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195 Research products, page 1 of 20

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  • Open Access English
    Authors: 
    Vries, Joost; Monteiro, Fanny; Wheeler, Glen; Poulton, Alex; Godrijan, Jelena; Cerino, Federica; Malinverno, Elisa; Langer, Gerald; Brownlee, Colin;
    Project: UKRI | GW4+ - a consortium of ex... (NE/L002434/1), UKRI | NSFGEO-NERC An unexpected... (NE/N011708/1), MZOS | Mechanism of long-term ch... (098-0982705-2731), EC | MEDSEA (265103), EC | SEACELLS (670390)

    Coccolithophores are globally important marine calcifying phytoplankton that utilize a haplo-diplontic life cycle. The haplo-diplontic life cycle allows coccolithophores to divide in both life cycle phases and potentially expands coccolithophore niche volume. Research has, however, to date largely overlooked the life cycle of coccolithophores and has instead focused on the diploid life cycle phase of coccolithophores. Through the synthesis and analysis of global scanning electron microscopy (SEM) coccolithophore abundance data (n=2534), we find that calcified haploid coccolithophores generally constitute a minor component of the total coccolithophore abundance (≈ 2 %–15 % depending on season). However, using case studies in the Atlantic Ocean and Mediterranean Sea, we show that, depending on environmental conditions, calcifying haploid coccolithophores can be significant contributors to the coccolithophore standing stock (up to ≈30 %). Furthermore, using hypervolumes to quantify the niche of coccolithophores, we illustrate that the haploid and diploid life cycle phases inhabit contrasting niches and that on average this allows coccolithophores to expand their niche by ≈18.8 %, with a range of 3 %–76 % for individual species. Our results highlight that future coccolithophore research should consider both life cycle stages, as omission of the haploid life cycle phase in current research limits our understanding of coccolithophore ecology. Our results furthermore suggest a different response to nutrient limitation and stratification, which may be of relevance for further climate scenarios. Our compilation highlights the spatial and temporal sparsity of SEM measurements and the need for new molecular techniques to identify uncalcified haploid coccolithophores. Our work also emphasizes the need for further work on the carbonate chemistry niche of the coccolithophore life cycle.

  • Open Access English
    Authors: 
    Pallacks, Sven; Ziveri, Patrizia; Martrat, Belén; Mortyn, P Graham; Grelaud, Michaël; Schiebel, Ralf; Incarbona, Alessandro; García-Orellana, Jordi; Anglada-Ortiz, Griselda;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | MEDSEA (265103)

    Three high resolution multicore records from two western Mediterranean Sea regions (Alboran and Balearic basins) have been analyzed for sea surface temperature (SST), coccolithophore and planktic foraminiferal abundance changes. Age-depth models at both sites were developed by a combination of 210Pb and 14C dating techniques, describing high sedimentation rates at both study sites, covering the time interval from the Medieval climate anomaly to present. Alkenone derived SST of core MedSeA-S3-c1 and MedSeA-S23-c3 are in good agreement with other results, tracing temperature changes through the Common Era (CE) and show a clear warming emergence at about 1850 CE. Analysis of relative abundance of calcareous nannoplankton assemblages (coccolithophores) was done on core MedSeA-S3-c1 (150 µm. Both cores show opposite abundance fluctuations of planktic foraminiferal species (Globigerina bulloides, Globorotalia inflata and Globorotalia truncatulinoides). The relative abundance changes of Globorotalia truncatulinoides plus Globorotalia inflata describe the intensity of deep winter mixing in the Balearic basin. In the Alboran Sea, Globigerina bulloides and Globorotalia inflata instead respond to local upwelling dynamics. Our data suggests that planktic foraminiferal abundance and species changes in the western Mediterranean Sea is already affected by accelerated anthropogenic warming, overprinting natural cycles in this region.

  • Open Access English
    Authors: 
    Segato, Delia; Villoslada Hidalgo, Maria Del Carmen; Edwards, Ross; Barbaro, Elena; Vallelonga, Paul T; Kjær, Helle Astrid; Simonsen, Marius; Vinther, Bo Møllesøe; Maffezzoli, Niccolò; Zangrando, Roberta; +4 more
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | ICE2ICE (610055), EC | ERA-PLANET (689443)

    This dataset presents the fire proxies levoglucosan, black carbon and ammonium measured in the RECAP ice core, in coastal East Greenland. The datasets cover a period of 5000 years and are averaged in 20 years bins. Raw concentrations of levoglucosan, black carbon and ammonium are also provided. Levoglucosan has been determined using high performance liquid chromatography/negative ion electrospray ionization – tandem mass spectrometry (HPLC/(-)ESI-MS/MS). Black carbon has been measured using a BC analyzer connected to the Continuous Flow Analysis system. Ammonium (NH4+) has been measured by fluorescence within the Continuous Flow Analysis setup.

  • Other research product . Other ORP type . 2020
    English
    Authors: 
    Penna, Pierluigi; Belardinelli, Andrea; Croci, Camilla Sofia; Domenichetti, Filippo; Martinelli, Michela;
    Country: Italy
    Project: EC | JERICO-NEXT (654410), EC | JERICO (262584), EC | NEXOS (614102)

    From 2003 to 2013, the Ancona section of CNR-IRBIM (formerly part of CNR-Institute of Marine Science) runned the "Fishery Observing System" (FOS) program aimed at using Italian fishing vessels as Vessels Of Opportunity (VOOs) for the collection of scientifically useful datasets (Falco et al. 2007). Some commercial fishing vessels, targetting small pelagic species in the northern and central Adriatic Sea, were equipped with an integrated system for the collection of information on catches, position of the fishing operation, depth and water temperature during the haul, producing a great amount of data that demonstrated to be helpful both for oceanographic and fishery biology purposes (Carpi et al. 2015; Aydo?du et a. 2016; Sparnocchia et al. 2016; Lucchetti et al. 2018). In 2012, thanks to the participation to some national and international projects (e.g. SSD-Pesca, EU-FP7 JERICO etc.), CNR started the development of a new modular "Fishery & Oceanography Observing System" (FOOS; Patti et al. 2013). New sensors for oceanographic and meteorological data allow nowadays the FOOS to collect more parameters, with higher accuracy and to send them directly to a data center in near real time (Martinelli et al. 2016; Sparnocchia et al. 2017). Furthermore, the FOOS is a multifunction system able to collect various kind of data from the fishing operations and also to send back to the fishermen useful information (e.g. weather and sea forecasts, etc.) through an electronic logbook with an ad hoc software embedded. The new FOOS installed on various kind of fishing vessels targetting different resources, allowed a spatial extension of the monitored areas in the Mediterranean Sea (Patti et al. 2013). CNR-IRBIM implemented the "AdriFOOS" observational system, by installing the FOOS on some commercial fishing boats operating in the Adriatic Sea. Since then the datacenter based in Ancona receives daily data sets of environmental parameters collected along the water column and close to the sea bottom (eg. temperature, salinity, etc.), together with GPS haul tracks, catch amounts per haul, target species sizes and weather information. Some temperature and salinity measurements acquired by the FOOS in the Adriatic Sea from January 2014 to March 2015 were published within the JERICO project and some oxygen and fluorescence profiles obtained in 2017 within the NEXOS project. The dataset here presented contains 14803 depth/temperature profiles collected by 10 vessels of the AdriFOOS fleet in the period 2012-2020. All the profiles were subjected to quality control.Data are flagged according the L20 (SEADATANET MEASURAND QUALIFIER FLAGS).

  • Open Access English
    Authors: 
    Friedrich, J.; Janssen, F.; Aleynik, D.; Bange, H. W.; Boltacheva, N.; Çagatay, M. N.; Dale, A. W.; Etiope, G.; Erdem, Z.; Geraga, M.; +29 more
    Project: EC | HYPOX (226213)

    In this paper we provide an overview of new knowledge on oxygen depletion (hypoxia) and related phenomena in aquatic systems resulting from the EU-FP7 project HYPOX ("In situ monitoring of oxygen depletion in hypoxic ecosystems of coastal and open seas, and landlocked water bodies", http://www.hypox.net). In view of the anticipated oxygen loss in aquatic systems due to eutrophication and climate change, HYPOX was set up to improve capacities to monitor hypoxia as well as to understand its causes and consequences. Temporal dynamics and spatial patterns of hypoxia were analyzed in field studies in various aquatic environments, including the Baltic Sea, the Black Sea, Scottish and Scandinavian fjords, Ionian Sea lagoons and embayments, and Swiss lakes. Examples of episodic and rapid (hours) occurrences of hypoxia, as well as seasonal changes in bottom-water oxygenation in stratified systems, are discussed. Geologically driven hypoxia caused by gas seepage is demonstrated. Using novel technologies, temporal and spatial patterns of water-column oxygenation, from basin-scale seasonal patterns to meter-scale sub-micromolar oxygen distributions, were resolved. Existing multidecadal monitoring data were used to demonstrate the imprint of climate change and eutrophication on long-term oxygen distributions. Organic and inorganic proxies were used to extend investigations on past oxygen conditions to centennial and even longer timescales that cannot be resolved by monitoring. The effects of hypoxia on faunal communities and biogeochemical processes were also addressed in the project. An investigation of benthic fauna is presented as an example of hypoxia-devastated benthic communities that slowly recover upon a reduction in eutrophication in a system where naturally occurring hypoxia overlaps with anthropogenic hypoxia. Biogeochemical investigations reveal that oxygen intrusions have a strong effect on the microbially mediated redox cycling of elements. Observations and modeling studies of the sediments demonstrate the effect of seasonally changing oxygen conditions on benthic mineralization pathways and fluxes. Data quality and access are crucial in hypoxia research. Technical issues are therefore also addressed, including the availability of suitable sensor technology to resolve the gradual changes in bottom-water oxygen in marine systems that can be expected as a result of climate change. Using cabled observatories as examples, we show how the benefit of continuous oxygen monitoring can be maximized by adopting proper quality control. Finally, we discuss strategies for state-of-the-art data archiving and dissemination in compliance with global standards, and how ocean observations can contribute to global earth observation attempts.

  • Open Access English
    Authors: 
    Steinacher, M.; Joos, F.; Frölicher, T. L.; Bopp, L.; Cadule, P.; Cocco, V.; Doney, S. C.; Gehlen, M.; Lindsay, K.; Moore, J. K.; +2 more
    Project: EC | EPOCA (211384), EC | MEECE (212085)

    Changes in marine net primary productivity (PP) and export of particulate organic carbon (EP) are projected over the 21st century with four global coupled carbon cycle-climate models. These include representations of marine ecosystems and the carbon cycle of different structure and complexity. All four models show a decrease in global mean PP and EP between 2 and 20% by 2100 relative to preindustrial conditions, for the SRES A2 emission scenario. Two different regimes for productivity changes are consistently identified in all models. The first chain of mechanisms is dominant in the low- and mid-latitude ocean and in the North Atlantic: reduced input of macro-nutrients into the euphotic zone related to enhanced stratification, reduced mixed layer depth, and slowed circulation causes a decrease in macro-nutrient concentrations and in PP and EP. The second regime is projected for parts of the Southern Ocean: an alleviation of light and/or temperature limitation leads to an increase in PP and EP as productivity is fueled by a sustained nutrient input. A region of disagreement among the models is the Arctic, where three models project an increase in PP while one model projects a decrease. Projected changes in seasonal and interannual variability are modest in most regions. Regional model skill metrics are proposed to generate multi-model mean fields that show an improved skill in representing observation-based estimates compared to a simple multi-model average. Model results are compared to recent productivity projections with three different algorithms, usually applied to infer net primary production from satellite observations.

  • Open Access English
    Authors: 
    Capet, A.; Beckers, J.-M.; Grégoire, M.;
    Project: EC | HYPOX (226213)

    The Black Sea northwestern shelf (NWS) is a shallow eutrophic area in which the seasonal stratification of the water column isolates the bottom waters from the atmosphere. This prevents ventilation from counterbalancing the large consumption of oxygen due to respiration in the bottom waters and in the sediments, and sets the stage for the development of seasonal hypoxia. A three-dimensional (3-D) coupled physical–biogeochemical model is used to investigate the dynamics of bottom hypoxia in the Black Sea NWS, first at seasonal and then at interannual scales (1981–2009), and to differentiate its driving factors (climatic versus eutrophication). Model skills are evaluated by a quantitative comparison of the model results to 14 123 in situ oxygen measurements available in the NOAA World Ocean and the Black Sea Commission databases, using different error metrics. This validation exercise shows that the model is able to represent the seasonal and interannual variability of the oxygen concentration and of the occurrence of hypoxia, as well as the spatial distribution of oxygen-depleted waters. During the period 1981–2009, each year exhibits seasonal bottom hypoxia at the end of summer. This phenomenon essentially covers the northern part of the NWS – which receives large inputs of nutrients from the Danube, Dniester and Dnieper rivers – and extends, during the years of severe hypoxia, towards the Romanian bay of Constanta. An index H which merges the aspects of the spatial and temporal extension of the hypoxic event is proposed to quantify, for each year, the intensity of hypoxia as an environmental stressor. In order to explain the interannual variability of H and to disentangle its drivers, we analyze the long time series of model results by means of a stepwise multiple linear regression. This statistical model gives a general relationship that links the intensity of hypoxia to eutrophication and climate-related variables. A total of 82% of the interannual variability of H is explained by the combination of four predictors: the annual riverine nitrate load (N), the sea surface temperature in the month preceding stratification (Ts), the amount of semi-labile organic matter accumulated in the sediments (C) and the sea surface temperature during late summer (Tf). Partial regression indicates that the climatic impact on hypoxia is almost as important as that of eutrophication. Accumulation of organic matter in the sediments introduces an important inertia in the recovery process after eutrophication, with a typical timescale of 9.3 yr. Seasonal fluctuations and the heterogeneous spatial distribution complicate the monitoring of bottom hypoxia, leading to contradictory conclusions when the interpretation is done from different sets of data. In particular, it appears that the recovery reported in the literature after 1995 was overestimated due to the use of observations concentrated in areas and months not typically affected by hypoxia. This stresses the urgent need for a dedicated monitoring effort in the Black Sea NWS focused on the areas and months concerned by recurrent hypoxic events.

  • Open Access
    Authors: 
    Hoppe, C. J. M.; Langer, G.; Rokitta, S. D.; Wolf-Gladrow, D. A.; Rost, B.;
    Project: EC | NEWLOG (267931), EC | PHYTOCHANGE (205150), EC | MEDSEA (265103), EC | MOLSPINQIP (211284)

    The growing field of ocean acidification research is concerned with the investigation of organism responses to increasing pCO2 values. One important approach in this context is culture work using seawater with adjusted CO2 levels. As aqueous pCO2 is difficult to measure directly in small-scale experiments, it is generally calculated from two other measured parameters of the carbonate system (often AT, CT or pH). Unfortunately, the overall uncertainties of measured and subsequently calculated values are often unknown. Especially under high pCO2, this can become a severe problem with respect to the interpretation of physiological and ecological data. In the few datasets from ocean acidification research where all three of these parameters were measured, pCO2 values calculated from AT and CT are typically about 30% lower (i.e. ~300 μatm at a target pCO2 of 1000 μatm) than those calculated from AT and pH or CT and pH. This study presents and discusses these discrepancies as well as likely consequences for the ocean acidification community. Until this problem is solved, one has to consider that calculated parameters of the carbonate system (e.g. pCO2, calcite saturation state) may not be comparable between studies, and that this may have important implications for the interpretation of CO2 perturbation experiments.

  • Open Access
    Authors: 
    Kluijver, A.; Soetaert, K.; Schulz, K. G.; Riebesell, U.; Bellerby, R. G. J.; Middelburg, J. J.;
    Project: EC | EPOCA (211384), EC | MEECE (212085)

    The potential impact of rising carbon dioxide (CO2) on carbon transfer from phytoplankton to bacteria was investigated during the 2005 PeECE III mesocosm study in Bergen, Norway. Sets of mesocosms, in which a phytoplankton bloom was induced by nutrient addition, were incubated under 1× (~350 μatm), 2× (~700 μatm), and 3× present day CO2 (~1050 μatm) initial seawater and sustained atmospheric CO2 levels for 3 weeks. 13C labelled bicarbonate was added to all mesocosms to follow the transfer of carbon from dissolved inorganic carbon (DIC) into phytoplankton and subsequently heterotrophic bacteria, and settling particles. Isotope ratios of polar-lipid-derived fatty acids (PLFA) were used to infer the biomass and production of phytoplankton and bacteria. Phytoplankton PLFA were enriched within one day after label addition, whilst it took another 3 days before bacteria showed substantial enrichment. Group-specific primary production measurements revealed that coccolithophores showed higher primary production than green algae and diatoms. Elevated CO2 had a significant positive effect on post-bloom biomass of green algae, diatoms, and bacteria. A simple model based on measured isotope ratios of phytoplankton and bacteria revealed that CO2 had no significant effect on the carbon transfer efficiency from phytoplankton to bacteria during the bloom. There was no indication of CO2 effects on enhanced settling based on isotope mixing models during the phytoplankton bloom, but this could not be determined in the post-bloom phase. Our results suggest that CO2 effects are most pronounced in the post-bloom phase, under nutrient limitation.

  • Open Access English
    Authors: 
    Wienberg, C.; Wintersteller, P.; Beuck, L.; Hebbeln, D.;
    Project: EC | HERMIONE (226354)

    The present study provides new knowledge about the so far largely unexplored Coral Patch seamount which is located in the NE Atlantic Ocean half-way between the Iberian Peninsula and Madeira. For the first time a detailed hydroacoustic mapping (MBES) in conjunction with video surveys (ROV, camera sled) were performed to describe the sedimentological and biological characteristics of this sub-elliptical ENE-WSW elongated seamount. Video observations were restricted to the southwestern summit area of Coral Patch seamount (water depth: 560–760 m) and revealed that this part of the summit is dominated by exposed hard substrate, whereas soft sediment is just a minor substrate component. Although exposed hardgrounds are dominant for this summit area and, thus, offer suitable habitat for settlement by benthic organisms, the benthic megafauna shows rather scarce occurrence. In particular, scleractinian framework-building cold-water corals are apparently rare with very few isolated and small-sized live occurrences of the species Lophelia pertusa and Madrepora oculata. In contrast, dead coral framework and coral rubble are more frequent pointing to a higher abundance of cold-water corals on Coral Patch during the recent past. This is even supported by the observation of fishing lines that got entangled with rather fresh-looking coral frameworks. Overall, long lines and various species of commercially important fish were frequently observed emphasising the potential of Coral Patch as an important target for fisheries that may have impacted the entire benthic community. Hydroacoustic seabed classification covered the entire summit of Coral Patch and its northern and southern flanks (water depth: 560–2660 m) and revealed extended areas dominated by mixed and soft sediments at the northern flank and to a minor degree at its easternmost summit and southern flank. Nevertheless, these data also predict most of the summit area to be dominated by exposed bedrock which would offer suitable habitat for benthic organisms. By comparing the locally restricted video observations and the broad-scale monitoring of a much larger and deeper seafloor area as derived by hydroacoustic seabed classification, it becomes obvious that habitat information obtained by in situ sampling may provide a rather scattered pattern about the entire seamount ecosystem. Solely with a combination of both methods, a satisfactory approach to describe the diverse characteristics of a seamount ecosystem can be derived which is in turn indispensable for future scientific monitoring campaigns as well as management and conservation purposes.

Advanced search in Research products
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The following results are related to European Marine Science. Are you interested to view more results? Visit OpenAIRE - Explore.
195 Research products, page 1 of 20
  • Open Access English
    Authors: 
    Vries, Joost; Monteiro, Fanny; Wheeler, Glen; Poulton, Alex; Godrijan, Jelena; Cerino, Federica; Malinverno, Elisa; Langer, Gerald; Brownlee, Colin;
    Project: UKRI | GW4+ - a consortium of ex... (NE/L002434/1), UKRI | NSFGEO-NERC An unexpected... (NE/N011708/1), MZOS | Mechanism of long-term ch... (098-0982705-2731), EC | MEDSEA (265103), EC | SEACELLS (670390)

    Coccolithophores are globally important marine calcifying phytoplankton that utilize a haplo-diplontic life cycle. The haplo-diplontic life cycle allows coccolithophores to divide in both life cycle phases and potentially expands coccolithophore niche volume. Research has, however, to date largely overlooked the life cycle of coccolithophores and has instead focused on the diploid life cycle phase of coccolithophores. Through the synthesis and analysis of global scanning electron microscopy (SEM) coccolithophore abundance data (n=2534), we find that calcified haploid coccolithophores generally constitute a minor component of the total coccolithophore abundance (≈ 2 %–15 % depending on season). However, using case studies in the Atlantic Ocean and Mediterranean Sea, we show that, depending on environmental conditions, calcifying haploid coccolithophores can be significant contributors to the coccolithophore standing stock (up to ≈30 %). Furthermore, using hypervolumes to quantify the niche of coccolithophores, we illustrate that the haploid and diploid life cycle phases inhabit contrasting niches and that on average this allows coccolithophores to expand their niche by ≈18.8 %, with a range of 3 %–76 % for individual species. Our results highlight that future coccolithophore research should consider both life cycle stages, as omission of the haploid life cycle phase in current research limits our understanding of coccolithophore ecology. Our results furthermore suggest a different response to nutrient limitation and stratification, which may be of relevance for further climate scenarios. Our compilation highlights the spatial and temporal sparsity of SEM measurements and the need for new molecular techniques to identify uncalcified haploid coccolithophores. Our work also emphasizes the need for further work on the carbonate chemistry niche of the coccolithophore life cycle.

  • Open Access English
    Authors: 
    Pallacks, Sven; Ziveri, Patrizia; Martrat, Belén; Mortyn, P Graham; Grelaud, Michaël; Schiebel, Ralf; Incarbona, Alessandro; García-Orellana, Jordi; Anglada-Ortiz, Griselda;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | MEDSEA (265103)

    Three high resolution multicore records from two western Mediterranean Sea regions (Alboran and Balearic basins) have been analyzed for sea surface temperature (SST), coccolithophore and planktic foraminiferal abundance changes. Age-depth models at both sites were developed by a combination of 210Pb and 14C dating techniques, describing high sedimentation rates at both study sites, covering the time interval from the Medieval climate anomaly to present. Alkenone derived SST of core MedSeA-S3-c1 and MedSeA-S23-c3 are in good agreement with other results, tracing temperature changes through the Common Era (CE) and show a clear warming emergence at about 1850 CE. Analysis of relative abundance of calcareous nannoplankton assemblages (coccolithophores) was done on core MedSeA-S3-c1 (150 µm. Both cores show opposite abundance fluctuations of planktic foraminiferal species (Globigerina bulloides, Globorotalia inflata and Globorotalia truncatulinoides). The relative abundance changes of Globorotalia truncatulinoides plus Globorotalia inflata describe the intensity of deep winter mixing in the Balearic basin. In the Alboran Sea, Globigerina bulloides and Globorotalia inflata instead respond to local upwelling dynamics. Our data suggests that planktic foraminiferal abundance and species changes in the western Mediterranean Sea is already affected by accelerated anthropogenic warming, overprinting natural cycles in this region.

  • Open Access English
    Authors: 
    Segato, Delia; Villoslada Hidalgo, Maria Del Carmen; Edwards, Ross; Barbaro, Elena; Vallelonga, Paul T; Kjær, Helle Astrid; Simonsen, Marius; Vinther, Bo Møllesøe; Maffezzoli, Niccolò; Zangrando, Roberta; +4 more
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | ICE2ICE (610055), EC | ERA-PLANET (689443)

    This dataset presents the fire proxies levoglucosan, black carbon and ammonium measured in the RECAP ice core, in coastal East Greenland. The datasets cover a period of 5000 years and are averaged in 20 years bins. Raw concentrations of levoglucosan, black carbon and ammonium are also provided. Levoglucosan has been determined using high performance liquid chromatography/negative ion electrospray ionization – tandem mass spectrometry (HPLC/(-)ESI-MS/MS). Black carbon has been measured using a BC analyzer connected to the Continuous Flow Analysis system. Ammonium (NH4+) has been measured by fluorescence within the Continuous Flow Analysis setup.

  • Other research product . Other ORP type . 2020
    English
    Authors: 
    Penna, Pierluigi; Belardinelli, Andrea; Croci, Camilla Sofia; Domenichetti, Filippo; Martinelli, Michela;
    Country: Italy
    Project: EC | JERICO-NEXT (654410), EC | JERICO (262584), EC | NEXOS (614102)

    From 2003 to 2013, the Ancona section of CNR-IRBIM (formerly part of CNR-Institute of Marine Science) runned the "Fishery Observing System" (FOS) program aimed at using Italian fishing vessels as Vessels Of Opportunity (VOOs) for the collection of scientifically useful datasets (Falco et al. 2007). Some commercial fishing vessels, targetting small pelagic species in the northern and central Adriatic Sea, were equipped with an integrated system for the collection of information on catches, position of the fishing operation, depth and water temperature during the haul, producing a great amount of data that demonstrated to be helpful both for oceanographic and fishery biology purposes (Carpi et al. 2015; Aydo?du et a. 2016; Sparnocchia et al. 2016; Lucchetti et al. 2018). In 2012, thanks to the participation to some national and international projects (e.g. SSD-Pesca, EU-FP7 JERICO etc.), CNR started the development of a new modular "Fishery & Oceanography Observing System" (FOOS; Patti et al. 2013). New sensors for oceanographic and meteorological data allow nowadays the FOOS to collect more parameters, with higher accuracy and to send them directly to a data center in near real time (Martinelli et al. 2016; Sparnocchia et al. 2017). Furthermore, the FOOS is a multifunction system able to collect various kind of data from the fishing operations and also to send back to the fishermen useful information (e.g. weather and sea forecasts, etc.) through an electronic logbook with an ad hoc software embedded. The new FOOS installed on various kind of fishing vessels targetting different resources, allowed a spatial extension of the monitored areas in the Mediterranean Sea (Patti et al. 2013). CNR-IRBIM implemented the "AdriFOOS" observational system, by installing the FOOS on some commercial fishing boats operating in the Adriatic Sea. Since then the datacenter based in Ancona receives daily data sets of environmental parameters collected along the water column and close to the sea bottom (eg. temperature, salinity, etc.), together with GPS haul tracks, catch amounts per haul, target species sizes and weather information. Some temperature and salinity measurements acquired by the FOOS in the Adriatic Sea from January 2014 to March 2015 were published within the JERICO project and some oxygen and fluorescence profiles obtained in 2017 within the NEXOS project. The dataset here presented contains 14803 depth/temperature profiles collected by 10 vessels of the AdriFOOS fleet in the period 2012-2020. All the profiles were subjected to quality control.Data are flagged according the L20 (SEADATANET MEASURAND QUALIFIER FLAGS).

  • Open Access English
    Authors: 
    Friedrich, J.; Janssen, F.; Aleynik, D.; Bange, H. W.; Boltacheva, N.; Çagatay, M. N.; Dale, A. W.; Etiope, G.; Erdem, Z.; Geraga, M.; +29 more
    Project: EC | HYPOX (226213)

    In this paper we provide an overview of new knowledge on oxygen depletion (hypoxia) and related phenomena in aquatic systems resulting from the EU-FP7 project HYPOX ("In situ monitoring of oxygen depletion in hypoxic ecosystems of coastal and open seas, and landlocked water bodies", http://www.hypox.net). In view of the anticipated oxygen loss in aquatic systems due to eutrophication and climate change, HYPOX was set up to improve capacities to monitor hypoxia as well as to understand its causes and consequences. Temporal dynamics and spatial patterns of hypoxia were analyzed in field studies in various aquatic environments, including the Baltic Sea, the Black Sea, Scottish and Scandinavian fjords, Ionian Sea lagoons and embayments, and Swiss lakes. Examples of episodic and rapid (hours) occurrences of hypoxia, as well as seasonal changes in bottom-water oxygenation in stratified systems, are discussed. Geologically driven hypoxia caused by gas seepage is demonstrated. Using novel technologies, temporal and spatial patterns of water-column oxygenation, from basin-scale seasonal patterns to meter-scale sub-micromolar oxygen distributions, were resolved. Existing multidecadal monitoring data were used to demonstrate the imprint of climate change and eutrophication on long-term oxygen distributions. Organic and inorganic proxies were used to extend investigations on past oxygen conditions to centennial and even longer timescales that cannot be resolved by monitoring. The effects of hypoxia on faunal communities and biogeochemical processes were also addressed in the project. An investigation of benthic fauna is presented as an example of hypoxia-devastated benthic communities that slowly recover upon a reduction in eutrophication in a system where naturally occurring hypoxia overlaps with anthropogenic hypoxia. Biogeochemical investigations reveal that oxygen intrusions have a strong effect on the microbially mediated redox cycling of elements. Observations and modeling studies of the sediments demonstrate the effect of seasonally changing oxygen conditions on benthic mineralization pathways and fluxes. Data quality and access are crucial in hypoxia research. Technical issues are therefore also addressed, including the availability of suitable sensor technology to resolve the gradual changes in bottom-water oxygen in marine systems that can be expected as a result of climate change. Using cabled observatories as examples, we show how the benefit of continuous oxygen monitoring can be maximized by adopting proper quality control. Finally, we discuss strategies for state-of-the-art data archiving and dissemination in compliance with global standards, and how ocean observations can contribute to global earth observation attempts.

  • Open Access English
    Authors: 
    Steinacher, M.; Joos, F.; Frölicher, T. L.; Bopp, L.; Cadule, P.; Cocco, V.; Doney, S. C.; Gehlen, M.; Lindsay, K.; Moore, J. K.; +2 more
    Project: EC | EPOCA (211384), EC | MEECE (212085)

    Changes in marine net primary productivity (PP) and export of particulate organic carbon (EP) are projected over the 21st century with four global coupled carbon cycle-climate models. These include representations of marine ecosystems and the carbon cycle of different structure and complexity. All four models show a decrease in global mean PP and EP between 2 and 20% by 2100 relative to preindustrial conditions, for the SRES A2 emission scenario. Two different regimes for productivity changes are consistently identified in all models. The first chain of mechanisms is dominant in the low- and mid-latitude ocean and in the North Atlantic: reduced input of macro-nutrients into the euphotic zone related to enhanced stratification, reduced mixed layer depth, and slowed circulation causes a decrease in macro-nutrient concentrations and in PP and EP. The second regime is projected for parts of the Southern Ocean: an alleviation of light and/or temperature limitation leads to an increase in PP and EP as productivity is fueled by a sustained nutrient input. A region of disagreement among the models is the Arctic, where three models project an increase in PP while one model projects a decrease. Projected changes in seasonal and interannual variability are modest in most regions. Regional model skill metrics are proposed to generate multi-model mean fields that show an improved skill in representing observation-based estimates compared to a simple multi-model average. Model results are compared to recent productivity projections with three different algorithms, usually applied to infer net primary production from satellite observations.

  • Open Access English
    Authors: 
    Capet, A.; Beckers, J.-M.; Grégoire, M.;
    Project: EC | HYPOX (226213)

    The Black Sea northwestern shelf (NWS) is a shallow eutrophic area in which the seasonal stratification of the water column isolates the bottom waters from the atmosphere. This prevents ventilation from counterbalancing the large consumption of oxygen due to respiration in the bottom waters and in the sediments, and sets the stage for the development of seasonal hypoxia. A three-dimensional (3-D) coupled physical–biogeochemical model is used to investigate the dynamics of bottom hypoxia in the Black Sea NWS, first at seasonal and then at interannual scales (1981–2009), and to differentiate its driving factors (climatic versus eutrophication). Model skills are evaluated by a quantitative comparison of the model results to 14 123 in situ oxygen measurements available in the NOAA World Ocean and the Black Sea Commission databases, using different error metrics. This validation exercise shows that the model is able to represent the seasonal and interannual variability of the oxygen concentration and of the occurrence of hypoxia, as well as the spatial distribution of oxygen-depleted waters. During the period 1981–2009, each year exhibits seasonal bottom hypoxia at the end of summer. This phenomenon essentially covers the northern part of the NWS – which receives large inputs of nutrients from the Danube, Dniester and Dnieper rivers – and extends, during the years of severe hypoxia, towards the Romanian bay of Constanta. An index H which merges the aspects of the spatial and temporal extension of the hypoxic event is proposed to quantify, for each year, the intensity of hypoxia as an environmental stressor. In order to explain the interannual variability of H and to disentangle its drivers, we analyze the long time series of model results by means of a stepwise multiple linear regression. This statistical model gives a general relationship that links the intensity of hypoxia to eutrophication and climate-related variables. A total of 82% of the interannual variability of H is explained by the combination of four predictors: the annual riverine nitrate load (N), the sea surface temperature in the month preceding stratification (Ts), the amount of semi-labile organic matter accumulated in the sediments (C) and the sea surface temperature during late summer (Tf). Partial regression indicates that the climatic impact on hypoxia is almost as important as that of eutrophication. Accumulation of organic matter in the sediments introduces an important inertia in the recovery process after eutrophication, with a typical timescale of 9.3 yr. Seasonal fluctuations and the heterogeneous spatial distribution complicate the monitoring of bottom hypoxia, leading to contradictory conclusions when the interpretation is done from different sets of data. In particular, it appears that the recovery reported in the literature after 1995 was overestimated due to the use of observations concentrated in areas and months not typically affected by hypoxia. This stresses the urgent need for a dedicated monitoring effort in the Black Sea NWS focused on the areas and months concerned by recurrent hypoxic events.

  • Open Access
    Authors: 
    Hoppe, C. J. M.; Langer, G.; Rokitta, S. D.; Wolf-Gladrow, D. A.; Rost, B.;
    Project: EC | NEWLOG (267931), EC | PHYTOCHANGE (205150), EC | MEDSEA (265103), EC | MOLSPINQIP (211284)

    The growing field of ocean acidification research is concerned with the investigation of organism responses to increasing pCO2 values. One important approach in this context is culture work using seawater with adjusted CO2 levels. As aqueous pCO2 is difficult to measure directly in small-scale experiments, it is generally calculated from two other measured parameters of the carbonate system (often AT, CT or pH). Unfortunately, the overall uncertainties of measured and subsequently calculated values are often unknown. Especially under high pCO2, this can become a severe problem with respect to the interpretation of physiological and ecological data. In the few datasets from ocean acidification research where all three of these parameters were measured, pCO2 values calculated from AT and CT are typically about 30% lower (i.e. ~300 μatm at a target pCO2 of 1000 μatm) than those calculated from AT and pH or CT and pH. This study presents and discusses these discrepancies as well as likely consequences for the ocean acidification community. Until this problem is solved, one has to consider that calculated parameters of the carbonate system (e.g. pCO2, calcite saturation state) may not be comparable between studies, and that this may have important implications for the interpretation of CO2 perturbation experiments.

  • Open Access
    Authors: 
    Kluijver, A.; Soetaert, K.; Schulz, K. G.; Riebesell, U.; Bellerby, R. G. J.; Middelburg, J. J.;
    Project: EC | EPOCA (211384), EC | MEECE (212085)

    The potential impact of rising carbon dioxide (CO2) on carbon transfer from phytoplankton to bacteria was investigated during the 2005 PeECE III mesocosm study in Bergen, Norway. Sets of mesocosms, in which a phytoplankton bloom was induced by nutrient addition, were incubated under 1× (~350 μatm), 2× (~700 μatm), and 3× present day CO2 (~1050 μatm) initial seawater and sustained atmospheric CO2 levels for 3 weeks. 13C labelled bicarbonate was added to all mesocosms to follow the transfer of carbon from dissolved inorganic carbon (DIC) into phytoplankton and subsequently heterotrophic bacteria, and settling particles. Isotope ratios of polar-lipid-derived fatty acids (PLFA) were used to infer the biomass and production of phytoplankton and bacteria. Phytoplankton PLFA were enriched within one day after label addition, whilst it took another 3 days before bacteria showed substantial enrichment. Group-specific primary production measurements revealed that coccolithophores showed higher primary production than green algae and diatoms. Elevated CO2 had a significant positive effect on post-bloom biomass of green algae, diatoms, and bacteria. A simple model based on measured isotope ratios of phytoplankton and bacteria revealed that CO2 had no significant effect on the carbon transfer efficiency from phytoplankton to bacteria during the bloom. There was no indication of CO2 effects on enhanced settling based on isotope mixing models during the phytoplankton bloom, but this could not be determined in the post-bloom phase. Our results suggest that CO2 effects are most pronounced in the post-bloom phase, under nutrient limitation.

  • Open Access English
    Authors: 
    Wienberg, C.; Wintersteller, P.; Beuck, L.; Hebbeln, D.;
    Project: EC | HERMIONE (226354)

    The present study provides new knowledge about the so far largely unexplored Coral Patch seamount which is located in the NE Atlantic Ocean half-way between the Iberian Peninsula and Madeira. For the first time a detailed hydroacoustic mapping (MBES) in conjunction with video surveys (ROV, camera sled) were performed to describe the sedimentological and biological characteristics of this sub-elliptical ENE-WSW elongated seamount. Video observations were restricted to the southwestern summit area of Coral Patch seamount (water depth: 560–760 m) and revealed that this part of the summit is dominated by exposed hard substrate, whereas soft sediment is just a minor substrate component. Although exposed hardgrounds are dominant for this summit area and, thus, offer suitable habitat for settlement by benthic organisms, the benthic megafauna shows rather scarce occurrence. In particular, scleractinian framework-building cold-water corals are apparently rare with very few isolated and small-sized live occurrences of the species Lophelia pertusa and Madrepora oculata. In contrast, dead coral framework and coral rubble are more frequent pointing to a higher abundance of cold-water corals on Coral Patch during the recent past. This is even supported by the observation of fishing lines that got entangled with rather fresh-looking coral frameworks. Overall, long lines and various species of commercially important fish were frequently observed emphasising the potential of Coral Patch as an important target for fisheries that may have impacted the entire benthic community. Hydroacoustic seabed classification covered the entire summit of Coral Patch and its northern and southern flanks (water depth: 560–2660 m) and revealed extended areas dominated by mixed and soft sediments at the northern flank and to a minor degree at its easternmost summit and southern flank. Nevertheless, these data also predict most of the summit area to be dominated by exposed bedrock which would offer suitable habitat for benthic organisms. By comparing the locally restricted video observations and the broad-scale monitoring of a much larger and deeper seafloor area as derived by hydroacoustic seabed classification, it becomes obvious that habitat information obtained by in situ sampling may provide a rather scattered pattern about the entire seamount ecosystem. Solely with a combination of both methods, a satisfactory approach to describe the diverse characteristics of a seamount ecosystem can be derived which is in turn indispensable for future scientific monitoring campaigns as well as management and conservation purposes.