It was hypothesized that mangroves, tropical wetlands, could be used for the finishing treatment of domestic wastewaters. Our aim was to determine if a nutrient-stressed mangrove could tolerate long-term discharges of pretreated wastewater (PW). Since 2008, in an in situ experimental system set up in Mayotte Island (Indian Ocean), domestic PW are discharged into two impacted areas (675 m2) dominated by different species of mangrove trees. Anthropogenic inputs during > 4.5 years led to an increase in vegetation growth associated with an increase in leaf pigment content, leaf surface and tree productivity. A marked increase in tree mortality was observed. There was no effect on crabs and meiofauna densities, but significant modifications of community structures. These effects may be directly linked to PW inputs, or indirectly to the modifications of the environment associated with higher tree growth. However, our results indicate that there was no major dysfunction the ecosystem.

An approach pooling geochemical analyses and ecotoxicological tests has been applied to assess the sediment quality of the Capibaribe River Estuary, Brazil. Toxicity tests were performed to compare a well-established, labor-intensive protocol using ovigerous females to a new, easier and faster protocol using nauplii of the epibenthic marine copepod Tisbe biminiensis. The endpoints of the nauplii toxicity test were comparable to those of the female test. Nauplii proved to be more sensitive than females as a biological model for indicating sediment toxicity. All sediments collected had at least one contaminant above the threshold effects level (TEL) proposed in the literature. Furthermore, more than one-third of samples exhibited contaminants above the probable effects level (PEL). The PCA revealed that nauplii mortality was associated with metals in October 2014, which was confirmed by the Spearman correlation factor. In contrast, no strong association among contaminants and toxicological endpoints in May 2015 was found.

In order to study the role of sediment re-suspension and deposition versus the role of organic complexation, we investigated the speciation of cadmium (Cd), copper (Cu) and lead (Pb) in samples collected in the Venice Lagoon during several campaigns from 1992 to 2006. The increment in Cd and Pb concentration in the dissolved phases, observed in the central and northern basins, can be linked to important alterations inside the lagoon caused by industrial and urban factors. The study focuses on metal partition between dissolved and particulate phases. The analyses carried out in different sites illustrate the complex role of organic matter in the sedimentation process. While Cd concentration in sediments can be correlated with organic matter, no such correlation can be established in the case of Pb, whose particulate concentration is related only to the dissolved concentration. In the case of Cu, the role of organic complexation remains unclear.

Great Lakes states are increasingly faced with questions regarding how plastic debris is impacting marine and coastal ecosystems. This is especially evident along the southern beaches of Lake Erie, where high population and industrial development have contributed to the plastics problem. In Ohio, the most common items found are cigarettes and other smoking related materials, including plastic cigar tips. Given the growing awareness of the issue, and the impact of plastics on beaches throughout the Great Lakes, a focus group convened to investigate strategies to help address the problem. The group was comprised of individuals with practical knowledge of plastic cigar tip use and disposal issues, including representatives of government agencies, nongovernmental organizations, community groups, and local academic institutions. This report represents the exploratory results of the focus group, complete with information regarding the what, why, and how of plastic cigar tip debris in the region, guidance on the material and social barriers to sustaining desired behaviors (cessation of use by minors and/or proper disposal), strategies to overcome those barriers, and suggestions for management and policy actions moving forward. Group members suggest that a combination of education and government-supported financial incentives may be the most effective approach, with community-based positive messaging backed by local taxes on smoking items that have plastic tips and rebates or other rewards for properly disposing of debris.

Microplastics are found in abundance in and on coastal sediments, and yet, whether exposure to this emerging pollutant negatively impact whole organism function is unknown. Focusing on a commercially important polychaete, Perinereis aibuhitensis, we demonstrated that presence of microplastics increased mortality and reduced the rate of posterior segment regeneration. The impact of the micro-polystyrene beads was size-dependent with smaller beads (8–12μm in diameter) being more detrimental than those bigger in size (32–38μm). This observed difference suggests microplastic impact could be affected by physical properties, e.g., sinking speed, surface area available for sorption of chemicals and bacteria, and selective feeding behaviors of the target organism.

Sulfur and iron are abundant and have close, complex interactions with the biogeochemical cycle of arsenic (As) in mangrove ecosystems. A hydroponic experiment was conducted to investigate the influences of variable SO42− and Fe2+ supplies on radial oxygen loss (ROL), iron plaque formation and As translocation in Avicennia marina upon exposure to As(III). The results indicate that A. marina is an As-tolerant plant, the application of iron and sulfur not only showed positive growth effects but also induced much higher amounts of ROL-induced iron plaque formation on root surfaces. The presence of iron plaque remarkably improved the proportion of As sequestration near this area but consequently reduced the proportion of As translocation in root. Therefore, it is concluded that iron plaque may act as a barrier for protection against As, and iron and sulfur play important roles in controlling the growth and translocation of As in A. marina seedlings.

We collected seven cores from five coastal ponds in St Thomas, USVI, dated them via 210Pb, and measured their Hg profiles. Levels ranged from 20 to 100ngg−1 and always increased upward to the surface or a shallow mixed zone. Taking into account differences in sediment accumulation rates and the presence or absence of a mixed zone, all sites revealed similar deposition histories. Mercury levels were at low, possibly pristine, values until the early to mid-20th century. Then they then doubled or quadrupled steadily until about 1990, after which Hg became relatively constant. We conclude that Hg in the sediments of these ponds came from long range deposition directly to the ponds and to their watersheds. Constant levels in recent years may be caused by transfer from watersheds, a pathway that is delayed compared to direct deposition from the atmosphere.

The objective of the present study was to assess the presence of 17 per- and polyfluoroalkyl substances (PFAS) in blood of two closely related top predators, the Scopoli's (Calonectris diomedea) and Cory's (C. borealis) shearwaters that breed allopatrically in Mediterranean and Atlantic basins. Among PFAS, perfluorooctanesulfononic acid (PFOS) and long chain perfluorinated carboxylic acids (PFCA) were detected in all samples, highlighting somehow the ubiquity of such pollutants. Scopoli's shearwaters from the Mediterranean showed significant higher levels in all PFAS when compared with those levels determined in the colony of Cory's shearwater from the Atlantic Ocean. Moreover, significant differences also arose within the Mediterranean colonies, with the colony of the Central Mediterranean (Zembra Island in Tunisia) having the lowest levels of all PFAS. Thus, our study suggests a marked geographical pattern regarding the presence of such contaminants, and emphasizes the necessity to study PFAS accumulation in birds inhabiting temperate regions.

Benzo[a]pyrene (BaP) is a polycyclic aromatic hydrocarbon (PAH) that is well known for its teratogenic, mutagenic and carcinogenic effects. In this study, we applied metabolomics to investigate the tissue-specific metabolic responses of the Pinctada martensii digestive glands and gills after a short-duration exposure to BaP (1 μg/L and 10 μg/L). After 72 h of exposure to BaP, the majority of metabolite changes were related to osmolytes, energy metabolites, and amino acids. BaP (1 μg/L) accelerated energy deterioration and decreased osmotic regulation, while BaP (10 μg/L) disturbed energy metabolism and increased osmotic stress in the digestive glands. Both BaP doses disturbed osmotic regulation and energy metabolism in the gills. BaP also induced neurotoxicity in both tissues. These findings demonstrated that BaP exhibited tissue-specific metabolic responses in P. martensii. The difference in these metabolite responses between the digestive glands and gills might prove to be suitable biomarkers for indicating exposure to specific marine pollutants.

Research into sediment-seagrass tissue metal relationships has been undertaken in Sydney estuary due to the recognized role contamination plays in threats to seagrass health. Seagrass (Halophila ovalis) leaf tissue concentrations are elevated in Cu, Pb and Zn and contain the highest reported root Cr concentrations. Seagrass metal concentrations were significantly different between species H. ovalis and Zostera capricorni; between root and leaf tissue; and between sampling locations. Greatest tissue enrichment was for Pb, however metals were not enriched in seagrass relative to surficial sediment. Fine and total sediment metal concentrations were temporally consistent between collection years 2013/15, whereas root tissue metals changed between years and sites and leaf metal contents were temporally inconsistent. Extractable metal concentrations in fine sediment (<62.5 μm) showed moderate significant correlation with root tissue and a weak significant relationship with leaf tissue, whereas total sediment metal showed no such relationships. Management implications are provided.