This study investigated the removal of microplastics from different treatment stages in three WWTPs and examined the performance of tertiary treatment that was done by coagulation and different technologies such as ozone (WWTP-A), membrane disc-filter (WWTP-B), and rapid sand filtration (WWTP-C). The results showed that the primary and secondary treatment processes effectively remove microplastics from wastewater with efficiencies ranging between 75% and 91.9%. The removal efficiency increased further to >98% after tertiary treatment. Microbeads and fragments were the major types of microplastics found in all wastewater sampling points. Microbeads found in the wastewater samples were classified as primary microplastics, that mainly came from personal care products, whereas secondary microplastics consisted of fragments, fibers, and sheets that were generated mainly due to fragmentation of larger plastics. Microplastics were still found in a high concentration in the final effluent, especially from WWTP-B, which is discharged into the Geumho river.

This study undertook to investigate the occurrence of microplastics (MPs) in the high and low-tide sediments of five coastal areas in Tamil Nadu, India. The abundance of microplastics vary from 439 ± 172 to 119 ± 72 (HTL) and 179 ± 68 to 33 ± 30 (LTL) items kg⁻¹ of sediments. The MP polymers found in the study sites are Polyethylene (73.2%), polypropylene (13.8%), nylon (8.2%), polystyrene (2.8%) and polyester (2%). The weathered surfaces might act as high-capacity carriers and this was confirmed by SEM-EDAX. The results of an analysis of the textures of the sediments do not ascribe any influence on microplastic abundance. The recreation, religious and fishing activities are the major contributors to plastic pollution in these beaches, which is borne out by the high abundance of MPs in the study sites. A regular and permanent waste management system should be put in place for the protection of beaches.

To explore the effects of coastal eutrophication and warming on phytoplankton biomass and cell size, we analyzed current and historical data for size-fractionated chlorophyll a (chla) in Xiangshan Bay, China. Results showed that micro- and nanophytoplankton overwhelmingly dominated (>84%) in all seasons. The contribution of micro-chla was significantly lower in warm than in cold seasons, whereas contribution of pico-chla showed the opposite result. Overall, the micro-chla contribution increased with decreasing pico-chla contribution from the stable, clear, eutrophic upper bay to the turbulent, turbid lower bay, indicating that phytoplankton size structure on a spatial scale was largely shaped by water column stability and light rather than by nutrients. Since the 1980s, phytoplankton biomass, primary productivity, and micro-chla contribution in Xiangshan Bay have increased sharply with increasing nutrient amounts and temperature. Additionally, it seems that algal bloom seasonality has shifted forward from spring to winter since the power plant operations in 2006.

The largest metropolitan centers in northeastern region of Brazil are all located near the coast, and industrial, tourist, and agro-industrial activities are the principal causes of water contamination due to discharges of untreated sewage. Adverse environmental conditions can often be detected by analyzing the genetic material of organisms exposed to pollutants, and furnish an overview of environmental quality. We evaluated possible damage to the DNA of one of the fish resources most widely consumed and commercialized by coastal communities in northeastern Brazil, Mugil curema (“tainha”). Erythrocytes from M. curema were analyzed by the presence of micronuclei and by comet assay (single cell gel electrophoresis, SCGE). Statistical comparisons to both tests revealed considerably greater genomic damage in polluted estuaries than in the control site (p < 0.05), suggesting strong genotoxic impacts on the specimens evaluated, principally among those taken near localities with dense demographic and industrial development.

Interest in the presence of pharmaceutically active compounds in the aquatic environment has been growing for over 20 years, yet very few studies deal with the metabolism of pharmaceuticals in marine organisms. In this study, the bioaccumulation under short-term conditions and metabolism of diclofenac were investigated. Mytilus trossulus was used as a representative of the Baltic benthic fauna. The mussels were exposed to diclofenac at a concentration of 133.33 μg/L for five days, following a five-day depuration phase. The highest concentration of diclofenac (7.79 μg/g dw) in tissues was determined on day 3. Subsequently, the concentration of diclofenac in tissues decreased rapidly to 0.86 μg/g dw on day 5. After five days of depuration, the concentration of diclofenac was 0.21 μg/g dw. Hydroxylated diclofenac metabolites were found both in tissues of mussels and water. This study shows that M. trossulus has the potential to accumulate diclofenac and metabolize it to 4-OH and 5-OH diclofenac.

Commercial marine organisms were collected from the coast of Xiangshan Bay to investigate the concentrations of eight heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) and evaluate the potential health risks. The results indicated considerable variations in the heavy metal concentrations among six species groups, of them mollusks (seasnail, benthic bivalve, and oyster) generally contained relative high levels of most metals, followed by crustaceans (crab and shrimp), by contrast, fish had low concentrations of all metals, except Hg. Three heavy metal groups were identified to interpret the accumulative characteristics in the marine organisms. Spatial distributions illustrated the geographical variations of heavy metal concentrations in the sampling areas. Moreover, maricultured organisms demonstrated lower heavy metal concentrations than did the wild. Health risks of most heavy metals exposed from marine organism consumption were safe, except for As which is associated with the high target cancer risk values.

Marine litter has adversely affected many marine species. However, information on its impacts on filter-feeding elasmobranchs (such as the whale shark, Rhinocodon typus) is scarce. The Philippines is an essential habitat for whale sharks, and the lack of data on marine litter and its effects on these organisms in the country is concerning. Beached carcasses present opportunities to provide useful data and insights on the issue. On the 7th August 2018, a live whale shark was found beached in Tagum City, the Philippines, and it eventually died. As part of the post-mortem examination, the gastrointestinal tract and gills of the specimen were examined. Marine litter was found lodged in its gills, and pieces of plastic were found inside its stomach (including several pieces likely from local sources within the Philippines). This study is the first documentation of litter in whale sharks from the Philippines, confirming their vulnerability to marine litter.

Several country–wide bans have recently been implemented for microbeads, which are a form of microplastics that are found in our oceans. The effect of the ban on reducing the overall quantity of microplastics in our oceans, however, may not be significant. This paper explores the scientific data related to microbeads to evaluate whether an underlying risk or combination of risks led to the ban, what impact public perception and activism had on this issue, and how this case study may be extrapolated to other emerging issues, such as per- and polyfluoroalkyl substances (PFAS). In some cases, the strategy for communicating with the public and managing the outrage can be equally as important as the regulatory and technical strategies.

The concentration of nine trace elements were analyzed in the different tissue organs of commonly available crabs (Portunus sanguinolentus, Portunus pelagicus and Scylla serrate) and bivalve (Polymesoda erosa) species collected from the Miri coast, Borneo in order to evaluate the potential health risk by consumption of these aquatic organisms. Among the analyzed organs, metal accumulation was higher in the gill tissues. The essential (Cu and Zn) and non-essential (Pb and Cd) elements showed the highest (i.e. Zn) and lowest concentrations (i.e. Cd) in their tissue organs, respectively. The estimated daily intake and hazard indices of all metals in the muscle indicate that the measured values were below the provisional tolerable daily intake suggested by the joint FAO/WHO Expert Committee on Food Additives. Compared to Malaysian and international seafood guideline values the results obtained from the present study are lower than the permissible limits and safe for consumption.

Sundarban along with its networks of rivers, creeks and magnificent mangroves form a unique ecosystem. Acid sulphate soils have developed in this ecosystem under anoxic reducing conditions. In the present study, we have investigated the distribution of acid sulphate soils along with its elemental characterization and possible sources in four reclaimed islands of Indian Sundarban like Maushuni (I1), Canning (I2), Bally (I3) and Kumirmari (I4). Elements show moderate to strong correlation with each other (P < 0.01; P < 0.05). Except Si, Ca and Pb, a higher enrichment factor was observed for K, Cr, Mn, Fe, Ni, Cu and Zn. Geo-accumulation index values of all sampling locations reveal that Cr, Fe, Cu and Zn are in Igₑₒ class 1. The pollution load index value of the reclaimed islands of Indian Sundarban varies between 1.31 and 1.48. The observation of this study could help to strategize policies to mitigate and manage acid sulphate soils in Indian Sundarban.