Similarities, differences and mechanisms of climate impact on terrestrial vs. marine ecosystems

Comparisons between terrestrial and marine ecosystems are generally not in the main stream of scientific literature even though Webb (2012) listed several points for which the transfer of knowledge and concepts related to one or to the other system would benefit our understanding of both. Even sharing this view, the leading hypothesis behind this contribution is that the pelagic system, where the dominant biotic component by number and biomass is microscopic, has specific features which strongly differentiate it from the above-the-surface terrestrial systems. Due to this, climate change, i.e. changes in temperature, precipitation and most importantly in the dynamics of the two fluid media, atmosphere and ocean, act with different mechanisms which prevents proceeding with analogies in many cases. In addition, the non-linearity of most of the processes and responses to perturbations requires, in order to obtain reliable forecasts or hindcasts, a detailed analysis of the path followed by the system which is normally overlooked in the step-change simulations or projections

A Conceptual Framework for Developing the Next Generation of Marine OBservatories (MOBs) for Science and Society

In the field of ocean observing, the term of “observatory” is often used without a unique meaning. A clear and unified definition of observatory is needed in order to facilitate the communication in a multidisciplinary community, to capitalize on future technological innovations and to support the observatory design based on societal needs. In this paper, we present a general framework to define the next generation Marine OBservatory (MOB), its capabilities and functionalities in an operational context. The MOB consists of four interconnected components or “gears” (observation infrastructure, cyberinfrastructure, support capacity, and knowledge generation engine) that are constantly and adaptively interacting with each other. Therefore, a MOB is a complex infrastructure focused on a specific geographic area with the primary scope to generate knowledge via data synthesis and thereby addressing scientific, societal, or economic challenges. Long-term sustainability is a key MOB feature that should be guaranteed through an appropriate governance. MOBs should be open to innovations and good practices to reduce operational costs and to allow their development in quality and quantity. A deeper biological understanding of the marine ecosystem should be reached with the proliferation of MOBs, thus contributing to effective conservation of ecosystems and management of human activities in the oceans. We provide an actionable model for the upgrade and development of sustained marine observatories producing knowledge to support science-based economic and societal decisions

TURBOGEN: Computer-controlled vertically oscillating grid system for small-scale turbulence studies on plankton

11 pages, 10 figures, 3 tablesIn recent years, there has been a renewed interest in the impact of turbulence on aquatic organisms. In response to this interest, a novel instrument has been constructed, TURBOGEN, that generates turbulence in water volumes up to 13 l. TURBOGEN is fully computer controlled, thus, allowing for a high level of reproducibility and for variations of the intensity and characteristics of turbulence during the experiment. The calibration tests, carried out by particle image velocimetry, showed TURBOGEN to be successful in generating isotropic turbulence at the typical relatively low levels of the marine environment. TURBOGEN and its sizing have been devised with the long-term scope of analyzing in detail the molecular responses of plankton to different mixing regimes, which is of great importance in both environmental and biotechnological processesRachel Macmasters is acknowledged for language check. A.A., M.I.F., D.I., M.R.d’A., and R.W. thank the Flagship project RITMARE—The Italian Research for the Sea Programme (Ricerca ITaliana per il MARE) for partial support. A.A. was funded by the European Union under FP7-People—GA No. 600407Peer Reviewe

Training the 21st Century Marine Professional: A new vision for marine graduate education and training programmes in Europe

Press release for the exhibition "Woven to Honor: The Steven G. Alpert Collection of Indonesian Textiles," December 20, 1987-February 7, 1988, held at the Dallas Museum of Art. The press release, dated December 17, 1987 announces and describes the exhibitions "Power and Gold" and "Woven to Honor." Includes schedule of related education programs

Legionella Infection Risk from Domestic Hot Water

We investigated Legionella and Pseudomonas contamination of hot water in a cross-sectional multicentric survey in Italy. Chemical parameters (hardness, free chlorine, and trace elements) were determined. Legionella spp. were detected in 33 (22.6%) and Pseudomonas spp. in 56 (38.4%) of 146 samples. Some factors associated with Legionella contamination were heater type, tank distance and capacity, water plant age, and mineral content. Pseudomonas presence was influenced by water source, hardness, free chlorine, and temperature. Legionella contamination was associated with a centralized heater, distance from the heater point >10 m, and a water plant >10 years old. Furthermore, zinc levels of <20 μg/L and copper levels of >50 μg/L appeared to be protective against Legionella colonization. Legionella species and serogroups were differently distributed according to heater type, water temperature, and free chlorine, suggesting that Legionella strains may have a different sensibility and resistance to environmental factors and different ecologic niches

Identifying the main sources of Silicate in coastal waters of the southern Gulf of Valencia (Western Mediterranean Sea)

[EN] Silicon is a major nutrient for siliceous primary producers, which can become a potential limiting nutrient in oligotrophic areas. Most of the silicon inputs to the marine environment come from continental discharges, from both superficial and ground waters. This study analyses the main sources of silicon and their dynamics along the southernmost 43 km of shoreline in the Gulf of Valencia (Western Mediterranean Sea). The salinity and silicate concentration in the different compartments (springs, freshwater wells, beach groundwater, surf zone and coastal waters) in this coastal area were determined. In addition, chlorophyll a and phytoplankton community were analyzed in the surf zone and coastal waters. Silicate concentrations in freshwater wells ranged between 130 and 150 mu M, whereas concentrations of this nutrient declined to 49 mu M in freshwater-seawater mixture transects. At the same time, there was a positive gradient in silicate for both freshwater and coastal waters southward. An amount of 18.7 t of dissolved silicate was estimated in the nearest first kilometre nearest to the coastline, 6 t of this silicate belonged to the background sea level. On the other hand, the sum of the main rivers in the area supplies 1.6 t of dissolved silicate per day. This implies that a large amount of the remaining 11.1 t must derive from submarine groundwater discharges, which would thus represent 59% of the coastal dissolved silicate budget. Overall, it is suggested that a subterranean transport pathway must contribute considerably to silicate concentrations throughout this zone, which is characterized as permeable. (c) 2017 Institute of Oceanology of the Polish Academy of Sciences. Production and hosting by Elsevier Sp. z o.o.The authors acknowledge the financial support for this study from the CNPq (Brazil - Grant 303672/2013-7). We are very grateful for the valuable comments of anonymous reviewers on previous versions of the manuscript.Sospedra, J.; Niencheski, LFH.; Falco, S.; Andrade, C.; Attisano, K.; Rodilla, M. (2018). Identifying the main sources of Silicate in coastal waters of the southern Gulf of Valencia (Western Mediterranean Sea). Oceanologia. 60(1):52-64. https://doi.org/10.1016/j.oceano.2017.07.004S526460

Taxonomic and Environmental Variability in the Elemental Composition and Stoichiometry of Individual Dinoflagellate and Diatom Cells from the NW Mediterranean Sea

Here we present, for the first time, the elemental concentration, including C, N and O, of single phytoplankton cells collected from the sea. Plankton elemental concentration and stoichiometry are key variables in phytoplankton ecophysiology and ocean biogeochemistry, and are used to link cells and ecosystems. However, most field studies rely on bulk techniques that overestimate carbon and nitrogen because the samples include organic matter other than plankton organisms. Here we used X-ray microanalysis (XRMA), a technique that, unlike bulk analyses, gives simultaneous quotas of C, N, O, Mg, Si, P, and S, in single-cell organisms that can be collected directly from the sea. We analysed the elemental composition of dinoflagellates and diatoms (largely Chaetoceros spp.) collected from different sites of the Catalan coast (NW Mediterranean Sea). As expected, a lower C content is found in our cells compared to historical values of cultured cells. Our results indicate that, except for Si and O in diatoms, the mass of all elements is not a constant fraction of cell volume but rather decreases with increasing cell volume. Also, diatoms are significantly less dense in all the measured elements, except Si, compared to dinoflagellates. The N:P ratio of both groups is higher than the Redfield ratio, as it is the N:P nutrient ratio in deep NW Mediterranean Sea waters (N:P = 20–23). The results suggest that the P requirement is highest for bacterioplankton, followed by dinoflagellates, and lowest for diatoms, giving them a clear ecological advantage in P-limited environments like the Mediterranean Sea. Finally, the P concentration of cells of the same genera but growing under different nutrient conditions was the same, suggesting that the P quota of these cells is at a critical level. Our results indicate that XRMA is an accurate technique to determine single cell elemental quotas and derived conversion factors used to understand and model ocean biogeochemical cycles

On the trophic regimes of the Mediterranean Sea: a satellite analysis

International audienceThe ten years of the SeaWiFS satellite surface chlorophyll concentration observations, presently available, were used to characterize the biogeography of the Mediterranean Sea and the seasonal cycle of the surface biomass in different areas of the basin. The K-means cluster analysis was applied on the satellite time-series of chlorophyll concentration. The resulting coherent patterns were then explained on the basis of the present knowledge of the basin's functioning. Winter biomass enhancements were shown to occur in most of the basin and last for 2-3 months depending on the region. Classical spring bloom regimes were also observed, regularly in the North Western Mediterranean, and intermittently in four other specific areas. The geographical correspondence between specific clusters and regions showing high values of mean chlorophyll concentration indicates that, at least in the Mediterranean Sea, accumulations of phytoplankton are observed only where specific temporal trends are present

Colonization by Clostridium difficile in a neonatal intensive care unit [Sulla circolazione di Clostridium difficile in un reparto di terapia intensiva neonatale]

The Authors carried out a prospective study of intestinal colonization by Clostridium difficile on 147 consecutive newborns of a neonatal intensive care unit in Italy. The cumulative risk of Clostridium difficile colonization was 31.3%. Multivariate analysis showed that the probability of Clostridium difficile colonization was statistically associated to duration of hospital stay (OR = 1.025, 95% CI = 1.005 - 1.046; p = 0.014) and previous antibiotic treatment (OR = 3.484, 95% CI = 1.320 - 9.199; p = 0.012). Analysis of restriction pattern of genomic DNA after SmaI digestion and Pulsed Field Gel Electrophoresis (PFGE) of first patient isolates demonstrated a clear clonal spread of the microrganism in the unit. Control of nosocomial Clostridium difficile should be based on the strict adherence to the routinary infection control measures and a well defined antibiotic policy

Influence of stratification on marine dissolved organic carbon (DOC) dynamics: The Mediterranean Sea case

•Strong influence of stratification on the DOC dynamics in the Mediterranean Sea.•More DOC will accumulate in a warmer and well stratified ocean.•DOC may contribute to oceanic carbon export more than is currently recognized.•DOC should be included in models studying the carbon cycle in a warmer ocean.•The Mediterranean Sea is a model system for studying C cycle in a warmer ocean. Vertical distributions of dissolved organic carbon (DOC) were determined in different seasons in the southern Adriatic and Tyrrhenian Seas to study the role of stratification in DOC patterns. These two seas are located at similar latitude but differ in extents of vertical stratification. Stratification affects DOC dynamics in both basins, but with interesting differences. In the Tyrrhenian Sea, where the upper water column was stratified during all cruises, DOC showed high surface layer values without substantial seasonality. By contrast, in the southern Adriatic Sea, the seasonal cycle of stratification forced opposite trends in the 0–50m and 50–800m stocks, with DOC removal from the upper 50m associated with DOC increase below 50m. Regarding DOC export via deep water formation in the southern Adriatic Sea, we estimate that 0.19TgCyr−1 was exported to the 50–800m layer by convective overturn, while 0.85–1.19TgCyr−1 was sequestered below 1000m due to a continental shelf pump mechanism. We hypothesize that enhanced stratification associated with a warmer ocean could further increase DOC concentrations in the mixed layer, changing the role of DOC in the oceanic carbon cycle