Effect of marine antifouling paint particles waste on survival of natural Bermuda copepod communities

The enzymatic and transcriptional adverse effects of hull in-water cleaning discharge on juvenile rockfish (Sebastes schlegeli)

The hull in-water cleaning (IWC) process creates chemical contaminants, including antifouling paint particle mixtures that are directly discharged into the coastal environment. Recent attention has also been paid to the international regulation of ship hull cleaning discharges in environmental media. However, few studies have investigated the adverse effects or toxic pathways on resident marine species. In this study, we evaluated the chemical concentration of IWC discharge in situ and its toxic effects on juvenile rockfish (Sebastes schlegeli), a major coastal fishery resource, using enzymatic and transcriptomic studies. Zinc (8.05 ± 0.96 to 189.96 ± 47.76 μg/L) was the most abundant substance in IWC discharge, followed by copper (0.87 ± 0.19 to 1.97 ± 0.60 μg/L). No mortality was observed after 7 days of exposure in any experimental group; however, reactive oxygen species and acetylcholinesterase activity varied in juvenile rockfish exposed to the highest concentration of IWC discharge (10-fold-diluted IWC discharge). The immune and detoxification systems in juvenile rockfish exposed to IWC discharge were also significantly affected in juvenile rockfish exposed to 10-fold-diluted IWC discharge (zinc: 189.96 ± 47.76 μg/L, copper: 1.97 ± 0.60 μg/L). The expression of genes related to oxidative stress, including Cu/Zn-SOD, GST, and CAT, increased significantly in fish in all the exposure groups. Specifically, brain transcriptomic analysis revealed disturbances in the nervous system and homeostatic processes. Although lethal toxicity was not significantly affected, these findings indicate the potential hazard posed by sub-lethal concentrations of IWC discharge to juvenile fish, which are at a high-level in the food chain. Our enzymatic and transcriptomic results showed that Zn-dominant IWC discharge exposure may cause neuronal and immune toxicity in marine fish species, providing relevant insights into the management of hull IWC discharge to protect coastal ecosystems against chemical contaminants.

Paint: a ubiquitous yet disregarded piece of the microplastics puzzle

Microplastics are widespread pollutants. Microplastics generated from the wear and tear of paints and coatings have recently been modeled to be a large source of microplastics to the environment. Yet, studies focused on microplastics broadly frequently overlook paint microplastics. In this article, we systematically reviewed the primary literature (turning up 53 relevant articles) on paint microplastic sources, identification methods, environmental concentrations, and toxicity to model organisms. Examples of sources of paint microplastics include paints from buildings and murals, crafts and hobbies, cars and roads, marine boats and structures, and industrial systems like pipes, sewers, and other infrastructure. Paint microplastics have been quantified in several marine samples from Europe and, to a lesser extent, East Asia. Reported concentrations of paint microplastics are up to 290,000 particles per kilogram of sediments, with the greatest concentration reported near a graffiti wall. Out of the toxicity studies testing paint microplastics, there have been 68 tested effects in total across all endpoints and organisms and 17 quantified lethal concentration 50% doses (ranging from 0.001 to 20 g/L). Of the tested effects, 45 observed endpoint values in the paint treatment were significantly different from the control (66%)-most of which were tests using antifouling paints. Overall, the number of studies on paint microplastics is small, limiting a holistic understanding of microplastics. Based on our synthesis of the state of the science on paint microplastics, we suggest a research agenda moving forward informed by research gaps.

Glass reinforced plastic (GRP) boats and the impact on coastal environment - Evidence of fibreglass ingestion by marine bivalves from natural populations

Classified as marine debris, man made materials are polluting the world's oceans. Recently, glass reinforced plastic (GRP) has been shown to degrade and contaminate the coasts. In this pioneering study, fibreglass particles have been detected in the soft parts of oysters and mussels collected from natural populations, in front of an active boatyard. The presence of particulate glass, with concentrations up to 11,220 particles/kg ww in Ostrea edulis and 2740 particles/kg ww in Mytilus edulis, was confirmed by micro Raman spectroscopy. The results showed higher accumulation during the winter months, when boat maintenance activities are peaking and, through repair work, the release of glass fibres in the environment is more likely. Bivalves are considered high risk species due to their sessile nature and extensive filter feeding behaviour. The microparticle inclusion may contribute to adverse impacts on physiological processes and eventually to a decline in the overall health and subsequent death of the animal. The high costs involved in the proper GRP disposal and the lack of recycling facilities worldwide lead to boat abandonement and further contamination of the coasts. For the first time this study presents the extensive fibreglass contamination of natural bivalve populations, in a popular South England sailing harbour, designated a biological and geological site of specific scientific interest (SSRI).

Exposure to hull cleaning wastewater induces mortality through oxidative stress and cholinergic disturbance in the marine polychaete Perinereis aibuhitensis

While wastewater and paint particles discharged from the in-water cleaning process of ship hulls are consistently released into benthic ecosystems, their hazardous effects on non-target animals remain largely unclear. In this study, we provide evidence on acute harmful effects of hull cleaning wastewater in marine polychaete Perinereis aibuhitensis by analyzing physiological and biochemical parameters such as survival, burrowing activity, and oxidative status. Raw wastewater samples were collected during ship hull cleaning processes in the field. Two wastewater samples for the exposure experiment were prepared in the laboratory: 1) mechanically filtered in the in-water cleaning system (MF) and 2) additionally filtered with a 0.45 μm filter in the laboratory (LF). These wastewater samples contained high concentrations of metals (zinc and copper) and metal-based booster biocides (copper pyrithione and zinc pyrithione) compared to those analyzed in seawater. Polycheates were exposed to different concentrations of the two wastewater samples for 96 h. Higher mortality was observed in response to MF compared to LF-exposed polychaetes. Both wastewater samples dose-dependently decreased burrowing activity and AChE activity. Drastic oxidative stress was observed in response to the two wastewater samples. MDA levels were significantly increased by MF and LF samples. Significant GSH depletion was observed with MF exposure, while increased and decreased GSH contents were observed in LF-exposed polychaetes. Enzymatic activities of antioxidant components, catalase, superoxide dismutase, and glutathione S-transferase were significantly modulated by both wastewater samples. These results indicate that even filtered hull cleaning wastewater can have deleterious effects on the health status of polychaetes.

Hull-cleaning wastewater poses serious acute and chronic toxicity to a marine mysid-A multigenerational study

We conducted a comprehensive assessment involving acute effects on 96-hour survival and biochemical parameters, as well as chronic effects on growth and reproduction spanning three generations of the marine mysid Neomysis awatschensis exposed to filtered wastewater to evaluate the potential impact of ship hull-cleaning wastewater on crustaceans. The analyzed wastewater exhibited elevated concentrations of metals, specifically zinc (Zn) and copper (Cu) and metal-based antifoulants, i.e., Cu pyrithoine (CuPT) and Zn pyrithoine (ZnPT). The results revealed dose-dependent reductions in survival rates, accompanied by a notable increase in oxidative stress, in response to the sublethal values of two wastewater samples: 1) mechanically filtered using the cleaning system (MF) and 2) additionally filtered in the laboratory (LF) for 96 h. Mysids exposed to MF displayed higher mortality than those exposed to LF. Furthermore, mysids subjected to continuous exposure of 0.001% LF across three generations exhibited significant inhibition of the feeding rate, more pronounced growth retardation along with an extended intermolt duration, and a diminished rate of reproduction compared to the control. A noteworthy inhibition of the feeding rate and growth was observed in the first generation exposed only to the LF sample. However, although the reproduction rate was not significantly affected. Collectively, these findings underscore the potential harm posed by sublethal concentrations of wastewater to the health of mysid populations under consistent exposure.

Microplastics in aquatic ecosystems of Africa: A comprehensive review and meta-analysis

Microplastic pollution is a global issue of great public concern. Africa is flagged to host some of the most polluted water bodies globally, but there is no enough information on the extent of microplastic contamination and the potential risks of microplastic pollution in African aquatic ecosystems. This meta-analysis has integrated data from published articles about microplastic pollution in African aquatic ecosystems. The data on the microplastic distribution and morphological characteristics in water, sediments and biota from African rivers, lakes, oceans and seas were extracted from 75 selected studies. Multivariate statistics were used to critically analyze the effects of sampling and detection methods, ecological risks, spatial distribution and similarity of microplastics in relation to the geographical distance between sampling sites. This study found that sampling methods have significant effect on abundance and morphological characteristics of microplastics and that African aquatic ecosystems are highly contaminated with microplastics compared to global data. The most prevalent colors were white, transparent and black, the most prevalent shapes were fibres and fragments, and the most available polymers were polypropylene (PP), polystyrene (PS) and polyethene terephthalate (PET). Microplastic polymers similarity decreased with an increase in geographical distance between sites. Risk levels of microplastics in African aquatic ecosystems were comparatively high, and more than 40 % of water and sediments showed highest level of ecological risk. This review provides recent information on the prevalence, distribution and risks of microplastics in African aquatic ecosystems.

Detrimental effects of hull cleaning wastewater on oxidative status, life cycle parameters, and population growth of the monogonont rotifer Brachionus manjavacas

While wastewater discharged from in-water cleaning process of ship hulls on rotifer consistently released into aquatic ecosystem, its detrimental effects on non-target animals are largely unclear. In this study, we provide evidence on detrimental effects of hull cleaning wastewater in the monogonont rotifer Brachionus manjavacas by analyzing biochemical and physiological parameters in its oxidative status, survival, lifespan, growth, fecundity, and population. The wastewater contained high concentrations of metals (Zn and Cu) and metal-based antifoulants (CuPT and ZnPT). Significant oxidative stress was observed in response to two wastewater samples [1) raw wastewater (RW) and 2) mechanical filtrated in the cleaning system (MF)]. Higher detrimental effects in survival, lifespan, fecundity, and population growth for 10 days were measured in the RW-exposed rotifers than those results analyzed in the MF-exposed rotifers. Two growth parameters, lorica length and width were also significantly modulated by both wastewater samples. These results indicate that even filtered hull cleaning wastewater would have deleterious effects on the maintenance of the rotifer population when they exposed constantly.

Toxicity of Aged Paint Particles to Soil Ecosystems: Insights from Caenorhabditis elegans

Despite the extensive global consumption of architectural paint, the toxicological effects of aged exterior paint particles on terrestrial biota remain largely uncharacterized. Herein, we assessed the toxic effect of aged paint particles on soil environments using the nematode Caenorhabditis elegans (C. elegans) as a test organism. Various types of paint particles were generated by fragmentation and sequential sieving (500-1000, 250-500, 100-250, 50-100, 20-50 μm) of paint coatings collected from two old residential areas. The paint particles exerted different levels of toxicity, as indicated by a reduction in the number of C. elegans offspring, depending on their size, color, and layer structure. These physical characteristics were found to be closely associated with the chemical heterogeneity of additives present in the paint particles. Since the paint particle sizes were larger than what C. elegans typically consume, we attributed the toxicity to leachable additives present in the paint particles. To assess the toxicity of these leachable additives, we performed sequential washings of the paint particles with distilled water and ethanol. Ethanol washing of the paint particles significantly reduced the soil toxicity of the hydrophobic additives, indicating their potential environmental risk. Liquid chromatography-mass spectrometry analysis of the ethanol leachate revealed the presence of alkyl amines, which exhibited a high correlation with the toxicity of the paint particles. Further toxicity testing using an alkyl amine standard demonstrated that a paint particle concentration of 1.2% in soil could significantly reduce the number of C. elegans offspring. Our findings provide insights into the potential hazards posed by aged paint particles and their leachable additives in the terrestrial environment.

Effect of wastewater from the in-water cleaning of ship hulls on attached and unattached microalgae

Environmental spills of in-water hull cleaning wastewater (HCW) containing heavy metals and biocides is inevitable, and the effects of HCW on microalgae are unknown. To investigate this, we conducted microcosm experiments by adding HCW to natural seawater. HCW samples were obtained from two different cleaning methods (soft: sponge, hard: brush), and 5 % or 10 % were added to natural seawater as treatments. Dissolved Cu concentrations were 5 to 10 times higher in the treatments than those in the control. There were significant differences in growth of unattached microalgae depending on HCW dose (chlorophyll a: 34.1 ± 0.8 μg L-1 in control vs. 12.6 ± 4.3 μg L-1 in treatments). Conversely, the biomass of attached microalgae increased with HCW dose, which was associated with most of the nutrient reduction later in the experiment, rather than unattached microalgae. Our findings suggest that HCW can significantly impact microalgal community, especially depending on spill volume.

Microplastic ingestion by adult milkfish Chanos chanos (Forsskål, 1775) in aquaculture system: The case of Butuan Bay, Philippines

The Philippines is an archipelago that relies on marine resources. Butuan Bay in the Philippines supports aquaculture, which can contribute to and can be impacted by plastic pollution. However, the microplastics (MP) in milkfish, an important aquaculture species in the area, are yet to be ascertained. This study determined the prevalence of microplastics in the surrounding seawater and in the gut of adult milkfish from cages in Butuan and Nasipit in Butuan Bay. Water samples in Nasipit and Butuan contain 0.20 items/L and 1.00 items/L, respectively. MPs in milkfish in Butuan (10.27 items/individual) were significantly higher than in Nasipit (5.40 items/individual). A total of 235 MPs in 29 out of 30 fish samples (97 %) from the two sites were detected. The dominant MP shape and color were fiber and blue, respectively. The presence of microplastics in the milkfish may indicate a possible risk to the fish species and human health.

Abundance and characteristics of microplastics in the Wanquan River estuary, Hainan Island

As the nexus where rivers and oceans meet, estuaries are vulnerable to microplastic (MP) pollution derived from rivers. However, few studies have focused on the pollution status of MPs in small estuarine areas. Here, the abundance and characteristics of MPs in surface water and sediment samples from a small estuary, the Wanquan River estuary, were studied. The average abundance of MPs was 6573 ± 2659 n/m³ in surface water and 1065 ± 696 n/kg dw in sediment samples from the Wanquan River estuary. Most of the MPs in water samples and sediments were red (92.9 % and 88.1 %) fragments (87.4 % and 95.5 %) with sizes <1.0 mm (90.8 % and 92.4 %) made up of antifouling paint particles (APPs) (83.5 % and 89.8 %), respectively. A significant positive correlation (p < 0.01) was found between the concentration of Cu²⁺ and the abundance of APPs in sediment samples from the Wanquan River estuary. The APPs in the sediments can act as a continuous source of toxic chemicals (e.g., Cu²⁺) to marine environments. The results of this study expand our knowledge about MP pollution in small estuaries, and the ecological risk of APPs in the Wanquan River estuary to aquatic organisms should not be ignored.

Characterization and distribution of plastic particles along Alexandria beaches, Mediterranean Coast of Egypt, using microscopy and thermal analysis techniques

Microplastics (MPs) contamination has become a global concern with potential impacts on the marine environment. Alexandria is the second-largest city in Egypt and a significant contributor of plastic litter inputs into the Eastern Mediterranean Sea. The current study provides an in-depth analysis of the plastic particles accumulated along Alexandria beaches. Types, composition, and potential sources of MPs were investigated using microscopy and thermal analysis. A mean value of 389.1 ± 285.9 items kg^-1 dry weight was detected in the shore sediments similar to other records from the Eastern Mediterranean region. An average of 457.4 ± 281.8 items m^-3 was recorded in the surface water, which was the highest recorded MPs density in onshore waters of the Mediterranean region. Thermogravimetric analysis (TGA) showed that plastics made up 0.5% - 72% of the materials extracted from the sediment samples, and 0.58% - 20.6% from the water samples. Differential scanning calorimetry (DSC) identified ten semi-crystalline polymers. Low-density polyethylene (LDPE) and polyethylene vinyl acetate (PEVA) were the common polymers. The single-use plastic bags and detergents were the land-based sources of marine plastic litter. The sea-based sources included antifouling paints, maintenance of ships, and abandoned fishing gears. Proper management plans of domestic waste input, polluter-pay strategy, and education programs aiming at the Fishermen and how plastic pollution would impact their livelihood are urgently needed.

Concentrations and risk assessment of metals and microplastics from antifouling paint particles in the coastal sediment of a marina in Simon's Town, South Africa

Maintenance of maritime vessels includes the removal of paint from hulls that are sources of metals, antifouling paint particles (APPs) and microplastics (MPs) that end up in the coastal environment. Simon's Town is a small urban town in False Bay, Cape Town, South Africa, where maritime activities take place (there is a naval harbour, marina and shipyard). The aim of this study was to measure metals, APPs and MPs in Simon's Town, to assess the impact of maritime activities and a storm water pipe in a sheltered marina. Sediment samples were collected from six sites during winter 2018. Sediment and extracted APPs were analysed for metal concentrations (Al, As, B, Ba, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Se, Sb, Sn, Sr, V and Zn) and MPs characterised based on type (shape and polymer), colour and size. Highest average metal concentrations in sediment for all sites were Fe (32228 ± SEM 4024), Al (12271 ± 1062) and Cu (1129 ± 407). Metals in paint particles were highest for Fe (80873 ± 19341), Cu (66762 ± 13082) and Zn (44910 ± 1400 µg/g). Metal and MP fragment concentrations were highest at the slipway of the shipyard, decreasing with increased distance from the slipway. MP filaments were highest close to the storm water outfall pipe. Our results suggest that shipyards are potential sources of metals and MP fragments (mainly APPs), with storm water pipes potential sources of MP filaments. Various indices applied to assess the potential impacts of metals and MPs suggest that these contaminants have the potential to adversely impact the intertidal ecosystem investigated.

Floating particles with high copper concentration in the sea-surface microlayer

This study sought to clarify whether suspended particles containing high Cu concentrations are present in the sea-surface microlayer (S-SML). For this reason, suspended particles (10-2000 μm) in the S-SML were collected periodically from a ship mooring pond during 2018-2020, and the acid-soluble Cu concentration in the suspended particles was measured as particulate Cu (P-Cu). The highest concentration of P-Cu in the S-SML of the pond was 75 μg L^-1 with a 90th percentile value of 2.5 μg L^-1. This is below P-Cu values reported for the S-SML in North American ports, but 140 times higher than this found in bulk seawater in the Atlantic Ocean. The highest P-Cu concentration in the S-SML of non-organism (abiotic) origin was 17 μg L^-1, and the abiotic P-Cu to P-Cu ratio varied from 0.2 to 100%, likely depending on the quality and quantity of biogenic material in the S-SML samples. It is assumed that the S-SML particles examined here contain high Cu concentrations originating from ship antifouling paints.

In Vitro Cyto- and Genotoxicity Assessment of Antibacterial Paints with Triclosan and Isoborneol

Surfaces with antimicrobial properties are gaining notoriety as an efficient method to avoid surface contamination. Self-disinfecting paints are a promising strategy towards cleaner indoor environments by preventing the colonization of walls with microorganisms. However, its widespread use needs an appropriate toxicological safety evaluation due to the potential for biological disturbance associated to its biocidal activity. In this work, the cyto- and genotoxic assessment of two self-disinfecting paints containing the antimicrobial substances triclosan (TCS) and isoborneol (ISB) is performed. HaCaT and A549 cell lines models were selected for the in vitro assessment. To evaluate the cytotoxicity, tests by direct contact and on extracts obtained from leaching were performed following ISO 10993, whereas the genotoxicity was assessed by comet assay and cytokinesis-block micronucleus (CBMN) assay. The results showed low levels of cyto- and genotoxicity under the models and conditions tested, indicating that these substances have commercial potential.

Seawater contamination associated with in-water cleaning of ship hulls and the potential risk to the marine environment

In-water cleaning can clear-off foulants from ship hulls to prevent transportation of non-indigenous species and reduce hull friction and consequent fuel use. However, during cleaning, antifouling paint residues containing toxic substances can be released into the environment. To understand the potential risks of in-water hull cleaning, cleaning effluents were collected and analyzed for total suspended solid (TSS), particle size distribution, and metal concentrations. TSS concentrations were 97.3-249 mg/L, corresponding to release rates of 12.9-37.5 g/m² from the hull surface. Particles with sizes of ≥8 μm contributed 75-94% of the TSS. Average Cu and Zn concentrations in the effluents were 209 μg/L and 1510 μg/L, respectively, which were used for risk assessment in two port scenarios. Although the risks vary with the scale of the hull cleaning and the ports, in-water cleaning poses clear risks to marine environments, unless the effluents are recovered or treated before being released.

Environmental pollution with antifouling paint particles: Distribution, ecotoxicology, and sustainable alternatives

Antifouling paint particles (APPs) are a type of paint particle loaded with toxic biocidal compounds. The present review focused on the current knowledge in respect of the abundance, distribution, and ecotoxicological effects of APPs in the marine environment. Also, the recent advances in nontoxic biobased antifouling paints were discussed as potential alternatives to contemporary marine coatings. The presence of APPs is mainly associated with boat maintenance in boatyards and port areas. Conventional microplastic assessments showed a significant contribution of paint particles to the morphological composition. Moreover, recent ecotoxicological studies demonstrated that environmental concentrations of APPs induce mortality (LC₅₀) in sediment dwellers and macroinvertebrates. Novel biocides from natural sources and biopolymer binders in the formulation of antifouling paints are proposed as potential alternatives to conventional antifouling paints. The toxicity of most natural biocides is negligible to nontargeted species, while biopolymers are expected to prevent the formation of APPs.

Paint fragments as polluting microplastics: A brief review

Paint particles are part of the increasingly important microplastics (MPs) pollution of our oceans. They contain polyurethanes, polyesters, polyacrylates, polystyrenes, alkyls and epoxies. In spite of their prevalence, paint fragments are often excluded from MP audits. This review, citing 127 references, discusses detection, characteristics, sources and ecological effects of paint fragments in our oceans, as well as the abundance of paint fragments in MP samples around the world and their colonization by marine microorganisms, which differs from that of non-paint MPs. Paint MPs arise from shipping and boating activities, road markings and external surfaces of buildings. Many paint fragments come from antifouling paints used on commercial vessels and leisure boats; these may be regarded as particular pollutants, not only containing but also leaching heavy metals and biocides. Some effects of antifouling paint particles on aquatic biota are caused by these toxins. Paint particles are an understudied portion of marine MP pollution.

Environmental concentrations of antifouling paint particles are toxic to sediment-dwelling invertebrates

Antifouling paint particles (APPs) and associated metals have been identified in sediments around boatyards and marinas globally, but the effects of APPs on benthic organisms are largely unknown. Sub-lethal endpoints were measured following laboratory exposures of the harbour ragworm (Hediste diversicolor) and the common cockle (Cerastoderma edule) to environmentally relevant concentrations of biocidal ('modern' and 'historic') and biocide-free ('silicone') APPs added to clean estuarine sediment. Further, the 5-day median lethal concentrations (LC₅₀) and effects concentrations (EC₅₀) for modern biocidal APPs were calculated. For ragworms, significant decreases in weight (15.7%; p < 0.01) and feeding rate (10.2%; p < 0.05) were observed in the modern biocidal treatment; burrowing behaviour was also reduced by 29% in this treatment, but was not significant. For cockles, the modern biocidal treatment led to 100% mortality of all replicates before endpoints were measured. In cockles, there was elevated levels of metallothionein-like protein (MTLP) in response to both modern and historic biocidal treatments. Ragworms had a higher tolerance to modern APPs (5-day LC₅₀:19.9 APP g L^-1; EC₅₀: 14.6 g L^-1) compared to cockles (5-day LC₅₀: 2.3 g L^-1 and EC₅₀: 1.4 g L^-1). The results of this study indicate that modern biocidal APPs, containing high Cu concentrations, have the potential to adversely affect the health of benthic organisms at environmentally relevant concentrations. The findings highlight the need for stricter regulations on the disposal of APP waste originating from boatyards, marinas and abandoned boats.