic matter in floodplain lakes of the central Amazon basin %A Sobrinho, R L %A Bernardes, Marcelo C %A Gwenaël Abril %A Kim, J-H %A Zell, C %A Jean-Michel Mortillaro %A Tarik Meziane %A Moreira-Turcq, P %A J S Sinningh Damsté %X


In this study, we investigated the seasonal and spatial pattern of sedimentary organic matter (SOM) in five floodplain lakes of the central Amazon basin (Cabaliana, Janauaca, Canaçari, Mirituba and Curuai) which have different morphologies, hydrodynamics and vegetation coverages. Surface sediments were collected in four hydrological seasons: low water (LW), rising water (RW), high water (HW) and falling water (FW) in 2009 and 2010. We inves-tigated commonly used bulk geochemical tracers such as the C/N ratio and the stable isotopic composition of organic carbon (13Cor). These results were compared with lignin phenol parameters as an indicator of vascular plant detritus and branched glycerol dialkyl glycerol tetraethers (brGDGTs) to trace the input of soil organic matter (OM) from land to the aquatic settings. We also applied the crenarchaeol as an indi- cator of aquatic (rivers and lakes) OM. Our data showed that during the RW and FW seasons, the surface sediments were enriched in lignin and brGDGTs in comparison to other seasons. Our study also indicated that floodplain lake sediments primarily consisted of allochthonous, C3 plant-derived OM. However, a downstream increase in C4 macrophyte-derivedOM contribution was observed along the gradient of increas-ing open waters – i.e., from upstream to downstream. Accordingly, we attribute the temporal and spatial difference in SOM composition to the hydrological dynamics between the floodplain lakes and the surrounding flooded forests.
 

%B Biogeosciences %V 13 %G eng %N 467– 482 %9 original %0 Journal Article %J Freshwater Biology %D 2015 %T Trophic opportunism of central Amazon floodplain fish %A Jean-Michel Mortillaro %A Marc Pouilly %A Wach, M %A Carlos E.C. Freitas %A Gwenaël Abril %A Tarik Meziane %B Freshwater Biology %V 60 %P 1659–1670 %G eng