Seagrasses have global distribution and are highly productive and economically valuable habitats. They are sensitive and vulnerable to a range of human-induced pressures, including ongoing exposure to marine litter, such as microplastic particles (<5 mm). In this study, a Zostera marina bed in Deerness Sound, Orkney was selected to determine whether microplastics accumulate in seagrass beds and adhere to seagrass blades. Sediment, seagrass blade, biota and seawater samples were collected. 280 microplastic particles (0.04 to 3.95 mm (mean = 0.95 mm ± 0.05 SE)) were observed in 94% of samples collected (n = 111). These were visually categorised into type (fibre, flake, fragment) and colour, and 50 were successfully identified as plastic using ATR-FTIR. Fibres contributed >50% of the total microplastics observed across all samples. This is the first known study on Z. marina to describe microplastic loading within a seagrass bed and to identify microplastic adherence to seagrass blades.

The current study aimed to develop a suitable molecular marker [Linear alkylbenzenes (LABs)] approach for pollution determination in mangrove oysters of peninsular Malaysia. C. belcheri species were collected from rivers of Merbok, Perai, Klang, Muar and PulauMerambong (An Island). The LABs were extracted from C. belcheri and determined using GC–MS. The LABs indices which included I/E, L/S and C13/C12 were applied to describe the sources and biodegradation of LABs. The results revealed that the maximum concentrations were detected in oysters from Klang (27.91 ng g⁻¹dw), while the lowest concentrations were detected in oysters from Merbok (8.12 ng g⁻¹dw). Moreover, I/E ratios varied between 2.83 and 6.40, indicating the secondary treatment effluents being discharged to coastal zones. The results of this study suggested that the oysters absorbed LABs mainly in dissolved phase. Therefore, mangrove oysters are a good biosensor for LABs contamination in the aquatic environment.

Due to regulations on phthalates, non-phthalate plasticizers (NPPs) are now used as an alternative. Limited studies have been conducted on the occurrence and distribution of NPPs. In this study, sediment samples were collected from 50 locations along the Korean coast to assess the occurrence, distribution, sources, and ecological risks of phthalates and NPPs. Phthalates and NPPs were detected in all sediments, indicating ubiquitous contamination of the coastal environment. Di(2-ethylhexyl)phthalate (DEHP) and di(2-ethylhexyl)terephthalate (DEHT) were dominant, suggesting that DEHT could be an emerging contaminant of concern. The highest concentrations of phthalates and NPPs were found in sediment samples from harbors, implying they are contaminated hotspots. Sedimentary organic carbon was a major factor governing the distribution of phthalates and NPPs. Significant correlations were observed among phthalates and NPPs, suggesting similar sources and geochemical behavior. DEHP concentration exceeded threshold values, indicating potential health risks to benthic organisms in sediments.

A phytoremediation experiment was carried out in mesocosms to investigate the performance of Rhizophora mangle in the remediation of polycyclic aromatic hydrocarbons (PAHs) in mangrove sediment contaminated with crude oil. The water pH of the experiments (phytoremediation and natural attenuation) ranged from 4.9 to 8.4 at 0 and 90 days, respectively. The oxy-reduction potential (Eh) ranged from oxidising (108.0 mV, time 0) to reducing (approximately −110.0 mV, time 90) environments. Dissolved oxygen (DO) ranged from 5.7 mg L⁻¹ (time 0) to 4.5 mg L⁻¹ and 3.6 mg L⁻¹ (time 90) in phytoremediation and natural attenuation, respectively. The sediments had silty texture and an average concentration of 5% organic matter (OM). Phytoremediation (60.76%) showed better efficiency in the remediation of the 16 PAHs compared to natural attenuation (49.57%). Principal component analyses showed a correlation between the concentrations of PAHs with pH, Eh, OM and DO in both experiments.

Gulls are generalist seabirds, increasingly drawn to urban environments where many species take advantage of abundant food sources, such as landfill sites. Despite this, data on items ingested at these locations, including human refuse, is limited. Here we investigate ingestion of prey and anthropogenic debris items in boluses (regurgitated pellets) from Pacific Gulls (Larus pacificus). A total of 374 boluses were collected between 2018 and 2020 in Tasmania. Debris was present in 92.51% of boluses (n = 346), with plastic (86.63%, n = 324) and glass (64.71%, n = 242) being the most prominent types. An abundance of intact, household items (e.g., dental floss, food wrappers) suggest the gulls regularly feed at landfill sites. In addition, the boluses are deposited at a roosting site located within an important wetland, thus we propose that the gulls may be functioning as a previously unrecognised vector of anthropogenic debris from urban centres to aquatic environments.

Meiofauna particularly marine nematodes around the Caiwei Guyot in the northwest Pacific Ocean and a Polymetallic Nodule Field in the northeast Pacific Ocean were studied. Due to the geographic structure, the Caiwei Guyot and the Polymetallic Nodule Field had different environmental characteristics. Meiofaunal abundances around the Guyot area ranged from 9.18 to 25.59 ind./10 cm², which were much lower than those in the Polymetallic Nodule Field. Marine nematode was the most dominant group. A total of 123 species, belonging to 74 genera and 29 families were found. Xyalidae (21.43%), Cyatholaimidae (9.82%), Linhomoeidae (8.03%) were the dominant families. The values of species number, Margalef's species richness and Shannon-Wiener diversity index ranged from 15 to 62, 4.75 to 12.84 and 2.58 to 3.93, respectively. The combination of water depth, silt-clay content and chlorophyll-a concentration can best explain the differences of nematode community. This study provides a baseline for deep-sea meiofauna distribution.

Mangroves are highly susceptible to oil exposure. Depending on the severity, oil exposure can result in initial defoliation and eventual recovery through to mass mortality and complete loss of habitat. Some aspects of the impact of oil on mangroves and their recovery are well studied, but the focus has been on short-term responses, and the understanding of the longer-term trajectory of mangrove recovery from oiling is very limited. Here, we combine field results from sampling in the two years following a significant oiling event, with analysis of canopy cover in aerial images from before the event to 26 years afterwards. Approximately 100 ha of a monospecific stand of Avicenna marina mangroves were oiled as a result of a spill from the Era tanker in Spencer Gulf in southern Australia in September 1992. While lightly oiled trees made a full recovery, trees in heavily oiled areas experienced mass defoliation and ultimately mortality within several months of the oiling event. An analysis of aerial images indicated that there was no recovery in heavily oiled areas for 10 years following the oiling event. Between 10 and 25 years, seedling establishment and growth saw canopy cover increase to 35% of pre-oiling cover within heavily oiled areas. Predictive modelling estimates that complete recovery of mangroves to pre-oiling cover will take 55 years (median prediction in 2047). Our findings indicate that although mangroves can recover following a heavy oiling event, the rate of recovery can be slow, with full recovery in the order of half a century, much longer than has previously been anticipated.

Heavy metal concentrations in sediments of the Gulf of Pozzuoli, GoP, and northwest of the Gulf beyond Monte di Procida, MdP, were determined. The enrichment factor, EF, revealed in GoP strong pollution with peaks for Cr and Cu of 61.1 and 96.9. High EF Cr, Cu, and Ni values were observed for MDP. Geoaccumulation index, Igeo, rates GoP extremely polluted by Cr and Cu, Igeo > 5, and MdP heavily polluted by Cr, moderately to heavily polluted by Cu, and heavily to extremely polluted by Ni. Contamination factor, Cf, was high in GoP and varied: Cu > Cr > Ni > Cd > Hg > Zn > Pb > As, and those of Cr, Cu and Ni largely surpassed the thresholds in MdP. The ecological and comprehensive ecological risk placed Cr, Cu, Hg and Ni at high or serious risk level in the Gulf, with a peak of 465 for Cu and at a moderate level in MdP except for a very high risk for Ni.

PURPOSE OF REVIEW: Biological aerosol particles play a crucial role in the Earth system, particularly in the land/ocean-atmosphere interactions. This paper aims to summarize the up-to-date research progresses on the characteristics, biomarkers as well as the health-related, climatic and ecological effects of biological aerosol particles in polluted regions, especially in East Asia and South Asia. RECENT FINDINGS: The atmospheric abundance, size distribution, and community structure of microorganisms show differences during haze and non-haze conditions. The long-distance transportation of dust-associated microorganisms influences the abundance and community structure of airborne microbes in downwind areas. Wildfire smoke or biomass burning potentially impacts the release, transport and dispersal of microorganisms in the atmosphere. Meteorological conditions and air pollutants likely interact with airborne microorganisms, pollen, and fluorescent biological aerosol particles. Molecular biomarkers including proteins and amino acids, sugars, and lipid compounds have been used to fingerprint the sources of biological aerosols and give important biogeochemical information of atmospheric aerosols. In addition to pathogenic and allergenic microorganisms and pollen, biological aerosol particles indicated by abundant endotoxins and antibiotic resistance genes could have significant impacts on public health. In polluted regions, the potential influences of biological aerosol particles on climate and ecosystems could be more complex. We comprehensively summarize the recent research progresses on the characteristics, biomarkers, influencing factors, and effects of biological aerosol particles in polluted regions, mostly in East Asia and South Asia. To further understand the complicated effects of biological aerosol particles in polluted regions, the development and application of novel approaches and techniques as well as in-depth investigations on the roles of biological aerosol particles in atmospheric chemistry, cloud formation, and public health need to be implemented.

While the ecosystem of the Great Barrier Reef (GBR), north-eastern Australia, is being threatened by the elevated levels of sediments and nutrients discharged from adjacent coastal river systems, the source of these detrimental pollutants are not well understood. Here we used a combined isotopic (δ¹³C, δ¹⁵N) and geochemical (Zn, Pt and S) signatures and stable isotope analysis in R (SIAR) mixing model to estimate the contribution of different land uses to the sediment and associated particulate nitrogen delivered to the Johnstone River. Results showed that rainforest was the largest contributor of suspended and bed sediments in the river estuary (both 33.1%), followed by banana (26.7%, 20.4%), sugarcane (21.5%, 21.4%) and grazing (18.7%, 25.1%). However, bananas and sugarcane land uses had the highest contribution to sediments delivered to the coast per unit of area. This will help land managers to prioritise on-ground activities to improve water quality in the GBR lagoon.