Investigation of recreational boats as a source of copper at anchorage sites using time-integrated diffusive gradients in thin film and sediment measurements

Active and passive biomonitoring of trace elements, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls in small Mediterranean harbours

Pollution particularly affects coastal ecosystems due to their proximity to anthropic sources. Among those environments, harbours are subjected to marine traffic but also to accidental and chronic pollution. These areas are thus exposed to complex mixtures of contaminants such as trace elements and organic contaminants which can impact marine species, habitats, and ecosystem services. The monitoring of these compounds is thus a crucial issue for assessment of environmental health. In this context, the aim of the present work was to evaluate the chemical contamination of harbours in Corsica (NW Mediterranean) by measuring the bioaccumulation of trace elements, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls in mussels, limpets, and sea cucumbers. The human health risks associated with seafood consumption were also assessed. Results reveal a relatively low contamination in the Corsican harbours studied compared to larger Mediterranean ports and suggest that the potential health risk for consumers eating seafood is low.

A baseline of copper associated with antifouling paint in marinas within a large fjord estuary

Marinas have been shown to contribute elevated concentrations of copper (Cu) to marine waters. The Cu can come primarily from antifouling paints which are designed to discourage biofouling of boat hulls. Legislation in Washington State, USA is being developed to limit or regulate the amount and rate of diffusion of Cu from antifouling paints. This study provides baseline data for Cu in five marinas of different configuration and size within Puget Sound, a large fjord estuary. Samples were collected over a year from multiple environmental media. We find strong evidence that Cu accumulates inside marinas to higher concentrations than outside marinas. Marinas that are more enclosed accumulated higher concentrations of Cu than more open marinas. Using a power analysis, we assessed the adequacy of the baseline dataset to measure progress as a result of future legislation towards the reduction of Cu to Puget Sound from marinas.

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.

Assessment of bottom sediment quality in Niterói harbor (Brazil, South America) through ecological indexes concerning nutrients and trace metals

Bottom sediment quality from the Niterói harbor at Guanabara Bay (Rio de Janeiro, Brazil) was evaluated based on concentrations of organic phosphorus (OP) and inorganic phosphorus (IP) and bioavailability of trace metals through BCR fractionation analysis (Zn, Cu, Pb, Cr, Ni, Cd). The study area revealed elevated concentrations of fine sediments and organic matter (TOC: 2.26-7.31%). OP presented extremely elevated concentrations between 0.57 and 47.04 μmol/g, whereas IP reached a maximum concentration of 4.99 μmol/g. The anoxic bottom at the study area was confirmed by high TOC/OP values in most stations. Phosphorus enrichment index (PEI) varied between 0.07 and 2.57, pointing to ecological risk at some stations. Trace metals were mostly bonded to the bioavailable fractions (exchangeable, reducible, oxidizable), and decreasing order of mobility was Zn > Cu > Pb > Cr > Ni > Cd. The Risk Assessment Code (RAC) suggested a high risk of bioavailability for Zinc and a medium risk for the other metals. Overall, the Niterói harbor revealed poor sediment quality suggesting a strong anthropogenic pressure in the area.

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.

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.

Cysteine-modified silica resin in DGT samplers for mercury and trace metals assessment

Diffusive gradients in thin-films (DGT) is an in situ passive sampling technique to assess labile trace metal concentrations in different environmental matrix. The technique is consisting of a diffusive domain backed up by a resin gel that binds free metals and metal complexes that dissociate in the diffusive domain. This technique requires specific resin for special metals, for example mercury (Hg), since the classic resin (Chelex-100) gel is not applicable for Hg measurement. A simultaneous determination of Hg with other metals by the DGT was not yet reported. Two biomolecule-based resins were prepared by glutaraldehyde immobilisation of cysteine onto 3-amino-functionalised silica and 3-aminopropyl-functionalised silica, respectively. The load of functional groups on modified resins was qualitatively and quantitatively characterised. The modified resins were applied in the DGT technique and the uptake efficiency, elution efficiency, and linear accumulation of analytes of the DGT were tested. This novel DGT technique, using two cysteine-modified resins, can accumulate Hg and other metals in a broad range of pH and ionic strength in solutions. In the Belgian coastal zone (BCZ), the concentrations of Hg and other trace metals sampled by cysteine-modified resin-DGTs were similar as those by the other two DGT assemblies for Hg and other trace metals, respectively. The cysteine-modified silica resin combined the features of Chelex-100 resin and 3-mercaptopropyl silica resin and allowed simultaneous determination of labile Hg and other trace metals. The resin with a higher load of functional groups also showed higher performance in the further application in the DGT technique.

Boating- and Shipping-Related Environmental Impacts and Example Management Measures: A Review

Boating and shipping operations, their associated activities and supporting infrastructure present a potential for environmental impacts. Such impacts include physical changes to bottom substrate and habitats from sources such as anchoring and mooring and vessel groundings, alterations to the physico-chemical properties of the water column and aquatic biota through the application of antifouling paints, operational and accidental discharges (ballast and bilge water, hydrocarbons, garbage and sewage), fauna collisions, and various other disturbances. Various measures exist to sustainably manage these impacts. In addition to a review of associated boating- and shipping-related environmental impacts, this paper provides an outline of the government- and industry-related measures relevant to achieving positive outcomes in an Australian context. Historically, direct regulations have been used to cover various environmental impacts associated with commercial, industrial, and recreational boating and shipping operations (e.g., MARPOL). The effectiveness of this approach is the degree to which compliance can be effectively monitored and enforced. To be effective, environmental managers require a comprehensive understanding of the full range of instruments available, and the respective roles they play in helping achieve positive environmental outcomes, including the pros and cons of the various regulatory alternatives.

Biotoxicity and life cycle assessment of two commercial antifouling coatings in marine systems

Two commercial coating systems, each one consisting of both a primer and an antifouling ("System 1" based on Copper Oxide and "System 2" based on Zinc Oxide), have been analyzed in order to investigate their environmental impacts through Life Cycle Assessment (LCA) and laboratory tests. A cradle-to-grave analysis has been performed in order to quantify the environmental footprint of each coating solution and to define which element, material, or process mainly affect the environmental impact of such products. Moreover, it was performed a comparison between the different products to determine the most environmentally sustainable choice. In addition to LCA, several incubations of coated metal samples, by means of an innovative incubation system developed by the authors, have also been performed in marine water (Gulf of Naples, Mediterranean Sea, Italy), as critical environment favoring metal corrosion and biofouling generation. The life cycle analysis has showed that the production phase presents the highest environmental impact in almost all categories, mainly due to the use of chemical compounds. Moreover, after the laboratory tests, strong biotoxicity and contaminant diffusion, contributing to the marine toxicity potential, have been observed for both the commercial paints. As a final remark, there are straightforward indications of a strong need for anti-Microbial-Induced-Corrosion commercial coatings to substitute the toxic compounds with others in order to develop a greener solution.

Effects of the Bioturbating Marine Yabby Trypaea australiensis on Sediment Properties in Sandy Sediments Receiving Mangrove Leaf Litter

Laboratory mesocosm incubations were undertaken to investigate the influence of burrowing shrimp Trypaea australiensis (marine yabby) on sediment reworking, physical and chemical sediment characteristics and nutrients in sandy sediments receiving mangrove (Avicennia marina) leaf litter. Mesocosms of sieved, natural T. australiensis inhabited sands, were continually flushed with fresh seawater and pre-incubated for 17 days prior to triplicates being assigned to one of four treatments; sandy sediment (S), sediment + yabbies (S+Y), sediment + leaf litter (organic matter; S+OM) and sediment + yabbies + leaf litter (S+Y+OM) and maintained for 55 days. Mangrove leaf litter was added daily to treatments S+OM and S+Y+OM. Luminophores were added to mesocosms to quantify sediment reworking. Sediment samples were collected after the pre-incubation period from a set of triplicate mesocosms to establish initial conditions prior to the imposition of the treatments and from the treatment mesocosms at the conclusion of the 55-day incubation period. Yabbies demonstrated a clear effect on sediment topography and leaf litter burial through burrow creation and maintenance, creating mounds on the sediment surface ranging in diameter from 3.4 to 12 cm. Within S+Y+OM sediments leaf litter was consistently removed from the surface to sub-surface layers with only 7.5% ± 3.6% of the total mass of leaf detritus added to the mesocosms remaining at the surface at the end of the 55-day incubation period. Yabbies significantly decreased sediment wet-bulk density and increased porosity. Additionally, T. australiensis significantly reduced sediment bio-available ammonium (NH4+bio) concentrations and altered the shape of the concentration depth profile in comparison to the non-bioturbated mesocosms, indicating influences on nutrient cycling and sediment-water fluxes. No significant changes for mean apparent biodiffusion coefficients (Db) and mean biotransport coefficients (r), were found between the bioturbated S+Y and S+Y+OM mesocosms. The findings of this study provide further evidence that T. australiensis is a key-species in shallow intertidal systems playing an important role as an ‘ecosystem engineer’ in soft-bottom habitats by significantly altering physical and chemical structures and biogeochemical function.

Natural and non-toxic products from Fabaceae Brazilian plants as a replacement for traditional antifouling biocides: an inhibition potential against initial biofouling

In this study, we screened for the antifouling activity of 15 species plant extracts from Brazilian the Brazilian Caatinga Fabaceae against the initial colonization of natural marine bacterial biofilm. We also investigated the potential toxicity of extracts against planktonic and benthic non-target organisms. Aqueous extracts of plants collected in the Caatinga biome (PE, Brazil) were prepared and tested at different concentration levels (0, 0.5, 1, 2, 4, and 8 mg mL^-1). Natural marine bacterial consortium was inoculated in multi-well plates and incubated with the different treatments for 48 h. The biofilm and planktonic bacterial density and biomass inhibition were evaluated along with biofilm biomass eradication. The extracts that showed the highest bacterial biofilm inhibition were evaluated for toxicity against microalgae and crustaceans. The biofilm and planktonic bacterial inhibition potential were evaluated through flow cytometry and spectrophotometry. The selected treatments were evaluated for their toxicity using the microalgae Chaetoceros calcitrans, the copepod Nitokra sp., and the brine shrimp Artemia salina as bioindicators. Our work demonstrates the biotechnological potential of Fabaceae plant compounds as a safe antifouling alternative. Anadenanthera colubrina var. cebil fruits and Apuleia leiocarpa leaf extracts showed antibiofilm activity (≥ 80%), while Myroxylon peruiferum and Dioclea grandiflora leaf extracts showed antibiotic activity. These extracts were safe to planktonic and benthic non-target organisms. The results of this study point to potential substitutes to highly toxic antifouling paints and shed light on the prospect of a yet to be explored biome for more sustainable alternatives in biofouling research.

Metal concentrations in waters, sediments and biota of the far south-east coast of New South Wales, Australia, with an emphasis on Sn, Cu and Zn used as marine antifoulant agents

Tin, Cu, Zn, Cd, Pb, Ag and Hg concentrations were measured in waters, sediments and three ubiquitous sedentary molluscs: the oyster, Saccostrea glomerata, a rocky intertidal gastropod, Austrocochlea porcata, and a sediment-dwelling gastropod, Batillaria australis, at 12 locations along the far south coast of NSW, Australia, from Batemans Bay to Twofold Bay during 2009. Metal concentrations in water for Sn, Cd, Ag and Hg were below detection limits (< 0.005 μg/L). Measurable water metal concentrations were Cu: 0.01-0.08 μg/L, Zn: 0.005-0.11 μg/L and Pb: 0.005-0.06 μg/L. Mean metal concentration in sediments were Sn < 0.01-2 μg/g, Cu < 0.01-605 μg/g, Zn 23-765 μg/g, Cd < 0.01-0.5 μg/g, Pb < 0.01-0.3 μg/g, Ag < 0.01-0.9 μg/g and Hg < 0.01-2.3 μg/g. Several locations exceeded the Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand (Australian and New Zealand guidelines for fresh and marine water quality 2000) low and high interim sediment quality guidelines' levels for Cu, Zn, Cd and Hg. Some sites had measurable Sn concentrations, but these were all well below the levels of tributyltin known to cause harm to marine animals. Elevated metal concentrations are likely to be from the use of antifoulants on boats, historical mining activities and agriculture in the catchments of estuaries. All molluscs had no measurable concentrations of Sn (< 0.01 μg/g) and low mean Ag (< 0.01-1.5 μg/g) and Hg (< 0.01-0.5 μg/g) concentrations. Mean Cu (24-1516 μg/g), Zn (45-4644 μg/g), Cd (0.05-5μg/g) and Pb (0.05-1.1 μg/g) in oysters were close to background concentrations. Oysters have Cd and Pb concentrations well below the Australian Food Standards Code (2002).] There were no significant correlations between metal concentrations in sediments and in organisms within locations, and no relationship with levels of boating activity and suspected antifouling contamination. Although not pristine, the low levels of metal contamination in sediments and molluscs in comparison with known metal-contaminated areas indicate that this region is not grossly contaminated with metals and suitable for the development of mariculture.].

Effects of Dissolved Organic Carbon on Copper Toxicity to Embryos of Mytilus galloprovincialis as Measured by Diffusive Gradient in Thin Films

Diffusive gradient in thin films (DGT) potentially better quantifies bioavailable copper (Cu) in seawater. Laboratory exposure of DGTs and Mytilus galloprovincialis embryos at varying concentrations of dissolved organic carbon and Cu were performed to resolve the degree to which mimicry of toxicity buffering occurs in passive sampler quantification. The results provide preliminary median effect concentrations (EC50s) ranging from 4.8 to 11.5 µg/L as C_DGT Cu over the span of 0.896 to 8.36 mg/L DOC. Environ Toxicol Chem 2019;00:1-6. Published 2019 Wiley Periodicals, Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Mapping the environmental risk assessment of marinas on water quality: The Atlas of the Spanish coast

Recreational sailing sector has an impact on water quality in marinas. This study proposes a standard procedure to assess the environmental risk of marinas on water quality. Risk is assessed through integrating environmental pressures, environmental conditions and societal responses (i.e. the Pressure-State-Response model). Pressures are estimated considering the main driving forces: navigation, port, dredging and external activities. State is estimated through combining the susceptibility, the ecological value and naturalness. Response is estimated through environmental management instruments and adopted measures. Managers and authorities can hierarchically classify marinas from a multi-scale spatial framework. This tool is particularly powerful for generating local, regional or national atlases to prioritize environmental planning actions. The method is applied to 320 marinas along the Spanish coast. This implementation confirms the usefulness, versatility and adaptability of this procedure as a tool for the environmental management of marinas.

Passive sampling monitoring of PAHs and trace metals in seawater during the salvaging of the Costa Concordia wreck (Parbuckling Project)

Passive sampling techniques were used for monitoring trace metals and polycyclic aromatic hydrocarbons (PAHs) in the seawater surrounding the Costa Concordia shipwreck (Isola del Giglio, Italy). The monitoring lasted two and a half years (2012-2014) and considered all four phases of the "parbuckling project": stabilisation of the wreckage, installation of steel caissons on both sides of the wreck, parbuckling, and refloating. Dissolved trace metals (Cd, Cr, Cu, Hg, Ni, Pb, and V) were measured with diffusive gradients in thin films (DGT), while freely dissolved PAHs were measured with semi-permeable membrane devices (SPMDs). Passive sampling allowed to detect very low concentrations of contaminants, and indicated significant differences among the sampling stations and among the different steps for salvaging the wreck. The results suggested that the main source of contamination was the heavy working vessel traffic at the disaster site, rather than the release of contaminants from the wreck.

Mortality and histopathological effects in harbour-transplanted snails with different exposure histories

Contaminants are important stressors in the aquatic environment and may exert selective pressures on organisms. We hypothesized that snails originating from a metal-contaminated habitat (B) would have increased tolerance to harbour contaminants (e.g. metals from antifouling paints), compared to snails originating from a relatively clean habitat (A). We assessed tolerance to metals in terms of survival and histopathological alterations after 2, 4 and 8 weeks of in situ exposure in three Baltic Sea boat harbours and three reference sites. We also hypothesized that any potential tolerance to contaminants would be associated with differences in genetic diversity between the two snail populations (evaluated as mitochondrial cytochrome c oxidase subunit I, COI). The results show that snails from population A survived to a higher extent compared to population B, possibly indicating either a lack of adaptation to metals in snails B or impaired health condition due to contaminant pre-exposure or a higher resilience of snails A. Moreover, the genetic diversity of COI was low within each population and did not differ between populations. In general, 83% of all the types of histopathological alterations (e.g. lysis and necrosis of gonads and digestive gland or granulocytoma and phagocytosis in the storage tissue, among others) had a higher probability of occurrence among harbour-exposed snails compared to reference-exposed snails, regardless of snail population origin. The only significant difference in histological effects between the two populations was in the frequency of parasite infestations and shell fouling, both being larger for population A than B. Interestingly, the rate of parasite infestations was higher for males than females from population A, whereas no sexual dichotomy was observed for population B. Our results show that exposure to harbour contaminants causes both lethal and sublethal toxicity to snails, and the association between many of the toxic responses and metals substantiates that antifouling substances contribute to the observed effects, although there is a large proportion of variation in our data that remains unexplained.

Metal contamination in harbours impacts life-history traits and metallothionein levels in snails

Harbours with limited water exchange are hotspots of contaminant accumulation. Antifouling paints (AF) contribute to this accumulation by leaching biocides that may affect non-target species. In several leisure boat harbours and reference areas in the Baltic Sea, chronic exposure effects were evaluated using caging experiments with the snail Theodoxus fluviatilis. We analysed variations in ecologically relevant endpoints (mortality, growth and reproduction) in concert with variation in metallothionein-like proteins (MTLP) levels. The latter is a biomarker of exposure to metals, such as copper (Cu) and zinc (Zn), which are used in AF paints as active ingredient and stabilizer, respectively. In addition, environmental samples (water, sediment) were analysed for metal (Cu and Zn) and nutrient (total phosphorous and nitrogen) concentrations. All life-history endpoints were negatively affected by the exposure, with higher mortality, reduced growth and lower fecundity in the harbours compared to the reference sites. Metal concentrations were the key explanatory variables for all observed adverse effects, suggesting that metal-driven toxicity, which is likely to stem from AF paints, is a source of anthropogenic stress for biota in the harbours.

The impact of a high magnitude flood on metal pollution in a shallow subtropical estuarine embayment

Drought-breaking floods pose a risk to coastal water quality as sediments, nutrients, and pollutants stored within catchments during periods of low flow are mobilized and delivered to coastal waters within a short period of time. Here we use subtidal surface sediment surveys and sediment cores to explore the effects of the 2011 Brisbane River flood on trace metals zinc (Zn), lead (Pb), copper (Cu), nickel (Ni), chromium (Cr), manganese (Mn), and phosphorus (P) deposition in Moreton Bay, a shallow subtropical bay in eastern Australia. Concentrations of Zn, Cu, and Pb in sediments in central Moreton Bay derived from the 2011 flood were the highest yet observed in the Bay. We suggest flushing of metal rich sediments which had accumulated on the Brisbane River floodplain and in its estuary during the preceding 10 to 40years of low flows to be the primary source of this increase. This highlights the importance of intermittent high magnitude floods in tidally influenced rivers in controlling metal transport to coastal waters in subtropical regions.

Ecological risks of trace metals in Guanabara Bay, Rio de Janeiro, Brazil: An index analysis approach

Total concentrations of Ni, Cr, Cu, Pb and Zn were determined in surface sediments from 30 stations in Guanabara Bay in 1999 and 2008. An approach using various environmental indices was used to assess contamination status of metals. This approach allowed the comparison with different coastal areas. Background Enrichment Index, Contamination index and Ecological Risk index (Pollution Load Index; Sediment Quality Guideline Quotient and Ecological Risk Index) were calculated for the metals. Results revealed a great load of organic matter and significant increases in Cu and Pb levels between 1999 and 2008. The concentrations of Cr and Zn were of great concern, surpassing the values of Probable Effect Level reference values. In spite of the differences of each index, results effectively revealed the striking contamination in Guanabara Bay concerning trace metals, and also suggested potential risk to local biota. The contamination of the northwest area was notably higher than the rest of the bay. In comparison with some other coastal bays around the world, Guanabara Bay stood out as a remarkably contaminated environment.

Release and detection of nanosized copper from a commercial antifouling paint

One major concern with the use of antifouling paints is the release of its biocides (mainly copper and zinc) into natural waters, where they may exhibit toxicity to non-target organisms. While many studies have quantified the release of biocides from antifouling paints, very little is known about the physicochemical state of released copper. For proper risk assessment of antifouling paints, characterization of copper released into water is necessary because the physicochemical state determines the metal's environmental fate and effects. In this study, we monitored release of different fractions of copper (dissolved, nano, and bulk) from a commercial copper-based antifouling paint. Release from painted wood and aluminum mini-bars that were submerged in natural waters was monitored for 180 days. Leachates contained both dissolved and particulate copper species. X-ray diffraction and X-ray photoelectron spectroscopy were used to determine the chemical phase of particles in the leachate. The amount of copper released was strongly dependent on water salinity, painted surface, and paint drying time. The presence of nanosized Cu2O particles was confirmed in paint and its leachate using single-particle inductively coupled plasma-mass spectrometry and electron microscopy. Toxicity of paint leachate to a marine phytoplankton was also evaluated.

Metal contamination at recreational boatyards linked to the use of antifouling paints-investigation of soil and sediment with a field portable XRF

The application of a field portable X-ray fluorescence spectrometer (FPXRF) to measure Cu, Zn, and Pb in soil and sediments at recreational boatyards by Lake Mälaren in Sweden was investigated. Confirmatory chemical analysis on freeze-dried samples shows that, ex situ, the FPXRF produces definitive level data for Cu and Zn and quantitative screening data for Pb, according to USEPA criteria for data quality. Good agreement was also found between the ex situ measurements and the in situ screening. At each of the two studied boatyards, >40 in situ soil measurements were carried out. Statistical differences in soil concentration based on land use were consequently found: the areas used for boat storage and maintenance were significantly higher in Cu and Zn than the areas used for car parking and transportation. The metal pollution in the boat storage areas is therefore shown to be directly linked to hull maintenance activities during which metal-containing antifouling paint particles are shed, end up on the ground, and consequently pollute the soil. In the boat storage areas, the Cu and Zn concentrations often exceeded the national guideline values for soil. In this study, they were also shown to increase with increasing age of the boatyard operation. Pb soil concentrations were only elevated at a few measurement points, reflecting the phasing out of Pb compounds from antifouling products over the past 2 decades. In the surface sediments, concentrations of Cu and Zn were 2-3 times higher compared to deeper levels. No decrease in metal concentration with time was found in the sediments, indicating that boat owners are not complying with the ban of biocide-containing paints in freshwater introduced over 20 years ago.

Pollutant Concentrations and Toxic Effects on the Red Alga Ceramium tenuicorne of Sediments from Natural Harbors and Small Boat Harbors on the West Coast of Sweden

This investigation set out to analyze the toxicity of surface sediments in a number of natural harbors and small boat harbors on the west coast of Sweden. This was done with the growth inhibition method with Ceramium tenuicorne. Also, concentrations of copper (Cu), lead (Pb), zinc (Zn), irgarol, organotin compounds, and polycyclic aromatic hydrocarbons (PAHs) in the sediments were analyzed. The small boat harbors were heavily polluted by Cu, Zn, butyltins, and PAHs, and to a lesser extent by Pb. The Cu, Pb, Zn, and butyltins probably originated from their past and/or present use in antifouling paints, whereas the PAHs probably had multiple sources, including boat motor exhausts. The measured toxicity of the sediment was generally related to their Cu, Zn, and butyltin content, although other toxic substances than those analyzed here probably contributed to the toxicity in some of the harbors. The natural harbor sediments contained less pollutants and were less toxic than the small boat harbor sediments. Nevertheless, our data indicate that the boating pressure today may be high enough to produce toxic effects even in natural harbors in pristine areas. The strongest relationship between toxicity and the major pollutants was obtained when the sediment toxicity was expressed as gram wet weight per liter compared with gram dry weight per liter and gram total organic carbon per liter. Hence, for pollutants that can be elutriated with natural sea water, sediment toxicity expressed as gram wet weight per liter appears preferable.

In situ evaluation of DGT techniques for measurement of trace metals in estuarine waters: a comparison of four binding layers with open and restricted diffusive layers

Four different DGT binding layers were used to make selective measurements of trace metals in coastal waters within The Broadwater (Gold Coast, Queensland). Chelex and PAMPAA (polyacrylamide-polyacrylic acid) binding layers were used to measure cations (Cd, Co, Cu, Mn, Ni, Pb, Zn), and Metsorb was used to measure anions (Al, As, Mo, Sb, V, W). A mixed binding layer (MBL) containing both Chelex and Metsorb was used to measure each of the trace metals and determine diffusive boundary layer (DBL) thicknesses. DGT measurements that were not corrected for the DBL thickness (0.049-0.087) were underestimated by 70% on average. Good agreement was observed between DGT-MBL and DGT-Chelex for measurement of Cd, Co, Cu, Ni, Pb and Zn, and between DGT-MBL and DGT-Metsorb for As, Sb and V. DGT-MBL measured significantly higher concentrations for Mn (compared with DGT-Chelex) and Al (compared with DGT-Metsorb). DGT-Chelex measured only 6-8% of Al species measured by either DGT-MBL or DGT-Metsorb. DGT-PAMPAA measurements of Cu, Pb and Al were lower than those of either DGT-MBL or DGT-Chelex varying from 74-81% for Cu to 54-70% for Pb and 51-55% for anionic Al(OH)4(-), suggesting that this binding layer may make more selective measurements. All measured trace metal concentrations were well below ANZECC water quality guidelines, except for Cu which was 2 to 10 times higher than trigger values. Each of the DGT techniques was deployed using both open and restricted diffusive layers (ODL and RDL). Most trace metal measurements were not significantly different with ODL and RDL for all binding layers. However, concentrations of Cu (CRDL/CODL = 0.68-0.75) and Al (CRDL/CODL = 0.73-0.79) were significantly different with DGT-MBL, DGT-Chelex and DGT-Metsorb.

Sediment Contaminants and Infauna Associated with Recreational Boating Structures in a Multi-Use Marine Park

Multi-use marine parks achieve conservation through spatial management of activities. Zoning of marine parks in New South Wales, Australia, includes high conservation areas and special purpose zones (SPZ) where maritime activities are concentrated. Although such measures geographically constrain anthropogenic impacts, we have limited understanding of potential ecological effects. We assessed sediment communities and contaminants adjacent to boating infrastructure (boat ramps, jetties and a marina) in a SPZ from the Clyde Estuary in Batemans Marine Park. Metal concentrations and fines content were elevated at boating structures compared to reference sites. Species richness was higher at sites with boating structures, where capitellid polychaetes and nematodes dominated the communities. Changes associated with boating structures were localised and did not extend beyond breakwalls or to reference sites outside the SPZ. The study highlights the benefits of appropriate zoning in a multi-use marine park and the potential to minimise stress on pristine areas through the application of spatial management.

Distribution of heavy metals in sediment cores of Lake Pamvotis (Greece): a pollution and potential risk assessment

Concentrations and vertical distributions of metals in surface sediments of Lake Pamvotis (NW Greece) were assessed using energy-dispersive X-ray fluorescence spectrometry. A wide range of values was determined, associated with the specific types of contaminating effluents draining into different parts of the lake. Overall, Cr levels ranged from 43 to 3295 mg kg(-1), Ni from 13 to 372 mg kg(-1), Cu from 15 to 24,985 mg kg(-1), Zn from 129 to 22,983 mg kg(-1), Zr from 64 to 4063 mg kg(-1) and Pb from 19 to 2634 mg kg(-1). Principal component analysis revealed distinct elemental fingerprints in each sampling location, while correlation analysis and hierarchical agglomerative cluster analysis provided insight to metal association and pollution sources. Enrichment factors and geoaccumulation indices were calculated to quantify sediment contamination, and potential ecotoxic effects were evaluated based on sediment quality guidelines. Moderate to very severe enrichment in Zn, Cu and Pb was evidenced in sediments near the lake's outflow. The proximity of these sampling points to a heavy traffic national road suggests that roadway runoff is the dominant source of elevated metal levels. Contribution from municipal sewage water discharges from the nearby communities should also be accounted for. Moderate to very severe Zn and Pb enrichment was determined in the vicinity on the main lake's inflow, primarily associated with runoff and leaching from agricultural land. Very severe to extremely severe Cr enrichment was detected in the same location, most likely associated with wastewater discharged into the lake over several decades, by nearby-operating leather tanneries. The above two locations were ranked at the highest priority level in terms of potential ecological risk.

Metal contamination of estuarine intertidal sediments of Moreton Bay, Australia

Trace element concentrations in surface intertidal sediments were analyzed to assess the level of contamination along the western side of Moreton Bay (Australia). The environmental risks posed by metals were evaluated using sediment quality guidelines, the Risk Assessment Code (RAC) and enrichment relative to background levels. Chromium, Ni, and Cu are the main contributors to sediment pollution. Sediments are also enriched in Zn, Cd and Pb by 1.5-3 times the regional background. Zinc, Cd and Co may pose high to very high risk to the aquatic biota due to their potential bioavailability, while Ni, As, Cu, Pb and Cr may pose medium risk at some of the investigated sites. Results emphasize the importance of using different methods for the assessment of sediment pollution at an estuarine site.

Legacy metals within urban aquatic environments and the challenge they pose to rehabilitation

Legacy metals, a result of previous environmentally unsound practices, pose a challenge to the rehabilitation of urban aquatic ecosystems. The current study focuses on a harbor in Vancouver, British Columbia, Canada, where use of antifouling paints for hull cleaning occurred for ca. 30 years. Sediment metal concentrations were mapped by depth and distance from where hulls were cleaned. By relating metal concentrations to the benthic invertebrate community and bivalve metal content, results indicate that cleaning activities severely impacted sediment quality. However, sewer outfalls, which integrate non-point sources of metals to the harbor, also contributed to poor sediment quality and high metal concentrations in bivalves. For the aquatic system to recover, non-point diffuse metal sources must be addressed, regardless of the challenge.

Assessment of the labile fractions of copper and zinc in marinas and port areas in Southern Brazil

The dissolved labile and labile particulate fractions (LPF) of Cu and Zn were analyzed during different seasons and salinity conditions in estuarine waters of marina, port, and shipyard areas in the southern region of the Patos Lagoon (RS, Brazil). The dissolved labile concentration was determined using the diffusive gradients in thin films technique (DGT). DGT devices were deployed in seven locations of the estuary for 72 h and the physicochemical parameters were also measured. The LPF of Cu and Zn was determined by daily filtering of water samples. Seasonal variation of DGT-Cu concentrations was only significant (p < 0.05) at one shipyard area, while DGT-Zn was significant (p < 0.05) in every locations. The LPF of Cu and Zn concentrations demonstrated seasonal and spatial variability in all locations, mainly at shipyard areas during high salinity conditions. In general, except the control location, the sampling locations showed mean variations of 0.11-0.45 μg L(-1) for DGT-Cu, 0.89-9.96 μg L(-1) for DGT-Zn, 0.65-3.69 μg g(-1) for LPF-Cu, and 1.35-10.87 μg g(-1) for LPF-Zn. Shipyard areas demonstrated the most expressive values of labile Cu and Zn in both fractions. Strong relationship between DGT-Zn and LPF-Zn was found suggesting that the DGT-Zn fraction originates from the suspended particulate matter. Water salinity and suspended particulate matter content indicated their importance for the control of the labile concentrations of Cu and Zn in the water column. These parameters must be taken into consideration for comparison among labile metals in estuaries.

Environmental and ecological changes associated with a marina

Anthropogenic modifications to waterways are common and their ecological consequences must be understood to effectively conserve local biodiversity. The facilitation of recreational boating activities often requires substantial alteration of natural areas, however the environmental and ecological consequences of such alterations are rarely described in the scientific literature. In this study, ecological and physico-chemical conditions were investigated in a recreational boating marina, located inside a marine park on the south-east coast of Australia. Recruitment panels were deployed for 8 weeks both inside and outside the marina, and differences in the composition of the developing fouling communities were observed. The recruitment of taxa, which often have short-lived larvae, was increased inside the marina (bryozoans, spirorbids and sponges) while the recruitment of taxa, which often have longer-lived larvae, was reduced or absent (barnacles, solitary ascidians and non-spirorbid polychaetes). Differences were also observed in environmental conditions inside the marina cf. directly outside. The marina environment had higher turbidity, temperature and pH along with higher concentrations of lead and copper in suspended sediments, while flow rates and trapped sediment loads were reduced inside the marina. The differences observed in the study suggest that there may be marked environmental changes associated with marina developments. The potential ecological consequences of these changes should be a primary consideration during the planning process, particularly for developments in locations of notable ecological value.

Rapid increase in copper concentrations in a new marina, San Diego Bay

Concentrations of copper in water rose rapidly following the introduction of boats to a new marina in San Diego Bay. Two months after the marina reached half its capacity, a majority of water samples exceeded chronic and acute criteria for dissolved copper, and copper concentrations in several samples exceeded the highest concentrations observed in another marina that has been listed as an impaired water body. A box model suggested that a small fraction of the leached copper was sequestered in sediment. Copper concentrations in water entering the marina from the bay was more than half the chronic concentration limit, so only 50% of marina boat capacity could be accommodated without exceeding the chronic criterion more than 50% of the time. Copper concentrations in water may increase rapidly following boat introduction in small marinas, but could return to pre-introduction levels by controlling boat numbers or reducing use of copper-based paints.

Evaluation of diffusive gradients in thin-films (DGTs) as a monitoring tool for the assessment of the chemical status of transitional waters within the Water Framework Directive

In this contribution, the potential use of diffusive gradients in thin-films (DGTs) for the chemical evaluation of transitional water bodies within the Water Framework Directive (WFD) has been studied. The water metal concentration has been evaluated in 13 estuaries in the southeastern Bay of Biscay. The DGTs were deployed in triplicate at two stations in each estuary, delimiting the tidal influence. The DGT results were in the ranges of 2-1570 ng L(-1) for cadmium, 66-515 ng L(-1) for copper, 30-3650 ng L(-1) for nickel and 0.8-95.5 μg L(-1) for zinc. The DGTs provided reliable average labile metal concentrations in highly dynamic systems that were comparable with DGT measurements in coastal and estuarine waters worldwide. In addition, it was possible to discriminate those estuaries more susceptible to environmental impacts, being consistent with the historical contamination of each estuary. Based on the obtained results, a sampling strategy for the monitoring of transitional water bodies using DGTs is proposed.

Toxicity to Melita plumulosa from intermittent and continuous exposures to dissolved copper

The concentrations of metal contaminants often fluctuate in estuarine waters; yet we have limited knowledge about the effects of intermittent exposures on estuarine organisms. Using 10-d lethality bioassays with the epibenthic amphipod Melita plumulosa, different combinations of intermittent (pulsed) dissolved Cu exposure were investigated, varying Cu concentration, pulse duration, and time between pulses. Negligible organism mortality was observed immediately after single 12- to 62-h duration pulsed exposures of 100 to 900 µg/L dissolved Cu. However, delayed mortality was observed in the subsequent 96-h nonexposure period, after which negligible additional mortality occurred during the remainder of the 240-h tests. For multiple pulsed exposures, increasing the time between pulses from 0 to 144 h did not result in significantly different mortality rates for 300 and 400 µg/L dissolved copper, indicating that the organisms did not recover between pulses. Organism mortality exhibited a strong relationship with the time-averaged concentration (TAC) resulting from the combination of exposure concentration and duration. The lethal concentration to 50 (LC50), 20 (LC20), and 10% (LC10) (95% confidence interval) of the test population for the combined TAC exposure-survival data were 86 (71-103), 44 (30-64), and 30 (18-49) µg Cu/L, respectively, which were similar to the respective values of 100 (87-114), 55 (43-70), and 39 (28-54) µg Cu/L determined for continuous exposure. The results from the current study support the use of analytical techniques capable of determining the time-averaged concentration of metals, because they will more accurately predict the effects of toxiciants on organisms than single time-point measurements.

Sub-cellular damage by copper in the cnidarian Zoanthus robustus

Sessile organisms may experience chronic exposure to copper that is released into the marine environment from antifoulants and stormwater runoff. We have identified the site of damage caused by copper to the symbiotic cnidarian, Zoanthus robustus (Anthozoa, Hexacorallia). External changes to the zoanthids were apparent when compared with controls. The normally flexible bodies contracted and became rigid. Histological examination of the zoanthid tissue revealed that copper had caused sub-cellular changes to proteins within the extracellular matrix (ECM) of the tubular body. Collagen in the ECM and the internal septa increased in thickness to five and seven times that of controls respectively. The epithelium, which stained for elastin, was also twice as thick and tough to cut, but exposure to copper did not change the total amount of desmosine which is found only in elastin. We conclude that copper stimulated collagen synthesis in the ECM and also caused cross-linking of existing proteins. However, there was no expulsion of the symbiotic algae (Symbiodinium sp.) and no effect on algal pigments or respiration (44, 66 and 110 microg Cu L(-1)). A decrease in net photosynthesis was observed only at the highest copper concentration (156 microg Cu L(-1)). These results show that cnidarians may be more susceptible to damage by copper than their symbiotic algae.

Comparison of toxicity and release rates of Cu and Zn from anti-fouling paints leached in natural and artificial brackish seawater

Biocide-containing anti-fouling paints are regulated and approved according to the added active ingredients, such as Cu. Biocide-free paints are considered to be less environmentally damaging and do not need an approval. Zn, a common ingredient in paints with the potential of causing adverse effects has received only minor attention. Laboratory experiments were conducted in artificial brackish seawater (ASW) and natural brackish seawater (NSW) to quantify release rates of Cu and Zn from biocide-containing and biocide-free labeled eroding anti-fouling paints used on commercial vessels as well as leisure boats. In addition, organisms from three trophic levels, the crustacean Nitocra spinipes, the macroalga Ceramium tenuicorne and the bacteria Vibrio fischeri, were exposed to Cu and Zn to determine the toxicity of these metals. The release rate of Cu in NSW was higher from the paints for professional use (3.2-3.6 microg cm(-)(2)d(-1)) than from the biocide leaching leisure boat paint (1.1 microg cm(-)(2)d(-1)). Biocide-free paints did leach considerably more Zn (4.4-8.2 microg cm(-)(2)d(-1)) than biocide-containing leisure boat paint (3.0 microg cm(-)(2)d(-1)) and ship paints (0.7-2.0 microg cm(-)(2)d(-1)). In ASW the release rates of both metals were notably higher than in NSW for most tested paints. The macroalga was the most sensitive species to both Cu (EC(50)=6.4 microg l(-1)) and Zn (EC(50)=25 microg l(-1)) compared to the crustacean (Cu, LC(50)=2000 microg l(-1) Zn, LC(50)=890 microg l(-1)), and the bacteria (Cu, EC(50)=800 microg l(-1) and Zn, EC(50)=2000 microg l(-1)). The results suggest that the amounts of Zn and Cu leached from anti-fouling paints may attain toxic concentrations in areas with high boat density. To fully account for potential ecological risk associated with anti-fouling paints, Zn as well as active ingredients should be considered in the regulatory process.

Assessment of low-level metal contamination using the Mediterranean mussel gills as the indicator tissue

PURPOSE

The aim of this study was to compare the level of metal contamination in two bays in the middle part of the Eastern Adriatic coastal zone in Croatia using the gills of mussels Mytilus galloprovincialis as indicator tissue. Despite the existing sources of contamination, previous studies with caged mussels only indicated moderate metal contamination of the Kastela Bay, contrary to the Trogir Bay in which marina and shipyard present a probable source of Cu- and Zn-contamination.

METHODS

The measurements of metallothioneins (MTs) and metals that induce MT synthesis (Cu, Zn, and Cd) were performed in the heat-treated gill cytosol and total proteins (TPs) in the untreated gill cytosol. MTs were determined by differential pulse voltammetry, Cu and Zn by flame atomic absorption spectrometry (AAS), Cd by graphite furnace AAS, and TPs by Bradford spectrophotometric procedure.

RESULTS

The results collected in four sampling campaigns (autumn periods from 2001 to 2004) indicated that MT levels in mussel gills (expressed on dry mass basis 2.3+/-0.3 mg g(-1)) were comparable with basal levels reported in the literature (2.5+/-0.8 mg g(-1)). Observed interindividual, temporal, and spatial MT variability could be associated with different confounding factors, such as the time of sampling, total protein concentration, and mussel size rather than cytosolic levels of Cu and Zn. Metal levels, expressed on wet mass basis, in the heat-treated gill cytosol ranged from 1.33 to 11.31 microg g(-1) for Zn, from 0.72 to 2.96 microg g(-1) for Cu, and from 0.036 to 0.100 microg g(-1) for Cd. The highest Zn level was measured at Vranjic (Kastela Bay)-the site influenced by untreated domestic wastewater, while somewhat increased Zn and the highest Cu levels were found at marina and shipyard locations (Trogir Bay). The highest Cd level was measured at Inavinil (Kastela Bay).

CONCLUSIONS

The observed association of gill MT levels with several biotic and abiotic factors limits its use as the biomarker of low-level metal exposure. Therefore, the use of the metal concentrations in the heat-treated gill cytosol of Mediterranean mussels should be considered for the assessment of the low-level metal contamination of coastal marine areas.

Pollutant fate and spatio-temporal variability in the choptank river estuary: factors influencing water quality

Restoration of the Chesapeake Bay, the largest estuary in the United States, is a national priority. Documentation of progress of this restoration effort is needed. A study was conducted to examine water quality in the Choptank River estuary, a tributary of the Chesapeake Bay that since 1998 has been classified as impaired waters under the Federal Clean Water Act. Multiple water quality parameters (salinity, temperature, dissolved oxygen, chlorophyll a) and analyte concentrations (nutrients, herbicide and herbicide degradation products, arsenic, and copper) were measured at seven sampling stations in the Choptank River estuary. Samples were collected under base flow conditions in the basin on thirteen dates between March 2005 and April 2008. As commonly observed, results indicate that agriculture is a primary source of nitrate in the estuary and that both agriculture and wastewater treatment plants are important sources of phosphorus. Concentrations of copper in the lower estuary consistently exceeded both chronic and acute water quality criteria, possibly due to use of copper in antifouling boat paint. Concentrations of copper in the upstream watersheds were low, indicating that agriculture is not a significant source of copper loading to the estuary. Concentrations of herbicides (atrazine, simazine, and metolachlor) peaked during early-summer, indicating a rapid surface-transport delivery pathway from agricultural areas, while their degradation products (CIAT, CEAT, MESA, and MOA) appeared to be delivered via groundwater transport. Some in-river processing of CEAT occurred, whereas MESA was conservative. Observed concentrations of herbicide residues did not approach established levels of concern for aquatic organisms. Results of this study highlight the importance of continued implementation of best management practices to improve water quality in the estuary. This work provides a baseline against which to compare future changes in water quality and may be used to design future monitoring programs needed to assess restoration strategy efficacy.

Toxicity of anti-fouling paints for use on ships and leisure boats to non-target organisms representing three trophic levels

Leachates of anti-fouling paints for use on ships and leisure boats are examined for their ecotoxicological potential. Paint leachates were produced in both 7 per thousand artificial (ASW) and natural seawater (NSW) and tested on three organisms, the bacterium Vibrio fischeri, the macroalga Ceramium tenuicorne, and the crustacean Nitocra spinipes. Generally, leaching in ASW produced a more toxic leachate and was up to 12 times more toxic to the organisms than was the corresponding NSW leachate. The toxicity could be explained by elevated concentrations of Cu and Zn in the ASW leachates. Of the NSW leachates, those from the ship paints were more toxic than those from leisure boat paints. The most toxic paint was the biocide-free leisure boat paint Micron Eco. This implies that substances other than added active agents (biocides) were responsible for the observed toxicity, which would not have been discovered without the use of biological tests.

Marine pollution from antifouling paint particles

Antifouling paint particles (APP) are generated during the maintenance of boats and are shed from abandoned structures and grounded ships. Although they afford a highly visible, colourful reflection of contamination in the vicinity of the source, little systematic study has been undertaken regarding the distribution, composition and effects of APP in the wider marine environment. This paper reviews the state of knowledge in respect of APP, with particular emphasis on those generated by recreational boatyards. The likely biogeochemical pathways of the biocidal and non-biocidal metals in current use (mainly Cu and Zn) are addressed in light of recent research and an understanding of the more general behaviour of contaminants in marine systems. Analyses of paint fragment composites from recreational facilities in the UK reveal chemical compositions that are similar to those representing the net signal of the original formulations; significantly, dry weight concentrations of Cu and Zn of up to about 35% and 15%, respectively, are observed and, relative to ambient dusts and sediment, elevated concentrations of other trace metals, like Ba, Cd, Cr, Ni, Pb and Sn, occur. These metals leach more rapidly from APP than a painted surface due to the greater surface area of pigments and additives exposed to the aqueous medium. In suspension, APP are subject to greater and more rapid environmental variation (e.g. salinity, pH, dissolved oxygen) than painted hulls, while settled APP represent an important source of persistent and degradable biocides to poorly circulating environments. Through diffusion and abrasion, high concentrations of contaminants are predicted in interstitial waters that may be accumulated directly by benthic invertebrates. Animals that feed non-selectively and that are exposed to or ingest paint-contaminated sediment are able to accelerate the leaching, deposition and burial of biocides and other substances, and represent an alternative vehicle for contaminant entry into the marine foodchain. Clearly, an extensive understanding of biocide behaviour on painted surfaces is not sufficient for predictive or management purposes regarding APP. Greater caution is required by boaters and boatyards during the removal and disposal of solid wastes, and more awareness or stricter enforcement of relevant codes of practice or legislation is recommended.

The influence of antifouling practices on marine invasions

Vessel hull-fouling is increasingly recognised as one of the major vectors for the transfer of marine non-indigenous species. For hundreds of years, copper (Cu) has been used as a primary biocide to prevent the establishment of fouling assemblages on ships' hulls. Some non-indigenous fouling taxa continue to be transferred via hull-fouling despite the presence of Cu antifouling biocides. In addition, several of these species appear to enjoy a competitive advantage over similar native taxa within metal-polluted environments. This metal tolerance may further assist their establishment and spread in new habitats. This review synthesises existing research on the links between Cu and the invasion of fouling species, and shows that, with respect to the vector of hull-fouling, tolerance to Cu has the potential to play a role in the transfer of non-indigenous fouling organisms. Also highlighted are the future directions for research into this important nexus between industry, ecology and environmental management.

Comparing differential tolerance of native and non-indigenous marine species to metal pollution using novel assay techniques

Recent research suggests anthropogenic disturbance may disproportionately advantage non-indigenous species (NIS), aiding their establishment within impacted environments. This study used novel laboratory- and field-based toxicity testing to determine whether non-indigenous and native bryozoans (common within marine epibenthic communities worldwide) displayed differential tolerance to the common marine pollutant copper (Cu). In laboratory assays on adult colonies, NIS showed remarkable tolerance to Cu, with strong post-exposure recovery and growth. In contrast, native species displayed negative growth and reduced feeding efficiency across most exposure levels. Field transplant experiments supported laboratory findings, with NIS growing faster under Cu conditions. In field-based larval assays, NIS showed strong recruitment and growth in the presence of Cu relative to the native species. We suggest that strong selective pressures exerted by the toxic antifouling paints used on transport vectors (vessels), combined with metal contamination in estuarine environments, may result in metal tolerant NIS advantaged by anthropogenically modified selection regimes.

Accumulation of Cu and Zn from antifouling paint particles by the marine macroalga, Ulva lactuca

The marine macroalga, Ulva lactuca, has been exposed to different concentrations of antifouling paint particles (4-200 mg L(-1)) in the presence of a fixed quantity of clean estuarine sediment and its photosynthetic response and accumulation of Cu and Zn monitored over a period of 2 days. An immediate (<2 h) toxic effect was elicited under all experimental conditions that was quantitatively related to the concentration of contaminated particles present. Likewise, the rate of leaching of both Cu and Zn was correlated with the concentration of paint particles added. Copper accumulation by the alga increased linearly with aqueous Cu concentration, largely through adsorption to the cell surface, but significant accumulation of Zn was not observed. Thus, in coastal environments where boat maintenance is practiced, discarded antifouling paint particles are an important source of Cu, but not Zn, to U. lactuca.

Effects of deposition of heavy-metal-polluted harbor mud on microbial diversity and metal resistance in sandy marine sediments

Deposition of dredged harbor sediments in relatively undisturbed ecosystems is often considered a viable option for confinement of pollutants and possible natural attenuation. This study investigated the effects of deposition of heavy-metal-polluted sludge on the microbial diversity of sandy sediments during 12 months of mesocosm incubation. Geochemical analyses showed an initial increase in pore-water metal concentrations, which subsided after 3 months of incubation. No influence of the deposited sediment was observed in denaturing gradient gel electrophoresis (DGGE) profiles of bacterial 16S rRNA genes, whereas a minor, transient impact on the archaeal community was revealed. Phylogenetic analyses of bacterial 16S rRNA clone libraries showed an abundance of members of the Flavobacteriaceae, the alpha- and gamma-Proteobacteria, in both the muddy and the sandy sediments. Despite the finding that some groups of clones were shared between the metal-impacted sandy sediment and the harbor control, comparative analyses showed that the two sediments were significantly different in community composition. Consequences of redeposition of metal-polluted sediment were primarily underlined with cultivation-dependent techniques. Toxicity tests showed that the percentage of Cd- and Cu-tolerant aerobic heterotrophs was highest among isolates from the sandy sediment with metal-polluted mud on top.