The inner 1/3 of Isahaya Bay which is a tributary of Ariake Sea in Japan was shut off from the sea by a dike for the reclamation and disaster prevention in 1997. On the other hand, several environmental and fisheries problems occurred in Ariake Sea after 1990s. Some fishermen insisted that the major reason for the decrease of fishing must be the influence of the dike construction and filed lawsuits. Now the court decision is fixed and Japanese government must open the gates to reintroduce sea water into the reservoir. We made numerical simulations of currents, hydrography and sediment transport to assess the influences of the gate opening. To choose the environmentally wise procedure of gate opening, it is needed to reduce the erosion and deposition of bottom sediments caused by the enhanced tidal current and to minimize the occurrence of hypoxia in the reservoir.

Plastics are the most common material of marine litter and have become a global pollution concern. They are persistent in the environment where they gradually degrade into increasingly smaller particles–microplastics (MP). Our study presents results of sea-surface monitoring for MP in the Slovenian part of the Trieste Bay in the Northern Adriatic Sea. In 17 trawls conducted over a 20-month period we found a high average concentration of 406×103MPparticles/km2. Over 80% of the particles were identified as polyethylene. The significant variability of MP concentrations obtained on different sampling dates is explained by use of surface current maps and a recently developed Markov chain marine litter distribution model for the Adriatic Sea.

A bacterial consortium was selected in the presence of Cu from sediment samples taken from Sepetiba Bay, Brazil, which is a site historically contaminated by metals. Bacteria were exposed to 0, 1, 6, 12.5, 25 and 50μg·mL−1 Cu, Pb and Cu+Pb for 11days of bioassay. Results showed Alcanivorax dominance (81%) and cell counts of 108cells·mL−1. However, a reduction in dehydrogenase activity was observed from the fifth day of exposure for all Cu, Pb, and Cu+Pb concentrations tested. Esterase activity tended to increase, indicating higher energy demand to complete the bacterial lifecycle. Pb concentrations in the filtered culture medium (0.2μm) were below the detection limit, indicating biosorption, whereas concentrations of Cu were close to the tested concentrations, indicative of efflux. Results suggest the need for biomarkers, such as esterase and dehydrogenase enzymatic activity, in the assessment of resistance and tolerance of communities previously exposed to stressors.

A single method modified for monitoring of emerging contaminants in river water was developed for large sample volumes. Water samples from rivers of the lagoon system in the city of Rio de Janeiro (Brazil) were analyzed by the SPE-HPLC-MS-TOF analytical method. Acetaminophen was detected in four rivers in the concentration range of 0.09μgL−1 to 0.14μgL−1. Salicylic acid was also found in the four rivers in the concentration range of 1.65μgL−1 to 4.81μgL−1. Bisphenol-A was detected in all rivers in the concentration range of 1.37μgL−1 to 39.86μgL−1. Diclofenac was found in only one river, with concentration of 0.22μgL−1. The levels of emerging organic pollutants in the water samples of the Jacarepaguá hydrographical basin are significant. The compounds are not routinely monitored and present potential risks to environmental health.

Considering the abuse of antibiotics worldwide, we investigated the abundance of three classes of antibiotic resistance genes (ARGs) and the concentrations of corresponding antibiotics in water and sediments of Bohai Bay. The results showed that sulI and sulII were detected in all samples, and their abundance range was 10−5–10−2/16S gene copies. The abundance of tetM and ermB were relatively higher than the other genes of tet-ARGs and erm-ARGs. Sulfonamides were the most prevalent antibiotics, and the concentrations of antibiotic in sediments were higher than those in water. The correlation analysis revealed that antibiotics had pertinence with corresponding ARGs, indicating that antibiotics play an important role in the creation and transfer of ARGs. The results of regression analysis indicated that the propagation and maintenance of sulI and sulII were facilitated by class I integrons.

Dramatic changes occurred in Narragansett Bay during the 1980s: water clarity increased, while phytoplankton abundance and chlorophyll concentration decreased. We examine how changes in total suspended solids (TSS) loading from wastewater treatment plants may have influenced this decline in phytoplankton chlorophyll. TSS loading, light and phytoplankton observations were compiled and a light- and temperature-dependent Skeletonema-based phytoplankton growth model was applied to evaluate chlorophyll supported by TSS nitrogen during 1983–1995. TSS loading declined 75% from ~0.60×106kgmonth−1 to ~0.15×106kgmonth−1 during 1983–1995. Model results indicate that nitrogen reduction related to TSS reduction was minor and explained a small fraction (~15%) of the long-term chlorophyll decline. The decline in NBay TSS loading appears to have increased water clarity and in situ irradiance and contributed to the long-term chlorophyll decline by inducing a physiological response of a ~20% reduction in chlorophyll per cell.

The effects of nutrient distribution and structure on the acidity of coastal waters were analyzed based on the data of 48 surface water samples collected in the southwestern coast of the Laizhou Bay and its adjacent rivers (SWLZB) which are heavily influenced by nutrient-laden discharges. The concentration and structure of nutrients varied considerably along the coast owing to different contributors. The studied inshore waters exhibited a sign of acidification. The pH was significantly negatively correlated with the concentration of NO3-N, NO2-N, NH4-N and DSi, but showed no obvious correlation with the concentration of PO4-P and the ratio of TDN/TDP, DSi/DIN and DSi/PO4-P, respectively. The results indicated that the distribution of nutrients might well be an important environmental factor affecting the acidification of the SWLZB in warmer months.

The major (Al) and trace metal (Cu, Pb, Zn, Cr, Cd, and As) concentrations in 29 surface sediment samples from the intertidal Jiaozhou Bay (JZB) are evaluated to assess the contamination level. The results show that the overall sediment quality in the area has been obviously impacted by trace metal contamination. The geoaccumulation index and the enrichment factor values indicate that no Cr or Cu contamination has occurred on the whole, only a few stations have been polluted by As, and some areas have been polluted by Cd, Pb, and Zn. Principal component analysis suggests that the Cu, Pb, Zn, and Cd are derived from anthropogenic inputs and that Cr, As, Cu, and Zn are influenced by natural weathering processes. Cu and Zn may originate from both natural and anthropogenic sources. The contamination in the northeastern JZB is higher than that in other areas of the bay.

The impact of Hurricane Sandy (October 29, 2012) on PAH exposure was investigated in adult Atlantic menhaden (Brevoortia tyrannus) collected along the NJ coast. Collections were made in August, September and/or October of 2011, 2012 and 2013. PAHs were monitored in raw fish oil using excitation–emission matrix (EEM) spectroscopy. Results showed that raw fish oils had relatively high levels of high molecular weight, PAH-like compounds (173 to 24,421ng/mL) compared to values reported for bile in other species. EEM profiles resembled that of crude oil and excluded matrix interference by some common biological molecules that also fluoresce. Concentrations and EEM profiles varied by collection; however, collection ship, month, year and fish size did not account for the data. Replicates showed that fish from the same catch had similar PAH exposure. Overall, Hurricane Sandy did not alter body burdens of PAHs in raw fish oil of menhaden.

PM2.5 and PM10 samples were collected in a rural area from December 2014 to August 2015 near a coal-fired power plant on the southeast coast of China. The total mercury concentrations in PM2.5 ranged from 116.2 to 1070.9 pg/m3 and in PM10 from 173.4 to 1456.8 pg/m3, with averages of 309.5 ± 94.9 and 387.5 ± 133.5 pg/m3, respectively. These were much higher than those found in many foreign cities. The concentrations of mercury in PM2.5 and PM10 varied seasonally, with the highest average concentration in winter. This was probably due to the seasonal variation of meteorological conditions and concentration of particulates. The highest mass-based concentration of mercury in PM2.5 and PM10 was observed in spring. This result might be related to the prevailing sea winds in spring. The spatial variation of particulate mercury conformed to the concentration distribution characteristics of pollutant discharged from coal-fired power plant elevated source at the downwind area. The seasonal variation in the concentrations of the four mercury species (including exchangeable particulate mercury: EXPM, HCl-soluble particulate mercury: HPM, elemental particulate mercury: EPM, and residual particulate mercury: RPM) were all identical to the seasonal variation of total particulate mercury (TPM) in PM2.5 and PM10 (winter > spring > summer). Owing to the variation of meteorological conditions, the proportion of different mercury species in TPM followed different seasonal trends. In contrast to RPM, the percentage of both HPM and EPM in PM2.5 was higher than in PM10.