River and coastal sediments were collected at 17 stations in Ulsan, the largest industrial city in South Korea, to evaluate the levels, profiles, emission sources, and spatial distribution of polycyclic aromatic hydrocarbons (PAHs). The mean concentration of Σ₁₆ PAHs was 722 ng/g, and fluoranthene was a predominant compound. PAHs with 4–6 rings showed higher proportions than PAHs with 2–3 rings. The stations located near industrial complexes showed elevated levels of indicator compounds for petroleum, coal, coke, and fuel combustion. Therefore, petrochemical industries, coal pier, non-ferrous industries, and vehicles were identified as the emission sources. As industrialization and urbanization progressed, an increase in PAH levels and profile changes were observed as a result of the increasing industrial fuel consumption and the increasing number of vehicles. This is the first study that confirmed the change of PAHs in sediment caused by the change of emission sources over time in Ulsan.

Microplastics are widespread pollutants in the marine environment, yet few studies have assessed the abundance and characteristics of microplastics in commercial species. This study evaluates the presence of ingested microplastics in the gastrointestinal tract of Nephrops norvegicus (n = 150), collected from five Irish prawn grounds. The efficiency of three digesting solutions was assessed. The most efficient digestion was the KOH (10%) solution incubated at 40 °C for a 48 h period. An average of 1.75 ± 2.01 items per individual was ingested by c. 69% of N. norvegicus examined. A total of 262 microplastic, predominantly fibres (98%), between 1 and 2 mm were recorded. Although, no spatial pattern was identified, samples from the North Irish Sea recorded highest occurrence of microplastics (~83%). A positive correlation was found between microplastic abundance and prawn carapace condition. Results indicate microplastic exposure in seafood for human consumption, in Ireland, is estimated to range from 15 to 4471 particles per year.

Oil Spill Chemicals (OSCs) represent a risk to the environment and human health, especially in nearshore environments used for recreational purposes. Importantly, the starting point for human health risk assessment is to define the concentration of OSCs at nearshore locations. The objective of this study was to evaluate nearshore sampling data of OSC concentrations in different environmental matrices within time-space specific categories. The categories correspond to OSC concentration values for samples collected prior to nearshore oiling, post nearshore oiling and at no time impacted by oil as predicted by historic oil spill trajectories generated by an Oil Spill Trajectory Model. In general, concentration values for the post category were higher than prior which were higher than unimpacted. Results show differences in PAH concentration patterns within each matrix and for each category. Concentration frequency distributions for most chemicals in each category were log-normally distributed.

Polychlorinated biphenyls (PCBs) were quantified in sediments from the lower reaches of the Niger, Ase and Forcados Rivers in Nigeria with the aim of elucidating the sources, spatial characteristics and likely ecological and human health risks relating to exposure to PCBs in the sediments. A total of 28 PCB congeners, including 7 indicator PCBs and 12 dioxin-like PCBs, were identified and quantified after Soxhlet extraction with acetone/n-hexane/dichloromethane by gas chromatography–mass spectrometry. The Σ28 PCB concentrations in sediments from the Niger, Ase and Forcados Rivers ranged from 13.5 to 277 ng g⁻¹, not detected to 1633 ng g⁻¹ and 6.9 to 78.6 ng g⁻¹ respectively. The PCB composition in sediments from these three rivers indicate the dominance of lower chlorinated (2-Cl to 5-Cl) congeners over higher chlorinated (6-Cl to 10-Cl) congeners. The ecological and human health risk assessment suggests potential risks for exposure of both organisms and humans to PCBs in sediments from these three river systems.

Corrosion and disintegration of munition shells from the World Wars increase the risk that explosives are released into the marine environment, exposing a variety of organisms. Only few studies investigated contamination of fish with explosives in the field under environmental conditions. Here we present a comprehensive study on the contamination status of dab (Limanda limanda) from a munition dumpsite and from reference sites in the Baltic Sea. Bile of 236 dab from four different study sites, including a dumpsite for conventional munitions, was investigated and explosive compounds were detected by high performance liquid chromatography-mass spectrometry. Five explosive compounds were identified, including 2,4,6-trinitrotoluene, 4-amino-2,6-dinitrolouene, and hexahydro-1,3,5-trinitro-1,3,5-triazine. 48% of the samples from the dumpsite contained at least one explosive compound. The results prove that toxic explosive compounds from a dumpsite in the Baltic Sea are accumulated by flatfish and may therefore pose a risk to fish health and human food safety.

To better understand the uptake, biotransformation and physiological response to tetrabromobisphenol A (TBBPA) in mangrove plants, a short term 14-day hydroponic assay with two mangrove species, Avicennia marina (A. marina) and Kandelia obovata (K. obovata), was conducted. Results showed that two mangrove species could uptake, translocate and accumulate TBBPA from solution. The hydroxylation and debromination metabolites of TBBPA, including OH-TBBPA, TriBBPA, MonoBBPA, and BPA, were found in both mangroves for the first time. The high-level TBBPA suppressed the growth and increased malondialdehyde (MDA) content of K. obovata, did not pose any negative affect on A. marina. The activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) of K. obovata significantly increased in the 7th day, whereas, SOD and POD activities at high-levels of TBBPA became comparable to the control in the 14th day. Contrastingly, the antioxidant enzymes activities of A. marina were positively stimulated by TBBPA during the 14-day of observation, indicating that A. marina was more tolerant of TBBPA.

An attempt was made in during August 2018 to study the plastic debris present in beach sediments at the remote islands of the Andaman and Nicobar Archipelago, India. The maximum number of plastic debris was noticed in the North and Middle Andaman Island sector and the Nicobar Island sector. White, irregular shaped polyethylene and polypropylene debris were the predominant plastic varieties found in the study area. The plastic litters disposed in the marine environment could be carried away by currents, which then circulate around the island and finally reach the coastal areas of the Andaman and Nicobar Archipelago. The plastic litter was contributed from tourist, shipping activities and improper handling of solid wastes.

Climate change effects such as ocean acidification (OA) are known to affect the trace metal distribution. This experimental study provides the first data on ²⁰⁹Po uptake rates and ²¹⁰Po concentration in five microalgae species under different pH scenarios. The experiment was conducted in replicates at three pH conditions 8.2, 8.0, and 7.5, representing the current and future climate change scenario as per IPCC RCP8.5. The ²⁰⁹Po uptake in the phytoplankton was highest in Thalassiosira weissflogi, i.e. 83% of the ²⁰⁹Po tracer was taken up at 8.2 pH whereas the lowest uptake was observed in Dunaliella salina equivalent to 20% at 7.5 pH. Similar behavior was observed in ²¹⁰Po concentrations in these microalgae, where ²¹⁰Po ranged between 3.16 ± 0.03 and 11.6 ± 0.04 Bq kg⁻¹ wet weight (ww), with the highest in the Thalassioria weissflogi at 8.2 pH, and the lowest in Dunaliella salina at 7.5 pH. The difference in ²⁰⁹Po uptake and ²¹⁰Po concentration was statistically significant (p < 0.001) both among species and the pH treatments in the order: Thalassiosira weissflogi > Tetraselmis suecica > Chaetoceros muelleri > Isochrysis galbana > Dunaliella salina and 8.2 > 8.0 > 7.5. A higher concentration of ²⁰⁹Po in seawater was measured at low pH condition in all the experimental tanks. Though the data clearly show the difference in concentration and uptake of polonium at different pH conditions, it is not known if lower pH is affecting the adsorbed or absorbed fraction. A detailed investigation will be required to understand the process as it can have a significant effect on biomagnification and marine food chain transfer under changing climatic scenarios.

Imposex is a condition in which females of dioecious marine snails develop rudimentary male characteristics. It is caused by tributyltin (TBT) used as an antifoulant in vessel paints since the late 1960s. Following the 2008 international ban on TBT, a decreasing rate of imposex has been observed worldwide. In Western Australia, imposex surveys of the whelk Thais orbita up to 2011 in the Perth metropolitan area suggested a decreasing trend but a significant recovery has not been confirmed. Collection of T. orbita from 11 sites in 2019 demonstrated a virtually complete recovery from imposex. Although it is generally accepted that male snails are not affected by TBT, the historical data set allowed confirmation that the male penis is of similar size in T. orbita collected at heavily affected sites and at relatively unaffected sites. Similarly, imposexed female snails had similar shell lengths to female snails at non-impacted sites.

Laguncularia racemosa and Sonneratia apetala are fast-growing exotic mangrove species in Southern China and widely used for afforestation. However, the invasiveness of the two exotic species is still unclear. We compared structural and physiological traits and energy-use related traits between L. racemosa and S. apetala, and with two natives (Kandelia obovata and Aegiceras corniculatum) in northern Fujian. Results showed that leaf construction cost based on mass (CCM) and caloric values of L. racemosa were significantly lower than S. apetala, and the two natives had highest CCM. Because lower CCM, L. racemosa grew faster with a taller height (4.83 m) and wider ground diameter circumference (40.03 cm) than S. apetala (4.43 m tall and 35.63 cm wide) and the two natives (2.42 m tall and 26.78 cm wide). These findings indicated that L. racemosa could be more invasive than S. apetala in mangrove forests in northern Fujian, China where it still grew well, which deserves more attention.