Abandoned, lost, or otherwise discarded fishing gear (ALDFG) is a global challenge that negatively affects marine environment through plastic pollution and continued capture of marine animals, so-called “ghost fishing”. In different pot fisheries, ghost fishing related to ALDFG is of concern, including pot fishery targeting swimming crab (Portunus trituberculatus). This study quantified the ghost fishing efficiency by comparing it to the catch efficiency of actively fished pots of the commercial fishery. The results showed that the ghost fishing affects both target and bycatch species. On average, the ghost fishing pots captured 12.53 % (confidence intervals: 10.45 %–15.00 %) undersized crab and 15.70 % (confidence intervals: 12.08 %–20.74 %) legal-sized crab compared to the actively fished pots. Few individuals of several bycatch species were also captured by ghost fishing pots. The results of this study emphasized the need to develop new management strategies for reducing marine pollution by ALDFG and associated negative effects in this pot fishery. | publishedVersion

Microplastics (MPs) were investigated at 19 sandy beaches along the eastern Mediterranean Moroccan coast. Sediment samples (5 mm–63 μ m) were analyzed to identify MPs abundance, size, shape, color and nature. MPs concentration ranged from 40 ± 7.4 to 230 ± 48.6 MPs kg 1 ; fibrous MPs were the most abundant (74.72 %), followed by fragments (20.26 %), films (3.27 %), pellets (1.42 %) and foams (0.33 %). Large MPs (1–5 mm) accounted for 58 %, while small (< 1 mm) for 42 %. The 1–2 mm fraction of sediments presented the greatest amounts (30.67 %) of MPs. Transparent (50 %) and blue (17 %) were most common colors and most of particles were angular and irregularly shaped. Fourier Transform Infrared Spectroscopy (FTIR) analysis showed that PE (Polyethylene), PS (Polystyrene) and PP (Polypropylene) and PVC (Polyvinyl chloride) were the most common polymers. These findings revealed a moderate level of microplastic pollution along the beaches of the eastern Moroccan Mediterranean coast.

In the last few decades, there has been a growing interest in understanding the behavior of personal care products (PCPs) in the aquatic environment. In this regard, the aim of this study is to estimate the accumulation and effects of four PCPs within the clam Ruditapes philippinarum. The PCPs selected were triclosan, OTNE, benzophenone-3, and octocrylene. A progressive uptake was observed and maximum concentrations in tissues were reached at the end of the exposure phase, up to levels of 0.68 μg g− 1, 24 μg g− 1, 0.81 μg g− 1, and 1.52 μg g− 1 for OTNE, BP-3, OC, and TCS, respectively. After the PCP post-exposure period, the removal percentages were higher than 65%. The estimated logarithm bioconcentration factor ranged from 3.34 to 2.93, in concordance with the lipophobicity of each substance. No lethal effects were found although significant changes were observed for ethoxyresorufin O-demethylase activity, glutathione S-transferase activity, lipid peroxidation, and DNA damage.

In December 2023, 25 tons of pellets were lost by the Toconao ship in the Northwest Atlantic Ocean in front of the Portuguese coast. In this work, a coastal stretch of 633 km in Asturias and Galicia (Spain) and Northern Portugal was investigated to assess pellets’ concentration on 31 beaches. Field surveys were carried out in March 2024 and focused on sampling plastic pellets deposited along the shoreline. All the 7263 sampled pellets were characterized by size, degradation level, and color, while one subset was characterized by weight (40 % of the total) and another subset by polymer type (15 % of the total) using FT-IR spectroscopy. The results reveal that 94 % of the surveyed sites containing pellets, whereas the concentration values vary significantly among beaches, ranging from 0 to 40.3 pellets/kgdw. By combining the accounted variables, it emerges that 48.0 % of the collected pellets can be linked to the Toconao spill.

The main objective of subsea mechanical dispersion (SSMD) is to reduce the oil droplet sizes from a subsea oil release, thereby influencing the fate and behaviour of the released oil in the marine environment. Subsea water jetting was identified as a promising method for SSMD and imply that a water jet is used to reduce the particle size of the oil droplets initially formed from the subsea release. This paper presents the main findings from a study including small-scale testing in a pressurised tank, via laboratory basin testing, to large-scale outdoor basin testing. The effectiveness of SSMD increases with the scale of the experiments. From a five-fold reduction in droplet sizes for small-scale experiments to more than ten-fold for large-scale experiments. The technology is ready for full-scale prototyping and field testing. Large-scale experiments performed at Ohmsett indicate that SSMD could be comparable to subsea dispersant injection (SSDI) in reducing oil droplet sizes. | publishedVersion

The main objective with subsea mechanical dispersion (SSMD) is to influence the fate of an oil spill in the marine environment by significantly reducing oil droplet sizes from subsea release of oil. Earlier studies have indicated that the capability of SSMD to reduce oil droplet sizes is comparable to subsea dispersant injection (SSDI). Earlier testing of SSMD has mainly used a low viscus paraffinic oil. Focus for this study was to study SSMD and SSDI effectiveness using five oil types spanning out a wide variation of relevant oil properties. Effectiveness was quantified as the reduction in oil droplet sizes measured by a Silhouette camera. Testing of the two technologies were completed in the same experiment on a simulated subsea release. The results show a variation in effectiveness for both technologies as a function of oil properties. SSMD and SSDI showed comparable effectiveness for all oils tested. | publishedVersion

Modeling studies illustrate the potential for long-range transport of plastics into the Arctic, although the degree to which this occurs remains relatively undocumented. We utilised a teaching exercise at a UArctic summer school graduate course in Nuuk, Greenland to conduct a preliminary in-depth analysis of beach litter sources in the Nuup Kangerlua fjord. Students and instructors collected and analysed 1800 litter items weighing 200 kg from one location in the fjord and another at its mouth. The results suggest a predominance of local sources to macrolitter, rather than long-range transport from Europe. Fisheries-related items and rope were common. Packaging which could be identified was largely suspected to be products distributed in Greenland, and soft plastics, which rarely disperse far from its source, were also common. The results suggest local measures to reduce mismanaged waste and emissions from fisheries are important for reducing marine litter in West Greenland. | publishedVersion

Plastic floating on the ocean surface represents about 1 % of all plastic in the ocean, despite the buoyancy of most plastics. Biofouling can help to sink debris, which could explain this discrepancy. A set of laboratory experiments was conducted to investigate biofilm-induced effects on the buoyancy of different plastic debris. Ten materials of different densities (buoyant/non-buoyant), sizes (micro/meso/macro), and shapes (irregular/spherical/cylindrical/ flat), including facemasks and cotton swabs, were evaluated. Biofilm was incubated in these materials from a few weeks to three months to investigate the effect of different growth levels on their buoyancy. Biofilm levels and rising/settling velocities were measured and compared at seven time-points. The results show a hindered buoyancy for solid materials, while hollow and open materials showed the opposite trend in early biofilm colonization stages. A relationship was established between biofilm-growth and equivalent sphere diameter that can be used to improve predictive modeling of plastic-debris transport. | This work was funded by the European Regional Development Funds (Interreg Maritime IT FR program) under the SPlasH & Co project (contract number D35F21002010001). The first author was supported by a Margarita Salas Postdoctoral Fellowship funded by the European Union-NextGenerationEU, Ministry of Universities and Recovery Transformation and Resilience Plan, through a call from the University of Cantabria and the Government of Cantabria through the Fénix program.

Decades of atmospheric and oceanic long-range transport from lower latitudes have resulted in deposition and storage of persistent organic pollutants (POPs) in Arctic regions. With increased temperatures, melting glaciers and thawing permafrost may serve as a secondary source of these stored POPs to freshwater and marine ecosystems. Here, we present concentrations and composition of legacy POPs in glacier- and permafrost-influenced rivers and coastal waters in the high Arctic Svalbard fjord Kongsfjorden. Targeted contaminants include polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs) and chlordane pesticides. Dissolved (defined as fraction filtered through 0.7 μm GF/F filter) and particulate samples were collected from rivers and near-shore fjord stations along a gradient from the heavily glaciated inner fjord to the tundra-dominated catchments at the outer fjord. There were no differences in contaminant concentration or pattern between glacier and tundra-dominated catchments, and the general contaminant pattern reflected snow melt with some evidence of pesticides released with glacial meltwater. Rivers were a small source of chlordane pesticides, DDTs and particulate HCB to the marine system and the particle-rich glacial meltwater contained higher concentrations of particle associated contaminants compared to the fjord. This study provides rare insight into the role of small Arctic rivers in transporting legacy contaminants from thawing catchments to coastal areas. Results indicate that the spring thaw is a source of contaminants to Kongsfjorden, and that expected increases in runoff on Svalbard and elsewhere in the Arctic could have implications for the contamination of Arctic coastal food-webs. | publishedVersion

Submarine tailing disposal (STD) in fjords from land-based mines is common practice in Norway and takes place in other regions worldwide. We synthesize the results of a multidisciplinary programme on environmental impacts of STDs in Norwegian fjords, providing new knowledge that can be applied to assess and mitigate impact of tailing disposal globally, both for submarine and deep-sea activities. Detailed geological seafloor mapping provided data on natural sedimentation to monitor depositional processes on the seafloor. Modelling and analytical techniques were used to assess the behaviour of tailing particles and process-chemicals in the environment, providing novel tools for monitoring. Toxicity tests showed biological impacts on test species due to particulate and chemical exposure. Hypersedimentation mesocosm and field experiments showed a varying response on the benthos, allowing to determine the transition zone in the STD impact area. Recolonisation studies indicate that full community recovery and normalisation of metal leakage rates may take several decades due to bioturbation and slow burial of sulfidic tailings. The results are synthesised to provide guidelines for the development of best available techniques for STDs. | publishedVersion