Environmental risk assessment of using antifouling paints on pleasure crafts in European Union waters

Metal record of copper-based antifouling paints in sediment core following marina construction and operation

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.

Isotopic (Cu, Zn, and Pb) and elemental fingerprints of antifouling paints and their potential use for environmental forensic investigations

Antifouling paints (APs) are one of the important sources of Cu and Zn contamination in coastal environments. This study applied for the first-time a multi-isotope (Cu, Zn, and Pb) and multi-elemental characterization of different AP brands to improve their tracking in marine environments. The Cu and Zn contents of APs were shown to be remarkably high ∼35% and ∼8%, respectively. The δ⁶⁵Cu_AE647, δ⁶⁶Zn_IRMM3702, and ²⁰⁶Pb/²⁰⁷Pb of the APs differed depending on the manufacturers and color (-0.16 to +0.36‰, -0.34 to +0.03‰, and 1.1158 to 1.2140, respectively). A PCA analysis indicates that APs, tires, and brake pads have also distinct elemental fingerprints. Combining isotopic and elemental ratios (e.g., Zn/Cu) allows to distinguish the environmental samples. Nevertheless, a first attempt to apply this approach in highly urbanized harbor areas demonstrates difficulties in source apportionments, because the sediment was chemically and isotopically homogeneous. The similarity of isotope ranges between the harbor and non-exhaust traffic emission sources suggests that most metals are highly affected by urban runoff, and that APs are not the main contributors of these metals. It is suspected that AP-borne contamination should be punctual rather than dispersed, because of APs low solubility properties. Nevertheless, this study shows that the common coastal anthropogenic sources display different elemental and isotopic fingerprints, hence the potential for isotope source tracking applications in marine environments. Further study cases, combined with laboratory experiments to investigate isotope fractionation during releasing the metal sources are necessary to improve non-traditional isotope applications in environmental forensics.

Potential disruptive effects of copper-based antifouling paints on the biodiversity of coastal macrofouling communities

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.

Cu isotope records of Cu-based antifouling paints in sediment core profiles from the largest European Marina, The Port Camargue

The intensive use of copper (Cu) compounds as an alternative biocide in antifouling paints (APs) has resulted in wide Cu contamination into the marine environment, especially near marina harbor activities. In this work, the applicability of Cu isotopes to discriminate Cu origins related to the use of Cu-based APs in marine environments was tested. To this, Cu isotopes in APs, shipyard sludges, and sediment cores sampled in the Cu-contaminated Mediterranean marina of Port Camargue were determined. APs represent an important dominant anthropogenic source for metals in this site, making it ideal to test Cu isotopes as tracers. The overall isotope composition of four sediment cores and a surface sample varied between -0.13 and 0.44 ‰ (δ⁶⁵Cu relative to NIST-976). Selected APs brands show a similar Cu concentration ~0.15 % and δ⁶⁵Cu average of 0.54 ± 0.05 ‰. The plot of δ⁶⁵Cu vs concentration for all datasets allowed dissociating natural and APs end-members. However, sample isotope systematics were not consistent with a conservative mixing binary source process. Heavily Cu-contaminated sediments show isotope signatures lighter than APs brands. However, the most Cu-contaminated sample, located directly above the careening area, shows a δ⁶⁵Cu slightly lighter than APs (0.44 ‰ vs 0.54 ‰, respectively). Results suggest the preferential releasing of a heavy isotope pool by APs when these compounds are solubilized in seawater. The isotope fractionation was attributed to potential chemical Cu coordination changes during its elemental partition between paint and marina seawater and the fractionation induced by the organic ligands in the water column, before deposition. Further laboratory experiments are recommended to model the isotope fractionation mechanisms related to Cu release by APs. Because the APs' isotope signature is modified in marine environments, the use of Cu isotopes as tracers of AP in marine environments is challenging and needs more investigation.

Metal and PAH loads from ships and boats, relative other sources, in the Baltic Sea

The Baltic Sea is a sensitive environment that is affected by chemical pollution derived from multiple natural and anthropogenic sources. The overall aim of this study was to estimate the load of metals and polycyclic aromatic hydrocarbons (PAHs) from shipping and leisure boating, relative other sources, to the Baltic Sea and to identify possible measures that could lead to major reductions in the loads of hazardous substances from maritime shipping and leisure boating. The use of copper-based antifouling paints, and operation of scrubbers in open loop mode, were the two most dominant identified sources of hazardous substances to the Baltic Sea. Open loop scrubbers accounted for 8.5 % of the total input of anthracene to the sea. More than a third of the total load of copper can be reduced if copper-free antifouling paints or other biocide-free antifouling strategies are used on ships and leisure boats.

Environmental Impact of Construction Products on Aquatic Systems—Principles of an Integrated Source–Path–Target Concept

Buildings exposed to water can release undesirable substances which, once transported to environmental compartments, may cause unwanted effects. These exposure pathways need to be investigated and included in risk assessments to safeguard water quality and promote the sustainability of construction materials. The applied materials, exposure conditions, distribution routes and resilience of receiving compartments vary considerably. This demonstrates the need for a consistent concept that integrates knowledge of emission sources, leaching processes, transport pathways, and effects on targets. Such a consistent concept can serve as the basis for environmental risk assessment for several scenarios using experimentally determined emissions. Typically, a source–path–target concept integrates data from standardized leaching tests and models to describe leaching processes, the distribution of substances in the environment and the occurrence of substances at different points of compliance. This article presents an integrated concept for assessing the environmental impact of construction products on aquatic systems and unravels currently existing gaps and necessary actions. This manuscript outlines a source–path–target concept applicable to a large variety of construction products. It is intended to highlight key elements of a holistic evaluation concept that could assist authorities in developing procedures for environmental risk assessments and mitigation measures and identifying knowledge gaps.

The Danubian cryptic invader Theodoxus fluviatilis (Gastropoda: Neritidae) in the River Rhine: a potential indicator for metal pollution?

Metal pollution poses a major threat to aquatic systems especially in anthropogenic influenced areas, in as much as metals are persistent in the environment. The freshwater snail Theodoxus fluviatilis has often been used as an indicator species for the ecological status in river monitoring. In the River Rhine, the native Northern-European form of T. fluviatilis is nowadays extinct, whilst the Danubian form is spreading along the river. The aim of our study was to investigate if the cryptic invader is affected by metal exposure present in the River Rhine and to discuss its potential as an indicator for metal pollution. Several environmental abiotic (14 water environmental variables plus five common metal concentrations in water and biofilm) and biotic parameters (biofilm mass) were measured across 23 sites along the River Rhine. Five population and six histopathological parameters were evaluated on snails collected at all 23 sites. Aqueous chromium concentration was positively correlated to the damage of male reproductive organs of T. fluviatilis, and higher ammonium concentration was correlated to a decrease in snail size and an increase in the proportion of juveniles. None of the analysed snail parameters was negatively correlated to concentrations of other metals measured, like copper and zinc. Therefore, based on the parameters evaluated, our results indicate that the Danubian form of T. fluviatilis is only restrictedly suitable as an indicator for metal pollution in the River Rhine system. Further field and laboratory investigations including other stressors are necessary to evaluate the indicator potential of the cryptic invader holistically.

Modelling copper emissions from antifouling paints applied on leisure boats into German water bodies

Copper-containing antifouling paints (AFP) are widely used for leisure boat maintenance. Cu emitted from AFP into German surface water bodies has been suggested to be a significant source of heavy metal pollution, threatening water quality. We developed two scenarios to model Cu emissions from AFP applied on leisure boats on national scale, which allow identifying regional hotspots. The top-down approach (scenario A) was based on a previous study on national AFP consumption, while in the bottom-up approach (scenario B), median and interquartile range of Cu release rates depending on salinity conditions were considered for emission estimation. Both scenarios clearly highlighted the locally high emission pressure on inland waters in popular watersport regions, identifying these as requiring intense protection. Scenario B generally predicted lower Cu emissions (sea: 11.05-25.53 t a^-1, inland: 14.15-34.59 t a^-1) than scenario A (sea: 22.53 t a^-1, inland: 47.97 t a^-1). To evaluate their relevance, scenario results were compared to emissions modelled with MoRE (Modelling of Regionalized Emissions), which is used as reporting tool on substance emissions by Germany. According to scenarios A and B, the emission from AFP accounted for 13 % and 4-9 % of the total Cu emissions into inland waters in 2016, respectively. Scenario results were similar or higher than other emission pathways such as industrial direct dischargers. Thus, we consider Cu emissions from AFP as a significant pathway to be included in the MoRE emission inventory. We recommend scenario B for implementation as it allows a more flexible adaptation for future modelling.

Nautical Tourism in Marine Protected Areas (MPAs): Evaluating an Impact of Copper Emission from Antifouling Coating

Copper (Cu) has a narrow range between optimal concentrations as a micronutrient critical for phytoplankton growth and concentrations potentially toxic to living organisms. This sensitivity indicates an ecosystem vulnerability that threatens not only nature but also human health due to bioaccumulation. An important source of elevated Cu concentrations in coastal environments are biocides used as antifouling protection on ships. A pilot study conducted in the Marine Protected Area (MPA) of the Krka Estuary (Croatia) over a period of 16 months investigated the relationship between ship traffic and Cu concentrations. The aim was to contribute to more informed environmental management by assessing the associated risks. In the study presented here, Cu concentrations were monitored, analyzed, and correlated with vessel traffic. Observations revealed that the seasonal increase in maritime traffic caused by nautical tourism was associated with an increase in Cu concentrations of more than five times, posing a toxicity risk to the environment. In order to understand the distribution of copper emissions, a mapping of maritime traffic was carried out by counting transits, radar imagery, and drone photography. This approach has proven sufficient to identify the potential risks to the marine environment and human health, thus providing an effective assessment tool for marine stakeholders.