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Evaluative processes struggle with the notion of diversity of a scientific workforce. Despite overwhelming evidence on the need for diverse teams in terms of division of labor, ethnic mix or gender among others, bibliometric methods have traditionally been focused on the development of impact and productivity indicators. In this paper we attempt at reviewing recent advances in the development of novel informetric approaches and methods to study diversity in science. Specifically, we focus on those related to the scientific workforce. We first review the changes with regard to data sources which have made possible such approaches. Then we revise the different proposals made by organizing these approaches into three groups: 1) informetric methods related to individuals’ characteristics (e..g, gender, age, mobility); 2) methods related to individuals’ context (e.g., career trajectory, social engagement); and 3) approaches related to team dynamics (e.g., author position, contribution statements). We then conclude by identifying the main gaps in the literature and pointing towards potential areas to explore.

Reliable quantitative vegetation reconstructions for Europe during the Holocene are crucial to improving our understanding of landscape dynamics, making it possible to assess the past effects of environmental variables and land-use change on ecosystems and biodiversity, and mitigating their effects in the future. We present here the most spatially extensive and temporally continuous pollen-based reconstructions of plant cover in Europe (at a spatial resolution of 1 degrees x 1 degrees) over the Holocene (last 11.7 ka BP) using the 'Regional Estimates of VEgetation Abundance from Large Sites' (REVEALS) model. This study has three main aims. First, to present the most accurate and reliable generation of REVEALS reconstructions across Europe so far. This has been achieved by including a larger number of pollen records compared to former analyses, in particular from the Mediterranean area. Second, to discuss methodological issues in the quantification of past land cover by using alternative datasets of relative pollen productivities (RPPs), one of the key input parameters of REVEALS, to test model sensitivity. Finally, to validate our reconstructions with the global forest change dataset. The results suggest that the RPPs.st1 (31 taxa) dataset is best suited to producing regional vegetation cover estimates for Europe. These reconstructions offer a long-term perspective providing unique possibilities to explore spatial-temporal changes in past land cover and biodiversity.

Reliable quantitative vegetation reconstructions for Europe during the Holocene are crucial to improving our understanding of landscape dynamics, making it possible to assess the past effects of environmental variables and land-use change on ecosystems and biodiversity, and mitigating their effects in the future. We present here the most spatially extensive and temporally continuous pollen-based reconstructions of plant cover in Europe (at a spatial resolution of 1° × 1°) over the Holocene (last 11.7 ka BP) using the ‘Regional Estimates of VEgetation Abundance from Large Sites’ (REVEALS) model. This study has three main aims. First, to present the most accurate and reliable generation of REVEALS reconstructions across Europe so far. This has been achieved by including a larger number of pollen records compared to former analyses, in particular from the Mediterranean area. Second, to discuss methodological issues in the quantification of past land cover by using alternative datasets of relative pollen productivities (RPPs), one of the key input parameters of REVEALS, to test model sensitivity. Finally, to validate our reconstructions with the global forest change dataset. The results suggest that the RPPs.st1 (31 taxa) dataset is best suited to producing regional vegetation cover estimates for Europe. These reconstructions offer a long-term perspective providing unique possibilities to explore spatial-temporal changes in past land cover and biodiversity.

The Eurasian (née European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60 % from 4826 to 8134. Much of the improvement in data coverage has come from northern Asia, and the database has consequently been renamed the Eurasian Modern Pollen Database to reflect this geographical enlargement. The EMPD can be viewed online using a dedicated map-based viewer at https://empd2.github.io and downloaded in a variety of file formats at https://doi.pangaea.de/10.1594/PANGAEA.909130 (Chevalier et al., 2019).

The Eurasian (née European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60% from 4826 to 8134. Much of the improvement in data coverage has come from northern Asia, and the database has consequently been renamed the Eurasian Modern Pollen Database to reflect this geographical enlargement. The EMPD can be viewed online using a dedicated map-based viewer at https://empd2.github.io and downloaded in a variety of file formats at https://doi.pangaea.de/10.1594/PANGAEA.909130 (Chevalier et al., 2019).

The subtropical gyres occupy about 70% of the ocean surface. While primary production (PP) within these oligotrophic regions is relatively low, their extension makes their total contribution to ocean productivity significant. Monitoring marine pelagic primary production across broad spatial scales, particularly across the subtropical gyre regions, is challenging but essential to evaluate the oceanic carbon budget. PP in the ocean can be derived from remote sensing however in situ depth-integrated PP (IPPis) measurements required for validation are scarce from the subtropical gyres. In this study, we collected >120 IPPis measurements from both northern and southern subtropical gyres that we compared to commonly used primary productivity models (the Vertically Generalized Production Model, VGPM and six variants; the Eppley-Square-Root model, ESQRT; the Howard–Yoder–Ryan model, HYR; the model of MARRA, MARRA; and the Carbon-based Production Model, CbPM) to predict remote PP (PPr) in the subtropical regions and explored possibilities for improving PP prediction. Our results showed that satellite-derived PP (IPPsat) estimates obtained from the VGPM1, MARRA and ESQRT provided closer values to the IPPis (i.e., the difference between the mean of the IPPsat and IPPis was closer to 0; |Bias| ~ 0.09). Model performance varied due to differences in satellite predictions of in situ parameters such as chlorophyll a (chl-a) concentration or the optimal assimilation efficiency of the productivity profile (PBopt) in the subtropical region. In general, model performance was better for areas showing higher IPPis, highlighting the challenge of PP prediction in the most oligotrophic areas (i.e. PP < 300 mg C m−2 d−1). The use of in situ chl-a data, and PBopt as a function of sea surface temperature (SST) and the mixed layer depth (MLD) from gliders and floats in PPr models would improve their IPP predictions considerably in oligotrophic oceanic regions such as the subtropical gyres wher

The subtropical gyres occupy about 70% of the ocean surface. While primary production (PP) within these oligotrophic regions is relatively low, their extension makes their total contribution to ocean productivity significant. Monitoring marine pelagic primary production across broad spatial scales, particularly across the subtropical gyre regions, is challenging but essential to evaluate the oceanic carbon budget. PP in the ocean can be derived from remote sensing however in situ depth-integrated PP (IPPis) measurements required for validation are scarce from the subtropical gyres. In this study, we collected >120 IPPis measurements from both northern and southern subtropical gyres that we compared to commonly used primary productivity models (the Vertically Generalized Production Model, VGPM and six variants; the Eppley-Square-Root model, ESQRT; the Howard–Yoder–Ryan model, HYR; the model of MARRA, MARRA; and the Carbon-based Production Model, CbPM) to predict remote PP (PPr) in the subtropical regions and explored possibilities for improving PP prediction. Our results showed that satellite-derived PP (IPPsat) estimates obtained from the VGPM1, MARRA and ESQRT provided closer values to the IPPis (i.e., the difference between the mean of the IPPsat and IPPis was closer to 0; |Bias| ~ 0.09). Model performance varied due to differences in satellite predictions of in situ parameters such as chlorophyll a (chl-a) concentration or the optimal assimilation efficiency of the productivity profile (PBopt) in the subtropical region. In general, model performance was better for areas showing higher IPPis, highlighting the challenge of PP prediction in the most oligotrophic areas (i.e. PP < 300 mg C m−2 d−1). The use of in situ chl-a data, and PBopt as a function of sea surface temperature (SST) and the mixed layer depth (MLD) from gliders and floats in PPr models would improve their IPP predictions considerably in oligotrophic oceanic regions such as the subtropical gyres wher

The subtropical gyres occupy about 70% of the ocean surface. While primary production (PP) within these oligotrophic regions is relatively low, their extension makes their total contribution to ocean productivity significant. Monitoring marine pelagic primary production across broad spatial scales, particularly across the subtropical gyre regions, is challenging but essential to evaluate the oceanic carbon budget. PP in the ocean can be derived from remote sensing however in situ depth-integrated PP (IPPis) measurements required for validation are scarce from the subtropical gyres. In this study, we collected >120 IPPis measurements from both northern and southern subtropical gyres that we compared to commonly used primary productivity models (the Vertically Generalized Production Model, VGPM and six variants; the Eppley-Square-Root model, ESQRT; the Howard–Yoder–Ryan model, HYR; the model of MARRA, MARRA; and the Carbon-based Production Model, CbPM) to predict remote PP (PPr) in the subtropical regions and explored possibilities for improving PP prediction. Our results showed that satellite-derived PP (IPPsat) estimates obtained from the VGPM1, MARRA and ESQRT provided closer values to the IPPis (i.e., the difference between the mean of the IPPsat and IPPis was closer to 0; |Bias| ~ 0.09). Model performance varied due to differences in satellite predictions of in situ parameters such as chlorophyll a (chl-a) concentration or the optimal assimilation efficiency of the productivity profile (PBopt) in the subtropical region. In general, model performance was better for areas showing higher IPPis, highlighting the challenge of PP prediction in the most oligotrophic areas (i.e. PP < 300 mg C m−2 d−1). The use of in situ chl-a data, and PBopt as a function of sea surface temperature (SST) and the mixed layer depth (MLD) from gliders and floats in PPr models would improve their IPP predictions considerably in oligotrophic oceanic regions such as the subtropical gyres wher

© 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group. Carrier state viral infection constitutes an equilibrium state in which a limited fraction of a cellular population is infected while the remaining cells are transiently resistant to infection. This type of infection has been characterized for several bacteriophages but not, to date, for archaeal viruses. Here we demonstrate that the rudivirus SIRV3 can produce a host-dependent carrier state infection in the model crenarchaeon Sulfolobus. SIRV3 only infected a fraction of a Sulfolobus islandicus REY15A culture over several days during which host growth was unimpaired and no chromosomal DNA degradation was observed. CRISPR spacer acquisition from SIRV3 DNA was induced by coinfecting with the monocaudavirus SMV1 and it was coincident with increased transcript levels from subtype I-A adaptation and interference cas genes. However, this response did not significantly affect the carrier state infection of SIRV3 and both viruses were maintained in the culture over 12 days during which SIRV3 anti-CRISPR genes were shown to be expressed. Transcriptome and proteome analyses demonstrated that most SIRV3 genes were expressed at varying levels over time whereas SMV1 gene expression was generally low. The study yields insights into the basis for the stable infection of SIRV3 and the resistance to the different host CRISPR-Cas interference mechanisms. It also provides a rationale for the commonly observed coinfection of archaeal cells by different viruses in natural environments.

© 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group. Carrier state viral infection constitutes an equilibrium state in which a limited fraction of a cellular population is infected while the remaining cells are transiently resistant to infection. This type of infection has been characterized for several bacteriophages but not, to date, for archaeal viruses. Here we demonstrate that the rudivirus SIRV3 can produce a host-dependent carrier state infection in the model crenarchaeon Sulfolobus. SIRV3 only infected a fraction of a Sulfolobus islandicus REY15A culture over several days during which host growth was unimpaired and no chromosomal DNA degradation was observed. CRISPR spacer acquisition from SIRV3 DNA was induced by coinfecting with the monocaudavirus SMV1 and it was coincident with increased transcript levels from subtype I-A adaptation and interference cas genes. However, this response did not significantly affect the carrier state infection of SIRV3 and both viruses were maintained in the culture over 12 days during which SIRV3 anti-CRISPR genes were shown to be expressed. Transcriptome and proteome analyses demonstrated that most SIRV3 genes were expressed at varying levels over time whereas SMV1 gene expression was generally low. The study yields insights into the basis for the stable infection of SIRV3 and the resistance to the different host CRISPR-Cas interference mechanisms. It also provides a rationale for the commonly observed coinfection of archaeal cells by different viruses in natural environments.

RESEARCHER ID G-8740-2015 (María Victoria Cabañas Criado) ORCID 0000-0002-4753-5665 (María Victoria Cabañas Criado) RESEARCHER ID B-5081-2017 (Daniel Lozano Borregón) ORCID 0000-0001-5902-9201 (Daniel Lozano Borregón) RESEARCHER ID L-6167-2014 (Daniel Arcos Navarrete) ORCID 0000-0002-5367-7272 (Daniel Arcos Navarrete) RESEARCHER ID M-3378-2014 (María Vallet Regí) ORCID 0000-0002-6104-4889 (María Vallet Regí), Aminopropyl modified mesoporous SiO2 nanoparticles, MCM-41 type, have been synthesized by the co-condensation method from tetraethylorthosilicate (TEOS) and aminopropyltriethoxysilane (APTES). By means of modifying TEOS/APTES ratio we have carried out an in-depth characterization of the nanoparticles as a function of APTES content. Surface charge and nanoparticles morphology were strongly influenced by the amount of APTES and particles changed from hexagonal to bean-like morphology insofar APTES increased. Besides, the porous structure was also affected, showing a contraction of the lattice parameter and pore size, while increasing the wall thickness. These results bring about new insights about the nanoparticles formation during the co-condensation process. The model proposed herein considers that different interactions stablished between TEOS and APTES with the structure directing agent have consequences on pore size, wall thickness and particle morphology. Finally, APTES is an excellent linker to covalently attach active targeting agents such as folate groups. We have hypothesized that APTES could also play a role in the biological behavior of the nanoparticles. So, the internalization efficiency of the nanoparticles has been tested with cancerous LNCaP and non-cancerous preosteoblast-like MC3T3-E1 cells. The results indicate a cooperative effect between aminopropylsilane presence and folic acid, only for the cancerous LNCaP cell line., Unión Europea. H2020, Ministerio de Economía y Competitividad (MINECO), Depto. de Química en Ciencias Farmacéuticas, Fac. de Farmacia, TRUE, pub

Over the past decades, as a consequence of human activity, there was an increase in nutrient inputs to the ocean and they are expected to enhance even more in the future. Coastal areas, accounting for a significant proportion of marine primary productivity, are the most vulnerable zones to anthropogenic impacts. The response of phytoplankton communities to an increase in organic and inorganic nutrients levels from natural allochthonous sources was assessed in microcosm experiments conducted in a coastal system affected by intermittent upwelling events (Ría de Vigo, NW Iberia). Three nutrient addition experiments were performed in spring, summer and autumn, when surface water was supplemented with 5 and 10% of atmospheric and riverine matter. Pico-, nano- and microphytoplankton abundances, chlorophyll a concentration (Chl a) and primary production rates (PP) were measured and compared with those in the control seawater sample (without additions) after 48 h of incubation. Simultaneous experiments with controlled additions of inorganic and organic nutrients were also performed in order to describe the limiting nutrient for phytoplankton growth at each experiment. The composition of the matter inputs and the structure of the phytoplankton communities determined the type of response observed. Phytoplankton responses varied among seasons, being positively correlated with dissolved inorganic nitrogen (DIN) concentrations. As expected, the phytoplankton responses to external nutrient inputs were stronger under low nutrient levels (summer) than when phytoplankton was already growing in nutrient replete conditions (spring). Null and negative responses to the natural inputs were observed in autumn, which suggests that the oceanic phytoplankton advected to this coastal system during downwelling events could be occasionally inhibited by these nutrient inputs. In a future global change scenario, characterized by enhanced nutrient inputs from riverine and atmospheric origin, the r

Anthropogenic pressures are changing the magnitude and nature of matter inputs into the ocean. The Ría de Vigo (NW Spain) is a highly productive and dynamic coastal system that is likely affected by such alterations. Previous nutrient-addition microcosm experiments conducted during contrasting hydrographic conditions suggested that heterotrophic bacteria are limited by organic carbon (C) and occasionally co-limited by inorganic nutrients in this coastal area. In order to assess short-term responses in biomass, production, and respiration of heterotrophic bacteria from the Ría de Vigo to increasing amounts of natural inputs of matter, we conducted 6 microcosm experiments, wherein surface seawater collected in spring, summer, and autumn was mixed with increasing amounts of dissolved natural matter concentrates from riverine and atmospheric origin. Simultaneous experiments with controlled inorganic and/or organic additions indicated that bacteria were co-limited by inorganic nutrients and C in spring and summer and primarily limited by C in autumn. Production responded more than biomass to increasing inputs of matter, whereas respiration did not change. The bacterial production response to increasing dissolved organic C load associated with riverine and atmospheric inputs was strongly related to the relative phosphorus (P) content of the dissolved matter concentrates. Our data suggest that bacterial production might decrease with the increase of P-deficient allochthonous matter inputs, which would have important biogeochemical consequences for C cycling in coastal areas.

Short-term experiments indicate that seawater acidification can cause a decrease in the rate of calcification by coccolithopores, but the relationship between carbonate chemistry and coccolithophore calcification rate in natural assemblages is still unclear. During the Malaspina 2010 circumnavigation, we measured primary production, calcificatiion, coccolithophore abundance, particulate inorganic carbon (PIC) concentration, and the parameters of the carbonate system, along basin-scale transects in the tropical Atlantic, Indian and Pacific oceans. Euphotic layer-integrated calcification and mean cell-specific calcification to primary production (CP/PP) ratio was relatively invariant among ocean basins, with an overall mean value of 0.05+-0.04. Extrapoling this value to the entire ocean would result in a global pelagic calcification rate of 2.4 PtC /year. The mean PIC concentration in surface waters was 1.8 +-1.6 mgC/m3 and its turnover time averaged 20 d. We combined our data of calcification, primary production, and carbonate chemistry from Malaspina 2010 with those obtained during two previous cruises in the northern Arabian Sea. Both the CP/PP ratio and cell-specific calcification were largely constant across a wide range of calcite saturation rate (1.5-6.5), [HCO3-]/[H+] (0.08-0.24; mol:umol), and pH (7.6-8.1), which indicates that calcification by natural coccolithophore assemblages was independent of carbonate chemistry. Our results suggest that coccolithophore calcification, at least in tropical regions, may not be decreasing in the currently acidifying ocean.

Anthropogenic pressures are changing the magnitude and nature of matter inputs into the ocean. The Ria de Vigo (NW Spain) is a highly productive and dynamic coastal system that is likely affected by such alterations. Previous nutrient-addition microcosm experiments conducted during contrasting hydrographic conditions suggested that heterotrophic bacteria are limited by organic carbon (C) and occasionally co-limited by inorganic nutrients in this coastal area. In order to assess short-term responses in biomass, production, and respiration of heterotrophic bacteria from the Ria de Vigo to increasing amounts of natural inputs of matter, we conducted 6 microcosm experiments, wherein surface seawater collected in spring, summer, and autumn was mixed with increasing amounts of dissolved natural matter concentrates from riverine and atmospheric origin. Simultaneous experiments with controlled inorganic and/or organic additions indicated that bacteria were co-limited by inorganic nutrients and C in spring and summer and primarily limited by C in autumn. Production responded more than biomass to increasing inputs of matter, whereas respiration did not change. The bacterial production response to increasing dissolved organic C load associated with riverine and atmospheric inputs was strongly related to the relative phosphorus (P) content of the dissolved matter concentrates. Our data suggest that bacterial production might decrease with the increase of P-deficient allochthonous matter inputs, which would have important biogeochemical consequences for C cycling in coastal areas.

We investigated the impacts of climate change-associated abiotic factors on the species composition and size structure of coastal phytoplankton communities. Surface coastal water collected off the coast of Málaga (Spain) was incubated outdoors during a 7 d microcosm experiment. The natural phytoplankton communities were exposed to high and low conditions of CO2, nutrients and light. During the first 2 d, a positive response to increased CO2 and nutrient concentration was observed in terms of abundance and chlorophyll in all size fractions (<2, 2 to 20, and >20 µm). After 2 d, a trophic cascade effect was observed within the phytoplankton communities for all treatments. The absence of mesozooplankton led to an increase in microzooplankton abundance,which coincided with a decrease in the abundance of phytoplankton <6 µm equivalent spherical dia meter (ESD). At the same time, an increased concentration of larger phytoplankton was observed. Consequently, a diatom bloom dominated by Leptocylindrus danicus and Chaetoceros sp. developed, peaking on Day 5 in the high-light treatment and on Day 6 in the low-light treatment.The cascade effect was evident in both the smaller and the larger ranges of the size-abundance spectra (SAS). Although this trophic interaction occurred in all treatments in a similar way, therewere still significant differences among treatments. Diatoms with cell sizes >20 µm ESD showed a positive response to the effects of increasing CO2 and nutrient concentration. These results high -light the importance of trophic interactions other than abiotic factors such as CO2 and nutrient availability in shaping the size structure of Mediterranean phytoplankton. More specifically, this work shows the importance of trophic cascade effects in scaling the plankton SAS and should be considered in both enclosure experiments and field measurements that deal with size distribution.

We investigated the impacts of climate change-associated abiotic factors on the species composition and size structure of coastal phytoplankton communities. Surface coastal water collected off the coast of Málaga (Spain) was incubated outdoors during a 7 d microcosm experiment. The natural phytoplankton communities were exposed to high and low conditions of CO2, nutrients and light. During the first 2 d, a positive response to increased CO2 and nutrient concentration was observed in terms of abundance and chlorophyll in all size fractions (<2, 2 to 20, and >20 µm). After 2 d, a trophic cascade effect was observed within the phytoplankton communities for all treatments. The absence of mesozooplankton led to an increase in microzooplankton abundance,which coincided with a decrease in the abundance of phytoplankton <6 µm equivalent spherical dia meter (ESD). At the same time, an increased concentration of larger phytoplankton was observed. Consequently, a diatom bloom dominated by Leptocylindrus danicus and Chaetoceros sp. developed, peaking on Day 5 in the high-light treatment and on Day 6 in the low-light treatment.The cascade effect was evident in both the smaller and the larger ranges of the size-abundance spectra (SAS). Although this trophic interaction occurred in all treatments in a similar way, therewere still significant differences among treatments. Diatoms with cell sizes >20 µm ESD showed a positive response to the effects of increasing CO2 and nutrient concentration. These results high -light the importance of trophic interactions other than abiotic factors such as CO2 and nutrient availability in shaping the size structure of Mediterranean phytoplankton. More specifically, this work shows the importance of trophic cascade effects in scaling the plankton SAS and should be considered in both enclosure experiments and field measurements that deal with size distribution.

We report on results of a microcosm experiment to study the interactive effects of elevated CO2, high organic and inorganic nutrient loading, and high irradiance on phytoplankton and bacterioplankton from the Mediterranean coastal ecosystem of the Alboran Sea. This experiment was part of the Group for Aquatic Productivity 9th international workshop and was conducted by Working Group 1 (WG1: Phytoplankton of coastal waters, www.gap9.uma.es). Over a 7 d period, we measured the variation in physical and chemical variables and the characteristics of phytoplankton and bacterioplankton in microcosms incubated under 8 treatments, representing full factorial combinations of 2 levels each of CO2 supply, nutrient concentrations and solar radiation exposure. For each treatment combination, we incubated triplicate microcosms consisting of 20 l polyethylene bags which were transparent to ultraviolet radiation. Sustained growth of phytoplankton biomass (chl a) occurred in all treatments. The absence of mesozooplankton in the microcosms resulted in a trophic cascade. Picophytoplankton were initially stimulated but then decreased, apparently due to microzooplankton grazing, and were largely replaced by diatoms. Bacteria were also initially stimulated and then decreased, but eventually recovered. Responses were modified markedly by nutrient enrichment and light availability, with moderate effects of elevated CO2. Relative to ambient CO2, elevated CO2 resulted in higher chl a under low irradiance, but lower chl a under high irradiance.

We conducted a microcosm experiment aimed at studying the interactive effects of high CO2, nutrient loading and irradiance on the metabolism of a planktonic community sampled in the Western Mediterranean near the coast of Málaga. Changes in the metabolism of phytoplankton and bacterioplankton were observed for 7 d under 8 treatment conditions, representing the full factorial combinations of 2 levels each of CO2, nutrient concentration and solar radiation exposure. The initial plankton sample was collected at the surface from a stratified water column, indicating that phytoplankton were naturally acclimated to high irradiance and low nutrient concentrations. Nutrient addition combined with high irradiance resulted in a significant increase in primary production. Nitrate uptake by phytoplankton was also stimulated under high nutrient conditions. High nutrients, high irradiance and the combination of low CO2 and high irradiance positively affected bacterial production. Light was the main factor affecting the respiration rates of the community, which were higher at the high light level. After 7 d of incubation, nutrient loading was the only factor that significantly affected the amount of particulate organic carbon (POC) accumulated in the microcosms. Therefore, the changes in metabolic rates produced at high CO2 had no effect on net production of particulate organic matter. If these results are extrapolated to the natural environment, it could be hypothesized that high levels of CO2 will have a limited impact on biological pump activity in the northern Alboran Sea since it is assumed that POC export towards deeper layers determines the potential for carbon sequestration

We studied the physiological response of phytoplankton to the interacting effects of 3 factors affected by global climate change: CO2, nutrient loading and irradiance. Treatments had a high and low level for each factor: CO2 was bubbled at 1000 ppm by volume versus present atmo spheric values; high nutrient treatments had a combination of inorganic and organic nutrients; and light treatments were obtained by covering the tanks with a single or double layer of screen. We measured esterase activity, oxidative stress (ROS), cell death, DNA damage, photosynthetic efficiency and 14C assimilation as particulate or dissolved organic material (POC and DOC respectively). Conditions simulating future global change scenarios showed similar chlorophyllnormalized primary productivity as present conditions. The main effect driving phytoplankton physiology was the downregulation of the photosynthetic apparatus by elevated CO2, which decreased esterase activity, ROS, cell death and DNA damage. Nutrient concentration and light acted as additional modulators, upregulating or contributing to downregulation. The percentage of DO14C extracellular release (PER) was low (0 to 27%), significantly lower under ultraviolet radiation (UVR) than under photosynthetically active radiation (PAR), and acted mainly to reequilibrate the internal balance when cells grown under UVR were exposed to PAR. PER was almost 3 times lower under high CO2, confirming a higher resource use efficiency of phytoplankton under future CO2 concentrations.

Experimental results related to the effects of ocean acidification on planktonic marine microbes are still rather inconsistent and occasionally contradictory. Moreover, laboratory or field experiments that address the effects of changes in CO2 concentrations on heterotrophic microbes are very scarce, despite the major role of these organisms in the marine carbon cycle. We tested the direct effect of an elevated CO2 concentration (1000 ppmv) on the biomass and metabolic rates (leucine incorporation, CO2 fixation and respiration) of 2 isolates belonging to 2 relevant marine bacterial families, Rhodobacteraceae (strain MED165) and Flavobacteriaceae (strain MED217). Our results demonstrate that, contrary to some expectations, high pCO2 did not negatively affect bacterial growth but increased growth efficiency in the case of MED217. The elevated partial pressure of CO2 ( pCO2) caused, in both cases, higher rates of CO2 fixation in the dissolved fraction and, in the case of MED217, lower respiration rates. Both responses would tend to increase the pH of seawater acting as a negative feedback between elevated atmospheric CO2 concentrations and ocean acidification.

Protocolo de recogida de muestras de agua para el análisis de la absor bancia y fluorescencia de la materia orgánica cromófora y su determina ción a bordo por espectrofotometría y espectrofluorimetría.

Experimental results related to the effects of ocean acidification on planktonic marine microbes are still rather inconsistent and occasionally contradictory. Moreover, laboratory or field experiments that address the effects of changes in CO2 concentrations on heterotrophic microbes are very scarce, despite the major role of these organisms in the marine carbon cycle. We tested the direct effect of an elevated CO2 concentration (1000 ppmv) on the biomass and metabolic rates (leucine incorporation, CO2 fixation and respiration) of 2 isolates belonging to 2 relevant marine bacterial families, Rhodobacteraceae (strain MED165) and Flavobacteriaceae (strain MED217). Our results demonstrate that, contrary to some expectations, high pCO2 did not negatively affect bacterial growth but increased growth efficiency in the case of MED217. The elevated partial pressure of CO2 ( pCO2) caused, in both cases, higher rates of CO2 fixation in the dissolved fraction and, in the case of MED217, lower respiration rates. Both responses would tend to increase the pH of seawater acting as a negative feedback between elevated atmospheric CO2 concentrations and ocean acidification.

Todas as ilustracións de C. Sobrino

Datos del editor: Data a pé de foto do autor: 1916, Capa il.: "C. Sobrino"

Shallow gas reservoirs in marine sediments from the Iberian margin or their escapes can be detected by using direct methods: measurement of high concentrations of methane or other hydrocarbons in the water column or sediment cores; identification of chemosynthetic communities and/or authigenic carbonates in the seafloor; and identification, using underwater videos, of pockmarks or carbonate mounds and mud volcanoes associated with the fluid escapes. Among indirect characterisation methods of anomalies in acoustic records are: presence of acoustic plumes in echo-sounders records; identification of acoustic blanking and/or acoustic turbidity in the high resolution seismic records; interpretation of reflectivity; and, morphologies of pockmarks or seamounts in sidescan sonar and multibeam echosounder records. This article is a compilation of acoustic-seismic, sedimentologic and morphologic evidence associated with the presence of shallow gas accumulations or escapes that appear in the Iberian margin and have been published in various papers. The description is divided into geographical sectors, beginning in the northeastern end of the Mediterranean margin and ending at the easternmost area of the Cantabrian margin, following a clockwise direction around the Iberian Peninsula., Shallow gas reservoirs in marine sediments from the Iberian margin or their escapes can be detected by using direct methods: measurement of high concentrations of methane or other hydrocarbons in the water column or sediment cores; identification of chemosynthetic communities and/or authigenic carbonates in the seafloor; and identification, using underwater videos, of pockmarks or carbonate mounds and mud volcanoes associated with the fluid escapes. Among indirect characterisation methods of anomalies in acoustic records are: presence of acoustic plumes in echo-sounders records; identification of acoustic blanking and/or acoustic turbidity in the high resolution seismic records; interpretation of reflectivity; and, morphologies of pockmarks or seamounts in sidescan sonar and multibeam echosounder records. This article is a compilation of acoustic-seismic, sedimentologic and morphologic evidence associated with the presence of shallow gas accumulations or escapes that appear in the Iberian margin and have been published in various papers. The description is divided into geographical sectors, beginning in the northeastern end of the Mediterranean margin and ending at the easternmost area of the Cantabrian margin, following a clockwise direction around the Iberian Peninsula.