Serge Heussner - Academia.edu (original) (raw)

Papers by Serge Heussner

Deep Sea Research Part I: Oceanographic Research Papers, 2000

Studies carried out in four submarine canyons in the northwestern Mediterranean Sea have resulted... more Studies carried out in four submarine canyons in the northwestern Mediterranean Sea have resulted in the discovery of a new fauna composed chie#y of hydromedusae. This "nding has led us to postulate the existence of a singular planktonic community in these canyons that is probably maintained by the #ux and deposit of organic material from the continental shelf. The speci"c composition and abundance of the populations di!er from canyon to canyon and seem to be related to vertical #uxes, topography, and both the hydrographic and ecological features of each canyon. This hydromedusan fauna is characterized by meroplanktonic species that appear to live out their entire life cycles inside the canyons. Those cycles seem to be linked to seasonal production processes related to factors such as canyon topography, sedimentation, and circulation of water masses within the canyons. The present study indicates that submarine canyons could be a new key habitat to an understanding of the biodiversity of coastal and shelf zones. The origin of the deep-water Mediterranean fauna is reviewed, and the hypothesis of a Tethys origin for some of the deep-water hydromedusae endemic to the Mediterranean is entertained.

Progress in Oceanography, Dec 1, 2017

Deep-sea Research Part I-oceanographic Research Papers, Aug 1, 2017

Information on the dynamics of deep-sea biota is extremely scant particularly for long-term time ... more Information on the dynamics of deep-sea biota is extremely scant particularly for long-term time series on deep-sea zooplankton. Here, we present the results of a deep-sea zooplankton investigation over one annual cycle based on samples from sediment trap moorings in three subbasins along the Mediterranean Sea. Deep-sea zooplankton assemblages were dominated by copepods, as in shallow waters, only in the Adriatic Sea (>60% of total abundance), but not in the deep Ionian Sea, where ostracods represented >80%, neither in the deep Alboran Sea, where polychaetes were >70%. We found that deep-sea zooplankton assemblages: i) are subjected to changes in their abundance and structure over time, ii) are characterized by different dominant taxa in different basins, and iii) display clear taxonomic segregation between shallow and nearbottom waters. Zooplankton biodiversity decreases with increasing water depth, but the equitability increases. We suggest here that variations of zooplankton abundance and assemblage structure are likely influenced by the trophic condition characterizing the basins. Our findings provide new insights on this largely unknown component of the deep ocean, and suggest that changes in the export of organic matter from the photic zone, such as those expected as a consequence of global change, can significantly influence zooplankton assemblages in the largest biome on Earth.

Deep-sea Research Part I-oceanographic Research Papers, Aug 1, 2000

A large amount of terrestrial organic matter is annually delivered by rivers to the continental s... more A large amount of terrestrial organic matter is annually delivered by rivers to the continental shelf, where this material is either buried or transferred to the deep sea by hydrodynamic processes such as storms. The relative amount of terrestrial organic matter in the marine sediments is often determined by analyzing the stable isotopes (δ 13 C and δ 15 N) and the C / N ratio of organic matter because the various particulate organic matter (POM) sources have distinct isotopic compositions. With the objective to refine and better interpret POM sources in the marine environment, we have monthly characterized terrestrial POM delivered by eight rivers discharging to the NW Mediterranean Sea: Rhône, Hérault, Orb, Aude, Têt, Fluvià, Ter and Tordera rivers. These rivers were simultaneously sampled from November 2008 to December 2009 and the concentrations of total suspended matter (TSM), particulate organic carbon (POC) and nitrogen (PN), as well as their stable isotopic ratios (δ 13 C and δ 15 N) were determined.

Biogeosciences, May 28, 2014

Journal of Marine Systems, Jun 1, 2002

Springer water, Dec 28, 2017

Mediterranean sea is one of the most sampled areas for floating microplastics (MPs). However, onl... more Mediterranean sea is one of the most sampled areas for floating microplastics (MPs). However, only few investigations have been conducted at small spatial and temporal scales in coastal areas. To fill this gap, MPs ( 300 μm), at different seasons in the Rhone area and every month during one year in the Tet area. After removal of organic matter, MPs were examined under a dissecting stereo microscope. Preliminary results show highly variable MP concentrations even at small scale. Indeed, concentrations ranged from 0.05 to 0.6 items.m−3 for the Tet area with an average of 0.2 items.m−3 and from 0.1 to 0.5 items.m−3 with an average of 0.3 items.m−3 for the Rhone area. Concentrations can change by a factor of 4 between two consecutive days at the same location and by a factor of 3 between two consecutive trawls on the same day. Fibers are the most abundant shape (40–90%), followed by fragments (0–50%). Foams and films are less represented (0–20%). FTIR analysis indicates that fragments and films were mostly polyethylene (PE) and polypropylene (PP), while foams were essentially made of polystyrene (PS). Fiber analysis is ongoing. Occasional presence of lint composed of hundreds of fibers can partly explain the high differences observed at small scales, as well as fast changing river inputs. These extended observations of floating MPS in the NW Mediterranean coastal environment underlines the necessity of performing replicate sampling to get a better insight into the spatial and temporal distribution patterns of these worrying pollutants.

Science, Jul 2, 2021

New data drastically drop previous estimates of microplastic river fluxes to the ocean, reducing ... more New data drastically drop previous estimates of microplastic river fluxes to the ocean, reducing the need for a missing ocean plastic sink.

Geochimica et Cosmochimica Acta, Sep 1, 2021

Please note that this is an author-produced PDF of an article accepted for publication following ... more Please note that this is an author-produced PDF of an article accepted for publication following peer review. The definitive publisher-authenticated version is available on the publisher Web site.

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Mediterranean Science Commission, 1997

5 pagesPeer reviewe

Fate and Impact of Microplastics in Marine Ecosystems, 2017

Marine Pollution Bulletin, 2022

We report lead (Pb) analyses in juvenile (n = 37; mean length = 24.7 ± 2.3 cm) and adult (n = 16;... more We report lead (Pb) analyses in juvenile (n = 37; mean length = 24.7 ± 2.3 cm) and adult (n = 16; mean length = 52.3 ± 9.3 cm) Centroscymnus coelolepis Mediterranean deep-sea sharks that are compared to Pb content in bathy-demersal, pelagic and shallow coastal sharks. Median Pb concentrations of C. coelolepis muscle (0.009-0.056 wet ppm) and liver (0.023-0.061 wet ppm) are among the lowest encountered in shark records. Stable Pb isotope imprints in adult C. coelolepis muscles highlight that most of Pb in C. coelolepis is from human origin. Lead isotopes reveal the persistence of gasoline Pb emitted in the 1970s in low-turnover adult shark's muscle while associated liver imprints are in equilibrium with recent pollutant Pb signatures suggesting an efficient pollutant Pb turnover metabolism. The comparison of Pb distribution between adult and juvenile cohorts suggests the role of dietary exposure and possible maternal offloading of Pb during gestation, likely associated to vitellogenesis in this aplacental viviparous deep-sea shark.

HAL (Le Centre pour la Communication Scientifique Directe), 1999

An array of six time series sediment traps and current meters was deployed in water depths of 230... more An array of six time series sediment traps and current meters was deployed in water depths of 2300 and 3000 m on two bottom-mounted moorings along the axis of the Cap-Ferret Canyon, a large depression in the southeastern part of the Bay of Biscay (northeastern Atlantic), as part of the ECOMARGE Atlantic experiment ECOFER. The 14-month experiment consisted of three successive deployments during which particle #uxes were collected over sampling periods of 16}27 d. Two large-aperture traps also were deployed to measure #uxes at a faster sampling rate (4}7 d). The recovered samples were analyzed for total mass, concentration of major constituents (organic and inorganic carbon, opal), activity of Pb (Radakovitch, O., Heussner, S., 1999. Fluxes and budget of Pb on the continental margin of the Bay of Biscay (northeastern Atlantic). Deep-Sea Research II 46, 2175}2203) and coccoliths (Beaufort, L., Heussner, S., 1999. Coccolithophorids on the continental slope of the Bay of Biscay } production, transport and contribution to mass #uxes. Deep-Sea Research II 46, 2147}2174). The temporal pattern of the major constituent #uxes essentially matched that of the total mass, suggesting that, in general, particle transfer to the slope is largely driven by events acting on the same time scale. The temporal variability of the measured concentrations and #uxes lacked in any obvious connection with large-scale driving forces, either external (wind, river discharge) or internal (biological production), which all exhibited a marked seasonal signal. The rapid

Marine Pollution Bulletin, May 1, 2011

Sediment cores from the deep Balearic basin and the Cretan Sea provide evidence for the accumulat... more Sediment cores from the deep Balearic basin and the Cretan Sea provide evidence for the accumulation of Cd, Pd and Zn in the top few centimeters of the abyssal Mediterranean sea-bottom. In both cores, 206Pb/ 207Pb profiles confirm this anthropogenic impact with less radiogenic imprints toward surface sediments. The similarity between excess 210Pb accumulated in the top core and the 210Pb flux suggests that top core metal inventories reasonably reflect long-term atmospheric deposition to the open Mediterranean. Pb inventory in the western core for the past 100 years represents 20-30% of sediment coastal inventories, suggesting that long-term atmospheric deposition determined from coastal areas has to be used cautiously for mass balance calculations in the open Mediterranean. In the deeper section of both cores, Al normalized trace metal profiles suggest diagenetic remobilization of Fe, Mn, Cu and, to a lesser extent, Pb that likely corresponds to sapropel event S1.

Journal of Marine Systems, Mar 1, 2008

In the frame of the EU-funded ADIOS project, the aim of this paper is to present the results of t... more In the frame of the EU-funded ADIOS project, the aim of this paper is to present the results of the total mass and the major constituent (organic matter, calcium carbonate, opal and lithogenics) fluxes obtained in the central part of the Algero-Balearic Basin (ABB). Two identical mooring lines, named A and B were equipped with three automated sediment traps and three current meters at 250 m, 1440 m and 2820 m of water depth, and another one, named C, was equipped with five sediment trap-current meter pairs at the corresponding depths of 250 m, 845 m, 1440 m, 2145 m and 2820 m. The samples were collected during an annual period, from April 2001 to May 2002 over sampling periods of 15-30 days. The presented particle fluxes data constitute the first one-year experimental study carried out in the open ABB, a region in which the continental inputs are expected to be minimums. This fact explains why the values of the mean annual fluxes were the lowest found in the whole Western Mediterranean Sea, ranging from 11.30 mg•m − 2 day − 1 (2145 m; station C) to 112.75 mg m − 2 day − 1 (250 m; station A). The temporal evolution of the particle fluxes in the upper waters shows the dominance of the atmospherically derived particles during summer and autumn, and a clear biological control during winter related to the primary productivity pathway. Along the whole water column, the calcium carbonate appears as the main relative contributor of the biogenic material (26%-30%), and the opal content presents the lowest values (6%-8%), suggesting that the study area is a carbonate-dominated ecosystem. Otherwise, even if the particles are derived from the atmosphere or internally produced by biological processes, it is clear that their transference from the upper to the deeper ocean is controlled by the stabilization of the water column and the distribution of the water masses in the Western Mediterranean Sea. In this context, the input of the Tyrrhenian Deep Water (TDW) into the AB7B at 800-1500 m of water depth strongly affects the distribution of the particle fluxes in the basin, being responsible of the minimum concentration zone at intermediate depths. Furthermore, current meter and flux data indicate a high influence of the Gulf of Lions water mass formation by spreading of dense cold water along the whole ABB, leading up to a maximum of particulate matter at depths higher than 2000 m.

Marine Chemistry, Sep 1, 2011

... M AN US CR IPT ACCEPTED MANUSCRIPT Use of organic biomarkers to trace the transport of marine... more ... M AN US CR IPT ACCEPTED MANUSCRIPT Use of organic biomarkers to trace the transport of marine and terrigenous organic matter through the southwestern canyons of the Gulf of Lion Catalina Pasquala, Cindy Leeb, Miguel Go ic, Tommaso Tesic,d, Anna Sanchez-Vidala ...