Riverine input is an important source of contaminants in the marine environments. Based on a hydrodynamic model, the dilution characteristics of riverine contaminants in the Seto Inland Sea and their controlling factors were studied. Results showed that contaminant concentration was high in summer and low in winter. Contaminant concentration decreased with the reduction of its half-life period, and the relationship between them followed power functions. Sensitivity experiments suggested that the horizontal current and vertical stratification associated with air-sea heat flux controlled the seasonal cycle of contaminant concentration in the water column; however, surface wind velocity was the dominant factor affecting the surface contaminant concentration. In addition, contaminant concentration in a sub-region was likely controlled by the variations in river discharges close to the sub-region. These results are helpful for predicting contaminant concentrations in the sea and are expected to contribute to assessing the potential ecological risks to aquatic organisms.

Micropollutants or contaminants of emerging concern (CECs) are released into the environment from a wide variety of sources. Due to the adverse effect on human health, micropollutant-containing wastewater needs to be treated before its discharge. A number of conventional physicochemical methods have been extensively studied for micropollutant degradation. However, owing to their one or more disadvantages, biological treatment using suitable microorganisms is of recent interest. Numerous bacteria and fungi are capable of degrading these micropollutants even at high concentrations. However, in order for the biological treatment to be commercially viable and industrially scalable, bioprocess development with efficient bioreactor systems is highly essential. This paper reviews state-of-the-art techniques for the removal of micropollutants by conventional biological systems such as activated sludge process, biofilm-based reactor, and trickling bed bioreactor. However, compared with conventional systems, advanced biological systems, namely two-phase partitioning bioreactor, membrane-based reactor, and cell-immobilized bioreactor systems, have not been examined and, hence, need detailed exploration. Such advanced treatment systems are capable of tolerating high pollutant load and are also able to treat highly water insoluble pollutants. Furthermore, hybrid systems comprising of a combination of different physicochemical and biological processes are discussed in this paper, which are not only capable of improving the treatment efficiency but also eliminate any accumulation of the toxic by-product produced during the treatment. Among the different hybrid systems, a combination of different biological systems is found to be highly efficient in treating micropollutant-containing wastewater. Finally, scope for future research prospects in the field are derived and addressed in details.

P-glycoprotein (P-gp) is a molecular pump, responsible for extruding xenobiotics. The aim of the study was to demonstrate the role of P-glycoprotein (P-gp) in cadmium (Cd) exhaustion. The activity of P-gp was regulated in Crassostrea gigas, which was previously exposed to Cd by using rifampicin (inducer) and verapamil (inhibitor), respectively. Comparing with Crassostrea gigas depurated in natural seawater, Cd content increased significantly from 14.28 mg/kg dw to 17.49 mg/kg dw accompanied by a changed metallothionein level from 9.84 μg/g fw to 10.67 μg/g fw after 25 μg/L verapamil treatment, while Cd content after 25 μg/L rifampicin treatment reduced to 12.21 mg/kg dw. Moreover, after treatment with rifampicin and verapamil, beneficial metal elements, fats, and proteins were maintained, and the tissue-dependent difference was found in the variation of antioxidant defenses and oxidative damage in Crassostrea gigas. In brief, the study provided new evidence on possibility of Cd removal by inducing P-glycoprotein.

Ports are subject to a variety of anthropogenic impacts, and there is mounting evidence of faecal contamination through several routes. Yet, little is known about pollution in ports by faecal indicator bacteria (FIB). FIB spatio-temporal dynamics were assessed in 12 ports of the Adriatic Sea, a semi-enclosed basin under strong anthropogenic pressure, and their relationships with environmental variables were explored to gain insight into pollution sources. FIB were abundant in ports, often more so than in adjacent areas; their abundance patterns were related to salinity, oxygen, and nutrient levels. In addition, a molecular method, quantitative (q)PCR, was used to quantify FIB. qPCR enabled faster FIB determination and water quality monitoring that culture-based methods. These data provide robust baseline evidence of faecal contamination in ports and can be used to improve the management of routine port activities (dredging and ballast water exchange), having potential to spread pathogens in the sea.

Anthropogenic contamination of beaches in the south of Brazil was assessed by detection of Escherichia coli, human mastadenovirus species C (HAdV-C) and F (HAdV-F) and hepatitis E virus (HEV). Sampling was carried out in October (2016), and in January, April and July (2017). Water, sediment, sea surface microlayer (SML), bivalves, and air sentinel samples were evaluated. Quantitative microbiological risk assessment (QMRA) was used to estimate the probability of swimmer infection. HAdV-C was present in 26% of the samples, for both qPCR and viral isolation. The highest rates of detection in genomic copies (GC) were in water (2.42E+10 GC/L), SML (2.08E+10 GC/L), sediment (3.82E+08 GC/g) and bivalves (3.91E+07 GC/g). QMRA estimated daily and annual risks with a maximum value (9.99E-01) in almost all of the samples. Viable HAdV-C was often detected in the SML, pointing that this is a source of infection for people bathing in these waters.

Microplastic pollution has gained significant attention, and there are growing concerns about its potential effects on aquatic environments. The lack of proper solid waste management in Egypt has resulted in the accumulation of plastic litter and its deposition in waterways. However, no attempts have been made to identify or assess marine plastic litter in Egypt. We provide, for the first time, a precise, simple, and cost-effective method to identify microplastics in Eastern Harbor by using differential scanning calorimetry (DSC). This screening revealed the presence of ten polymers in seawater and shoreline sediments. Most of the extracted microplastics are secondary microplastics, as they appear to be remnants of larger plastic fragments.

This study presents baseline records of trace metals for two commercial shrimps from the inner continental shelf of southeast Brazil (~22°S). Organisms were sampled in 2004, 10 years before the beginning of large port activities in coastal waters. The concentrations of trace metals in muscle tissues (μg.g⁻¹ w.w.) of Xyphopenaues kroyeri and Artemesia longinaris are as follows: Al: 141.57 and 146.71, Fe: 83.17 and 91.68, Zn: 28.69 and 29.70, Cu: 7.19 and 3.94, Mn: 1.47 and 1.72, Pb: 1.14 and 0.60, V: 0.66 and 0.56, Ni: 0.38 and 0.34, Cr: 0.42 and 0.29, and Cd: 0.15 and 0.14, respectively. Significantly higher concentrations of Cu and Pb were recorded for X. kroyeri. In general, the concentrations are below the maximum permissible limits for metals in fishery/food products, as established by the Brazilian Agency for Sanitary Vigilance (ANVISA), except for Pb and Cr. These baseline records are relevant for future monitoring.

Mussels pose health risks to consumers through accumulation of trace metals from the ocean. Saldanha Bay, South Africa, has heavy industry and international shipping, creating concerns over pollution levels for aquaculture facilities. Samples of C. meridionalis and M. galloprovincialis were collected from mussel rafts over two-years and analysed for trace metal content using Inductively Coupled Plasma Mass Spectrometry. Aluminium, Cr, Fe, Zn, Cd and Pb were higher in M. galloprovincialis, while C. meridionalis accumulated more Cu and Mn. Temporal fluctuations occurred for Fe and As concentrations in C. meridionalis, and Fe, As, Hg and Pb in M. galloprovincialis. Arsenic exceeded South African regulatory limits (3 mg/kg) once in each species (max = 3.4 mg/kg w.w.). Lead concentrations in M. galloprovincialis were within EU regulatory limits for bivalves (1.5 mg/kg) but exceeded SA regulatory limits for fish (0.5 mg/kg) four times. Overall, farmed mussels from Saldanha Bay were determined to be safe for human consumption.

A floating plastic monitoring program was conducted for two years on a weekly basis in Banderas Bay, Mexico. A total of 94 samples were collected from May 2016 to April 2018 in the southern part of the bay. Half (57%) of them contained plastic debris; 79% of it being <5 mm in length. Polypropylene and Polyethylene were the most abundant polymers, accounting for 45% and 43% of the plastic pieces (pp), respectively. The highest abundance of plastic pieces was found in July 2016, with a maximum of 0.3 pp/m³ found in one sample. The amount of floating plastics was significantly higher in the hurricane season compared to the dry season (p < 0.001). This suggests that rainfall may play a significant role in the offload of plastics from land-based sources into the bay.

Total metal concentrations and acid-volatile sulfide (AVS) measurements coupled with simultaneously extracted metals (SEM) were determined in heterogeneous sediments from Maluan Bay, China. Zn was the predominant component of SEM, while Cd was the least. In sediment cores, AVS increased with sediment depth, followed by a decrease with large variation, while SEM fluctuated. Multiple empirical sediment quality guidelines (SQGs) and equilibrium partitioning (EqP) approaches were applied to assess the contamination degree, sediment quality and potential risks associated with bioavailable metals, indicating that not all sediments with [SEM]-[AVS] > 0 were capable of causing toxicity because TOC is also an important metal-binding phase. In order to screen out the physicochemical variability and the complexity and large variance of datasets, multivariate statistical techniques were utilized to comprehensively reveal pollution status by visualized factor scores. Collectively, this study favors the integrative utilization of multifarious methods to scientifically diagnose the pollution characterization for sustainable coastal management.