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Microplastics (MPs) were sampled in three seasons from 2016 to 2018 in the Bay of Marseille, northwestern Mediterranean Sea, adjacent to a highly urbanized area. Six sites were selected according to their different characteristics (river mouth, treatment plants, protected marine area). Surface floating MPs were characterized (number, weight, typology and polymer) as was zooplankton. In addition, mussels were submerged and used to investigate ingestion. Finally, a hydrodynamic model was used to improve understanding of dispersion mechanisms. The annual averages of floating MPs values ranged from 39,217 to 514,817 items/km2. The MPs collected were mainly fragments principally composed of polyethylene and polypropylene. The mean abundance ratio (MPs/zooplankton) was 0.09. On average 87% of mussel pools were contaminated and ingested 18.73 items/100 g of flesh. Two hydrodynamic patterns were identified: the first retaining the MPs in the harbor, and the second dispersing them outside.

From an environmental perspective, there is a need to reduce the amount of biocides in chemically-active antifouling (AF) coatings, as these biocides can cause severe damage to marine life. In this study, six active molecules known as booster biocides were added at 3 wt% in solvent and aqueous-based acrylic paints. DCOIT, dichlofluanid, zinc pyrithione, copper pyrithione, tralopyril and zineb were used alone and mixed with a lower amount of copper (I) oxide and copper thiocyanate (10 wt%) than is currently used or with zinc oxide fillers. Field immersion tests were carried out in the Atlantic Ocean (Ste Anne du Portzic) and the Mediterranean Sea (Toulon), with contrasting physicochemical properties of water and macrofoulers' biodiversity. Microscopic analyses showed that AF coatings reduced the bacterial density differently for short immersion times at Ste Anne du Portzic. After four/five months of immersion, results, including multidimensional analyses, showed first specific patterns in the macrofoulers' assemblages depending on the site. In addition, the structure of macrofoulers' assemblages was affected by the biocide itself and by the combination of the biocide and the binder. When efficient, AF coatings appeared to decrease the richness with a strongest effect at Toulon. DCOIT was the most performing booster biocides whatever the immersion site and the polymer binder used. DCOIT was found to be efficient against marine bacteria and macrofoulers at Ste Anne du Portzic. The combination of zinc pyrithione with ZnO fillers in an aqueous-based AF paints exhibited the highest activity in the Mediterranean Sea over 16 months of immersion.

Concerning in situ passive sampler deployment, several technical priorities must be considered. In particular, deployment time must be sufficiently long not only to allow a significant quantity to be accumulated to facilitate analysis but also to ensure that the signal is above the quantification limit and out of the blank influence. Moreover, regarding the diffusive gradient in thin films (DGT) technique, deployment time must also be sufficiently long (at least 5 days) to avoid the interactions of the solutes with the material diffusion layer of the DGT and for the steady state to be reached in the gel. However, biofouling occurs in situ and modifies the surface of the samplers. In this article, we propose a kinetic model which highlights the biofouling effect. This model was able to describe the mitigation of the flux towards the DGT resin observed on Cd, Co, Mn, Ni and Zn during a 22-day deployment in the Seine River. Over a period of 22 days, biofouling had a significant impact on the DGT concentrations measured, which were decreased twofold to threefold when compared to concentrations measured in unaffected DGTs.

Since 1998, the European Biocidal Products Directive (BPD; 98/8/EC), applied to 23 product types (PT) for specific uses, including PT 21 the « antifouling products », regulates biocidal products before they are placed on the market. On the one hand, the efficacy of active substances and their formulations must be demonstrated for their specific employment ; on the other hand their non impact on workers neither users and environment must be proved and specifically against non target species. Standard protocols for the assessment of efficacy or ecotoxicity of antifouling substances are proposed within the framework of the Ecopaint and Paintclean projects which are founded by the french industry Ministery and labellised by the “Pôle Mer” (Paca and Brittany). The potential toxicity of actives substances as well as paints or their elutriates is assessed in vitro on six trophic levels following marine TGD recommendations (2003): bacteria, phytoplancton, crustacea, mollusc, echinoderm and fish. The potential impact of antifouling paints on the modification of the condition index of oysters (10 to 12 months exposure) is observed in situ. The efficacy of active substances and paints is also tested both in vitro and in situ In in vitro testing, the adhesion of marine pioneer bacteria is followed in presence of not of the active substances . While the biofouling development is observed on painted surfaces exposed on rafts as well as on vessel hulls during 12 months. In situ exposure could be performed in specific and/or different environments and on different kind of vessels (geographic zone, speed, duration of exposure…).

full-scale mechanical prototype line was deployed to a depth of 2500 m to test the leak tightness of the electronics containers and the pressure-resistant properties of an electromechanical cable under evaluation for use in the ANTARES deep-sea neutrino telescope. During a month-long immersion study, line parameter data were taken using miniature autonomous data loggers and shore-based optical time domain reflectometry. Details of the mechanical prototype line, the electromechanical cable and data acquisition are presented. Data taken during the immersion study revealed deficiencies in the pressure resistance of the electromechanical cable terminations at the entry points to the electronics containers. The improvements to the termination, which have been integrated into subsequent detection lines, are discussed. The line also allowed deep-sea acoustic measurements with a prototype hydrophone system. The technical setup of this system is described, and the first results of the data analysis are presented. (c) 2007 Elsevier B.V. All rights reserved.

A study of thermoplastic matrix composites has been performed to investigate their use in underwater applications such as oceanography, submarine, and sub-sea offshore structures. This article first presents six candidate materials. Results from simple mechanical and seawater aging screening tests on flat specimens are then described. Glass/epoxy and carbon/epoxy composites are used as reference materials. Two materials emerged from this process, glass/PEI and carbon/PEEK. Cylinders of both were manufactured and subjected to hydrostatic pressure tests, and results are compared to those for glass/epoxy and carbon/epoxy cylinders of similar geometry. The carbon/PEEK material appeared most promising. It resisted pressures in excess of 90 MPa and was retained for damage tolerance assessment studies. Drop weight impact damage zones were smaller in carbon/PEEK than carbon/epoxy for the same impact energies but the loss in residual collapse strength was more rapid in the thermoplastic composite. This was attributed to a change in failure mode, impact damage initiated a local buckling failure.

The microalgae Alexandrium minutum produces neurotoxins responsible for paralytic shellfish poisoning, which upon accumulation in shellfish represent a human health risk. This species recurrently forms toxic blooms in the Northern part of the French Brittany coast. At present, algae identification relies on tedious microscope observations mostly performed by skilled taxonomists in laboratories. Newly emerging fields of molecular taxonomy, nanoscale technology and biotechnology offer opportunities for the development of in-situ biosensors for the detection and the monitoring of toxic algae.

Biofouling reduction is a major problem for underwater instrumentation, involving optical measurements or viewing. This paper presents an effective window protection technique based on seawater electrolysis for producing active chlorine species. This is achieved by depositing a transparent conductive tin dioxide coating by spray pyrolysis. A number of laboratory and in situ experiments were performed in order to assess the effectiveness of this window protection technique. It was found that Sb doping was more efficient with respect to electrical energy management and long term SnO2 coating stability than the fluorine doping. In the present state of the art, biofouling prevention was proved to be effective over 5 months at least, La prévention du biofilm est un problème majeur dans la mise en oeuvre d’équipements sous-marins impliquant des mesures optiques ou simplement l’obtention d'images. Le présent article a pour but de décrire brièvement les travaux qui ont permis de valider une technique de protection par voie électrochimique. Le principe repose sur une électrolyse contrôlée de l’eau de mer pour produire des espèces chlorées à la surface même de la fenêtre a protéger. Ceci est réalisé en déposant par la technique de pyrolyse de spray un film de dioxyde d’étain, transparent et conducteur. Sur la base de nombreuses études en laboratoire et sur des sites naturels, la validité du procédé a été démontrée. En particulier, il a été établi que le dopage à l'antimoine offrait la meilleure stabilité et permettait de minimiser la consommation en énergie électrique. Dans l’état de l’art actuel, on a pu maintenir la transparence de fenêtres immergées en milieu marin pendant 5 mois au moins