Marine aerobic biofilm as biocathode catalyst

Stainless steel electrodes were immersed in open seawater and polarized for some days at − 200 mV vs. Ag/AgCl. The current increase indicated the formation of biofilms that catalysed the electrochemical reduction of oxygen. These wild, electrochemically active (EA) biofilms were scraped, resuspended in seawater and used as the inoculum in closed 0.5 L electrochemical reactors. This procedure allowed marine biofilms that are able to catalyse oxygen reduction to be formed in small, closed small vessels for the first time. Potential polarisation during biofilm formation was required to obtain EA biofilms and the roughness of the surface favoured high current values. The low availability of nutrients was shown to be a main limitation. Using an open reactor continuously fed with filtered seawater multiplied the current density by a factor of around 20, up to 60 µA/cm2, which was higher than the current density provided in open seawater by the initial wild biofilm. These high values were attributed to continuous feeding with the nutrients contained in seawater and to suppression of the indigenous microbial species that compete with EA strains in natural open environments. Pure isolates were extracted from the wild biofilms and checked for EA properties. Of more than thirty different species tested, only Winogradskyella poriferorum and Acinetobacter johsonii gave current densities of respectively 7% and 3% of the current obtained with the wild biofilm used as inoculum. Current densities obtained with pure cultures were lower than those obtained with wild biofilms. It is suspected that synergetic effects occur in whole biofilms or/and that wild strains may be more efficient than the cultured isolates

Cathodic disbonding tests operating at large cathodic potentials for long periods need current monitoring, pH control and anode isolation

Metallic structures in service in seawater are protected coupling cathodic protection and paints, where the former may induce disbondment of the latter. A preliminary evaluation of the cathodic disbondment risk can be made by cathodic disbondment tests, CDTs. Many CDTs use cathodic potentials as large as E < -1400 mV vs SCE applied up to 90 days. Only two CDT protocols require contemporary anode isolation, current and pH monitoring, without its correction. These three aspects were considered to develop a hybrid CDT; it consisted in polarizing steel panels at -1500 mV vs SCE for 12 weeks. The chemical effects related to the anodic processes were investigated. The observed pH acidic shift was justified by the increasing current demand due to paint damage and brucite precipitation on the panels. The necessity of anode isolating glass to prevent chlorine related chemical attack over the paints, potentially affecting the disbondment result, was verified. In conclusion, current monitoring, pH control and anode isolation are highly suggested to correctly interpret the cathodic disbondment results when CDTs requiring large electronegative potentials are applied for long periods

Microplastics ingestion in the ephyra stage of Aurelia sp. triggers acute and behavioral responses

For the first time, we report a correspondence between microplastics (MP) ingestion and ecotoxicological effects in gelatinous zooplankton (Cnidarian jellyfish). The ephyra stage of the jellyfish Aurelia sp. was exposed to both environmental and high concentrations of fluorescent 1–4 μm polyethylene MP (0.01–10 mg/L). After 24 and 48 h, MP accumulation, acute (Immobility) and behavioral (Frequency pulsation) endpoints were investigated. MP were detected by confocal and tomographic investigations on gelatinous body and mouth, either attached on the surface or ingested. This interaction was responsible for impairing ephyrae survival and behavior at all tested concentrations after 24 h. Acute and behavioral effects were also related to mechanical disturbance, caused by MP, triggering a loss of radial symmetry. Contaminated ephyrae exposed to clean seawater showed full recovery after 72 h highlighting the organisms without the microspheres, attached on body jellyfish surface around the mouth and lappets. In conclusion, short-term exposure to MP affects ephyrae jellyfish health, impairing both their survival and behavior. Polyethylene MP temporarily affect both Immobility and Frequency of pulsation of Aurelia sp. jellyfish. This study provides a first step towards understanding and clarifying the potential impacts of MP contamination in gelatinous zooplankton

Beach Care Project. Evento di divulgazione scientifica sulla raccolta e differenziazione dei rifiuti solidi urbani sul litorale di Capaci nell’ambito del progetto 4Elements

Nel mese di novembre 2021 è stata organizzata un’operazione di beach cleaning presso la spiaggia del comune di Carini vicino Palermo dal nome “Beach Care Project”, in collaborazione col comune e diverse associazioni ambientaliste sul territorio come LiberAmbiente, Muoversi a Carini, Plastic free e Proloco. L’obiettivo dei due giorni di lavoro in programma sono stati, oltre alla rimozione di rifiuti di ogni genere dal litorale interessato, la divulgazione scientifica e un’azione di formazione condotta dagli esperti CNR con gli scolari partecipanti sui temi della sostenibilità ambientale, la raccolta differenziata dei rifiuti e la protezione dell’ambiente ponendo l’accento sul concetto di condotta civica “green” a 360°. All’evento è intervenuto un elicottero del N.O.E. dei Carabinieri e tutta l’operazione è stata condotta con l’ausilio di una pala meccanica per la raccolta dei rifiuti pesanti messa a disposizione del partner del progetto “CNH Industrial”

Report on JERICO Biofouling Monitoring Program (BMP)

The main aim for this document is to report after the Biofouling Monitoring Program (BMP) aiming at identifying major organisms responsible for biofouling in different geographical areas, as an input to the development and application of a more suitable approach to any specific region. This report is strongly linked to the JERICO deliverable D4.3 “Report on Biofouling Prevention Methods”, available at http://www.jerico-fp7.eu/deliverables/d4-3-report-on-biofouling-prevention-methods

Towards a summary of ecotoxicological knowledge regarding the Mediterranean Ostreopsis cf. ovata

Giussani, V. ... et. al.-- 7th Biannual ECOtoxicology MEeting (BECOME 2016), Managing aquatic and terrestrial environments: an ecotoxicological perspective, 22-24 November 2016, Livorno.-- 5 pages, 1 figure, 1 tableMediterranean Benthic Harmful Algal Blooms represent a phenomenon of particular interest and harmful proliferations of Ostreopsis spp. are increasing. During the last years several toxicological studies have been performed to assess the toxicity of this genus, highlighting that O. cf. ovata is the most toxic species, at least in the Mediterranean area. For this reason, it has been selected for an ecotoxicological investigationon different on model organisms: crustaceans (larvae of Amphibalanus amphitrite, Artemia salina, Tigriopus fulvus), echinoderms (larvae and juveniles of Paracentrotus lividus), cnidaria (polyps and ephyrae of Aurelia sp.) and fish (juveniles of Dicentrarchus labrax). Our outcomes report a different sensitivity to O. cf. ovata of all tested organisms and improve data availability for the risk assessment of exposure to Ostreopsis by using, for example, the > Species Sensitivity Distributions (SSDs) > approachPeer Reviewe

Assessing photosynthetic biomarkers in lichen transplants exposed under different light regimes

tThe present work is a methodological study testing alternative exposure conditions of lichen transplantsfor biomonitoring studies. We evaluated the effects of different light regime on the vitality of lichenby analysing the photosynthetic efficiency of transplanted thalli of the fruticose species Pseudeverniafurfuracea (L.) Zopf. var. furfuracea. In particular, we tested the hypothesis that shading lichen transplantsis necessary to ensure sufficient lichen vitality during the exposure time. Thalli of P. furfuracea wereexposed in a polluted area within the harbour of Genoa (N-Italy) for 4 weeks under two experimentalconditions: 5 thalli were covered with a shade cloth, whereas 5 thalli were kept in the light. We showedthat, under the same environmental conditions (i.e., climate and pollution regime), shading the thalliminimised the photoinhibition and prolonged the vitality of the lichen. Thus, we recommend shadinglichen transplants during biomonitoring surveys to better detect the effects of pollution on the lichens

Potentiodynamic study of Al-Mg alloy with superhydrophobic coating in photobiologically active/not active natural seawater

Superhydrophobic coating technology is regarded as an attractive possibility for the protection of materials in a sea environment. DC techniques are a useful tool to characterize metals' behavior in seawater in the presence/absence of coatings and/or corrosion inhibitors. In this work, investigations concerning Al-5%Mg alloy with and without a sprayed superhydrophobic coating were carried out with potentiodynamic scans in photobiologically active and not active seawater (3 weeks of immersion).In not photobiologically active seawater, the presence of the superhydrophobic coating did not prevent pitting corrosion. With time, the coating underwent local exfoliations, but intact areas still preserved superhydrophobicity. In photobiologically active seawater, on samples without the superhydrophobic coating (controls) pitting was inhibited, probably due to the adsorption of organic compounds produced by the photobiological activity. After 3 weeks of immersion, the surface of the coating became hydrophilic due to diatom coverage. As suggested by intermediate observations, the surface below the diatom layer is suspected of having lost its superhydrophobicity due to early stages of biofouling processes (organic molecule adsorption and diatom attachment/gliding). Polarization curves also revealed that the metal below the coating underwent corrosion inhibiting phenomena as observed in controls, likely due to the permeation of organic molecules through the coating.Hence, the initial biofouling stages (days) occurring in photobiologically active seawater can both accelerate the loss of superhydrophobicity of coatings and promote corrosion inhibition on the underlying metal. Finally, time durability of superhydrophobic surfaces in real seawater still remains the main challenge for applications, where the early stages of immersion are demonstrated to be of crucial importance