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Biofouling starts by the formation of a biofilm consisting of bacteria, diatoms seaweed or phytoplankton. Unfortunately, the adhering of the biofouling organisms’ causes serious problems to the marine industry. The present study examined soft corals collected from Hurghada’s Egyptian Red Sea coast as a source for antifouling agents. Bioactive compounds, specifically 8-epi-sarcophinone and ent-sarcophine, were extracted from Sarcophyton glaucum, whereas Alismol and Gorgosterol were obtained from Sclerophytum leptoclados. Their structural analyses were investigated using 1H and 13C NMR spectra. The biocidal weights (10 mg in 10 g) of paint formulations were executed to unprimed steel and then submerged for 215 days in the water of the Eastern Harbor (E.H.) of Alexandria, Egypt. Additionally, the hydrographic properties of seawater were determined. The results showed that all paint formulations exhibited good antifouling properties. After 215 days of immersion, the steel panels coated by Gorgosterol, 8-epi-sarcophinone, and ent-sarcophine demonstrated the best performance against fouling organisms. The steel-coated panel containing Gorgosterol showed only 1% tubeworms, 8-epi-sarcophinone had 5% barnacles and 1% tubeworms, while ent-sarcophine showed 3% barnacles and 10% tubeworms. Overall, the results indicated that natural compounds have the potential to serve as effective and environmentally friendly alternatives to synthetic compounds in antifouling paint formulations.

Biofouling starts by the formation of a biofilm consisting of bacteria, diatoms seaweed or phytoplankton. Unfortunately, the adhering of the biofouling organisms' causes serious problems to the marine industry. The present study examined soft corals collected from Hurghada's Egyptian Red Sea coast as a source for antifouling agents. Bioactive compounds, specifically 8- epi -sarcophinone and ent -sarcophine, were extracted from Sarcophyton glaucum , whereas Alismol and Gorgosterol were obtained from Sclerophytum leptoclados. Their structural analyses were investigated using 1H and 13C NMR spectra. The biocidal weights (10 mg in 10 g) of paint formulations were executed to unprimed steel and then submerged for 215 days in the water of the Eastern Harbor (E.H.) of Alexandria, Egypt. Additionally, the hydrographic properties of seawater were determined. The results showed that all paint formulations exhibited good antifouling properties. After 215 days of immersion, the steel panels coated by Gorgosterol, 8- epi -sarcophinone, and ent -sarcophine demonstrated the best performance against fouling organisms. The steel-coated panel containing Gorgosterol showed only 1% tubeworms, 8- epi -sarcophinone had 5% barnacles and 1% tubeworms, while ent -sarcophine showed 3% barnacles and 10% tubeworms. Overall, the results indicated that natural compounds have the potential to serve as effective and environmentally friendly alternatives to synthetic compounds in antifouling paint formulations. [ABSTRACT FROM AUTHOR]

Marine biofouling is a global issue with economic and ecological implications. Existing solutions, such as biocide-based antifouling paints, are toxic for the environment. The search for better antifouling agents remains crucial. Recent research focuses on eco-friendly antifouling paints containing natural compounds like enzymes. This study evaluates enzymatic extracts from fishery residues for antifouling potential. Extracts from Pleoticus muelleri shrimp, Illex argentinus squid, and Lithodes santolla king crab were analyzed. Proteolytic activity and thermal stability were assessed, followed by bioassays on mussel byssus thread formation and barnacle cypris adhesive footprints. All three extracts demonstrated proteolytic activity and 24-h stability at temperate oceanic temperatures, except I. argentinus. P. muelleri extracts hindered cyprid footprint formation and mussel byssus thread generation. Further purification is required for L. santolla extract to assess its antifouling potential activity. This study introduces the use of fishery waste-derived enzyme extracts as a novel antifouling agent, providing a sustainable tool to fight against biofouling formation. [ABSTRACT FROM AUTHOR]

The antifouling booster biocides are frequently studied for toxic effects on the aquatic ecosystems. The present investigation proposes passive silicone rubber samplers as a collection method for biocides, once these methods can concentrate substances in aqueous matrices at very low levels. Through the passive sampler-water partition coefficient (Ksw) and the analyte chemical nature, we can optimize their extraction from the membrane to apply in the sample medium. We used the co-solvent method to determine the Ksw of three third-generation antifouling biocides, chlorothalonil, dichlofluanid, and dichlorooctylisothiazolinone (DCOIT), with log Ksw = 2.24, 4.01, and 2.38, respectively. Improving extraction also led to a recovery range higher than 70%, determinations were carried out by gas chromatography with an electron capture detector. Biocides concentration in seawater samples from Itaqui port (São Marcos Bay, northern Brazil) ranged from 0.058 to 0.72 µg L-1 for chlorothalonil, 0.001 to 0.008 µg L-1 for dichlofluanid, and 0.018 to 0.64 µg L-1 for DCOIT.

In this work, an experimental investigation of the hydrodynamic resistance of a flat plate painted with newly developed marine antifouling paints of polyurethane (PU) and silicone (Si) formulations was performed. In total, six different paint systems of Si, PU, and acrylic formulations were applied, both experimental and commercial. The total resistance of each painted condition of the plate was measured through towing tank tests for the range of 0.75-2.5 m/sec, with a step of 0.25 m/sec. The Si and PU formulations exhibited similar hydrodynamic behavior, fluctuating around the smooth condition, whereas the acrylic system exhibited the highest resistance increase of all. The roughness function calculation was based on Ra and the correlation with the Colebrook roughness function was generally limited for most systems. Extrapolation to ship scale revealed that no significant drag differences are expected in the as-painted condition among the different paint system types. [ABSTRACT FROM AUTHOR]

This research aimed to reduce reliance on chemical antifouling agents; it was conducted at depths of 0.5 and 1.5 meters in the Eastern Harbor, at Alexandria, Mediterranean Sea. This study delves into the realm of environmentally sustainable antifouling solutions by exploring the efficacy of natural crude extracts from two Red Sea sponge species, Acanthella acuta (Extract A) and Carteriospongia sp. (Extract B). The results revealed a rich diversity of fouling organisms, encompassing six phyla, seven classes, eleven orders, twenty-two families, and thirty-three species. Noteworthy absences were noted at specific depths, indicating depth-dependent variations in fouling communities . The application of extract A at 0.5 meters depth demonstrated significant reductions in fouling biomass and shifts in dominant species. Treatment 3 stood out with the lowest biomass (9.69 ± 2.83 g/m² ) and the fewest species (only 2 species). At 1.5 meters depth, extract B exhibited consistent trends with treatment 6 displaying the lowest biomass (20.85 ± 23.35 g/m2 ) and also species diversity (only 2 species). Meanwhile, Extract B showcased compelling antifouling potential. At 0.5 meters depth, treatment 4 exhibited notable reductions in fouling biomass, dominated by Balanus amphitrite, Balanus eburneus, and Balanus sp. At 1.5 meters depth, treatment 6 emerged as the most effective, with the lowest biomass (249.3 ± 120.4 g/m² ) and a streamlined species composition. This study underscores the promise of natural crude extracts from the Red Sea sponges as potent alternatives for environmentally friendly antifouling strategies. The observed variations in fouling biomass and species composition offer critical insights for the development and application of these extracts in combating fouling organisms, presenting a significant stride toward sustainable marine ecosystem conservation. [ABSTRACT FROM AUTHOR]

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Edible bivalves constitute an important bioresource from an economic point of view, and studies on their immune responses to environmental pollutants are crucial for both the preservation of biodiversity and economic reasons. The worldwide diffusion of copper(I)-based antifouling paints has increased copper leaching into coastal environments and its potential impact on both target and nontarget organisms. In this study, immunotoxicity assays were carried out with short-term (60 min) cultures of hemocytes from the bivalves Mytilus galloprovincialis--a mussel dominant in the macrofouling community--and Ruditapes philippinarum--a clam dominant in the soft-sediment community--exposed to CuCl to compare the toxic effects on their immune responses. The LC50 values were similar, 40 μM (3.94 mg L-1) for the mussel and 44 μM (4.33 mg L-1) for the clam. In both species, apoptosis occurred after exposure to 1 µM (98.9 μg L-1) CuCl, the concentration able to significantly increase the intracellular Ca2+ content. Biomarkers of cell morphology and motility revealed microfilament disruption, a significant decrease in yeast phagocytosis and lysosome hydrolase (β-glucuronidase) inhibition beginning from 0.5 µM (49.5 μg L-1) CuCl in both the mussel and clam. The same concentration of CuCl affected biomarkers of oxidative stress, as a significant decrease in reduced glutathione content in the cytoplasm and inhibition of mitochondrial cytochrome-c oxidase (COX) were detected in both species. Comparison of the biomarkers showed that clam is more sensitive than the mussel regarding alterations to the lysosomal membrane and reactive oxygen species (ROS) production, which supports the potential harmful effects of antifouling biocides on the survival of nontarget pivotal species in the coastal community. [ABSTRACT FROM AUTHOR]

Recently, nanotechnology-based paints have been employed in the field of biofouling prevention. The green production of copper oxide nanoparticles (GB-CuONPs) with Ulva fasciata water extract was described in this study. The aqueous U. fasciata extract contains diverse compounds that act as reducing and stabilizing agents for GB-CuONPs. The GB-CuONPs were characterized by different instruments. SEM indicated monoclinic phase (tenorite) clustered nanoparticles. EDX spectrum comprised C, N, Zn, Cu, and O peaks. FT-IR showed peaks that could be attributed to proteins, carbohydrates and polyphenols. The average crystallite size was 35.2 nm. XRD assigned the reflection lines of monoclinic GB-CuONPs. The antimicrobial activity of GB-CuONPs was studied against three Gram-negative and two Gram-positive bacterial strains. Antifouling efficacy of different concentrations (0, 0.25, 0.50, 1.00, and 1.50%) from GB-CuONPs was evaluated in situ for 200 days. Low weights of fouling organisms were formed on all the panels, ranging between 0.0495 and 0.1451 g/cm2. Their effectiveness may be attributed to the biocide’s gradual release from the coatings. Panels treated with formulations containing (1.00% and 1.50%) GB-CuONPs showed good antifouling activity during the study period, with only 5% of barnacles. The surrounding seawater parameters of the immersed coated steel panels were within the typical range for this area.

Edible bivalves constitute an important bioresource from an economic point of view, and studies on their immune responses to environmental pollutants are crucial for both the preservation of biodiversity and economic reasons. The worldwide diffusion of copper(I)-based antifouling paints has increased copper leaching into coastal environments and its potential impact on both target and nontarget organisms. In this study, immunotoxicity assays were carried out with short-term (60 min) cultures of hemocytes from the bivalves Mytilus galloprovincialis—a mussel dominant in the macrofouling community—and Ruditapes philippinarum—a clam dominant in the soft-sediment community—exposed to CuCl to compare the toxic effects on their immune responses. The LC50 values were similar, 40 μM (3.94 mg L-1) for the mussel and 44 μM (4.33 mg L-1) for the clam. In both species, apoptosis occurred after exposure to 1 µM (98.9 μg L-1) CuCl, the concentration able to significantly increase the intracellular Ca2+ content. Biomarkers of cell morphology and motility revealed microfilament disruption, a significant decrease in yeast phagocytosis and lysosome hydrolase (β-glucuronidase) inhibition beginning from 0.5 µM (49.5 μg L-1) CuCl in both the mussel and clam. The same concentration of CuCl affected biomarkers of oxidative stress, as a significant decrease in reduced glutathione content in the cytoplasm and inhibition of mitochondrial cytochrome-c oxidase (COX) were detected in both species. Comparison of the biomarkers showed that clam is more sensitive than the mussel regarding alterations to the lysosomal membrane and reactive oxygen species (ROS) production, which supports the potential harmful effects of antifouling biocides on the survival of nontarget pivotal species in the coastal community.

This work concerns development of alternative antifouling paints for marine applications using composite metal oxides derived from TiO2 and WO3. Composite metal oxides with a variety of tungsten content were prepared via a sol–gel process using titanium isopropoxide and sodium tungstate dihydrate as the precursors. The crystalline phase, bandgap energy, morphology, surface structure, and electronic states of the synthesized products were then characterized and confirmed by XPS, XRD, UV/Vis spectroscopy, SEM-EDX, and TEM techniques. Photocatalytic performance polymer film loaded with composite metal oxides containing 10% by mole of WO3 (10%WO3@TiO2) was confirmed both under UV irradiation and in the dark. The results are discussed in light of oxygen vacancies and the presence of heterojunctions between the TiO2 and WO3 domains in the composites, which eventually lead to suppression of charges recombination. Finally, antifouling and the antimicrobial efficacy of the polymer film loaded with composite metal oxide particles (10%WO3@TiO2) were evaluated under static marine immersion conditions using Zobell Marine agar. After 30 days, the percentage fouling coverage (16.35%), colonies number (CFU value 12 × 103), and percentage reduction of colonies (92.94%), were obtained, which significantly outperformed those of the control (the bare substrate). [ABSTRACT FROM AUTHOR]

Recently, nanotechnology-based paints have been employed in the field of biofouling prevention. The green production of copper oxide nanoparticles (GB-CuONPs) with Ulva fasciata water extract was described in this study. The aqueous U. fasciata extract contains diverse compounds that act as reducing and stabilizing agents for GB-CuONPs. The GB-CuONPs were characterized by different instruments. SEM indicated monoclinic phase (tenorite) clustered nanoparticles. EDX spectrum comprised C, N, Zn, Cu, and O peaks. FT-IR showed peaks that could be attributed to proteins, carbohydrates and polyphenols. The average crystallite size was 35.2 nm. XRD assigned the reflection lines of monoclinic GB-CuONPs. The antimicrobial activity of GB-CuONPs was studied against three Gram-negative and two Gram-positive bacterial strains. Antifouling efficacy of different concentrations (0, 0.25, 0.50, 1.00, and 1.50%) from GB-CuONPs was evaluated in situ for 200 days. Low weights of fouling organisms were formed on all the panels, ranging between 0.0495 and 0.1451 g/cm2. Their effectiveness may be attributed to the biocide's gradual release from the coatings. Panels treated with formulations containing (1.00% and 1.50%) GB-CuONPs showed good antifouling activity during the study period, with only 5% of barnacles. The surrounding seawater parameters of the immersed coated steel panels were within the typical range for this area. [ABSTRACT FROM AUTHOR]

The expanded use of copper(I)-based antifouling paints (AF) has increased copper leaching into coastal environments, requiring attention and legislative restrictions for potential long-term effects on benthic populations. The ecological succession of macrofouling communities was analysed on wooden and stainless steel panels coated with four copper(I)-based AF (Paints A–D) immersed for 10 months in the Lagoon of Venice. With the exception of Paint B, which contained only copper(I) compounds and was based on hard-matrix technology, the other paints were based on self-polishing matrices and various booster biocides. The booster content was a mix of TBT compounds for Paint A, dichlofluanid for Paint C, Irgarol 1051, and chlorothalonil for Paint D. The macrofouling communities appeared dissimilar to those on the reference uncoated panels as regard the species richness, the coverage areas, and the biocoenosis structure. Generally, green algae, bryozoans, and barnacles were the most tolerant taxa and a negative species selection occurred for sponges, serpulids, and ascidians. Paints A and D showed the highest performance, and Paint D also prevented molluscs on wood panels. Paints B and C rapidly decreased their efficiency, the first probably due to the insoluble matrix with the highest biocidal leaching rate, and the second due to the presence of a booster with low toxicity. Paint B also inhibited red algae and molluscs, but Paint C did not reveal significant differences in types of species settlements with reference panels. [ABSTRACT FROM AUTHOR]

Shipyard activities have contributed to the release of anthropogenic metals in sediment in the Amazon delta estuary, but no studies of the issue have been carried out in northern Brazil. This study evaluated the sediment that is under the influence of shipyard activities in the Guajará Bay and in the channel of the Maguari River, in Belém, Pará (PA) state, northern Brazil. Sediment samples were collected in the vicinity of the shipyards, while samples of paint and metal fragments were collected from hulls of abandoned vessels. Metals under analysis were Cu, Zn, Pb, Ni, Cr, Ba, V, Li, Fe and Al. Mean Cu concentrations found in the sediment in two shipyards — 28.3 mg kg−1 and 41.0 mg kg−1 — were above the threshold effect level (TEL) for the amphipod Hyalella azteca. The highest concentrations of metals found in paint fragments from abandoned vessels were 29,588 mg kg−1 Ba, 9,350 mg kg−1 Zn, 1,097 mg kg−1 Pb and 548 mg kg−1 Cr. This fact suggests that vessel abandonment is a major source of contamination in shipyard areas. The principal component analysis (PCA) showed that most metals under study are closely related to sediment contamination in the shipyards. Geoaccumulation index and screening concentrations of inorganic contaminants for metals in freshwater ecosystems confirmed that a shipyard was contaminated by copper. Results may support further studies of contamination and application of waste management to shipyards and vessel graveyards around the world. [ABSTRACT FROM AUTHOR]

Some of the antifouling booster biocides affects the marine ecosystem negatively. The booster biocides that are resistant to degradation are accumulated in the sediment of the oceans. One of the sedentary organisms in the Mediterranean Sea is Anemonia viridis. This study aims at showing the toxicities of common biocides such as irgarol, seanine-211, zinc omadine, and acticide on the fluorescence by GFPs of A. viridis. The decreases in the fluorescence intensities of the GFP were measured within different booster biocide concentrations. The results show that fluorescent intensities of GFP proteins decrease more than 50% when they are exposed to different concentrations of irgarol, zinc omadine, acticide. In conclusion, ecosystem health should be prioritized when new antifouling paint compositions are proposed. From the results, it seems that A. viridis can be considered as a vulnerable organism and it is sensitive to booster biocides within self-polishing antifouling paint formulations. [ABSTRACT FROM AUTHOR]

Fouling has significant economic influences on sea transportation and other submerged surfaces. This work aims to compare between sarcophine and synthesized ZnO nanospheres as active antifouling ingredients. The two compounds were applied on unprimed steel and were immersed in the seawater of the Eastern Harbour (E.H.), Alexandria, Egypt. Seawater hydrographic parameters were measured. 1H and 13C NMR spectra were carried out to study the structural analysis of sarcophine. ZnO nanospheres were characterized through SEM, XRD, and UV-V instruments. Each of sarcophine and ZnO nanospheres was blended solely by 2% (w/w) with a designed paint formulation of two paint ingredients besides the blank. Duplicate paint formulations were applied on unprimed steel, hanged, and immersed in the E.H. on 30/12/2018. Panels’ surfaces were followed visually and by photographic inspection for fouling succession over different interval times. They lasted for 200 days. Sarcophine showed the least fouled surface by about 15% of tubeworms and barnacles than ZnO or the blank. Most fouling were around the edges of the panel. This is due to its smoother surface, besides it has higher molecular weight than ZnO nano-particles. The hydrographic parameters of the E.H. seawater were within the normal range that these paint formulations are environmentally safe.

High-strength naval steel panels were coated by spraying with five commercial antifouling paints. The first set of coated specimens was subjected to electrochemical measurements and the anticorrosion properties of the paints were evaluated under controlled laboratory conditions. A second series of coated samples was statically exposed for nine months in thirteen different harbors, located in the Mediterranean Sea and the Atlantic Ocean, where their in-field antifouling efficiency was determined. The corrosion performance obtained by the electrochemical measurements provides predictions that best match the fouling protection observed at the field sites. The results indicate that the corrosion's resistivity values determined in the laboratory were in a good agreement with the fouling level observed by examining the sea samples. The reported complementary data show that the laboratory measurements are representative of the sea-field conditions and confirm the originality of the proposed approach, which might lead to the development of innovative low-drag antifouling coatings for the hulls of ships, vessels, and speed crafts. [ABSTRACT FROM AUTHOR]

Antifouling paints incorporate biocides in their composition seeking to avoid or minimize the settlement and growing of undesirable fouling organisms. Therefore, biocides are released into the aquatic environments also affecting several nontarget organisms and, thus, compromising ecosystems. Despite global efforts to investigate the environmental occurrence and toxicity of biocides currently used in antifouling paints, the specific active ingredients that have been used in commercial products are poorly known. Thus, the present study assessed the frequencies of occurrence and relative concentrations of biocides in antifouling paint formulations registered for marketing worldwide. The main data were obtained from databases of governmental agencies, business associations, and safety data sheets from paint manufacturers around the world. The results pointed out for 25 active ingredients currently used as biocides, where up to six biocides have been simultaneously used in the examined formulations. Cuprous oxide, copper pyrithione, zinc pyrithione, zineb, DCOIT, and cuprous thiocyanate were the most frequent ones, with mean relative concentrations of 35.9 ± 12.8%, 2.9 ± 1.6%, 4.0 ± 5.3%, 5.4 ± 2.0%, 1.9 ± 1.9%, and 18.1 ± 8.0% (w/w) of respective biocide present in the antifouling paint formulations. Surprisingly, antifouling paints containing TBT as an active ingredient are still being registered for commercialization nowadays. These results can be applied as a proxy of biocides that are possibly being used by antifouling systems and, consequently, released into the aquatic environment, which can help to prioritize the active ingredients that should be addressed in future studies. [ABSTRACT FROM AUTHOR]

The problem of underwater hull fouling has been mostly noticed by the pleasure boat owners when reducing the boat speed. In order to decrease the fouling of the underwater part of the hull, antifouling paints have been used. Some kinds of antifouling paints have become a serious environmental problem due to its very harmful effect on marine organisms and also, indirectly, on humans. Scientific research conducted in this domain has confirmed contamination by toxic compounds as a result of the usage of antifouling paints over long period of time. The paper is focused on underwater hull maintenance, especially when applying antifouling systems on pleasure crafts owned by tourists and local residents, in the example of the village ports of a small island. A survey was conducted among the residents who use ports to determine their knowledge regarding the harmful effects of biocidal coatings and the possible harmless maintenance of the underwater hull part. This paper aims to indicate the necessary equipment and procedures in the two small local ports in order to maintain pleasure boats in environmentally acceptable manner.

The most representative organisms of the Harbor of Gaeta Gulf in South Italy were analyzed for biofouling by visual census and confirmed later by molecular approach on an artificial Conatex panel dipped 3 m into a eutrophic area during the Covid-19 pandemic. Mitochondrial Cytochrome C oxidase subunit 1(COI) gene was sequenced from 20 different marine species (flora: 2 families, 2 orders; fauna: 16 families, 11 orders) to test whether the morphology-based assignment of the most common biofouling member was supported by DNA-based species identification. Twelve months of submersion resulted in generation of sufficient data to obtain a facies climax represented mainly by the bivalve mollusk, Mytilus galloprovincialis. Specific diversity and variations of the biofouling biomasses were analyzed using two different anti-biofouling paints: an endocrine disrupting chemical (EDC)-containing metal biocide, and a biocide-free paint. Also, their effects on detoxification and reproductive health of M. galloprovincialis were evaluated using glutathione S-transferase enzymatic activity and RTqPCR expression of the fertility antioxidant gene glutathione peroxidase 4 (gpx4). The obtained data provide useful indications on which future investigations may be focused and may become a potential management tool for a harbor biofouling database to assist local administrations in EDCs protection of autochthonous benthic communities and their fertility using innovative antifouling paints. [ABSTRACT FROM AUTHOR]

Marinas are central hubs of global maritime leisure and transport, yet their operations can deteriorate the environmental quality of sediments. In response, this study investigated the metal contamination history associated with antifouling paint uses in a sediment core collected from Bracuhy marina (Southeast Brazil). Analysis target major and trace elements (Cu, Zn, Pb, Cd and Sn), rare earth elements (REEs), and Pb isotopes. The modification in Pb isotopic ratios and REEs pattern unequivocally revealed sediment provenance disruption following the marina construction. Metal distribution in the sediment core demonstrates that concentrations of Cu and Zn increased by up to 15 and 5 times, respectively, compared to the local background. This severe Cu and Zn contamination coincides with the onset of marina operations and can be attributed to the use of antifouling paints. [Display omitted] • Sediment provenance changed following the marina construction. • Rare Earth Elements coupled with Pb isotopes indicate disruption in sedimentary dynamics. • Cu and Zn contamination from antifouling paints begins post marina operation. • Cu enrichment in sediment is 15 times the local natural background. [ABSTRACT FROM AUTHOR]

Fouling has significant economic influences on sea transportation and other submerged surfaces. This work aims to compare between sarcophine and synthesized ZnO nanospheres as active antifouling ingredients. The two compounds were applied on unprimed steel and were immersed in the seawater of the Eastern Harbour (E.H.), Alexandria, Egypt. Seawater hydrographic parameters were measured. 1H and 13C NMR spectra were carried out to study the structural analysis of sarcophine. ZnO nanospheres were characterized through SEM, XRD, and UV-V instruments. Each of sarcophine and ZnO nanospheres was blended solely by 2% (w/w) with a designed paint formulation of two paint ingredients besides the blank. Duplicate paint formulations were applied on unprimed steel, hanged, and immersed in the E.H. on 30/12/2018. Panels' surfaces were followed visually and by photographic inspection for fouling succession over different interval times. They lasted for 200 days. Sarcophine showed the least fouled surface by about 15% of tubeworms and barnacles than ZnO or the blank. Most fouling were around the edges of the panel. This is due to its smoother surface, besides it has higher molecular weight than ZnO nano-particles. The hydrographic parameters of the E.H. seawater were within the normal range that these paint formulations are environmentally safe. [ABSTRACT FROM AUTHOR]

Metals are used as alternatives of antifouling paints in aquaculture and toxic to cultured fish and shellfish. To assess antifouling paints, metal levels in sediment and in oyster (Crassostrea gigas) collected from a Japanese aquaculture were investigated. Elevated metal concentrations in sediment were found in the part of the aquaculture with high density of fish nets, and significantly positive correlations among the metals in sediments indicated that source(s) of these metals were common. The levels of metals were slightly higher in oyster tissues collected near bottom than near surface of seawater of the aquaculture. The levels of Cr, Ni, and As in dry oyster tissues from the aquaculture were higher than those from most Japanese coastal areas, while Cu, Zn, and Pb in dry basis were lower than those from other areas. Estimated daily intake (EDI) for men and women followed the order of Zn > Cu > As>Cd > Cr > Ni > Pb. Non-carcinogenic health hazard (HQ) and hazard index values (total HQ) of Cd, Cr, Ni, Cu, Zn, As, Cd, and Pb were lower than 1, indicating that women and men would experience no risks of studied metals if they ingested the oysters collected from Shidugawa Bay, but target cancer risk (TR) of As suggested that oyster may pose potential health risk for adult men and women via oyster consumption. Thus, continuous monitoring of trace elements in sediments and seafoods influenced by antifouling paints should be recommended. [ABSTRACT FROM AUTHOR]

Organotin compounds are persistent pollutants and are considered chemicals of high environmental concern. In the present study, the distribution and degradation of tributyltin were evaluated in field sediments and through an ex situ experiment. For this, sediment samples from two locations were analysed: Luis Piedrabuena Harbour, with higher maritime traffic, and Cerro Avanzado, which receives less impact from anthropogenic activities. The results indicated that pollution levels at Luis Piedrabuena Harbour have decreased compared with studies performed 9 years ago for the same area. On the contrary, traces of organotin compounds have been found for the first time at Cerro Avanzado. Moreover, the butyltin degradation index indicated that organotin compounds undergo an advanced degradation process in the collected samples at both sites. Ex situ experiments revealed a limited capacity of sediments to retain tributyltin, and suggested an active role of bioturbation activity in the degradation of these compounds. In addition, visualisation using chemometric techniques (principal components analysis) allowed a simpler analysis of two sediment characteristics: the degree of contamination and the degradation levels of organotin compounds. • Update on contamination of two sites with different anthropogenic pressure. • At Luis Piedrabuena Harbour, MBT and DBT were predominantly detected, indicating an advanced degradation process of TBT. • For the first time, traces concentrations of both TBT and its degradation products were recorded at Cerro Avanzado. [ABSTRACT FROM AUTHOR]

To evaluate the effects of antifouling paints and biocides on larval settlement and metamorphosis, newly hatched swimming larvae of the compound ascidian Botryllus schlosseri, a dominant species of soft-fouling in coastal communities, were exposed to (i) substrata coated with seven antifouling paints on the market containing different biocidal mixtures and types of matrices and (ii) sea water containing various concentrations of eight biocidal constituents. All antifouling paints showed high performance, causing 100% mortality and metamorphic inhibition, with ≥75% not-settled dead larvae. All antifouling biocides prevented the settlement of larvae. The most severe larval malformations, i.e., (i) the formation of a bubble encasing the cephalenteron and (ii) the inhibition of tail resorption, were observed after exposure to metal and organometal compounds, including tributyltin (TBT) at 1 μM (325.5 µg L−1), zinc pyrithione (ZnP) at 1 μM (317.7 µg L−1), and CuCl at 0.1 μM (98.99 µg L−1), and to antimicrobials and fungicides, including Sea-Nine 211 at 1 μM (282.2 µg L−1) and Chlorothalonil at 1 μM (265.9 µg L−1). The herbicides seemed to be less active. Irgarol 1051 was not lethal at any of the concentrations tested. Diuron at 250 μM (58.2 mg L−1) and 2,3,5,6-tetrachloro-4-(methylsulphonyl)pyridine (TCMS pyridine) at 50 μM (14.8 mg L−1) completely inhibited larval metamorphosis. These results may have important implications for the practical use of different antifouling components, highlighting the importance of their testing for negative impacts on native benthic species.

Dichlofluanid has long been employed as a fungicide in agriculture and has been massively introduced in antifouling paints for boat hulls over the last two decades. One of the most important toxic effects of antifoulants is represented by immunosuppression in marine invertebrates, which can be analysed in vitro with a number of short-term toxicity assays on haemocytes. Among bioindicators, the colonial ascidian Botryllus schlosseri is a useful candidate; it is a filter-feeding organism living in the water-sediment interface that is found worldwide and is sensitive to antifouling xenobiotics. Dichlofluanid adversely affects both immunocyte lines (phagocyte and cytotoxic lines) after exposure to sublethal concentrations. At 0.05 μM (16.65 μg/L), dichlofluanid induced haemocyte apoptosis and cell shrinkage with a decrease in both motility and phagocytosis. At the lowest concentration (0.01 μM, 3.33 μg/L), inhibition of pivotal enzymatic activities of phagocytes and cytotoxic cells occurred. At the highest concentration (0.1 μM, 33.3 μg/L), dichlofluanid increased glutathione oxidation, leading to stress conditions. The effects of dichlofluanid on immune defence responses are similar to those of organometal-based antifoulants (i.e., organotin compounds and zinc pyrithione), and its use in coastal areas requires attention.

In search of new sustainable alternatives to reduce the use of metallic antifouling pigments in marine paints, three n-alkyl 2-furoates were synthesized by safe procedures framed within the green chemistry concepts. These compounds were characterized by current organic analysis, and their antifouling properties were first evaluated on Artemia salina nauplii in the laboratory. Then, antifouling paints formulated with these compounds were assayed in a marine environment. Both laboratory and field tests indicate that n-alkyl 2-furoates have strong antifouling activity and are safe chemicals for marine paints. [ABSTRACT FROM AUTHOR]

In this article authors present a general consideration of the underwater part of ship's hull protection by protective coatings, paying particular attention to antifouling paints. Following the presentation of the importance of ship's hull maintenance and protection in order to make navigation safer and to keep the ship in operation for as long as possible, a summary is made of the main types of antifouling products used throughout the history up to the present time. As far back as a thousand years BC, people had developed techniques to protect objects from falling into disrepair and understood the importance of preserving construction materials in order to prolong their useful life and value. Marine industry has been developing day by day and attention is increasingly focused on the safety of ships and crews, as well as on the protection of marine environment. Tin-free self-polishing copolymer (SPC) and foul release technologies are currently applied, in addition to many alternative solutions being suggested. Modern approaches to effective environment-friendly antifouling systems and their performance are highlighted. [ABSTRACT FROM AUTHOR]

This study was devoted to examining the application of copper dodecanoate as a non-contaminant antifouling pigment due to its low copper content and fatty acid nature. For this purpose, antifouling paints with mono-component epoxy resin and rosin matrixes were formulated, and their antifouling efficiency was evaluated. Before its incorporation into the different formulations, the synthesized pigment was characterized. Immersion tests in a marine environment were carried out for 12 months to evaluate the antifouling efficiency of the developed paints; the results were compared with those from a commercial paint. The antifouling efficiency of the new epoxy formulation was found to be considerably higher than that of the rosin formulation and very similar to that of the commercial paint. Most importantly, the release of copper from the epoxy paint formulated with copper dodecanoate was 73.5% lower than that of the commercial paint, suggesting prolonged activity of the developed paint.

A growth inhibition test has been developed based on two clones of the red macroalga Ceramium tenuicorne , one originating from 7 PSU and the other from 20 PSU. The species can be adapted to different salinities and the test can be carried out between 4 and 32 PSU. This test became an ISO standard in 2010 (ISO 107 10) for testing of chemicals and water effluents. In this study new and published data has been compiled on toxicity of single substances, waste waters from pulp mills, leachates from antifouling paints, harbour sediments and soil used for maintenance of leisure boats. The results show that the alga is sensitive to both metals and organic compounds and to biocides used in antifouling paints. By testing leachates from antifouling paints these could be ranked according to their toxicity. Similarly, the toxicity of waste waters from pulp mills was determined and the efficiency of secondary treatment evaluated. Further, the test method proved useful to test the toxicity in sediment samples. Sediments from small town harbours and ship lanes were shown to be harmful and compounds originating from antifouling paints were responsible for a large part of the inhibiting effect. The alga proved to be sensitive to contaminants leaking from boat yard soil. The growth inhibition test is a robust test that has high repeatability and reproducibility and easily can be applied on water, soil and sediment samples without being too costly. The species is found worl-wide in temperate waters, which makes the results relevant for large areas. In the Baltic Sea C. tenuicorne is the most common red alga species and is thus particularly relevant for this area. The overall results show that contaminants from boat activities and the use of antifouling paints in particular pose a threat to the environment. [ABSTRACT FROM AUTHOR]

A conformal novel and low-cost series of elastomeric high-molecular weight polydimethylsiloxane (PDMS)/controlled SiO 2 -doped ZnO nanocomposites were accurately synthesized via hydrosilation curing. Different concentrations of doped nanospheres were inserted in the nanocomposite via in situ technique. The synergetic effect of micronanobinary scale roughness and controlled fouling on different kinds of substrates was determined. The hydrophobicity, roughness, and free-energy properties were investigated as self-cleaning and fouling release (FR) factors. The nanocomposites were also subjected to various tests on surface adhesion and mechanical properties, such as impact, T-bending, crosscut, and abrasion resistance. The anticorrosive features of nanocomposites were investigated through salt spray test. The mechanical tests and salt spray test exhibited the most profound effect by incorporation of 0.5% SiO 2 -doped ZnO nanospheres, indicating well distributed SiO 2 -doped ZnO nanofillers (0.5%). Results indicate that the nanocomposites retained the nanostructure characteristics under thermal and irradiation treatments. Furthermore, microfoulants of chosen bacterial progenies were applied on vinyl-ended PDMS/spherical SiO 2 -doped ZnO nanocomposites for about one month of laboratory assessments. These studies indicated the importance of good distribution of doped nanofillers on enhancing FR ability in the modeled nanocoatings. A particular increase in contact angle (CA, 167° ± 2) and the decrease in free energy of surface (9.24 mN/m) and microroughness indicated the FR functionality of these nanocomposites. Our findings show evidence that the developed nanocomposites demonstrated inert and nonwettable properties, superior physical characteristics, surface innerness and lotus effect, long-term durability under UV radiation, and thermal stability and resistance against a wide range of pH solutions, making them promising as efficient environment-friendly self-cleaning for coating of ship hulls. [ABSTRACT FROM AUTHOR]

This review summarized booster biocides studies from Latin America and the Caribbean during the last two decades. Studies were focused on six countries, with most of them in Brazil. In water and sediment, diuron and Irgarol were the most abundant and frequent biocides, probably due to their former intense use. Antifouling paint particles were also reported and had mainly DCOIT, which is currently the most used booster biocide. Toxicity of individual booster biocides was tested in laboratory, and most effects were related to chlorothalonil, DCOIT, dichlofluanid, and Irgarol, including, but not limited to DNA damage, fertility decrease, and mortality at different trophic levels. This review highlighted the need for further studies on environmental occurrence of booster biocides in Latin America and Caribbean associated to ecotoxicological studies. Such information is essential to determine the potential ecological risks and to create directives regarding safe limits of booster biocides in aquatic systems. [Display omitted] • Irgarol and diuron were the most detected biocides in water and sediments. • DCOIT is the most frequent and most abundant biocide in APP samples. • Further environmental and ecotoxicological studies should be performed. • Toxicity was assessed for different organisms under laboratory conditions. • An improvement for booster biocides analysis in biological matrices is urgent. [ABSTRACT FROM AUTHOR]

Because of its high toxicity, TBT (trybutiltin) was banned since 2003, which resulted in a greater re-use of Cu as based-biocide in antifouling paints (AFP). The aim of this work is to determine if metals form of AFP are transferred to benthic organisms from Guanabara Bay (GB) (Rio de Janeiro, Brazil). Metal concentrations were measured in two main fouling algae species Ulva flexuosa and U. fasciata and one isopod species, Sphaeroma serratum, in two GB marinas areas from sites with artificial substrate covered by AFP and natural substrate.In addition, control samples were collected in an adjacent open ocean area. Concentrations of Cd, Cr, Cu, Pb and Zn were determined by Atomic Absortion Spectrophotometry. Higher concentrations of Cu, Pb and Zn were detected in both algal species from GB in relation to control areas. Among samples of algae and isopod species from GB, populations collected over artificial surfaces covered by AFP presented significantly higher metal concentration than population of rocky natural substrate. Our data showed that the leaching of metals by antifouling paints present on decks and boats are being taken up by algae and isopods. These results indicate that antifouling coatings are the main source of heavy metal to biota of GB marina area.Devido sua alta toxicidade, o TBT está banido desde 2003, o que resultou na re-utilização de tintas a base de cobre. O objetivo deste trabalho é determinar se os metais provenientes das tintas anti-incrustantes (AFP) são transferidos para organismos bentônicos da Baía de Guanabara (BG) (Rio de janeiro, Brasil). Concentrações de metais foram analisadas em duas espécies de algas Ulva flexuosa e U. fasciata e no isópoda, Sphaeroma serratum, em duas áreas de marinas em locais de substrato artificial coberto com tintas AFP e em locais de substrato natural. Também foram coletadas amostras em uma área oceânica (controle). Concentrações de Cd, Cr, Cu, Pb e Zn foram determinadas por Espectrofotometria de Absorção Atômica. Concentrações mais elevadas de Cu, Pb e Zn foram detectadas na BG em ambas espécies de algas em relação a área controle. Dentre as espécies de algas e do isópoda da BG, as populações coletadas sobre as superfícies cobertas com AFP apresentaram concentrações significativamente mais elevadas do que as populações do substrato natural. Os resultados obtidos demonstram que a liberação de metais presentes nas AFP dos decks e embarcações, estão sendo acumulados pelas algas e isópodas. Esses resultados indicam que o revestimento com AFP é a principal fonte de metais para a biota de marinas em áreas da BG.

Imposex incidence and biometric parameters were investigated in six muricid species along of 1200 km of Ecuadorian shore and in Galapagos archipelago. The obtained data, were compared to previous studies performed in the same area in 2009. The results showed that moderate imposex levels still occur in coastal areas of Ecuador, even after global TBT ban. However, a reduction in imposex parameters was detected in the sampled sites, indicating probably relationship to the global TBT ban issued by IMO at 2008. On the other hand, the levels currently reported in present study indicates that TBT environmental concentrations are still high enough to produce biological effects in studied areas. In addition, imposex incidence in four muricid species from Galapagos islands were detected suggesting that this marine protected area is under threat of antifouling contamination. These findings, after TBT global ban, denotes that current regulations and conservation plans still need to address such an issue and incorporate more restrictive management rules, particularly in complex coastal areas, vulnerable and unique systems such as the Galapagos Islands. [ABSTRACT FROM AUTHOR]

Tributyltin (TBT) and other organotin compounds have been restricted for use on leisure boats since 1989 in the EU. Nonetheless, release of TBT is observed from leisure boats during hull maintenance work, such as pressure hosing. In this work, we used a handheld X-ray Fluorescence analyser (XRF) calibrated for antifouling paint matrixes to measure tin, copper and zinc in antifouling paints coated on leisure boats in Sweden. Our results show that over 10% of the leisure boats (n = 686) contain >400 μg/cm 2 of tin in their antifouling coatings. For comparison, one layer (40 μm dry film) of a TBT-paint equals ≈ 800 μg Sn/cm 2 . To our knowledge, tin has never been used in other forms than organotin (OT) in antifouling paints. Thus, even though the XRF analysis does not provide any information on the speciation of tin, the high concentrations indicate that these leisure boats still have OT coatings present on their hull. On several leisure boats we performed additional XRF measurements by progressively scraping off the top coatings and analysing each underlying layer. The XRF data show that when tin is detected, it is most likely present in coatings close to the hull with several layers of other coatings on top. Thus, leaching of OT compounds from the hull into the water is presumed to be negligible. The risk for environmental impacts arises during maintenance work such as scraping, blasting and high pressure hosing activities. The data also show that many boat owners apply excessive paint layers when following paint manufacturers recommendations. Moreover, high loads of copper were detected even on boats sailing in freshwater, despite the more than 20 year old ban, which poses an environmental risk that has not been addressed until now. [ABSTRACT FROM AUTHOR]