http://hdl.handle.net/2268/138 Search this channel search http://orbi.ulg.ac.be/simple-search http://hdl.handle.net/2268/148513 Title: Late Holocene changes in cyanobacterial community structure in maritime Antarctic lakes <br/> <br/>Author, co-author: Fernandez-Carazo, Rafael; Verleyen, Elie; Hodgson, Dominic A; Roberts, Stephen J; Waleron, Kzrysztof; Vyverman, Wim; Wilmotte, Annick <br/> <br/>Abstract: Despite the dominance of cyanobacteria in polar freshwater aquatic ecosystems, little is known about their past biodiversity and response to climate and environmental changes. We explored the use of light microscopy of microfossils, high performance liquid chromatography of the fossil pigment composition and denaturing gradient gel electrophoresis of fossil 16S rRNA genes to study past and present-day differences in cyanobacterial community structure in response to climate changes in two adjacent maritime Antarctic lakes with contrasting depths (4 and 26 m) and light climates. Light microscopy was of limited use because of degradation of cell structures. Fossil cyanobacterial pigment concentrations were below the detection limits of our method in several sediment samples in the deep lake, but abundant and diverse inthe sediment core from the shallow pond, probably as a consequence of increased light availability and/or a more diverse and abundant benthic cyanobacterial flora. Total carotenoid and chlorophyll concentrations were highest in both lakes between ca. 2,950 and 1,800 cal yr BP, which coincides with the late Holocene climate optimum recognised elsewhere in maritime Antarctica. Cyanobacterial molecular diversity was higher in the top few centimeters of the sediments in both lakes. In deeper sediments, the taxonomic turnover of cyanobacteria appeared to be relatively small in response to past climate anomalies in both lakes, underscoring the broad tolerance of cyanobacteria to environmental variability. This, however, may in part be explained by the low taxonomic resolution obtained with the relatively conserved 16S rRNA gene and/or the preferential preservation of particular taxa. Our results highlight the potential of fossil DNA in lake sediments to study colonization and succession dynamics of lacustrine cyanobacteria and warrant further investigation of the factors that affect preservation of cyanobacterial DNA. Wed, 15 May 2013 11:04:47 GMT http://hdl.handle.net/2268/148305 Title: Evaluation of gross primary production, community respiration, and net community production in various benthic communities (Posidonia oceanica seagrass meadow, Posidonia oceanica litter, epilithic macro-algae) in the Bay of Revellata (Corsica) using optodes <br/> <br/>Author, co-author: Champenois, Willy; Lepoint, Gilles; Borges, Alberto Mon, 13 May 2013 07:22:51 GMT http://hdl.handle.net/2268/148098 Title: Seasonal and inter-annual variations of gross primary production, community respiration, and net community production of a seagrass meadow <br/> <br/>Author, co-author: Borges, Alberto; Champenois, Willy Thu, 09 May 2013 12:25:40 GMT http://hdl.handle.net/2268/148097 Title: The influence of biogeochemical processes on the pH dynamics in the seasonally hypoxic saline Lake Grevelingen, The Netherlands <br/> <br/>Author, co-author: Hagens, M; Slomp, C; Meysman, F; Brenner, H; Borges, Alberto; Middelburg, J Thu, 09 May 2013 10:18:33 GMT http://hdl.handle.net/2268/147925 Title: Similar local and landscape processes affect both a common and a rare newt species <br/> <br/>Author, co-author: Denoël, Mathieu; Perez, Amélie; Cornet, Yves; Ficetola, G. Francesco <br/> <br/>Abstract: Although rare species are often the focus of conservation measures, more common species may experience similar decline and suffer from the same threatening processes. We tested this hypothesis by examining, through an information-theoretic approach, the importance of ecological processes at multiple scales in the great crested newt Triturus cristatus, regionally endangered and protected in Europe, and the more common smooth newt, Lissotriton vulgaris. Both species were similarly affected by the same processes, i.e. suitability of aquatic and terrestrial components of their habitat at different scales, connectivity among breeding sites, and the presence of introduced fish. T. cristatus depended more on water depth and aquatic vegetation than L. vulgaris. The results show that environmental pressures threaten both common and rare species, and therefore the more widespread species should not be neglected in conservation programs. Because environmental trends are leading to a deterioration of aquatic and terrestrial habitat features required by newt populations, populations of the common species may follow the fate of the rarest species. This could have substantial conservation implications because of the numerical importance of common species in ecosystems and because commonness could be a transient state moving towards rarity. On the other hand, in agreement with the umbrella species concept, targeting conservation efforts on the most demanding species would also protect part of the populations of the most common species. Mon, 06 May 2013 08:38:26 GMT http://hdl.handle.net/2268/147065 Title: Stables isotopes in the fin whale Balaenoptera physalus from the Mediterranean Sea: implications for management and conservation <br/> <br/>Author, co-author: Das, Krishna; Lepoint, Gilles; Michel, Loïc; Ody, Denis; Tasciotti, Aurélie <br/> <br/>Abstract: The fin whale (Balaenoptera physalus) is the commonest large whale species in the Mediterranean Sea, found mostly over deep, offshore waters of the western and central portion of the region. This whale is known to feed mainly on krill in contrast to its Atlantic counterpart, displaying a more diversified diet. δ13C and δ15N values were analysed by IR-MS (Isoprime 100) coupled to an N-C-S elemental analyser (Vario MICRO Cube, Elementar) in 113 skin biopsies from Mediterranean fin whales sampled in 2010 and 2011 during WWF campaign at sea. A lipid normalization equation was applied (adapted from Post al. 2007) because the measured C:N ratio was > 3.5. Normalized δ13C and δ15N values ranged from -20.3 to -17.3 ‰ and from 5.9 to 8.9 ‰, respectively. These values are in good agreement with those collected previously on baleen plates from Mediterranean fin whales (Bentaleb et al., 2011). A mean enrichment of 3.4 ‰ was observed between δ15N values measured in fin whale skin biopsies and Mediterranean krill (Meganyctiphanes norvegica) confirming the importance of the krill as a major food source. The narrow width of the isotopic niche of the Mediterranean fin whale (evaluated by SIBER Stable Isotope Bayesian Ellipses) compared to the Atlantic fin whale (Ryan et al. 2012) raises many concerns in the context of global changes and long-term consequences. One could expect that species displaying narrow niches would be more susceptible to ecosystem fragmentation and other anthropogenic impacts. Thu, 18 Apr 2013 07:44:57 GMT http://hdl.handle.net/2268/146796 Title: Denitrification, anammox and fixed nitrogen removal in the water column of a tropical great lake <br/> <br/>Author, co-author: Darchambeau, François; Roland, Fleur; Crowe, SA; De Brabandere, L; Llirós, M; Garcia-Armisen, T; Inceoglu, O; Michiels, C; Servais, P; Morana, CDT; Bouillon, S; Meysman, F; Veuger, B; Masilya, PM; Descy, JP; Borges, Alberto Mon, 15 Apr 2013 07:15:07 GMT http://hdl.handle.net/2268/146793 Title: Two year study of CO2, CH4 and N2O dynamics and fluxes in four rivers in Belgium (Meuse, Ourthe, Geer and Blanc Gravier) <br/> <br/>Author, co-author: Borges, Alberto; Darchambeau, François; Beulen, Aurore Mon, 15 Apr 2013 05:38:06 GMT http://hdl.handle.net/2268/146790 Title: Biogeochemistry, transport fluxes and emission of greenhouse gases from the Niger River (West Africa): preliminary results after two years of monitoring <br/> <br/>Author, co-author: Darchambeau, François; Bouillon, S; Alhou, B; Borges, Alberto Sun, 14 Apr 2013 19:37:40 GMT http://hdl.handle.net/2268/146789 Title: Teleconnections between ecosystem productivity and climate indices in a tropical great lake <br/> <br/>Author, co-author: Darchambeau, François; Borges, Alberto; Sarmento, H; Leporcq, B; Isumbisho, PM; Alunga, G; Masilya, PM; Descy, JP Sun, 14 Apr 2013 19:34:59 GMT http://hdl.handle.net/2268/146788 Title: Carbon cycling in the epilimnion of Lake Kivu (East Africa): surface net autotrophy and emission of CO2 to the atmosphere sustained by geogenic inputs <br/> <br/>Author, co-author: Borges, Alberto; Bouillon, S; Morana, CDT; Servais, P; Descy, JP; Darchambeau, François Sun, 14 Apr 2013 19:34:19 GMT http://hdl.handle.net/2268/146773 Title: Variability of North Sea pH and CO2 pumping in response to North Atlantic Oscillation forcing <br/> <br/>Author, co-author: Salt, L; Thomas, H; Prowe, F; Borges, Alberto; de Baar Sun, 14 Apr 2013 08:34:17 GMT http://hdl.handle.net/2268/146623 Title: The dimethylsulphide propionate (DMSP) content in microalgae and its influence on DMS emission: Experimental and modelling study in the Southern North Sea <br/> <br/>Author, co-author: Gypens, N; Paulet, S; Borges, Alberto; Parent, JP; Lancelot, C Thu, 11 Apr 2013 06:21:32 GMT http://hdl.handle.net/2268/146622 Title: The influence of biogeochemical processes on the pH dynamics in the seasonally hypoxic saline Lake Grevelingen <br/> <br/>Author, co-author: Hagens, M; Slomp, C; Meysman, F; Borges, Alberto; Middelburg, J Thu, 11 Apr 2013 06:16:46 GMT http://hdl.handle.net/2268/146621 Title: From a source to a sink: the role of biological activities on atmospheric CO2 exchange along the river-ocean continuum <br/> <br/>Author, co-author: Gypens, N; Passy, P; Lancelot, C; Garnier, J; Billen, G; Borges, Alberto Thu, 11 Apr 2013 06:08:11 GMT http://hdl.handle.net/2268/146170 Title: Biogeochemistry and carbon mass balance of a coccolithophore bloom in the northern Bay of Biscay (June 2006) <br/> <br/>Author, co-author: Harlay, Jérôme; Chou, Lei; Van Oostende, Nicolas; Sabbe, Koen; Borges, Alberto <br/> <br/>Abstract: Primary production (PP), calcification (CAL), bacterial production (BP) and dark community respiration (DCR) were measured along with a set of various biogeochemical variables, in early June 2006, at several stations at the shelf break of the northern Bay of Biscay. The cruise was carried out after the main spring diatom bloom that, based on the analysis of a time-series of remotely sensed chlorophyll-a (Chl-a), peaked in mid-April. Remotely sensed sea surface temperature (SST) indicated the occurrence of enhanced vertical mixing (due to internal tides) at the continental slope, while adjacent waters on the continental shelf were stratified, as confirmed by vertical profiles of temperature acquired during the cruise. The surface layer of the stratified water masses (on the continental shelf) was depleted of inorganic nutrients. Dissolved silicate (DSi) levels probably did not allow significant diatom development. We hypothesize that mixing at the continental slope allowed the injection of inorganic nutrients that triggered the blooming of mixed phytoplanktonic communities dominated by coccolithophores (Emiliania huxleyi) that were favoured with regards to diatoms due to the low DSi levels. Based on this conceptual frame, we used an indicator of vertical stratification to classify the different sampled stations, and to reconstruct the possible evolution of the bloom from the onset at the continental slope (triggered by vertical mixing) through its development as the water mass was advected on-shelf and stratified. We also established a carbon mass balance at each station by integrating in the photic layer PP, CAL and DCR. This allowed computation at each station of the contribution of PP, CAL and DCR to CO2 fluxes in the photic layer, and how they changed from one station to another along the sequence of bloom development (as traced by the stratification indicator). This also showed a shift from net autotrophy to net heterotrophy as the water mass aged (stratified), and suggested the importance of extracellular production of carbon to sustain the bacterial demand in the photic and aphotic layers. Fri, 05 Apr 2013 12:35:47 GMT http://hdl.handle.net/2268/146160 Title: Surface Ocean CO2 Atlas (SOCAT) gridded data products <br/> <br/>Author, co-author: Sabine, C. L. Br; Hankin, S. Br; Koyuk, H. Br; Bakker, D. C. E. Br; Pfeil, B. Br; Olsen, A. Br; Metzl, N. Br; Kozyr, A. Br; Fassbender, A. Br; Manke, A. Br; Malczyk, J. Br; Akl, J. Br; Alin, S. R. Br; Bellerby, R. G. J. Br; Borges, Alberto; Boutin, J. Br; Brown, P. J. Br; Cai, W. J. Br; Chavez, F. P. Br; Chen, A. Br; Cosca, C. Br; Feely, R. A. Br; González-Dávila, M. Br; Goyet, C. Br; Hardman-Mountford, N. Br; Heinze, C. Br; Hoppema, M. Br; Hunt, C. W. Br; Hydes, D. Br; Ishii, M. Br; Johannessen, T. Br; Key, R. M. Br; Körtzinger, A. Br; Landschützer, P. Br; Lauvset, S. K. Br; Lefèvre, N. Br; Lenton, A. Br; Lourantou, A. Br; Merlivat, L. Br; Midorikawa, T. Br; Mintrop, L. Br; Miyazaki, C. Br; Murata, A. Br; Nakadate, A. Br; Nakano, Y. Br; Nakaoka, S. Br; Nojiri, Y. Br; Omar, A. M. Br; Padin, X. A. Br; Park, G. H. Br; Paterson, K. Br; Perez, F. F. Br; Pierrot, D. Br; Poisson, A. Br; Ríos, A. F. Br; Salisbury, J. Br; Santana-Casiano, J. M. Br; Sarma, V. V. S. S. Br; Schlitzer, R. Br; Schneider, B. Br; Schuster, U. Br; Sieger, R. Br; Skjelvan, I. Br; Steinhoff, T. Br; Suzuki, T. Br; Takahashi, T. Br; Tedesco, K. Br; Telszewski, M. Br; Thomas, H. Br; Tilbrook, B. Br; Vandemark, D. Br; Veness, T. Br; Watson, A. J. Br; Weiss, R. Br; Wong, C. S. Br; Yoshikawa-Inoue, H. P <br/> <br/>Abstract: As a response to public demand for a well-documented, quality controlled, publically available, global surface ocean carbon dioxide (CO2) data set, the international marine carbon science community developed the Surface Ocean CO2 Atlas (SOCAT). The first SOCAT product is a collection of 6.3 million quality controlled surface CO2 data from the global oceans and coastal seas, spanning four decades (1968–2007). The SOCAT gridded data presented here is the second data product to come from the SOCAT project. Recognizing that some groups may have trouble working with millions of measurements, the SOCAT gridded product was generated to provide a robust, regularly spaced CO2 fugacity (fCO2) product with minimal spatial and temporal interpolation, which should be easier to work with for many applications. Gridded SOCAT is rich with information that has not been fully explored yet (e.g., regional differences in the seasonal cycles), but also contains biases and limitations that the user needs to recognize and address (e.g., local influences on values in some coastal regions). Fri, 05 Apr 2013 11:41:32 GMT http://hdl.handle.net/2268/146157 Title: A uniform, quality controlled Surface Ocean CO2 Atlas (SOCAT) <br/> <br/>Author, co-author: Pfeil, B. Br; Olsen, A. Br; Bakker, D. C. E. Br; Hankin, S. Br; Koyuk, H. Br; Kozyr, A. Br; Malczyk, J. Br; Manke, A. Br; Metzl, N. Br; Sabine, C. L. Br; Akl, J. Br; Alin, S. R. Br; Bates, N. Br; Bellerby, R. G. J. Br; Borges, Alberto; Boutin, J. Br; Brown, P. J. Br; Cai, W. J. Br; Chavez, F. P. Br; Chen, A. Br; Cosca, C. Br; Fassbender, A. J. Br; Feely, R. A. Br; González-Dávila, M. Br; Goyet, C. Br; Hales, B. Br; Hardman-Mountford, N. Br; Heinze, C. Br; Hood, M. Br; Hoppema, M. Br; Hunt, C. W. Br; Hydes, D. Br; Ishii, M. Br; Johannessen, T. Br; Jones, S. D. Br; Key, R. M. Br; Körtzinger, A. Br; Landschützer, P. Br; Lauvset, S. K. Br; Lefèvre, N. Br; Lenton, A. Br; Lourantou, A. Br; Merlivat, L. Br; Midorikawa, T. Br; Mintrop, L. Br; Miyazaki, C. Br; Murata, A. Br; Nakadate, A. Br; Nakano, Y. Br; Nakaoka, S. Br; Nojiri, Y. Br; Omar, A. M. Br; Padin, X. A. Br; Park, G. H. Br; Paterson, K. Br; Perez, F. F. Br; Pierrot, D. Br; Poisson, A. Br; Ríos, A. F. Br; Santana-Casiano, J. M. Br; Salisbury, J. Br; Sarma, V. V. S. S. Br; Schlitzer, R. Br; Schneider, B. Br; Schuster, U. Br; Sieger, R. Br; Skjelvan, I. Br; Steinhoff, T. Br; Suzuki, T. Br; Takahashi, T. Br; Tedesco, K. Br; Telszewski, M. Br; Thomas, H. Br; Tilbrook, B. Br; Tjiputra, J. Br; Vandemark, D. Br; Veness, T. Br; Wanninkhof, R. Br; Watson, A. J. Br; Weiss, R. Br; Wong, C. S. Br; Yoshikawa-Inoue, H. P <br/> <br/>Abstract: A well-documented, publicly available, global data set of surface ocean carbon dioxide (CO2) parameters has been called for by international groups for nearly two decades. The Surface Ocean CO2 Atlas (SOCAT) project was initiated by the international marine carbon science community in 2007 with the aim of providing a comprehensive, publicly available, regularly updated, global data set of marine surface CO2, which had been subject to quality control (QC). Many additional CO2 data, not yet made public via the Carbon Dioxide Information Analysis Center (CDIAC), were retrieved from data originators, public websites and other data centres. All data were put in a uniform format following a strict protocol. Quality control was carried out according to clearly defined criteria. Regional specialists performed the quality control, using state-of-the-art web-based tools, specially developed for accomplishing this global team effort. SOCAT version 1.5 was made public in September 2011 and holds 6.3 million quality controlled surface CO2 data points from the global oceans and coastal seas, spanning four decades (1968–2007). Three types of data products are available: individual cruise files, a merged complete data set and gridded products. With the rapid expansion of marine CO2 data collection and the importance of quantifying net global oceanic CO2 uptake and its changes, sustained data synthesis and data access are priorities. Fri, 05 Apr 2013 11:34:42 GMT http://hdl.handle.net/2268/145719 Title: Installation d’un parc à éoliennes sur le Wenduine Bank: aspects écologiques et socio-économiques. <br/> <br/>Author, co-author: Bouquegneau, Jean-Marie; Djenidi, Salim; Hecq, Jean-Henri Thu, 28 Mar 2013 12:06:17 GMT http://hdl.handle.net/2268/145672 Title: Establishing research strategies, methodologies and technologies to link genomics and proteomics to seagrass productivity, community metabolism, and ecosystem carbon fluxes <br/> <br/>Author, co-author: Mazzuca, Silvia; Bjork, M; Beer, S; Felisberto, P; Gobert, Sylvie; Procaccini, G; Runcie, J; Silva J; Borges, Alberto; Brunet, C; Buapet, P; Champenois, Willy; Costa, MM; D'esposito, D; Gullstrom, M; Lejeune, Pierre; Lepoint, Gilles; Olivé, I; Rasmusson, LM; Richir, Jonathan; Ruocco, M; Serra, IA; Spadafora, A; Santos, R <br/> <br/>Abstract: A complete understanding of the mechanistic basis of marine ecosystem functioning is only possible through integrative and interdisciplinary research.This enables the prediction of change and possibly the mitigation of the consequences of anthropogenic impacts. One major aim of the European Cooperation in Science and Technology (COST) Action ES0609 “Seagrasses productivity. From genes to ecosystem management,” is the calibration and synthesis of various methods and the development of innovative techniques and protocols for studying seagrass ecosystems. During 10 days, 20 researchers representing a range of disciplines (molecular biology, physiology, botany, ecology, oceanography, and underwa- ter acoustics) gathered at The Station de Recherches Sous-marines et Océanographiques (STARESO, Corsica) to study together the nearby Posidonia oceanica meadow. STARESO is located in an oligotrophic area classified as “pristine site” where environmental distur- bances caused by anthropogenic pressure are exceptionally low. The healthy P. oceanica meadow, which grows in front of the research station, colonizes the sea bottom from the surface to 37 m depth. During the study, genomic and proteomic approaches were integrated with ecophysiological and physical approaches with the aim of understanding changes in seagrass productivity and metabolism at different depths and along daily cycles. In this paper we report details on the approaches utilized and we forecast the potential of the data that will come from this synergistic approach not only for P. oceanica but for seagrasses in general. <br/> <br/>Commentary: TECHNOLOGY REPORT Wed, 27 Mar 2013 11:01:57 GMT