Search

It has been suggested that the seafloor may be a sink for the plastic debris that enters the ocean. Therefore, the collection of data in the seafloor sediments regarding the co-presence of microplastics (MPs) and contaminants associated to plastic is considered a relevant topic. However, the number of studies addressing their possible correlation in this environment is still limited, and very little is known about the mechanisms that determine the release of plastic additives from plastic items. Starting from this basis, we investigated the presence of MPs and eleven phthalic acid esters (PAEs) in the continental shelf offshore Barcelona. Following a shelf-slope continuum approach, we sampled sediments from five stations, and we performed analysis by means of infrared micro spectroscopy (µFTIR) and liquid chromatography tandem mass spectrometry (LC–MS/MS). MPs were found to range from 62.0 to 931.1 items/kg d.w. with maximum concentration in the submarine canyon Besòs and at the highest depth. Moreover, different trends in the size distribution of fibers and non-fibers were observed, indicating the occurrence of a size dependent selection mechanism during transport and accumulation. PAEs resulted comprised between 1.35 to 2.41 mg/kg with Di(2-ethylhexyl)phthalate (DEHP) the most abundant congeners (1.04 mg/kg). Statistical analysis revealed no correlation between the Σ11PAEs and the total MPs concentration, but correlation between DEHP and fibers (σ = 0.667, p = 0,037), that resulted both correlated to the distance to the coast (ρ = 0.941 with p = 0,008 and ρ = 0.673 with p = 0.035, respectively).

The training received during primary and secondary education is crucial for the development of our behavior in adulthood. For this reason, at this early stage, it is important to know our environment and its dynamics to appreciate it. The Spanish Secondary Compulsory Education (SCE) comprises four academic years and is taken by students aged 12-16. The learning of geosciences during this level takes place only in the first, third and fourth year. Biology and geology are part of the same subject, being mandatory in the first and third year and optional in the last year. The students lose their interest in science as they advance from primary to secondary education and cease to see it as a viable option for their future (Zamalloa and Sanz, 2020). Several authors have also detected this lack of interest in science of young people (Ali et al., 2013; Christidou, 2011). This disinterest is manifested in expressions such as "Science does not provide food", "You have to study hard" or "Science is boring". To avoid this lack of motivation, educational models should be reoriented towards an educational system in which students are at the center of their learning and not simply focused on the systematic acquisition of memorized concepts to pass an exam. The discipline of Earth Sciences, or Geosciences, face a more difficult challenge than many other sciences given that students do not learn geology during early stages of their academic life (Adetunji et al., 2012). In many places such as the USA (Lewis, 2008), Australia (Dawborn-Gundlach et al., 2017), some countries of northern Europe (King, 2013), Argentina and other Latin American countries (Lacreu 2017; UNESCO, 2019) and Spain (Pedrinaci, 2012) geoscience subjects are underrepresented and frequently in the optional subjects, it is selected by students who are unmotivated. Given this context, the present study investigates the structure of geoscience education in the frame of the SCE system from Catalonia and the degree of geological knowledge acquired by the students.

Research on microplastics has rapidly expanded in recent years and has led to the discovery of vast amounts of microplastics floating offshore in all main oceanic gyres and including the Mediterranean Sea. However, there is a lack of information from a few meters from the coastline where the largest plastic mass flux is suspected to occur. The reason behind is the general use of manta trawls towed by boats or research vessels to obtain samples, which hinders nearshore sampling. We have designed a manta trawl to collect samples in the nearshore from any type of recreational sports floating gear like kayaks, sailboats, rowing boats, windsurf boards and others. Data generated is comparable to that obtained with traditional scientific equipment towed from boats. During one year, starting from October 2020, 12 social, environmental and sports associations along the NW Mediterranean coast are acquiring scientific samples in the nearshore within the frame of two citizen science monitoring projects lead by the Spanish delegation of the non-governmental organization Surfrider Foundation Europe and the University of Barcelona. The projects represent a paradigm shift in microplastic research, allowing to fill the gap in knowledge of this transition coastal area, and actively involving citizens in the generation of new monitoring data (https://surfingforscience.org/).Our results reveal that densities of floating plastics in the nearshore along the NW Mediterranean coast are on average similar to those found offshore. However, we observe high variability due to meteorological and oceanographic conditions (i.e. the occurrence of eastern storms). We also observe that whereas floating microplastics dominate offshore, greater proportions of mesoplastics and macroplastics dominate at the nearshore waters, especially in between the breakwaters in Barcelona city. Indeed, the breakwaters, that protect Barcelona beaches against wave action and coastal erosion, behave as plastic traps. This is an indication of the importance of the nearshore as a source of plastic fragments to the open sea and calls for increased research in this area.

The Remolar beach-dune system (700 m long and more than 100 m wide, 070N direction) borders a campground that was closed (2003), due to the Barcelona airport expansion. In order to recover and restore the dune ecosystem, a series of soft measures were performed. After 10 years, a study of the morphology, sedimentology, and vegetation of the ecosystem was carried out to evaluate the results of these measures. For this purpose, a series of topographic and ground-penetrating radar (GPR) profiles, grain-size analysis, and an analysis of plant communities found along the profiles were carried out. The data obtained were compared with data from a former 2004 study. The results show that the morphology of the dunes recovered, and a new primary dune has arisen. The system now has a greater process of aggradation than of progradation. The vegetation has recovered the global composition of dune systems, with a typical community of embryo dunes and others of primary dunes that are set in strips parallel to the coast. Despite this improvement, the opportunistic and ruderal component in the primary dune vegetation evidences a strong anthropic inheritance in the system.

This paper gathers the available information on submarine landslides identified in the northeastern Iberian continental margin and presents new data on both already known landslides and new, previously unknown ones. The 2,000 km2, 26 km3 resulting deposit of the BIG'95 debris flow in the Ebro margin; the 4 up to 16 km2, 0.4 km3 Eivissa slides in the Eivissa Channel; the 2 up to 65.6 km2, 1.46 km3 Barcelona slides in the shallow southern Catalan margin; and the western Gulf of Lions debris flow in the deep north Catalan margin are presented. This compilation is completed with several other previously undescribed small-scale mass-wasting deposits together with those observed in the Balearic Promontory. The amount and widespreading of submarine landslide deposits in the northern Iberian margins demonstrate that these margins are not an exception to the common occurence of these kind of structures worldwide, and give an idea on these phenomena recurrence even in margins considered moderately quiet, in terms of seismicity.

Quantifying fluxes of particulate trace metals to the deep sea is a necessary step to understand their role in many oceanographic processes. The Gulf of Vera, in the SW Mediterranean Sea, is an ideal place to quantify these fluxes given the presence of a metal-rich mine tailings deposit in Portmán Bay, in its northern shore. Portmán Bay is one of the most extreme cases in Europe of mine waste impacts on coastal ecosystems, both inshore and offshore. About 57 million tons of tailings enriched in Fe, Pb, Mn, Zn, As, Ti and other metals were dumped there from 1957 to 1990 [1].In the frame of the NUREIEV project, five mooring lines equipped with sediment traps and current meters were deployed in the wider Gulf of Vera. Three of the moorings were located in the middle course of three submarine canyons, one in the open continental slope and one in the deep basin. The monitoring period lasted for an annual cycle (March 2015 - March 2016). Our research focused on (1) measuring the temporal variability of particle fluxes in the study area, and (2) determining the concentration of particulate trace metals and metalloids (Zn, Pb, As, Ni, Cd, Cu, Co) as well as other metals (Fe, Mn, Ti) in settling particles.Preliminary results within the following project NUREIEVA indicate that marine storms are the main processes triggering the transfer of particulate matter to the deep margin, mainly through hundred meters thick nepheloid layers moving not only along the submarine canyons but also across the open slope. High metal fluxes after storms reached up to 120.4 mg Pb m-2d-1, 282.3 mg Zn m-2d-1 and 40.4 mg As m-2d-1 in the canyon stations, four orders of magnitude higher than calculated in open Ligurian Sea [2]. This suggests that submarine canyons are efficient pathways for the transfer of pollutants from the shelf to the deep margin and basin [3].Peak metal concentrations found so far in the wider Gulf of Vera exceed those found in other canyons in the Mediterranean Sea [2, 4]. The hypothesis that this could be related to the release of metals from the mine tailings deposit in Portmán is plausible but would require further work to be confirmed, including determination of enrichment factors in each station, and discerning between Portmán’s and other potential metal sources. [1] Oyarzun, R. et al., 2013. Sci. Total Environ. 454-455, 245-249.[2] Heimbürger, L.E. et al., 2012. Chem. Geol. 291, 141-151.[3] Canals, M. et al., 2013. Prog. Oceanogr. 118, 1-27.[4] Palanques, A. et al., 2008. Mar. Geol. 248, 213-227.

Special issue Bridging the gap between the shallow and deep oceans: The key role of submarine canyons.-- 12 pages, 7 figures, 3 tables, supplementary data https://doi.org/10.1016/j.pocean.2018.07.001, A detailed study of 15 sediment cores from Blanes Canyon and its immediate surroundings (NW Mediterranean Sea) was conducted to compare historic sedimentation rates and evaluate the possible impact of bottom-trawling intensification on the sedimentary regimes over the past 50 years. The canyon axis and flanks, as well as the adjacent open slope, were sampled at water depths ranging from 300 m to 2200 m. Grain size, dry bulk density, and Pb concentration profiles were measured to assess possible changes in sedimentation rates over the last century and their temporal and spatial relationship to bottom trawling effort. Sedimentation rates in the upper canyon axis (900–1200 m) had the highest rates of 0.9–2.1 cm·yr, quantified since the 1970s. Farther downcanyon, sedimentation rates increased two to five times after the 1970s, from 0.1–0.2 cm·yr to 0.2–0.8 cm·yr, which coincides with a rapid growth of the total engine power of the fishing fleet operating in the study area. The enhanced sedimentation rates occur downslope of the main fishing grounds and decrease downcanyon as the distance from trawling grounds increases. These results highlight the ability of bottom trawling to resuspend bottom sediments, leading to net erosion of the canyon rims and flanks. In turn, large volumes of sediment are advected towards the canyon's interior, ultimately increasing sediment deposition along the canyon axis. Natural sedimentation rates at similar along-canyon distance from shore in the untrawled continental slope (900–1500 m) and in the lower canyon axis (1500–2200 m) are comparable (0.08–0.20 cm·yr), suggesting distance from coastal sediment sources as the main control on regional sedimentation in deeper parts of the margin. While submarine canyons have been regarded as preferential cross-margin conduits for sediment dispersal, they can also potentially function as modern depocenters for trawling-induced sedimentation, This research has been also supported by the I-MarCat research project of Institut d’Estudis Catalans (IEC, Catalonia, ref. PR2015-S06-CANALS/SCiT-SCB), and from the Spanish research project ABIDES (CTM2015-65142-R) and the EC DG Environment contract IDEM (Implementation of the MSFD to the DEep Mediterranean Sea). The autonomous government of Catalonia, Generalitat de Catalunya, also helped through its grants 2014 SGR-1068, 2014 SGR-1642 and 2017 SGR-1588. This work is contributing to the ICTA ‘Unit of Excellence’ (MinECo, MDM2015-0552). S.P. is supported by a predoctoral F.P.U. grant from the Spanish government

To assess the origin and degradation state of the organic particles sinking towards the sea bottom of the Mallorca continental slope, the major inorganic and organic components of the total mass flux and its biochemical composition (in terms of protein, carbohydrate, lipid and phytopigment contents) have been analysed. Two instrumented lines were deployed at the western (Soller station, Balearic sub-basin) and southern (Cabrera station, Algerian sub-basin) slopes of Mallorca Island, 900 m depth from November 2009 to January 2011. The two locations are characterized by putatively different environmental settings. Settled material at Soller station has higher lithogenic contents when compared with the Cabrera one. Such difference can be explained by the synergistic presence in the Soller station of large inputs of resuspended material due to the mesoscale variability of the Balearic current and the impact of bottom trapped waves. On the other hand, at the Cabrera station sinking particles are characterized by OM and opal percentages higher than those recorded at the Soller station. This result points out that organic particles reaching the sea floor at the Cabrera station have a pre-eminent pelagic origin. Based on analyses of the C and N stable isotopes of the sinking material, our results also highlight that, overall, the OM reaching the sea floor at the Mallorca slope is mostly of marine origin. In general, the OM settled at the Soller station has a higher nutritional value than that at the Cabrera one. Such a difference, occurring across a relatively reduced spatial scale, let us hypothesizing that the nutritionally richer particles descending in the Cabrera station are exposed to a less energetic environment than that in the Soller setting. This would lead to higher settling velocity of particles in the Soller setting which in turn would result in lower degradation rates of particles during their descent towards the sea bottom.

Nature Ecology & Evolution 1, 0144 (2017); published 24 April 2017; corrected 22 May 2017. In the original version of this Article Rut Pedrosa-Pamies's name was listed incorrectly. This has been updated in all versions of the Article.

Submarine volcanic eruptions are major catastrophic events that allow investigation of the colonization mechanisms of newly formed seabed. We explored the seafloor after the eruption of the Tagoro submarine volcano off El Hierro Island, Canary Archipelago. Near the summit of the volcanic cone, at about 130 m depth, we found massive mats of long, white filaments that we named Venus’s hair. Microscopic and molecular analyses revealed that these filaments are made of bacterial trichomes enveloped within a sheath and colonized by epibiotic bacteria. Metagenomic analyses of the filaments identified a new genus and species of the order Thiotrichales, Thiolava veneris. Venus’s hair shows an unprecedented array of metabolic pathways, spanning from the exploitation of organic and inorganic carbon released by volcanic degassing to the uptake of sulfur and nitrogen compounds. This unique metabolic plasticity provides key competitive advantages for the colonization of the new habitat created by the submarine eruption. A specialized and highly diverse food web thrives on the complex three-dimensional habitat formed by these microorganisms, providing evidence that Venus’s hair can drive the restart of biological systems after submarine volcanic eruptions, SI

In this study, we investigate the strength and efficiency of carbon sequestration in the Southern European Seas (SES), by analyzing the export of POC at three deep sites located in the Western Mediterranean Sea (WMED), the Eastern Mediterranean Sea (EMED) and the Black Sea (BS). We combine estimations of satellite and algorithm-generated primary production data, calculated POC fluxes out of the euphotic layer and POC fluxes measured by sediment traps at the mesopelagic and bathypelagic layers during a one year period, with an ultimate goal to obtain a better understanding of the functioning of the biological pump in the SES. Annual particulate primary production based on satellite estimations (SeaWiFS) at the three sites, averages 205, 145 and 225 gC m − 2 y − 1 at the WMED, EMED and BS, respectively. According to our findings, the fraction of primary production that is exported out of the euphotic zone in the SES ranges between 4.2% and 11.4%, while the fraction reaching the mesopelagic layer (1000–1400 m depth) ranges between 0.6% and 1.8%. Finally, the fraction of primary production exported at the bathypelagic layer (2000–2800 m depth) is found to be 0.6%, 0.3% and 1.4% in the WMED, EMED and BS, respectively. The role of various processes responsible for the replenishment of surface waters with nutrients, giving rise to productivity episodes and organic carbon export to depth at the three SES sites is considered.

Deep flow variability in Blanes canyon is analyzed by means of a unique dataset in which the canyon was instrumented at its axis and at the two canyon walls, from March 2003 to July 2004. The mean intensity of deep currents range between 3.5cms-1 (at the canyon axis, 1500m) and 5.4cms-1 (upstream canyon wall, 900m). A wavelet analysis shows that the energy is concentrated in the 2-30day band, and it is mainly associated to single (not periodical, not wave-related) events, uncoupled at the different canyon sites. An empirical orthogonal function analysis shows two main patterns of current variability explaining 65% of the total variance. The first mode represents intensifications of the typical along-bathymetry pattern of currents over the canyon. The second mode corresponds to near-bottom upwelling events along the canyon axis with water exiting the canyon through the canyon head. After discussing possible forcing mechanisms, it is here suggested that such deep upwelling events are associated to offshore displacements of the Northern Current. Namely, the interaction of the current with the particular shape of the canyon topography at large depths (>1800m) would be responsible for the observed deep upwelling events. © 2013 Elsevier Ltd., This study was supported by the Spanish national research Project RECS (REN2002-04556-C02-01)

To ascertain whether the Blanes submarine canyon functions as a conduit of labile organic compounds to the deep margin, we analyzed phytopigment, protein, carbohydrate and lipid contents of sinking particles during a 6-months period comprised between a large storm event and the spring phytoplankton bloom. Four sediment traps were deployed, at 300, 900, 1200, and 1500 m depth along the axis of the canyon from November 2008 to April 2009. Fluxes of all study variables (organic carbon, proteins, carbohydrates and lipids) peaked from mid to late December. Afterwards, organic matter fluxes in the upper canyon decreased to values comparable (BC1200) or much lower (BC900) than those observed at the beginning of the monitoring period. The algal fraction of biopolymeric C (i.e. the percentage contribution of phytopigments to biopolymeric C utilized here as an indicator of particles’ freshness), ranging from 14 to about 100%, was generally low (median value about 32%), and showed the highest values from November to early December 2008 at all stations, except for the station at 1200 m which peaks in April 2009. A severe storm that occurred the 26th of December 2008 determined a strong increase in the downward transport of organic matter along the Blanes Canyon, though associated with a decrease in its nutritional quality. Values of the protein to carbohydrate ratio (utilized here as an indicator of particles’ nutritional quality) ranged from 0.4 to >2.0, increasing from late winter to early spring at 900 and 1200 m depth in association with the spring phytoplankton bloom in superficial waters. The material collected by sediment traps in spring had a higher nutritional value than in autumn–winter at both stations. According to the optimal foraging theory, the results of this study suggest that, following winter episodic events, deep-sea detritus feeders would need to ingest more detritus to fulfill their requirements for labile food than in spring, when fresher material is derived from sinking particles associated with phytoplankton blooms. We conclude that whilst submarine canyons like the Blanes Canyon act as major conduits for material exported from the continental shelf after high-energy episodic events, the supply of labile food to the deep-sea benthic ecosystem is connected to biological processes occurring at the sea surface.

10 páginas, 7 figuras, 3 tablas., Rivers are the primary pathway for organic matter transport from the terrestrial to the marine environment and, thus, river fluxes are critical in regulating the quantity of terrestrial organic matter that reaches the coastal ecosystems. Hydrodynamic processes typical of the coastal zone can lead to the transport of terrestrial organic matter across the continental shelf and beyond. Such organic matter can eventually reach the deep margin and basin ecosystems. Riverine inputs of organic matter to the sea can be a significant food source to marine ecosystems contributing to carbon cycling in these ecosystems. In order to assess the marine carbon cycle it is essential to know the biogeochemical characteristics and temporal dynamics of the fluvial organic matter input discharged by rivers to the coastal zone. In this study we present a one and a half year long (November 2008 to May 2010) assessment on organic carbon (OC) and nitrogen (N) inputs from the three main rivers discharging into the North Catalan margin (Tordera, Ter and Fluvià, from south to north). Furthermore, we investigate the characteristics of the particulate organic matter discharged by these rivers by means of stable isotopic (d13C and d15N) and grain size analyses. We found that the hydrological regime of the rivers is a relevant factor in regulating the quantity and mediating the quality of organic matter inputs to the North Catalan margin. Overall, the three main rivers discharging into the study area deliver 1266 and 159 tonnes of terrestrial OC and N per year, respectively, to the coastal zone. Most of the OC and N load is transported during floods, which indicates that the Mediterranean climate of the area, with a strong seasonal contrast in precipitation, determines the timing of the main inputs of OC and N to the sea. Therefore, the annual OC and N load experiences a high temporal variability associated to the number and magnitude of floods with in each hydrological year. In addition, we found that water reservoirs along the rivers act as traps for terrestrial organic matter, reducing its delivery and ultimate burial into marine sediments. River hydrology also affects the quality of organic matter that reaches the coastal zone (both in terms of C and N) by shifting the relative weight of the various sources of terrestrial organic matter. During low river discharge (i.e., in summer and early autumn) the main contributor to the organic matter pool is mostly associated with freshwater primary producers, whereas with relatively high water flows (i.e., in winter and spring) the main contributor is associated with erosion and release of soil organic matter. Furthermore, the impact of waste water treatment plants into the studied rivers results in the alteration of the isotopic signal of suspended N. The three studied rivers play a major role in transporting terrestrial organic matter to the North Catalan margin, but the fraction that is exported to the deep margin by high-energy episodic hydrodynamic events, such as large coastal storms, has a minor importance., This research has been supported by a FP7 Marie Curie Reintegration Grant (PERG04-GA-2008-239175), the HERMIONE (FP7- ENV-2008-1-226354), DOS MARES (CTM2010-21810-C03), ISONEF (CGL2008-05504-C02-02) and GRACCIE-CONSOLIDER (CSD2007- 00067) research projects, and a Generalitat de Catalunya Grups de Recerca Consolidats Grant (2009 SGR 1305).

Este artículo contiene 13 páginas, 3 figuras, 3 tablas., The emerging field of blue carbon science is seeking cost-effective ways to estimate the organic carbon content of soils that are bound by coastal vegetated ecosystems. Organic carbon (Corg/ content in terrestrial soils and marine sediments has been correlated with mud content (i.e., silt and clay, particle sizes < 63 μm), however, empirical tests of this theory are lacking for coastal vegetated ecosystems. Here, we compiled data (n D1345) on the relationship between Corg and mud contents in seagrass ecosystems (79 cores) and adjacent bare sediments (21 cores) to address whether mud can be used to predict soil Corg content. We also combined these data with the 13C signatures of the soil Corg to understand the sources of Corg stores. The results showed that mud is positively correlated with soil Corg content only when the contribution of seagrass-derived Corg to the sedimentary Corg pool is relatively low, such as in small and fast-growing meadows of the genera Zostera, Halodule and Halophila, and in bare sediments adjacent to seagrass ecosystems. In large and long-living seagrass meadows of the genera Posidonia and Amphibolis there was a lack of, or poor relationship between mud and soil Corg content, related to a higher contribution of seagrass-derived Corg to the sedimentary Corg pool in these meadows. The relatively high soil Corg contents with relatively low mud contents (e.g., mud-Corg saturation) in bare sediments and Zostera, Halodule and Halophila meadows was related to significant allochthonous inputs of terrestrial organic matter, while higher contribution of seagrass detritus in Amphibolis and Posidonia meadows disrupted the correlation expected between soil Corg and mud contents. This study shows that mud is not a universal proxy for blue carbon content in seagrass ecosystems, and therefore should not be applied generally across all seagrass habitats. Mud content can only be used as a proxy to estimate soil Corg content for scaling up purposes when opportunistic and/or low biomass seagrass species (i.e., Zostera, Halodule and Halophila) are present (explaining 34 to 91% of variability), and in bare sediments (explaining 78% of the variability). The results obtained could enable robust scaling up exercises at a low cost as part of blue carbon stock assessments., This work was supported by the ECU Faculty Research Grant Scheme, the ECU Early Career Research Grant Scheme, and the CSIRO Flagship Marine & Coastal Carbon Biogeochemical Cluster (Coastal Carbon Cluster) with funding from the CSIRO Flagship Collaboration Fund. Peter Macreadie was supported by an ARC DECRA DE130101084.

12 pages, 9 figures, Submarine canyons can efficiently drain sediments from continental margins just as river systems do in subaerial catchments. Like in river systems, submarine canyons are often arranged as complex drainage networks that evolve from patterns of erosion and deposition. In the present paper we use a morphometric analysis of submarine canyon-channel long-profiles to study the recent sedimentary history of the Valencia Trough turbidite system (VTTS) in the NW Mediterranean Sea. The VTTS is unique in that it drains sediment from margins with contrasting morphologies through a single “trunk” conduit, the Valencia Channel. The Valencia Channel has been active since the late Miocene, evolving in response to Plio-Quaternary episodes of erosion and deposition. The integrated analysis of long-profiles obtained from high-resolution bathymetric data across the entire turbidite system shows evidence for transient canyon incision in the form of knickpoints and hanging tributaries. Multiple factors appear to have triggered these periods of incision. These include a large debris flow at 11,500 yr BP that disrupted the upper reaches of the VTTS and glacio-eustatic lowstands that forced shifting of sediment input to the VTTS. Based on these inferences, long-term time-averaged incision rates for the Valencia Channel have been estimated. The evidence we present strongly suggests that Foix Canyon has played a key role in the drainage dynamics of the VTTS in the past. This study builds conceptually on a recent modeling study that provides a morphodynamic explanation for the long-term evolution of submarine canyon thalweg profiles. The procedure and results from this work are of potential application to other submarine sediment drainage systems, past and present, including those containing mid-ocean type valleys like the Valencia Channel, This research was supported by the HERMIONE project, EC contract 226354-HERMIONE, funded by the European Commission's Seventh Framework Programme, and the HERMES Project, EC contract GOCE-CT-2005-511234, funded by the European Commission's Sixth Framework Programme under the priority “Sustainable Development, Global Change and Ecosystems”. It has also benefited from inputs by the PROMETEO (CTM2007-66316-C02-01/MAR), EDINSED3D (CTM2007-64880/MAR), and the GRACCIE CONSOLIDER (CSD2007-00067) projects, funded by the Spanish RTD Programme. GRC Geociències Marines is supported by Generalitat de Catalunya “Grups de Recerca Consolidats” grant 2009 SGR 1305

Sinking particles through the pelagic ocean have been traditionally considered the most important vehicle by which the biological pump sequesters carbon in the ocean interior. Nevertheless, regional scale variability in particle flux is a major outstanding issue in oceanography. Here, we have studied the regional and temporal variability of total particulate organic matter fluxes, as well as chloropigment and total hydrolyzed amino acid (THAA) compositions and fluxes in the Canary Current region, between 20–30° N, during two contrasting periods: August 2006, characterized by warm and stratified waters, but also intense winds which enhanced eddy development south of the Canary Islands, and February 2007, characterized by colder waters, less stratification and higher productivity. We found that the eddy-field generated south of the Canary Islands enhanced by >2 times particulate organic carbon (POC) export with respect to stations (FF; far-field) outside the eddy-field influence. We also observed flux increases of one order of magnitude in chloropigment and 2 times in THAA in the eddy-field relative to FF stations. Principal Components Analysis (PCA) was performed to assess changes in particulate organic matter composition between stations. At eddy-field stations, higher chlorophyll enrichment reflected "fresher" material, while at FF stations a higher proportion of pheophytin indicated greater degradation due to microbes and microzooplankton. PCA also suggests that phytoplankton community structure, particularly the dominance of diatoms versus carbonate-rich plankton, is the major factor influencing the POC export within the eddy field. In February, POC export fluxes were the highest ever reported for this area, reaching values of ~15 mmol C m−2 d−1 at 200 m depth. Compositional changes in pigments and THAA indicate that the source of sinking particles varies zonally and meridionally and suggest that sinking particles were more degraded at near-coastal stations relative to open ocean stations.

Special issue Sediment Dynamics in the Gulf of Lions; the Impact of Extreme Events.-- 13 pages, 8 figures, To investigate the role of coastal canyons in the transfer of organic matter from the shelf to the slope and basin, we deployed sediment trap/current meter pairs at the head of five canyons in the Gulf of Lions (GoL) between November 2003 and May 2004. Analysis of organic carbon, biogenic silica, Corg isotopic composition, Corg/total nitrogen, chloropigments, and amino acids clearly shows the seasonal influence and effect of extreme meteorological events on the composition of collected particles. The sampling period was divided into three >scenarios>. The first corresponded to a large easterly storm and flood of the Rhone river during stratified water column conditions; the composition of material collected during this event was influenced by increased transfer of riverine and coastal particulate matter, with a lower Corg content. During the second >fall-winter> scenario, northern and northwestern winds blowing over the shelf caused cooling and homogenization of the shelf water column; particles collected at this time reflected the homogeneous source of particulate matter transported through canyons; particles sitting in the vicinity of canyon heads are most likely swept downslope by the general south-westward circulation. Organic tracers indicate a degraded origin for organic matter transported during this period. A third >spring> scenario corresponded to northern winds alternating with eastward windstorms that triggered and/or enhanced the cascading of dense waters accumulated on the bottom of the shelf due to previous cooling. These conditions occurred in conjunction with increased phytoplankton productivity in shelf surface waters. Organic matter advected mainly by dense shelf water cascading was fresher due to the transport of newly produced particles and a variable terrestrial fraction; this fraction depended on the proportion of resuspended material accumulated during previous high discharge periods that was involved in each transport pulse. The tight link shown between meteorological conditions and organic matter transport is important for continental margin geochemical studies as future changes in climatic conditions may lead to dramatic changes in carbon sequestration capability and in the ecosystems of deep margin environments. © 2008 Elsevier Ltd. All rights reserved, J. Fabres was supported by the European Community’s Sixt Framework Program through the Marie Curie Outgoing International Fellowship. J. Velez was supported by Stony Brook’s NSFAlliance for Graduate Education and the Professoriate (AGEP) program. C. Lee and F. Batista were supported by the US NSF’s MedFlux program. This study was supported by the EUROSTRATAFORM Project funded by the EU (EVK3-CT-2002-00079, EU Fifth Framework Program: Energy, Environment and Sustainable Development). This is contribution no. 1602 of ISMAR-CNR Sede di Bologna

With the aim of improving the knowledge of the open ocean carbon cycle, we present a budget of particulate organic carbon (POC) fluxes carried out in the deep central part of the Algero-Balearic Basin (ABB) at 2850 m water depth based on a single mooring equipped with five automated sediment traps deployed from April 2001 to May 2002 at depths of 250, 845, 1440, 2145 and 2820 m. Suspended particulate matter (SPM) and superficial sediments were also used as indicators of hydrodynamics and carbon burial, respectively. The data reveal that the fraction of primary production buried in the sediment, which finally leads to the sequestration of carbon dioxide from the atmosphere, is 0.16%, lower than the values found in the nearby continental margin regions such as the Alboran Sea (0.48–0.89%) but of the same order as recorded at other Mediterranean sites at similar depths, such as the Ionian Sea (0.11%). As they sink through the water column, the particles exhibit decreases in flux that are similar to those observed elsewhere, but also show variations that appear to correlate with hydrological features of the water masses present in the basin, as revealed by SPM concentrations and compositions. The input of the tyrrhenian deep water (TDW) into the ABB at 800–1500 m of water depth exhibits low suspended POC concentrations and low sinking POC fluxes were also observed in this depth range. Gulf of Lions water mass formation appears to also contribute to elevated suspended POC concentrations and perhaps POC accumulation in the traps and sediments by spreading of dense cold water along the whole ABB that supplied POC at depths higher than 2000 m.

The carbon cycle of the Arctic Ocean is tightly regulated by land-atmosphere-cryosphere-ocean interactions. Characterizing these environmental exchanges and feedbacks is critical to facilitate projections of the carbon cycle under changing climate conditions. The environmental drivers of sinking particles including organic carbon (OC) to the deep-sea floor are investigated with four moorings including sediment traps and currentmeters at the Arctic gateway in the eastern Fram Strait, which is the area where warm anomalies are transported northwards to the Arctic. Particles fluxes were collected over one year (July 2010-July 2011) and have been analysed to obtain the content of the lithogenic fraction, calcium carbonate, OC and its stable isotopes, opal, and the grain size. Records of near bottom current speed and temperature along with satellite observations of sea ice extent and chlorophyll-a concentration have been used for evaluation of the environmental conditions.We found increased lithogenic fluxes (up to 9872mgm-2d-1) and coarsening grain size of settling particles in late winter-early spring. At the same time, intensifications of the northward flowing west Spitsbergen current (WSC) were recorded. The WSC was able to resuspend and transport northwards sediments that were deposited at the outlet of Storfjordrenna and on the upper slope west of Spitsbergen. The signal of recurrent winnowing of fine particles was also detected in the top layer of surface sediments. In addition, an increased arrival of sea ice transported ice rafted detritus (>414 detrital carbonate mineral grains larger than 1mm per m2) from the southern Spitsbergen coast along with terrestrial organic matter was observed beyond 1000m of water depth during winter months. Finally, the downward particle fluxes showed typical temporal variability of high latitudes, with high percentages of the biogenic compounds (opal, organic carbon and calcium carbonate) linked to the phytoplankton bloom in spring-summer. However, on an annual basis local planktonic production was a secondary source for the downward OC, since most of the OC was advected laterally by the WSC. Overall, these observations demonstrated the sensitivity of the downward flux of particles to environmental conditions such as hydrodynamics, sea ice rafting, and pelagic primary production. Future alteration of the patterns of natural drivers due to climate change is thus expected to cause major shifts in the downward flux of particles, including carbon, to the deep sea ecosystems. © 2015 Elsevier Ltd., This research has been supported by the projects HERMIONE (FP7-ENV-2008-1-226354) and GRACCIE-CONSOLIDER (CSD2007-00067), and a Catalan Government Grups de Recerca Consolidats grant (2009 SGR 1305). LL was partly supported by the CNR-DTA project SNOW (Sensor Network for Oceanography in shallow Water - Kongsfjord experiment), and AS by a “Ramon y Cajal” contract from MICINN. BF is affiliated with the Centre of Excellence: Arctic Gas hydrate, Environment and Climate (CAGE) funded by the Norwegian Research Council (grant no. 223259). We are grateful to S. Buenz and the crew of RV Helmer Hansen (University of Tromsø) for their valuable support during the cruises, and R. Duran, S. Kunesch, J. Carbonne, A. Rumin, S. Aliani, and X. Rayo who assisted with the field and laboratory work. This is contribution N. XXXX of the CNR-ISMAR of Bologna.

Surface sediments collected from deep slopes and basins (1018–4087 m depth) of the oligotrophic eastern Mediterranean Sea have been analysed for bulk elemental and isotopic composition of organic carbon, total nitrogen and selected lipid biomarkers, jointly with grain size distribution and other geochemical proxies. The distribution and sources of sedimentary organic matter (OM) have been subsequently assessed and general environmental variables, such as water column depth and physical circulation patterns, have been examined as causative factors of deep-sea sediment characteristics. Lithogenic and biogenic carbonates are the dominant sedimentary fractions, accounting for up to 85.4 and 66.5 % of the total weight respectively. The low OC and TN contents in the surface sediments of the study area, which ranged from 0.15 to 1.15 % and 0.06 to 0.11 % respectively, reflect the oligotrophic character of the eastern Mediterranean Sea. Both bulk and molecular organic tracers reflect a mixed contribution from autochthonous and allochthonous sources for the sedimentary OM, as indicated by relatively degraded marine OM, terrestrial plant waxes and anthropogenic OM (e.g. degraded petroleum by-products) respectively. Wide regional variations have been observed amongst the studied proxies, which reflect the multiple factors controlling sedimentation in the deep eastern Mediterranean Sea. Our findings highlight the role of deep eastern Mediterranean basins as depocentres of organic-rich fine-grained sediments (mean 5.4 ± 2.4 μm), with OM accumulation and burial being attributed to aggregation mechanisms and hydrodynamic sorting. A multi-proxy approach is applied aiming to investigate the biogeochemical composition of sediment samples, which sheds new light on the sources and transport mechanisms along with the impact of preservation vs. diagenetic processes on the composition of sedimentary OM in the deep basins of the oligotrophic eastern Mediterranean Sea.

8 pages, 3 figures, 2 tables, The finding of perfluoroalkyl substances (PFASs) in particles sinking to the deep northwestern Mediterranean Sea confirms the role of the latter as ballast for the transfer of pollutants to the deep sea. The transfer of particulate matter down to the deep is enhanced during atmosphere-driven, high-energy physical oceanographic processes like dense shelf water cascading (DSWC), which is caused by winter surface heat losses and evaporation. Here we present data from samples collected during winter 2012, when dense shelf water formation and subsequent cascading triggered the flushing of large amounts of PFASs through a submarine canyon to depths in excess of 1000. m. The finding of quantifiable concentrations of long-chain PFOA, PFOS and PFNA substances and significantly high concentrations of the short-chain substances PFHxA and PFBA indicates that these compounds, sorbed onto particulate matter, are quickly and directly transferred to the ocean's interior, thus highlighting the role of DSWC in removing those pollutants from the coastal ocean. Eventually, uncertainties about our results arising from the limited number of samples available are counterbalanced by their intrinsic value as intense DSWC events, like the one in 2012, occur only every 5-7. years in the study area, which seriously restricts sampling opportunities. Our results add PFASs to the list of persistent organic pollutants like polychlorinated biphenyls, chlorobenzenes or polycyclic aromatic hydrocarbons known to be conveyed to the deep marine environment. © 2015 Elsevier B.V., This research has been supported by PERSEUS (FP7-OCEAN-2011-3-287600), DOSMARES (CTM2010-21810-C03), and NUREIEV (CTM2013-44598-R) research projects, and the Generalitat de Catalunya (Consolidated Research Groups grants 2014 SGR 291, 2014 SGR 418 and 2014 SGR 1068). [...] AS is supported by a “Ramon y Cajal” contract from MICINN

The compilation of several multibeam data sets unveils for the first time the seafloor of almost the entire northeastern Iberian margin, in the northwestern Mediterranean Basin. This is achieved thanks to an international effort involving mainly Spanish and French research institutions. Submarine canyons, turbiditic channels, landslides and a mid-oceanic valley are the main sedimentary features observed. The size and shape of these features vary throughout the margin. However, the morphometric analysis performed leads to the subdivision of the margin in three main segments: North Catalan Margin (NCM), South Catalan Margin (SCM) and Ebro Margin (EM). We address a non-frequently used scale to tackle the question of which are the main mechanisms controlling the morphological variability between these margins. This is the mesoscale (from one to several hundred kilometres), which allows a comprehensive, holistic and detailed analysis of the seascaping mechanisms shaping the continental margin of northeastern Iberia. Preliminary results suggest that factors controlling the seascape involve a combination of tectonics, long-term fluvial sediment flux to the margin, sediment grain size, basin depth and slope gradient. Modelling of these morphogenetic relationships will contribute to a better knowledge of the seascape development in mid-latitude siliciclastic margins.

As part of the “Mediterranean Targeted Project II—MAss Transfer and Ecosystem Response” (MTPII-MATER) EU-funded research project, particle flux data was obtained from three instrumented arrays moored along the 1°30′ W meridian in the Eastern Alboran Sea. The mooring lines were deployed over 11 months, from July 1997 to May 1998, and were equipped with sediment trap-current metre pairs at 500–700, 1000–1200 and 2000–2200 m of water depth. The settling material was analysed to obtain total mass, lithogenic, calcium carbonate, organic carbon and opal fluxes. Integrated analysis of sediment trap and current meter data with sea-surface satellite images reveals that particle flux distribution is a function of primary production, mid-water lateral advection and near bottom nepheloid input. The spreading to the east and to the south of phytoplankton-rich water from the upwelling off the Spanish coast is controlled by the position and size of the Western and Eastern Alboran gyres, and drives the seasonal arrival of biogenic material down to the sea floor. Discrete lateral advection events unrelated to vertical entries of material can also supply particulate matter at 1000–1200 and 2000–2200 m of water depth as noted at the northern and southern stations. To achieve a better understanding of the carbon cycle in the area we have attempted to constrain the production, transfer and burial of particulate organic carbon, providing the first estimates of particulate organic carbon export in the Alboran Sea. Results suggest that sea surface circulation and associated productivity signal control the efficiency of the biological pump in the area. The export production in the Eastern Alboran Sea is higher than in other Mediterranean sites, with 0.5–0.9% of the carbon fixed during photosynthesis transferred down the water column and buried in the deep sediments. In addition, a large portion is supplied by lateral advection and through a benthic nepheloid layer, which represent a significant source of organic carbon to the deep Eastern Alboran Sea.

Particulate biogenic barium (bio-Ba) fluxes obtained from three instrumented arrays moored in the Alboran Sea, the westernmost basin in the Mediterranean Sea, are presented in this study. The mooring lines were deployed over almost 1 year, from July 1997 to May 1998, and were equipped with sediment traps at ∼500–700 m depth, ∼1000–1200 m depth and 30 m above the seafloor (∼1000–2200 m). The results obtained support the growing body of evidence that the relationship between particulate bio-Ba and Corg throughout the water column in margin systems is clearly different from this relation in the open ocean. In the Alboran Sea, the annual averaged bio-Ba fluxes range from 0.39 to 1.07 μmol m−2 day−1, with mean concentrations of 1.31–1.69 μmol g−1 and bio-Ba/Corg ratios lower than in the open ocean. The low bio-Ba values obtained also indicate that calculating bio-Ba is extremely sensitive to the detrital Ba/Al ratio of each sample. The lithogenic Ba fraction in the Alboran Sea continental margin area contributes between 24% and 85% of the total Ba. Increased bio-Ba export efficiency was observed after periods of high primary productivity and suggests that the processes limiting the bio-Ba formation in the study area relate to settling dynamics of organic matter aggregates. Furthermore, the ballasting effect of the abundant lithogenic and carbonate particles may limit decomposition of organic matter aggregates and enhance the transfer of particles rich in Corg and relatively poor in bio-Ba to the deep seafloor. Lateral input of freshly sedimented biogenic material, including particulate bio-Ba, has been observed on the lower continental slope in the western Alboran Sea. These observations emphasize that the use of the bio-Ba as a proxy of export productivity from the surface ocean must be used cautiously in highly dynamic environments such as those in the Alboran Sea.

Microbiological and biogeochemical studies were carried out in sediments and near bottom waters in the upwelling area off the Malaga coast and in the Almeria-Oran frontal zone. In these nutrient-rich conditions, metabolic activity is potentially limited by oxygen availability through the sediment depth. In the surficial sediments of the frontal zone, however, oxygen penetrated to a depth of 4 cm, allowing oxic mineralisation processes to occur throughout the layer. In the surficial sediments of the upwelling area, oxygen penetration was limited to the top 2.5 cm, leading to anoxic conditions. Glutamate respiration and global oxygen uptake rates were clearly higher than in the frontal zone. In the superficial sediments of the frontal zone, bacteria were less abundant and showed the lowest potential rate for mineralisation processes, but the highest rate for proteolysis. This discrepancy is probably due to differences in the quality of organic inputs into the two areas, with labile organic compounds reaching the sea bottom in the shallower upwelling zone. Such inputs enhance the mineralisation of low molecular weight monomers, whilst inhibiting the polymer hydrolysis processes. Conversely, in the deeper frontal zone, labile monomers become exhausted, decreasing the mineralisation rates. Concomitantly, bacteria have to develop ectoenzymatic activities in order to extract their carbon and energy from the available semi-labile polymers. Consequently, the theoretical relationship between the mineralisation and hydrolysis processes are tightly coupled in the upwelling area, and uncoupled in the frontal zone., La distribution de facteurs biogéochimiques et de divers processus microbiens a été étudiée dans les eaux proches du fond et les sédiments superficiels dans la zone de l'upwelling de Malaga et au niveau du front Almeria-Oran. Dans ces conditions relativement eutrophes, les activités métaboliques sont limitées par la disponibilité de l'oxygène moléculaire dans l'épaisseur sédimentaire. Toutefois, dans les sédiments de la zone frontale l'oxygène pénètre jusqu'à 4 cm de profondeur, permettant le développement de processus oxiques à travers cette couche. Par contre, dans la zone d'upwelling, où la vitesse potentielle de respiration du glutamate et la consommation globale d'oxygène sont nettement supérieures à celles de la zone frontale, la pénétration de l'oxygène est limitée à 2,5 cm, conduisant à l'anoxie à partir de ce niveau. Dans les sédiments superficiels de la zone frontale, les bactéries sont moins abondantes, et moins actives dans le processus de respiration du glutamate, que leurs homologues de la zone d'upwelling. Par contre, leur potentiel d'hydrolyse des polypeptides est plus développé. Cette divergence est probablement due à la différence de qualité des apports en matières organiques dans les deux zones. Par rapport à la zone frontale, dans la zone d'upwelling moins profonde les apports au domaine benthique incluent une fraction plus labile. Ces apports en matériel labile dopent les processus de minéralisation des monomères, alors que par un effet de retro-inhibition ils ralentissent l'hydrolyse des polymères. À l'opposé, dans la zone frontale plus profonde, le matériel atteignant le domaine benthique a été épuisé de sa fraction labile, ce qui provoque un ralentissement des vitesses de minéralisation des monomères. Simultanément, les bactéries doivent développer des activités ectoenzymatiques pour pouvoir extraire des polymères semi-réfractaires disponibles le carbone nécessaire à leur métabolisme. En conséquence, les relations entre les processus d'hydrolyse et de minéralisation sont couplés dans la zone d'upwelling et découplés dans la zone frontale.

Settled material recorded by two near bottom sediment traps deployed from November 2009 to February 2011 at northern (Sóller) and southern (Cabrera) slopes of Mallorca Island (Western Mediterranean) is studied with the aim of discerning their possible origin. The total settled particulate mass fluxes (TMF) at Sóller station were found to be, on average, 2.8 times greater than at Cabrera location during the deployment period, although both time series had a similar temporal evolution. It is suggested that wind episodes affecting the entire area were the common forcing, causing a primary production enhancement and being responsible of the similar temporal behavior. The greater sediment amounts collected in Sóller are explained on the basis of two physical mechanisms: 1) a number of successive eddies generated by instabilities of the Balearic Current that are regularly observed on satellite images, some of which have been reported to reach the seabed, thus increasing near bottom velocities and causing sediment resuspension. And 2) bottom trapped waves that are evidenced from a wavelet analysis in Sóller which could affect the TFM by enhancing sediment resuspension or advecting material from the surrounding areas. © 2014 Elsevier B.V., This research has been supported by IDEADOS project (CMT2008-04489-C03-03). The work of A. Amores was funded by a JAE-PreDoc grant from Consejo Superior de Investigaciones Científicas (CSIC) and cofunded by Programa Operativo FSE 2007–2013. A. C. was also supported by GRACCIE (CSD2007-00067, Consolider-IngenioProgram) research projects, a Generalitat de Catalunya “Grups de Recerca Consolidats” grant (2009 SGR-1305)

International audience; In this study, we investigate the strength and efficiency of carbon sequestration in the Southern European Seas (SES), by analyzing the export of POC at three deep sites located in the Western Mediterranean Sea (WMED), the Eastern Mediterranean Sea (EMED) and the Black Sea (BS). We combine estimations of satellite and algorithm-generated primary production data, calculated POC fluxes out of the euphotic layer and POC fluxes measured by sediment traps at the mesopelagic and bathypelagic layers during a one year period, with an ultimate goal to obtain a better understanding of the functioning of the biological pump in the SES.Annual particulate primary production based on satellite estimations (SeaWiFS) at the three sites, averages 205, 145 and 225 gC m− 2 y− 1 at the WMED, EMED and BS, respectively. According to our findings, the fraction of primary production that is exported out of the euphotic zone in the SES ranges between 4.2% and 11.4%, while the fraction reaching the mesopelagic layer (1000–1400 m depth) ranges between 0.6% and 1.8%. Finally, the fraction of primary production exported at the bathypelagic layer (2000–2800 m depth) is found to be 0.6%, 0.3% and 1.4% in the WMED, EMED and BS, respectively. The role of various processes responsible for the replenishment of surface waters with nutrients, giving rise to productivity episodes and organic carbon export to depth at the three SES sites is considered.

The past existence of a giant ice stream off the northern end of the Antarctic Peninsula is suggested by a convex-upward, elongated sediment body now at a mean water depth of 1000 m. Because of its morphological characteristics, i.e., a set of parallel to subparallel ridges and grooves to 100 km long, with an overall width of 25 km, we call this depositional body a bundle structure. We hypothesize that bundle structures form by accumulation of basal deformation till under their parent ice streams. From its location, size, and overall characteristics the bundle structure described here constitutes the best preserved, largest, deepest, and relatively low latitude evidence of giant ice streams that flowed offshore Antarctica during glacial maxima. Bundle structures reveal the very dynamic behavior of ice caps in the northern Antarctic Peninsula during the last glacial maximum, with catchment areas draining rapidly under marine-based critical subglacial conditions. Bundle structures represent a new megascale streamlined glacial landform.

Special issue Integrated study of a deep submarine canyon and adjacent open slopes in the Western Mediterranean Sea: an essential habitat.-- 13 pages, 7 figures, 2 tables, To characterize the temporal and spatial variability of total mass fluxes in the Blanes submarine canyon and the nearby southern open slope, eight near-bottom sediment traps were deployed at 300, 900, 1200 and 1500m along the canyon axis, and at 900, 1200, 1500 and 1800m of water depth on the southern open slope from November 2008 to November 2009. The results obtained show that mass fluxes were higher into the canyon, ranging from 0.05 to 82.67gm-2d-1, compared with those from the open slope that ranged from 0.01 to 9.91gm2d-1. Both environments were highly influenced by atmospheric forcing and showed increased total mass fluxes during autumn and winter months. The spatial distribution of total mass fluxes and major constituents (organic matter, carbonate, opal and lithogenics) highlights the contrasts amongst the two physiographic domains in the study area (canyons vs. open slope). The temporal evolution of particle fluxes shows three distinct situations succeeding each other along the year. These are determined by: (1) storms in autumn and winter, driving 60% of the annual total mass flux in Blanes Canyon and 44% in the open slope stations, and also 60% and 40% of the annual OC flux in Blanes Canyon and the southern open slope, respectively; (2) open sea convection in late winter and spring, which is accompanied by a phytoplankton bloom and drives 13% of the settling OC in the canyon and 34% in the open slope; and (3) dust inputs and resuspension by bottom trawling in late spring and -summer months, driving 17% of the annual OC flux in the canyon and 18% in the slope. © 2013 Elsevier Ltd., This research has been supported by Spanish and EU funded projects PROMETEO (CTM2007-66316-C02-01/MAR), DOS MARES (CTM2010-21810-C03-01), GRACCIE-CONSOLIDER (CSD2007-00067), PERSEUS (GA 287600) and REDECO (CTM2008-04973-E/MAR) RTD projects. University of Barcelona researchers are supported by grant 2009 SGR 1305 of Generalitat de Catalunya. P.L.F. benefited from a Spanish FPI Grant (BES-2008-009374)

Special issue Integrated study of a deep submarine canyon and adjacent open slopes in the Western Mediterranean Sea: an essential habitat.-- 13 pages, 5 figures, 5 tables, supplementary data https://doi.org/10.1016/j.pocean.2013.07.017, Submarine canyons are efficient pathways transporting sediments and associated pollutants to deep sea. The objective of this work was to provide with the first assessment of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) levels and accumulation in deep-sea megafauna (crustacean and fish) and sediments in the Blanes submarine canyon (North-Western Mediterranean Sea). The influence of the selected species habitats (pelagic, nektobenthic, and benthic) and the trophic chain level on the accumulation of dioxins was also investigated. Bottom sediment and biota samples were collected at different depths and locations inside the canyon and in the adjacent slope outside the canyon influence. ∑2,3,7,8-PCDD/F concentrations in sediments varied from 102 to 680pgg-1 dry weight (d.w.) (1-6 WHO98-TEQpgg-1d.w.). Dioxins are enriched in bottom sediments at higher depths inside the canyon and in particular in the deepest parts of the canyon axis (1700m depth), whereas no enrichment of dioxins was verified at the deepest sediments from the adjacent open slope outside the canyon influence. The proportion of ∑2,3,7,8-PCDF (furans) to ∑2,3,7,8-PCDD (dioxins) increased for sediments with higher soot carbon content consistent with the higher affinity of PCDF for sorption onto soot carbon. Higher ∑2,3,7,8-PCDD/F levels were found in crustaceans than in fish, ranging from 220 to 795pgg-1 lipid weight (l.w.) (13-90 WHO98-TEQpgg-1l.w.) and 110 to 300pgg-1l.w. (22-33 WHO98-TEQpgg-1l.w.) in crustaceans and fish, respectively. Dioxin highest concentrations were found in nektobenthic organisms, i.e., benthic organism with swimming capabilities (both fish and crustaceans). These higher levels are consistent with the higher trophic level and predicted biomagnification factors (BMFs) of nektobenthic species. The reduced availability of sediment-bound PCDD/F for benthic species mainly due to soot and organic carbon sorption of these contaminants most probably influenced this result too. While biomagnification exerts a clear influence on the total dioxin concentrations in biota, life habits seem to exert an influence in the differential congener-specific accumulation of dioxins rather than in the total concentration. Thus, pelagic species reflected the estimated congener pattern from the surface water dissolved phase and phytoplankton, whereas the dioxin pattern in benthic and nektobenthic species was more similar to the estimated pattern in the deep-water dissolved phase and the sediment. The three crustacean species considered in this study bioaccumulated higher amounts of other dioxin congeners (non-2,3,7,8-PCDD/Fs) compared to fish. An interplay of several factors, such as biota habitats, differential uptake of water column dioxin (dissolved and particle-bound fractions), and different metabolization capabilities and rates (CYP-mediated metabolism) may explain the differences observed in dioxin patterns among crustacean species and between fish and crustaceans in the Blanes submarine canyon. © 2013 Elsevier Ltd., The present work was funded by the MICYT projects RECS II (REN02/04556/C02/MAR to Manuel Espino and JBC), PROMETEO (CTM2007-66316-C02/MAR to M. Canals and JBC), DOS MARES (CTM2010-21810-C03-03/MAR to M. Canals and JBC), and GRACCIE (CSD2007-00067, Consolider-Ingenio Program). The European Commission projects HERMIONE (FP7/2007-2013, grant agreement no. 226354) and PERSEUS (FP7-OCEAN-2011-287600). The Generalitat de Catalunya ‘‘Grups de Recerca Consolidats’’ grant (2009 SGR-1305)

10 pages, 7 figures, 1 table, It is generally assumed that episodic nutrient pulses by cyclonic eddies into surface waters support a significant fraction of the primary production in subtropical low-nutrient environments in the northern hemisphere. However, contradictory results related to the influence of eddies on particulate organic carbon (POC) export have been reported. As a step toward understanding the complex mechanisms that control export of material within eddies, we present here results from a sediment trap mooring deployed within the path of cyclonic eddies generated near the Canary Islands over a 1.5-year period. We find that, during summer and autumn (when surface stratification is stronger, eddies are more intense, and a relative enrichment in CaCO3 forming organisms occurs), POC export to the deep ocean was 2-4 times higher than observed for the rest of the year. On the contrary, during winter and spring (when mixing is strongest and the seasonal phytoplankton bloom occurs), no significant enhancement of POC export associated with eddies was observed. Our biomarker results suggest that a large fraction of the material exported from surface waters during the late-winter bloom is either recycled in the mesopelagic zone or bypassed by migrant zooplankton to the deep scattering layer, where it would disaggregate to smaller particles or be excreted as dissolved organic carbon. Cyclonic eddies, however, would enhance carbon export below 1000 m depth during the summer stratification period, when eddies are more intense and frequent, highlighting the important role of eddies and their different biological communities on the regional carbon cycle. © 2013 Alonso-González et al., This work was funded through the Spanish “Plan Nacional de I+D” under the RODA (CTM2004-06842-C03-03/MAR), PUMP (CMT2012-33355) and HOTMIX (CTM2011-30010-C02-01) projects. A.S-V. and A.C. acknowledge a Generalitat de Catalunya “Grups de Recerca Consolidats” grant (2009 SGR-1305). The ROMS model configuration was developed at UCLA, where ROMS development is supported by the Office of Naval Research (currently grant N00014-08-1-0597). The ROMS work was partially supported by the National Center for Supercomputing Applications under the grant number OCE030007 and utilized the abe system

From October 2005 through October 2006 sediment traps were moored along the Lacaze–Duthiers and Cap de Creus submarine canyons and on the adjacent southern open slope in the Gulf of Lion (Northwestern Mediterranean). During the Winter 2006 (January–March), an intense Dense Shelf Water Cascading (DSWC) event was found to be a major driver of particle transport, increasing lateral advection of material at all stations. In this study, we assessed the sources and degradation of organic matter (OM) advected along canyons during both DSWC and quiescent conditions using specific organic biomarkers, including pigments, lignin phenols and amino acids. Three major events of fresh, marine OM inputs were detected during the study period. The largest one was in spring (March–May), with smaller events also observed in winter (December 2005) and summer (August 2006), suggesting that both spring blooms and sporadic blooms associated with wind-driven mixing affects carbon fluxes in this system. The DSWC event that partially overlapped the spring-bloom enhanced the overall transfer of OM down canyons. The lignin phenol data show no significant, along-canyon dilution and are consistent with constant advection of terrigenous material. In contrast, amino acid and chloropigment compositions indicate that part of the OM is degraded both prior to reaching the canyons and within the canyons themselves. Overall, our results illustrate the importance of both seasonal and sporadic pelagic and continental shelf/lateral events in controlling the exchange of organic matter across this margin.

represents an additional source of 14 C‐depleted organic carbon supplied to the ocean, in parallel with the weathering of fossil organic carbon delivered by rivers from land. To understand the dynamics and implications of this reexposure at the shelf edge, a biogeochemical study was carried out in the Gulf of Lions (Mediterranean Sea) where erosive processes, driven by shelf dense water cascading, are currently shaping the seafloor at the canyon heads. Mooring lines equipped with sediment traps and current meters were deployed during the cascading season in the southwestern canyon heads, whereas sediment cores were collected along the sediment dispersal system from the prodelta regions down to the canyon heads. Evidence from grain‐size, X‐radiographs and 210 Pb activity indicate the presence in the upper slope of a shelly‐coarse surface stratum overlying a consolidated deposit. This erosive discontinuity was interpreted as being a result of dense water cascading that is able to generate sufficient shear stress at the canyon heads to mobilize the coarse surface layer, eroding the basal strata. As a result, a pool of aged organic carbon (D 14 C= −944.5 ± 24.7‰; mean age 23,650 ± 3,321 ybp) outcrops at the modern seafloor and is reexposed to the contemporary carbon cycle. This basal deposit was found to have relatively high terrigenous organic carbon (lignin = 1.48 ± 0.14 mg/100 mg OC), suggesting that this material was deposited during the last low sea‐level stand. A few sediment trap samples showed anomalously depleted radiocarbon concentrations (D 14 C= −704.4 ± 62.5‰) relative to inner shelf (D 14 C= −293.4 ± 134.0‰), mid‐shelf (D 14 C= −366.6 ± 51.1‰), and outer shelf (D 14 C= −384 ± 47.8‰) surface sediments. Therefore, although the major source of particulate material during the cascading season is resuspended shelf deposits, there is evidence that this aged pool of organic carbon can be eroded and laterally advected downslope.

[1] Here we present results from sediment traps that separate particles as a function of their settling velocity, which were moored in the Canary Current region over a 1.5-year period. This study represents the longest time series using “in situ” particle settling velocity traps to date and are unique in providing year-round estimates. We find that, at least during half of the year in subtropical waters (the largest ocean domain), more than 60% of total particulate organic carbon is contained in slowly settling particles (0.7–11 m d−1). Analyses of organic biomarkers reveal that these particles have the same degradation state, or are even fresher than rapidly sinking particles. Thus, if slowly settling particles dominate the exportable carbon pool, most organic matter would be respired in surface waters, acting as a biological source of CO2 susceptible to exchange with the atmosphere. In the context of climate change, if the predicted changes in phytoplankton community structure occur, slowly settling particles would be favored, affecting the strength of the biological pump in the ocean.

15 páginas, 8 figuras, 3 tablas., Settling particles were collected using sediment traps deployed along three transects in the Lacaze-Duthiers and Cap de Creus canyons and the adjacent southern open slope from October 2005 to October 2006. The settling material was analyzed to obtain total mass fluxes and main constituent contents (organic matter, opal, calcium carbonate, and siliciclastics). Cascades of dense shelf water from the continental shelf edge to the lower continental slope occurred from January to March 2006. They were traced through strong negative near-bottom temperature anomalies and increased current speeds, and generated two intense pulses of mass fluxes in January and March 2006. This oceanographic phenomenon appeared as the major physical forcing of settling particles at almost all stations, and caused both high seasonal variability in mass fluxes and important qualitative changes in settling material. Fluxes during the dense shelf water cascading (DSWC) event ranged from 90.1 g m−2 d−1 at the middle Cap de Creus canyon (1000 m) to 3.2 g m−2 d−1 at the canyon mouth (1900 m). Fractions of organic matter, opal and calcium carbonate components increased seaward, thus diminishing the siliciclastic fraction. Temporal variability of the major components was larger in the canyon mouth and open slope sites, due to the mixed impact of dense shelf water cascading processes and the pelagic biological production. Results indicate that the cascading event remobilized and homogenized large amounts of material down canyon and southwardly along the continental slope contributing to a better understanding of the off-shelf particle transport and the internal dynamics of DSWC events., This research has been supported by HERMES (GOCE-CT-2005-511234-1), SESAME (GOCE-036949), HERMIONE (FP7-ENV-2008-1-226354), and GRACCIE (CSD2007-00067, Consolider-Ingenio Program) research projects, a Generalitat de Catalunya “Grups de Recerca Consolidats” grant (2009 SGR-1305) and a FP7 Marie Curie Reintegration Grant (PERG04-GA-2008-239175). C. Pasqual is supported by an F.P.U. grant from the Spanish government.

[1] Oceanic eddy generation by tall deep-water islands is common phenomenon. It is recognized that these eddies may have a significant impact on the marine system and related biogeochemical fluxes. Hence, it is important to establish favourable conditions for their generation. With this objective, we present an observational study on eddy generation mechanisms by tall deep-water islands, using as a case study the island of Gran Canaria. Observations show that the main generation mechanism is topographic forcing, which leads to eddy generation when the incident oceanic flow is sufficiently intense. Wind shear at the island wake may acts only as an additional eddy-generation trigger mechanism when the impinging oceanic flow is not sufficiently intense. For the case of the island of Gran Canaria we have observed a mean of ten generated cyclonic eddies per year. Eddies are more frequently generated in summer coinciding with intense Trade winds and Canary Current.

13 pages, 9 figures, We present a 1-yr (2005-2006) record of organic carbon (OC) and total nitrogen (TN) contents and their isotopic ratios (δ13Coc and δ15N) in sinking particles from the western Gulf of Lions. Maximum OC and TN fluxes recorded in January 2006 and March-April 2006 were associated with negative near-bottom temperature anomalies. This reveals large inputs of resuspended organic matter from the shelf basinwards to depths > 1500 m by dense shelf-water cascading. The first pulse of organic matter had low δ13Coc (-25.5%0) and N: C (0.08) and high δ15N (6.6%0) values, indicative of the arrival of organic matter of terrestrial origin. In contrast, the second pulse had high δ13Coc (-21.9%0) and N: C (0.15) and extremely low δ15N (0.0%0) values, indicative of the transfer of organic matter with higher marine contribution. Though downslope export of organic matter from the adjacent shelf predominated, particles escaping from surface waters remained an important source of organic matter during low-energy and low-flux periods and especially during summer conditions, with significant contribution of N2 fixation to organic matter export. Overall, our results suggest the export of organic matter from different sources to the deep Mediterranean basin, which in turn might alter within a couple of months the quality of the sedimentary organic matter deposited on the sea floor and thus the dynamics of the deep ecosystems. © 2009, by the American Society of Limnology and Oceanography, Inc, This research has been supported by a Marie Curie Individual Fellowship (re. MEIF-CT-2006-024068) to A. Sanchez-Vidal, the research projects Hotspot Ecosystem Research on the Margins of European Seas (ref. GOCE-CT-2005-511234-1), Southern European Seas: Assessing and Modelling Ecosystem Changes (ref. GOCE-036949), Estudio Integrado de Cañones y Taludes Profundos del Mediterráneo Occidental: un hábitat esencial (ref. CTM2007-66316-C02-01/MAR), Multidisciplinary Research Consortium on Gradual and Abrupt Climate Changes, and Their Impacts on the Environment (ref. CSD2007-00067, Consolider Ingenio 2010 Program), and a Generalitat de Catalunya ‘‘Grups de Recerca Consolidats’’ grant (2005 SGR-00152)

13 páginas,10 figuras, 5 tablas., Within the framework of the multidisciplinary RECS project and with the aim of describing the particleflux transfer from the continental shelf to the deep basin, an array of five mooring lines equipped with a total of five pairs of PPS3/3 sequential-sampling sediment traps and RCM-7/8 current meters were deployed 30 m above the bottom from March 2003 to March 2004 inside and outside the BlanesCanyon. One mooring line was located in the upper canyon at 600 m depth, one in the canyon axis at 1700 m depth and other two close to the canyon walls at 900 m depth. A fifth mooring line was deployed in the continental open slope at 1500 m water depth. The highest near-bottom downward particleflux (14.50 g m−2 d−1) was recorded at the trap located in the upper canyon (M1), where continental inputs associated with the presence of the Tordera River are most relevant. On the other hand, the downward fluxes (4.35 g m−2 d−1) in the canyon axis (M2) were of the same order as those found in the western flank (M3) of the canyon. Both values were clearly higher than the value (1.95 g m−2 d−1) recorded at the eastern canyon wall (M4). The open slope (M5) mass flux (5.42 mg m−2 d−1) recorded by the sediment trap located outside the canyon system was three orders of magnitude lower than the other values registered by the inner canyon stations. The relevance of our data is that it explains how the transport pathway in the canyon occurs through its western flank, where a more active and persistent current toward the open ocean was recorded over the entire year of the experiment. Off-shelf sediment transport along the canyon axis showed clear differences during the period of the study, with some important events leading to strong intensifications of the current coupled with large transport of particlefluxes to the deepest parts of the canyon. Such events are primarily related to increases in river discharge and the occurrence of strong storms and cascading events during the winter. In summary, in this study it is shown that the dynamics of the water masses and the currents in the study area convert the sharp western flank of the BlanesCanyon in a more active region that favors erosion processes than the eastern flank, which has a smoother topography and where the absence of erosional conditions yields to steadier sedimentary processes., D.Z. benefited from a Spanish FPU Grant (AP2000-0524), and MMF was aided by a Juan de la Cierva grant from the Spanish Ministry of Science. Support from the government of Spain and the Fulbright Commission for a post-doctoral fellowship to J.G-O. (ref 2007-0516) is gratefully acknowledged by J. García-Orellana. GRC Geociències Marines was additionally funded by the ‘‘Generalitat de Catalunya’’ through its excellency research groups program (ref. 2005 SGR-00152). This study was also supported by the Spanish national research project RECS (REN2002-04556-C02-01).

5 pages, 3 figures, 2 tables.-- Supporting information http://onlinelibrary.wiley.com/doi/10.1029/2007GL032825/suppinfo, During winter 2005–2006, particle fluxes and near-bottom currents were measured in and around the Lacaze-Duthiers and Cap de Creus submarine canyons (western Gulf of Lion). Current anomalies show the occurrence of a major dense shelf water cascading event down to the slope, the latest recorded up to date in the area. Concomitant increased total mass fluxes highlight the ability of cascading waters to transport large amounts of coarse sediment and organic matter, which is predominantly of terrestrial origin. In addition, results reveal that the current regime and associated grain size sorting is the responsible for a geochemical gradient of settling organic particles along the slope, This research has been supported by a Marie Curie individual Fellowship (MEIF-CT-2006-024068) to A. Sánchez Vidal, a FPU fellowship to C. Pasqual, an by the HERMES (GOCE-CT-2005-511234-1), SESAME (GOCE-036949) and PROMETEO (CTM2007-66316-C02-01/MAR) research projects

Special issue EUROSTRATAFORM VOL. 1: Source to Sink Sedimentation on the European Margin.-- 20 pages, 14 figures.-- Erratum to “Suspended sediment fluxes and transport processes in the Gulf of Lions submarine canyons. The role of storms and dense water cascading” [Marine Geology 234/1–4 (2006) 43–61] https://doi.org/10.1016/j.margeo.2007.01.007, Contemporary suspended sediment transport was studied in seven submarine canyons of the Gulf of Lions (GoL). Current meters equipped with turbidity sensors were moored 4 m above bottom at 300 m depth in the canyon axis from November 2003 to May 2004. Sediment transport events were monitored and studied in relation to forcing conditions. There was a large flood in early December, during which discharges from all of the coastal rivers increased by more than one order of magnitude. A smaller flood of the Rhone River occurred later in mid-January followed by a persistent high river discharge that lasted until mid-February. There were also several E-SE storm events during the measurement period, two of them causing large swell, one in early December (max Hs: 8.4 m), coinciding with the major river flood, and one in late February (max Hs: 7 m) during a period of lower river discharge. Most of the variability in down-canyon current speeds was linked to strong downwelling induced by E-SE storms and to cascading of dense shelf water induced by N and NW winds. The intensity and timing of these processes strongly varied spatially. Eastern storms generated higher waves and induced stronger downwelling in the western than in the eastern sector of the GoL. Shelf dense water cascading events were enhanced during eastern storms and they were also more intense in the western sector of the GoL. These events occurred frequently from January to May along the western canyons and from February to April along the eastern canyons. From February to April they occurred simultaneously in all the canyons. Sediment transport was mainly down-canyon and mostly concentrated during storm-induced downwelling and dense water cascading events. During the high river discharge season most of the newly-supplied and resuspended sediment remained stored on the shelf. However, during the late February storm and cascading event, the stored sediment was quickly resuspended and transported, mainly through the westernmost submarine canyon (Cap de Creus), following a flushing pattern. Later, although minor storms and shelf dense water cascading hardly increased suspended sediment concentrations within the canyons, they induced strong near-bottom cunrent velocities, increasing down-canyon sediment fluxes and generating small but significant sediment transport events. Most of the shelf-canyon transfer took place during the late February storm and cascading event through the Cap de Creus canyon where the net suspended sediment flux was between one and two orders of magnitude higher than in the other canyons, This study was supported by the EUROSTRATAFORM Project funded by the EU (EVK3-CT-2002-00079, EU Fifth Framework Programme: Energy, Environment and Sustainable Development)

12 pages, 7 figures, Acquisition of swath bathymetry data west of the North Antarctic Peninsula (NAP), between 63°S and 66°S, and its integration with the predicted seafloor topography of Smith and Sandwell [Global seafloor topography from satellite altimetry and ship depth soundings. Science 277, 1956-1962.] reveal the links between the continental rise depositional systems and the NAP palaeo-ice sheet dynamics. The NAP Pacific margin consists of a wide continental shelf dissected by several troughs, tens of kilometres wide and long. The Biscoe Trough, which has been almost entirely surveyed with multibeam sonar, shows spectacular fan-shaped streamlining sea-floor morphologies revealing the presence of ice streams during the Last Glacial Maximum. In the study area the continental rise comprises the six northernmost sediment mounds of the NAP Pacific margin and the canyon-channel systems between them. These giant sediment mounds have developed since the early Neogene by southwest flowing bottom currents, which have redistributed along the margin the fine-grained component of the turbiditic currents flowing down canyon-channel systems. The widespread evidence of shallow slope instability within the sediment mounds has been identified from both swath bathymetry and topographic parametric sonar seismic reflection profiles. Bathymetric data show that the heads of all the rise canyon-channel systems coincide geographically with the mouths of the major glacial troughs on the continental shelf edge. This suggests a close genetic link between these morphological features and allows considering a glacio-sedimentary model for the western NAP outer margin seascape development. This model considers the availability of depositional space on the continental rise as the limiting factor for mound development. The depositional space, in turn, is controlled by the spacing between glacial maxima shelf-edge reaching ice streams. This model takes into account both glacial and interglacial scenarios and gives new insights on evaluating the palaeoenvironmental record of the continental rise sediment mounds. © 2005 Elsevier Ltd. All rights reserved, This study was supported by the Spanish (COHIMAR project, ref. REN2000-0896/ANT), Italian and Belgian Antarctic programs, Fullbright Commission GEMARANT project and Generalitat de Catalunya Grant 2001SGR-00076 to excellence research groups. Support from the Spanish ‘‘Ministerio de Educación, Cultura y Deporte’’ (D.A.) and ‘‘Ministerio de Ciencia y Tecnologı´a’’ (R.U.) through FPU and ‘‘Ramon y Cajal’’ fellowships, respectively, is greatly acknowledged