Assessing combined effects of long-term exposure to copper and marine heatwaves on the reef-forming serpulid Ficopomatus enigmaticus through a biomarker approach.

Sessile benthic organisms can be affected by global changes and local pressures, such as metal pollution, that can lead to damages at different levels of biological organization. Effects of exposure to marine heatwaves (MHWs) alone and in combination with environmentally relevant concentration of copper (Cu) were evaluated in the reef-forming tubeworm Ficopomatus enigmaticus using a multi-biomarker approach. Biomarkers of cell membrane damage, enzymatic antioxidant defences, metabolic activity, neurotoxicity, and DNA integrity were analyzed. The exposure to Cu alone did not produce any significant effect. Exposure to MHWs alone produced effects only on metabolic activity (increase of glutathione S-transferase) and energy reserves (decrease in protein content). MHWs in combination with copper was the condition that most influenced the status of cell homeostasis of exposed F. enigmaticus. The combination of MHWs plus Cu exposure induced increase of protein carbonylation and glutathione S-transferase activity, decrease in protein/carbohydrate content and carboxylesterase activity. This study on a reef-forming organism highlighted the additive effect of a climate change-related stressor to metals pollution of marine and brackish waters.

In vitro screening of imidazolium and pyrrolidinium based ionic liquids toxicity on subcellular fractions of the Mediterranean mussel Mytilus galloprovincialis.

Ionic liquids (ILs) have been considered eco-friendly alternatives to conventional organic solvents. However, several studies have reported that ILs exert toxicity towards aquatic invertebrates. Applying in vitro methodology, the aim of the present study was to evaluate the potential effect of three ILs on the biochemical performance of exposed Mytilus galloprovincialis digestive gland and gills cellular fractions. Carboxylesterase might be involved in the derived toxicity mechanism of ILs as activity levels increased significantly in digestive gland exposed fractions. This group of ILs did not seem to induce genotoxicity, except in gills cellular fractions exposed to 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. In the literature, in vitro methodology has been suggested as an important complement to animal testing and in silico studies. The present research underlines its efficacy as a quick pre-screening before in vivo testing, particularly with heterogenic groups of substances with high variability in composition, such as ILs and deep eutectic solvents.

Multi-biomarker approach for the (eco)toxicity of UV-filter environmental pollution on the Mediterranean mussel Mytilus galloprovincialis in a multiple stressor context. The case of 4-MBC under salinity shifts.

Marine-coastal ecosystems are rapidly transforming because of climate change (CC). At the same time, the impacts of emerging organic contaminants (i.e., organic UV-filters) on these ecosystems are intensifying. In the Mediterranean, the consequences of these disturbances are occurring at a fast pace making this area a potential sentinel site to be investigated. While singular effects of organic UV-filters or CC-related factors on marine biota have been relatively described, their combined impact is still largely unknown. Thus, the objective of this study was to assess the long-term responses of the Mediterranean mussel Mytilus galloprovincialis towards anticipated salinity changes (decreases-S20 or increases-S40) when exposed to environmentally relevant concentrations of the UV-filter 4-methylbenzylidene camphor (4-MBC). An integrated multi-biomarker approach was applied, featuring general and oxidative stress, antioxidant and biotransformation enzyme capacity, energy metabolism, genotoxicity, and neurotoxicity biomarkers. Results showed that both projected salinities, considered separately, exerted non-negligible impacts on mussels' health status, with greater biological impairments found at S 40. Combining both stressors resulted in an evident increase in mussels' susceptibility to the UV-filter, which exacerbated the toxicity of 4-MBC. The dominant influence of salinity in the climate change-contaminant interaction played a crucial role in this outcome. The most severe scenario occurred when S 20 was combined with 4-MBC. In this situation, mussels exhibited a decrease in filtration rate, metabolic capacity and deployment of energy reserves increased, with an upregulation of biotransformation and inhibition of antioxidant enzyme activities. This exposure also led to the observation of cellular and DNA damage, as well as an increase in AChE activity. Furthermore, salinity-dependent bioaccumulation patterns were evaluated revealing that the lowest values in contaminated mussels are found at S 20. Overall, the present findings provide evidence that projected CC/pollutant scenarios may represent high risks for mussels' populations, with global relevant implications for the ecosystem level.

Introducing energy into marine environments: A lab-scale static magnetic field submarine cable simulation and its effects on sperm and larval development on a reef forming serpulid.

Non-chemical sources of anthropogenic environmental stress, such as artificial lights, noise and magnetic fields, are still an underestimate factor that may affect the wildlife. Marine environments are constantly subjected to these kinds of stress, especially nearby to urbanized coastal areas. In the present work, the effect of static magnetic fields, associated with submerged electric cables, was evaluated in gametes and early life stages of a serpulid polychaete, namely Ficopomatus enigmaticus. Specifically, biochemical/physiological impairments of sperm, fertilization rate inhibition and incorrect larval development were assessed. We evaluated differences between two selected magnetic field induction values (0.5 and 1 mT) along a range of exposure times (30 min-48 h), for a sound evaluation on this species. We found that a magnetic induction of 1 mT, a typical value that can be found at distance of tens of cm from a submerged cable, may be considered a biologically and ecologically relevant for sessile organisms and for coastal environments more generally. This value exerted statistically significant effects on membranes, DNA integrity, kinetic parameters and mitochondrial activity of sperm cells. Moreover, a significant reduction in fertilization rate was observed in sperm exposed to the same magnetic induction level (1 mT) for 3 h, compared to controls. Regarding early larval stages, 48-h exposure did not affect the correct development. Our results represent a starting point for a future focus of research on magnetic field effects on early life stages of aquatic invertebrates, using model species as representative for reef-forming/encrusting organisms and ecological indicators of soft sediment quality.

Toxicity of ionic liquids in marine and freshwater microorganisms and invertebrates: state of the art.

The variety of applications and expected growth in ionic liquid production are raising concerns about the release of these compounds into aquatic systems. Up to date, 103 studies have provided ecotoxicological data regarding the exposure effects of Ionic Liquids towards aquatic microorganisms and invertebrate species: 61 were devoted to freshwater species (n = 28), while marine species (n = 12) were mentioned in 42. The aim of this review, by gathering published studies on ionic liquids and model aquatic organisms, was to present the toxic effects described in distinct species and to understand which are the main factors influencing the toxicity of some ionic liquids. In accordance with the most recognized pattern, freshwater species were featured in a higher number of publications than marine ones. After literature analysis, algal species were the most represented organisms in aquatic toxicity assessments. Among tested compounds, the imidazolium cations in combination with long alkyl-chain anions, showed to be the most toxic one. In analytical terms, it is not straightforward to find the undissociated compound in a natural compartment, as ionic liquids are composed of ionic components, easily subjected to dissociation. Given the aforementioned, the present review paper points out the need of increasing the number of organisms being assessed in ionic liquids toxicity assays, in order to start defining monitoring procedures. Moreover, such would allow a better understanding of ionic liquids contamination status and, also, the opportunity to remark the effectiveness of new in silico methods for the ecotoxicity assessment of this kind of substances.

Nitroxide-Containing Amphiphilic Random Terpolymers for Marine Antifouling and Fouling-Release Coatings.

Two types of amphiphilic random terpolymers, poly(ethylene glycol methyl ether methacrylate)-ran-poly(2,2,6,6-tetramethylpiperidinyloxy methacrylate)-ran-poly(polydimethyl siloxane methacrylate) (PEGMEMA-r-PTMA-r-PDMSMA), were synthesized and evaluated for antifouling (AF) and fouling-release (FR) properties using diverse marine fouling organisms. In the first stage of production, the two respective precursor amine terpolymers containing (2,2,6,6-tetramethyl-4-piperidyl methacrylate) units (PEGMEMA-r-PTMPM-r-PDMSMA) were synthesized by atom transfer radical polymerization using various comonomer ratios and two initiators: alkyl halide and fluoroalkyl halide. In the second stage, these were selectively oxidized to introduce nitroxide radical functionalities. Finally, the terpolymers were incorporated into a PDMS host matrix to create coatings. AF and FR properties were examined using the alga Ulva linza, the barnacle Balanus improvisus, and the tubeworm Ficopomatus enigmaticus. The effects of comonomer ratios on surface properties and fouling assay results for each set of coatings are discussed in detail. There were marked differences in the effectiveness of these systems against the different fouling organisms. The terpolymers had distinct advantages over monopolymeric systems across the different organisms, and the nonfluorinated PEG and nitroxide combination was identified as the most effective formulation against B. improvisus and F. enigmaticus.

Gene expression and biochemical patterns in the digestive gland of the mussel Mytilus galloprovincialis (Lamarck, 1819) exposed to 17α-ethinylestradiol.

Contaminants of emerging concern (CECs) are a class of chemicals that can spread throughout the environment and may cause adverse biological and ecological effects. While there are many different classes of CECs, one of the most well documented in the aquatic environment are pharmaceutical drugs, such as natural and synthetic estrogens. In particular, the widespread presence of the synthetic estrogen 17 α-Ethinylestradiol (EE2) in water may lead to bioaccumulation in sediment and biota. EE2 is the primary component in contraceptive pills, and is a derivative of the natural hormone estradiol (E2). In this study, the mussel Mytilus galloprovincialis was exposed to EE2 in a semi-static and time-dependent experiment, for a total exposure period of 28 days. Biochemical and transcriptomics analyses were performed on mussel digestive glands after exposure for 14 (T14) and 28 (T28) days. Metabolic and DNA impairments, as well as activation of antioxidant and biotransformation enzymes activation, were detected in T28 exposed mussels. RNA-Seq analysis showed significant differential expression of 160 (T14 compared to controls), 33 (T28 compared to controls) and 79 (T14 compared to T28) genes. Signs of stress after EE2 treatment included up-regulation of gene/proteins involved with immune function, lipid transport, and metabolic and antibacterial properties. This study elucidates the underlying mechanisms of EE2 in a filter feeding organisms to elucidate the effects of this human pharmaceutical on aquatic biota.

Posidonia oceanica (L.) (Delile, 1813) extracts as a potential booster biocide in fouling-release coatings.

Since the banning of tributyltin, the addition of inorganic (metal oxides) and organic (pesticides, herbicides) biocides in antifouling paint has represented an unavoidable step to counteract biofouling and the resulting biodeterioration of submerged surfaces. Therefore, the development of new methods that balance antifouling efficacy with environmental impact has become a topic of great importance. Among several proposed strategies, natural extracts may represent one of the most suitable alternatives to the widely used toxic biocides. Posidonia oceanica is one of the most representative organisms of the Mediterranean Sea and contains hundreds of bioactive compounds. In this study, we prepared, characterized, and assessed a hydroalcoholic extract of P. oceanica and then compared it to three model species. Together, these four species belong to relevant groups of biofoulers: bacteria (Aliivibrio fischeri), diatoms (Phaeodactylum tricornutum), and serpulid polychaetes (Ficopomatus enigmaticus). We also added the same P. oceanica extract to a PDMS-based coating formula. We tested this coating agent with Navicula salinicola and Ficopomatus enigmaticus to evaluate both its biocidal performance and its antifouling properties. Our results indicate that our P. oceanica extract provides suitable levels of protection against all the tested organisms and significantly reduces adhesion of N. salinicola cells and facilitates their release in low-intensity waterflows.

Are natural deep eutectic solvents always a sustainable option? A bioassay-based study.

The traditional use of organic solvents in various branches of industry is being rethought as these compounds very often display high volatility, toxicity and lipophilicity (related to the ability to interact with biological membranes). More recently, developments in the field of Green Chemistry are focusing on the design of more sustainable and cost-effective solvent alternatives like Ionic Liquids (ILs), bio-based solvents and natural deep eutectic solvents (NADESs). The present study aimed at performing an ecotoxicological screening of 15 NADESs using an extensive set of marine and freshwater bioassays, based on different endpoints as the following: immobilization of the crustacean Daphnia magna, growth inhibition of Raphidocelis subcapitata and of Phaeodactylum tricornutum, larval development alterations on the serpulid Ficopomatus enigmaticus and bioluminescence inhibition of Aliivibrio fischeri. What emerged was a general absence of toxicity of all samples. However, both algal assays showed a certain degree of biostimulation, up to over 100% growth increase in respect to controls with 8 out of 15 compounds tested with Raphidocelis subcapitata. Despite NADESs-induced negligible toxicity effects to invertebrates, encouraging their labelling as "sustainable" solvents, the liability of their intentional or accidental release into aquatic systems may represent a serious risk in terms of ecosystem functioning impairments.

Polyethylene Glycol-b-poly(trialkylsilyl methacrylate-co-methyl methacrylate) Hydrolyzable Block Copolymers for Eco-Friendly Self-Polishing Marine Coatings.

Hydrolyzable block copolymers consisting of a polyethylene glycol (PEG) first block and a random poly(trialkylsilyl methacrylate (TRSiMA, R = butyl, isopropyl)-co-methyl methacrylate (MMA)) second block were synthesized by RAFT polymerization. Two PEGs with different molar masses (Mn = 750 g/mol (PEG1) and 2200 g/mol (PEG2)) were used as macro-chain transfer agents and the polymerization conditions were set in order to obtain copolymers with a comparable mole content of trialkylsilyl methacrylate (~30 mole%) and two different PEG mole percentages of 10 and 30 mole%. The hydrolysis rates of PEG-b-(TRSiMA-co-MMA) in a THF/basic (pH = 10) water solution were shown to drastically depend on the nature of the trialkylsilyl groups and the mole content of the PEG block. Films of selected copolymers were also found to undergo hydrolysis in artificial seawater (ASW), with tunable erosion kinetics that were modulated by varying the copolymer design. Measurements of the advancing and receding contact angles of water as a function of the immersion time in the ASW confirmed the ability of the copolymer film surfaces to respond to the water environment as a result of two different mechanisms: (i) the hydrolysis of the silylester groups that prevailed in TBSiMA-based copolymers; and (ii) a major surface exposure of hydrophilic PEG chains that was predominant for TPSiMA-based copolymers. AFM analysis revealed that the surface nano-roughness increased upon immersion in ASW. The erosion of copolymer film surfaces resulted in a self-polishing, antifouling behavior against the diatom Navicula salinicola. The amount of settled diatoms depended on the hydrolysis rate of the copolymers.

The Culturable Mycobiota of Sediments and Associated Microplastics: From a Harbor to a Marine Protected Area, a Comparative Study.

Fungi are an essential component of marine ecosystems, although little is known about their global distribution and underwater diversity, especially in sediments. Microplastics (MPs) are widespread contaminants worldwide and threaten the organisms present in the oceans. In this study, we investigated the fungal abundance and diversity in sediments, as well as the MPs, of three sites with different anthropogenic impacts in the Mediterranean Sea: the harbor of Livorno, the marine protected area "Secche della Meloria"; and an intermediate point, respectively. A total of 1526 isolates were cultured and identified using a polyphasic approach. For many of the fungal species this is the first record in a marine environment. A comparison with the mycobiota associated with the sediments and MPs underlined a "substrate specificity", highlighting the complexity of MP-associated fungal assemblages, potentially leading to altered microbial activities and hence changes in ecosystem functions. A further driving force that acts on the fungal communities associated with sediments and MPs is sampling sites with different anthropogenic impacts.

The influence of salinity on the toxicity of chemical UV-filters to sperms of the free-spawning mussel Mytilus galloprovincialis (Lamark, 1819).

Marine-coastal systems have been increasingly exposed to multiple stressors, including anthropogenic pollution and variations of Climate Change (CC) related factors, whose coexistence could create associated environmental and ecotoxicological risks. Among emergent stressors, 4-methylbenzylidenecamphor (4-MBC) and benzophenone-3 (BP-3) UV-filters are compounds widely used in increasing consumer products, resulting in their ubiquity in aquatic environments and possible pressing challenges on gamete susceptibility. Since most marine invertebrates reproduce by external fertilization, after spawning, gametes may be exposed to several pressures, affecting reproductive success and outcome. The present study focuses on the spermiotoxicity of the environmentally relevant UV-filters 4-MBC and BP-3 combined with salinity shifts, as potential modulators of their harmful effects. For this, Mytilus galloprovincialis male gametes were exposed in vitro to environmentally relevant and slightly higher concentrations (1, 10 and 100 µg/L) of 4-MBC or BP-3 under three different salinities (S 20, 30 and 40). Sperm quality endpoints associated with oxidative status, viability, motility, kinetics, and genotoxicity were evaluated. Similarities and differences in sperm responses among all conditions were highlighted by principal coordinates analysis (PCO). Results showed that salinity acting alone posed greater sperms impairments at the lowest (20) and highest (40) tested levels. When salinity acts as a co-varying stressor, salinity-dominant interactive effects resulted evident, especially for 4-MBC at S 40 and BP-3 at S 20. These findings were pointed out as the worst exposure conditions for M. galloprovincialis sperms, since caused major toxicological effects in terms of: (I) oxidative stress, sperm structural impairments, motility and kinetic alterations in 4-MBC-exposed sperms; (II) DNA damage, compromised mitochondrial activity and hyperactivation in BP-3-exposed ones. Overall, it stands out that salinity influences UV-filter toxicological pathways and, thereby, the potential environmental risk of these contaminants on M. galloprovincialis male gametes, especially in an expected salinity stress scenario.

UV-filters in marine environments: a review of research trends, meta-analysis, and ecotoxicological impacts of 4-methylbenzylidene-camphor and benzophenone-3 on marine invertebrate communities.

The potential adverse effects of UV-filter pollution in marine environments have been the focus of research in recent years. This systematic review aims to determine the extent of this emerging problem, both quantitatively and qualitatively, combining temporal and science mapping analyses to explore the development of the field of UV-filters in the marine environment (from 1990 to 2021), and to outline new research frontiers. The temporal trend analysis revealed an exponential growth of published studies over the last decade (70% since 2016), confirming the emerging role of this topic in environmental science. The meta-analysis determined that 4-methylbenzylidene-camphor (4-MBC) and benzophenone-3 (BP-3) are top-priority environmental pollutants due to their increasing usage and, in turn, a frequent occurrence in marine ecosystems. This meta-analysis determined the focus on these two contaminants for this review. A critical discussion of the applications, regulatory aspects, and environmental occurrences of these selected compounds was provided. The present study also focused on the most recent (2015-2021) field and laboratory studies investigating the ecotoxicological impacts of 4-MBC and BP-3 on marine invertebrates. This review highlights the need for more research efforts to fill the knowledge gaps on the realistic effects these compounds may have when considered individually, in combination, or as subsequent exposures. Overall, this review aims to establish guidelines for further studies to understand the effect of UV-filters on marine ecosystems and marine invertebrate communities.

Ecotoxicological effects of the UV-filter 4-MBC on sperms and adults of the mussel Mytilus galloprovincialis.

Present in an increasing number of products, UV-filters are continuously discharged into aquatic environments. Despite potential risks for inhabiting organisms are recognized, the effects of UV-filter 4-methylbenzylidenecamphor (4-MBC) on marine invertebrates are poorly investigated. By combining in vitro/in vivo exposures through a multi-biomarker approach on sperms and adults, the present study evaluated how 4-MBC affect the mussel species Mytilus galloprovincialis, providing ecologically relevant information on organisms' responses. From the obtained results, considering mortality as endpoint, sperms revealed a greater sensitivity (EC50:347 µg/L) than adults (EC50: not calculable). From an ecotoxicological perspective, this resulted in a derived threshold concentration (LOEC) of 100 µg/L and 72 µg/L, respectively. Effects at the cell/molecular level were provided by general redox-status imbalance and oxidative stress. Sperms showed functional and structural impairments, hyperactivation and DNA damage, while adults showed physiological, metabolic/energetic dysfunctions, DNA damage and activation of oxidative and biotransformation enzymes. High 4-MBC bioaccumulation was also observed in exposed mussels (BCFs:14.0-32.0 L/kg). These findings suggest that 4-MBC may impair fitness and survival of the broadcast spawning mussel M. galloprovincialis, affecting reproduction success and population growth.

Biochemical response of Ficopomatus enigmaticus adults after exposure to organic and inorganic UV filters.

With the increase of UV filters usage and consequent release into aquatic environments, the concerns about their potential ecological risks are also increasing. According to this, in the present study, adult polychaetes of the species Ficopomatus enigmaticus were chronically exposed to three concentrations (0.01, 0.1 and 0.5 mg/L) of organic and inorganic filters (Ethylhexyl methoxycinnamate (EHMC) and nanoparticulate Zinc oxide (nZnO), respectively) in order to analyse biochemical responses related to cellular damage, antioxidant defence, biotransformation mechanisms and, lastly, neurotoxicity. Despite major lipid peroxidation caused by EHMC was observed, both UV filters have produced the same response patterns. In details, a clear concentration-dependent activation of glutathione S-transferases and a significant decrease of acetylcholinesterase levels defined an important neurotoxic effect was observed for both contaminants. These results become important to expand the limited scientific literature on biochemical responses of marine and brackish water invertebrates to organic and inorganic UV filters.

Polyethylene microplastics reduce filtration and respiration rates in the Mediterranean sponge Petrosia ficiformis.

Microplastic (MP) pollution represents a distinctive mark of the Anthropocene. Despite the increasing efforts to determine the ecological impacts of MP on marine biodiversity, our understanding of their toxicological effects on invertebrate species is still limited. Despite their key functional roles, sponges (Phylum Porifera) are particularly understudied in MP research. These filter-feeders extract and retain particles from the water column, across a broad size range. In this study, we carried out a laboratory experiment to assess the uptake of MPs (polyethylene, PE) by the Mediterranean sponge Petrosia ficiformis, how MPs influence key biological process after different times of exposure (24h and 72h) and whether they can be subsequently eliminated. MP uptake increased with time of exposure, with 30.6% of the inoculated MP particles found in sponge samples after 72h. MPs impaired filtration and respiration rates and these effects were still evident 72h after sponges had been transferred in uncontaminated water. Our study shows that time of exposure represents a key factor in determining MP toxicity in sponges. In addition, our results suggest that sponges are able to incorporate foreign particles and may thus be a potential bioindicator for MP pollutants.

Differential gene expression and chemical patterns of an intertidal crab inhabiting a polluted port and an adjacent marine protected area.

The acquisition of data to safeguard marine protected areas located close to ports is important in order to develop plans that allow effective protection from pollution as well as sustainable development of the port. The area Secche della Meloria is a Marine Protected Area (MPA-MEL) three miles from Livorno Harbour (LH), which is characterized by a long history of pollution. Here we studied the bioaccumulation and transcriptomic patterns of the marbled crab, Pachygrapsus marmoratus (Fabricius, 1787) (Crustacea; Brachyura, Grapsidae), inhabiting the two selected sites. Results showed that the two crab populations are significantly different in their chemical composition of trace elements and Polyciclic Aromatic Hydrocarbons (PAHs), and gene expression patterns (1280 DEGs). Enrichment analysis indicated that crabs at LH had the highest stress response genes, and they were associated with higher levels of bioaccumulation detected in body tissues. We are confident that the significant differential gene expression profiles observed between crabs, characterized by significant chemical differences, is associated with responses to contaminant exposure.

A multi-bioassay integrated approach to assess antifouling potential of extracts from the Mediterranean sponge Ircinia oros.

The phylum Porifera and their symbionts produce a wide variety of bioactive compounds, playing a central role in their ecology and evolution. In this study, four different extracts (obtained by non-polar and semi-polar extraction methodologies) of the Mediterranean sponge Ircinia oros were tested through a multi-bioassay integrated approach to assess their antifouling potential. Tests were performed using three common species, associated with three different endpoints: the marine bacterium Aliivibrio fischeri (inhibition of bioluminescence), the marine diatom Phaeodactylum tricornutum (inhibition of growth), and different development stages of the brackish water serpulid Ficopomatus enigmaticus (gametes: sperm motion, vitality inhibition and cellular damage; larvae: development; adults: AChE (acetylcholinesterase)-inhibitory activity). The effects of extracts were species specific and did not vary among different extraction methodologies. In particular, no significant reduction of bioluminescence of A. fischeri was observed for all tested samples. By contrast, extracts inhibited P. tricornutum growth and had toxic effects on different F. enigmaticus' developmental stages. Our results suggest that the proposed test battery can be considered a suitable tool as bioactivity screening of marine natural products.

Amphiphilic Polyphosphonate Copolymers as New Additives for PDMS-Based Antifouling Coatings.

Poly(ethyl ethylene phosphonate)-based methacrylic copolymers containing polysiloxane methacrylate (SiMA) co-units are proposed as surface-active additives as alternative solutions to the more investigated polyzwitterionic and polyethylene glycol counterparts for the fabrication of novel PDMS-based coatings for marine antifouling applications. In particular, the same hydrophobic SiMA macromonomer was copolymerized with a methacrylate carrying a poly(ethyl ethylene phosphonate) (PEtEPMA), a phosphorylcholine (MPC), and a poly(ethylene glycol) (PEGMA) side chain to obtain non-water soluble copolymers with similar mole content of the different hydrophilic units. The hydrolysis of poly(ethyl ethylene phosphonate)-based polymers was also studied in conditions similar to those of the marine environment to investigate their potential as erodible films. Copolymers of the three classes were blended into a condensation cure PDMS matrix in two different loadings (10 and 20 wt%) to prepare the top-coat of three-layer films to be subjected to wettability analysis and bioassays with marine model organisms. Water contact angle measurements showed that all of the films underwent surface reconstruction upon prolonged immersion in water, becoming much more hydrophilic. Interestingly, the extent of surface modification appeared to be affected by the type of hydrophilic units, showing a tendency to increase according to the order PEGMA < MPC < PEtEPMA. Biological tests showed that Ficopomatus enigmaticus release was maximized on the most hydrophilic film containing 10 wt% of the PEtEP-based copolymer. Moreover, coatings with a 10 wt% loading of the copolymer performed better than those containing 20 wt% for the removal of both Ficopomatus and Navicula, independent from the copolymer nature.

Ecotoxicological screening of UV-filters using a battery of marine bioassays.

The present study aimed to assess the toxicity of seven UV-filters: zinc oxide nanoparticles (nZnO, particle size <100 nm), titanium dioxide nanoparticles (nTiO2, primary particle size 21 nm), 2-ethylhexyl-4-methoxycinnamate (EHMC), 4-methylbenzylidene camphor (4-MBC), avobenzone (AVO), octocrylene (OCTO) and benzophenone-3 (BP-3) on three species: Aliivibrio fischeri (inhibition of bioluminescence), Phaeodactylum tricornutum (growth inhibition) and Ficopomatus enigmaticus (larval development success). Results showed nTiO2 to be the most toxic for P. tricornutum (EC50 0.043 mg L-1), while no effect was observed in A. fischeri and F. enigmaticus. EHMC was the most toxic to A. fischeri (EC50 0.868 mg L-1 (15 min) and 1.06 mg L-1 (30 min)) and the second most toxic to P. tricornutum. For F. enigmaticus, the lowest percentages of correct development resulted from 4-MBC exposure, with EC50 of 0.836 mg L-1. Overall, AVO induced low toxicity to every assessed species and OCTO was the least toxic for F. enigmaticus larvae. Considering the results obtained for F. enigmaticus, further larval development assays were performed with nZnO and EHMC under different light (light vs darkness) and temperature (20 and 25 °C) conditions, showing higher percentages of correct development at 25 °C, independently on light/darkness conditions. Under different temperature and photoperiod conditions, nZnO was more toxic than EHMC. Overall, nZnO and EHMC were among the most toxic UV filters tested and, when testing the effects of these UV-filters with temperature the results highlight that the impacts are liable to be lessened at higher temperatures (25 °C compared with 20 °C), in the case of this estuarine polychaete species. Nevertheless, further experiments are necessary to describe the effects of these two UV-filters at different organization levels, to study the toxicity of eventual degradation by-products and to provide more information on the combination of different stressors.