Analysis of paint traces to determine the ship responsible for a collision

Microfiber Hotspots' Association with Ships in a Remote Port before and during Covid-19

During monthly water quality monitoring of Norwegian coastal waters, the sea surface waters off Brønnøysund, a remote port in Norway, exhibited an unexpectedly high abundance of microfibers. We further conducted monitoring of microplastics and microfibers from the surface waters off the city before and during the Covid-19 pandemic. Analysis of the microfiber characteristics, which were primarily comprised of cellulosic and polyester fibers, revealed similarities with those found in the global ocean, but at concentrations that were 1-4 orders of magnitude higher, with the maximum concentration reaching 491 n/L (0.34 mg/L). Source apportionment of microfibers using multivariate analyses based on simultaneous water chemistry data showed positive correlations with ships. Contrary to previous assumptions that marine microfibers were derived from land-based sources, our findings revealed that gray water discharge from ships significantly contributed to microfibers in the oceans. The demonstrated causations using path modeling between microfibers, gray water, shipping, and noncargo shipping activities call for urgent research and regulatory actions toward addressing plastic pollution in the UN Decade of Ocean Science.

Occurrence and chemical characteristics of microplastic paint flakes in the North Atlantic Ocean

Non-fibrous microplastics sampled by the Continuous Plankton Recorder (CPR) Survey throughout the North Atlantic Ocean during 2018 have been recorded and a selection (n = 17, or 16.7%) physically and chemically characterised. The average abundance of non-fibrous particles captured by the plankton silks and detectable by microscopy was estimated to be around 0.01 m^-3, with the highest concentrations evident in shelf seas of northwest Europe. Amongst the samples analysed, median size was 180 μm and, based on visible properties (e.g., brittleness, layering) and infra-red spectra, all but one were identified as flakes of paint. Semi-quantitative analysis by energy-dispersive X-ray fluorescence spectrometry with a collimated beam revealed that six flakes from European shelf seas were Cu-based antifouling formulations (without evidence of organo-Sn compounds), and five with a broader geographical distribution were Pb-based formulations of likely marine origin. Other elements regularly detected included Cr, Fe, Ti and Zn that were present in pigments or as contaminants from the underlying substrate. After fibres, paint flakes appear to be the most abundant type of microplastic in the oceans that, because of the abundance and mobility of metallic additives, deserve closer scientific attention.

Microplastic load and polymer type composition in European rocky intertidal snails: Consistency across locations, wave exposure and years

Microplastics (<5 mm) are emerging pollutants in oceans worldwide. As such small particles are easily ingested, microplastics are found in numerous pelagic and benthic organisms. However, information on microplastics in rocky intertidal organisms and habitats is relatively scant. Therefore, we examined snails and water samples from wave-sheltered and wave-exposed rocky intertidal habitats in Helgoland (North Sea), Cap Ferrat and Giglio (Mediterranean) and Madeira (Atlantic Ocean) in 2019-2020 for microplastics. Furthermore, we examined snails from the same habitats in Helgoland, Cap Ferrat and Giglio in 2007-2009. In total, we performed 362 individual micro-Fourier-transform infrared spectroscopy (μFTIR) measurements on the snails and water samples. While the snails contained 50 microplastics (composed of nine polymer types), the water samples contained 24 microplastics (comprising six polymer types). Microplastic load and polymer type composition in the snails were rather similar across locations, wave exposure and years. Also, microplastic load and polymer composition in the water samples were similar across locations and wave exposure. Moreover, snail and water microplastic loads were significantly correlated which indicates that snails are useful bioindicators for microplastic loads in rocky intertidal habitats. Interestingly, the majority of the microplastics consisted of paint chips that likely derived from ships. Overall, our study provides the first comprehensive microplastic record in rocky intertidal organisms across locations, wave exposure and years that can serve as a baseline to examine historic and future microplastic dynamics in rocky intertidal systems.

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.