Certain ultra-violet filter (UVF) components of solar creams have negative impacts on coral reefs and have been prohibited in international tourism destinations (i.e., Hawaii, Florida, and Palau) to protect coral reefs. In the Mediterranean coasts which are also hotspots of international tourism and where endemic seagrass Posidonia oceanica forms extensive meadows, the accumulation of UVF components have not been studied. We report for the first time, that the rhizomes of P. oceanica internally accumulated UVFs BP3, BP4, AVO, 4MBC and MeBZT and the paraben preservative MePB. The components BP4 and MePB occurred in higher concentrations reaching up to 129 ng g⁻¹ dw and 512 ng g⁻¹ dw, respectively. This work emphasizes the need for more experimental studies on the effects of UVFs on seagrasses and check if we should follow suit to prohibit certain UVFs to protect this species as what has been done in other regions to protect corals.

This baseline study describes the microplastic (MPs) problem on seven beaches located on Agadir, central Atlantic coast of Morocco. Microplastics abundances (densities) ranged from 7680 MPs/kg to 34,200 MPs/kg above other world beaches. The following shapes were found: fibers, fragments, films, and pellets. Fibers were the dominant typology with a 73%. Polyethylene (PE) was the predominant polymer in all beaches with an average percentage of 59%, followed by Polypropylene (PP - 18%), Polystyrene (PS - 9%), Polyvinyl chloride (PVC - 8%), and Ethylene-vinyl acetate (EVA - 6%). Microplastics abundances presented in this work suggest continuous inputs of plastics of all sizes and types. Also, all observed shapes highlight a combination of sources (primary and secondary). Central Atlantic Moroccan beaches are currently affected by extreme values of MPs that demand urgent interventions to restore environmental quality.

The present study aimed to assess the levels of heavy metals and metalloids present in six seaweeds and their potential impact on consumption. The highest concentration of 11 metals, i.e., Be (0.47 mg/kg), Co (4.34 mg/kg), Cr (23.46 mg/kg), Cu (11.96 mg/kg), Fe (2290.26 mg/kg), Li (11.55 mg/kg), Ni (13.75 mg/kg), Pb (6.67 mg/kg), Ti (736.62 mg/kg), Tl (0.14 mg/kg), and V (33.09 mg/kg) were observed in Enteromorpha intestinalis (green seaweeds). Besides, the highest concentration of Ca (1071.09 mg/kg), Cd (5.81 mg/kg), Mn (1003.41 mg/kg), Sr (2838.86 mg/kg), and Zn (41.95 mg/kg) were found in Padina tetrastromatica (brown seaweeds). Eight metals (Pb, Cd, Zn, Cu, Ni, Mn, Cr, Fe) have been used to assess the potential health risk for adults, but no potential health risk was detected (HQ value > 1). The HI value of E. intestinalis and P. tetrastromatica were >1, implying that these two seaweeds are not safe for human consumption as there is a carcinogenic health risk for adults.

Microplastics (MPs) were collected at six locations along Kenya's marine nearshore surface waters using a 300 μm mesh-size manta net. The samples were washed over a 125-μm mesh size sieve No.120 into a glass jar and preserved in 70% ethanol. MPs were sorted, counted visually under a dissecting microscope then identified using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. A total of 1473 particles with an overall mean concentration of 0.58 ± 1.29 MPs m⁻³, were collected. Fragments were the most common types representing 55% of the total MPs, followed by films (40%) and fibers (2%). Polypropylene (PP) was dominant (52%), high-density polyethylene (HDPE) comprised 38% and low density polyethylene (LDPE) 10% of the total MPs. This study provided baseline information, in which Malindi was identified as a hot spot for MPs pollution. Furthermore, the outcomes will assist policy formulations and management strategies aimed at controlling marine plastics.

Studies show that a driver of coastal debris is the rate between debris deposition and resuspension; however, the influence of beach zone topography on the distribution of debris remains poorly understood. Using five years of marine debris data collected by the COASST citizen science program, we explored the spatiotemporal trends in debris abundance within two regions of the United States Pacific Northwest and investigated whether higher debris loads are associated with beach zones that have a higher propensity to trap debris. We found that beaches with larger wood zones had higher debris loads, adding to the growing evidence that backshore areas of beaches act as sinks for debris. Higher debris loads were also associated with beaches that had larger wrack zones suggesting that onshore transport from the marine reservoir is a dominant source of debris. This study provides a long-term baseline of marine debris which managers could use to inform source reduction interventions.

Particle size plays an important role in determining the behaviour, fate and effects of microplastics (MPs), yet little is known about MPs <300 μm in aquatic environments. Therefore, we performed the first assessment of MPs in marine surface waters around the Whitsunday Islands region of the Great Barrier Reef Marine Park, Australia, to test for the presence of small MPs (50–300 μm) in-situ. Using a modified manta net, we demonstrate that MPs were present in all marine surface water samples, with a mean sea surface concentration of 0.23 ± 0.03 particles m⁻³. Microplastics were mainly blue, clear and black fibres and fragments, consisting of polyethylene terephthalate, high-density polyethylene and polypropylene plastic polymers. Tourism and marine recreation were considered the major contributing sources of MPs to surface waters around the Whitsunday Islands. Between 10 and 124 times the number of MPs exist in the 50 μm–300 μm size class, compared with the 1 mm–5 mm size range. This finding indicates that the global abundance of small MPs in marine surface waters is grossly underestimated and warrants further investigation. Research into the occurrence, characteristics and environmental fate of MPs <300 μm is needed to improve our understanding of the cumulative threats facing valuable ecosystems due to this smaller, potentially more hazardous size class.

In this study, we evaluated the combined effects of exposure to BP3 (at an environmentally relevant concentration of 1 μg/L) with temperature increasing (24 °C) in the marine bivalve Amarilladesma mactroides. The BP3 (1 μg/L) at 20 °C increased ROS and antioxidants in the digestive glands of clams, without causing significant effect on lipid peroxidation (LPO). However, at high temperature (24 °C), BP3 suppressed increases in antioxidant defenses, mainly glutathione peroxidase, lead to a rise in LPO in the digestive gland, however this condition increased hemocyte viability. The Integrated Biological Responses (IBR) approach show that temperature influences BP3 effects, as the highest score was observed in animals exposed to 1 μg/L of BP3 at 20 °C (9.35), while the lowest was observed in BP3 group at 24 °C (1.02). These results draw attention to the harmful effects of BP3 on bivalves, especially in a scenario of thermal stress.

This editorial presents results of the MANA (MANagement of Atolls) project compiled in the form of a Marine Pollution Bulletin collection of 14 articles. MANA is a project funded by the French Agence National pour la Recherche that specifically addresses the development of knowledge and management tools for pearl farming atolls, with a focus on the spat collecting activity in French Polynesia. The 14 papers cover the range of thematic tasks described in the initial project, including atoll geomorphology and bathymetry, climate forcing, atoll lagoon and rim hydrodynamics, typology of atolls, evaluation of remote sensing data for monitoring atoll lagoons, and development of numerical models and spatially-explicit tools that altogether have contributed to the applied objectives. In addition, this editorial draws an update on the pearl farming industry in French Polynesia with the latest statistics, and discusses the next targeted priorities for research programs focusing on pearl farming atolls.

Accidental oil spills from pipelines or tankers have posed a big threat to marine life and natural resources. This paper presents a novel lightweight bilateral segmentation network for detecting oil spills on the sea surface. A novel deep-learning semantic-segmentation algorithm is firstly created for analyzing the characteristics of oil spill images. A Bilateral Segmentation Network (BiSeNetV2) is then selected as the basic network architecture and evaluated by using experimental comparison of the current mainstream networks on detection accuracy and real-time performances for oil samples. Furthermore, the Gather-and-Expansion (GE) layer of the semantic branch in the traditional network is redesigned and the parameter complexity is reduced. A dual attention mechanism is deployed in the two branches of the BiSeNetV2 to solve the problem of inter-class similarity. Finally, experimental results are given to show the good detection accuracy of the proposed network.

During offshore petroleum production, large volumes of produced water are continuously discharged. The environmental impact from such discharges is typically assessed with numerical models, which simulate the transport and dilution of the produced water plume in order to predict environmental concentrations of its chemical constituents. In this study we investigate the effects of model resolution (800 m and 4 km) on produced water dispersion. We also compare two different types of models, a Lagrangian particle model, and an Eulerian grid-based ocean model to assess the Eulerian consistency of the Lagrangian model. We consider a point source off the coast of mid-Norway, during two different seasons (winter and spring). In general, the two models are in reasonable agreement. We find a substantial difference in tracer distribution and concentrations between the two resolutions, and to a lesser extent between seasons; in particular, the 800 m model shows lower concentrations along the coast.