The environmental behaviors and migration patterns of antibiotic resistance genes (ARGs) have attracted considerable research interest. However, there has been little research concerning the effects of corresponding and non-corresponding contaminants on the fate of ARGs in coastal environments. In the present study, the distribution of intI1, sul1, sul2, qnrS and aac(6′)-Ib were analyzed in water and sediment samples of Laizhou Bay in the context of corresponding and non-corresponding contaminants. The abundance of intI1, sul1 and sul2 genes exhibited a clear decreasing trend extending from the inner estuary to the coastal area. Strong and positive correlations existed between sul1/sul2 and sulfonamide antibiotic residues in sediments, and between the abundances of intI1 and sul1/sul2. Statistical analyses indicated that non-corresponding contaminants were partially correlated with ARG abundances. These results suggest that non-corresponding contaminants may have direct or indirect influences on the abundances of ARGs and intI1 in the Laizhou Bay.

Studies documenting the effects of land-derived suspended particulate matter (SPM, i.e., particulate organic matter and mineral sediment) on marine ecosystems are typically disconnected from terrestrial studies that determine their origin, transport and fate. This study reviews sources, transport, transformations, fate and effects of SPM along the ‘ridge-to-reef’ continuum. We show that some of the SPM can be transported over long distances and transformed into large and easily resuspendible organic-rich sediment flocs. These flocs may lead to prolonged reductions in water clarity, impacting upon coral reef, seagrass and fish communities. Using the Great Barrier Reef (NE Australia) as a case study, we identify the latest research tools to determine thresholds of SPM exposure, allowing for an improved appreciation of marine risk. These tools are used to determine ecologically-relevant end-of-basin load targets and reliable marine water quality guidelines, thereby enabling enhanced prioritisation and management of SPM export from ridge-to-reef.

Passive sampling techniques were used for monitoring trace metals and polycyclic aromatic hydrocarbons (PAHs) in the seawater surrounding the Costa Concordia shipwreck (Isola del Giglio, Italy). The monitoring lasted two and a half years (2012–2014) and considered all four phases of the “parbuckling project”: stabilisation of the wreckage, installation of steel caissons on both sides of the wreck, parbuckling, and refloating. Dissolved trace metals (Cd, Cr, Cu, Hg, Ni, Pb, and V) were measured with diffusive gradients in thin films (DGT), while freely dissolved PAHs were measured with semi-permeable membrane devices (SPMDs). Passive sampling allowed to detect very low concentrations of contaminants, and indicated significant differences among the sampling stations and among the different steps for salvaging the wreck. The results suggested that the main source of contamination was the heavy working vessel traffic at the disaster site, rather than the release of contaminants from the wreck.

The Gulfwatch Contaminants Monitoring Program is part of the Canada-US, Gulf of Maine Council on the Marine Environment (GOMC). Programs monitoring legacy toxic substances, i.e., chemical contaminants, such as Gulfwatch, collect and analyse environmental samples (e.g., blue mussels), interpret the data, and report on chemical levels and trends (spatial and temporal) in coastal waters. This study explored the extent to which its extensive information (data, reports, papers) has been used broadly and by Nova Scotia, a GOMC member. A mixed-methods study was conducted, using quantitative and qualitative metrics. Citations to some Gulfwatch papers and analysis of use of the Gulfwatch website showed that its data and information were accessed, mostly by government departments. However, interviews revealed that the departments were not using the data to inform Nova Scotia provincial coastal policy or practices. Recommendations are presented to improve the visibility and use of information provided by long-term, environmental monitoring programs.

Environmental antimicrobial resistance (AMR) has drawn increasing attention due to its great risk to human health. The aim of this study was to investigate AMR and genotyping of Vibrio parahaemolyticus isolates (n = 114) recovered from shrimp mariculture environment in China. The isolates exhibited a high rate of resistance to streptomycin (78.9%), ampicillin (64.9%) and gentamicin (53.5%). Furthermore, multi-drug resistance was highly prevalent (61.4%), in which 95.9% of these ampicillin-resistant isolates were primarily mediated by blaCARB-17. Surprisingly, doxycylcine, florfenicol, and trimethoprim/sulfamethoxazole (TMP/SMZ) resistance genes occurred in susceptible isolates. Moreover, 114 isolates were grouped into unique pulsed field gel electrophoresis patterns. These findings suggest the need for the prudent use of antimicrobial agents on mariculture farms, in order to control the dissemination of antimicrobial resistant V. parahaemolyticus.

Tar balls are prevalent in oceans and the coastal environment; however, their origins are not well constrained on a global scale. To address this, we used gas chromatography to analyze the molecular composition of a unique set of 100 pelagic tar balls collected in the Western North Atlantic and Caribbean Sea between 1988 and 2016. Hierarchal cluster analysis (HCA) was employed to classify the samples into groups based on the relative proportions of resolved and unresolved hydrocarbon distributions. Additional analysis of polycyclic aromatic hydrocarbons revealed that 28% of samples originated from heavy fuel oils and therefore had anthropogenic origins consistent with the classifications based on HCA. Other samples examined could originate from anthropogenic or natural origins, such as natural seeps. This study provides a preliminary record of 100 classified pelagic tar ball samples and demonstrates an approach to determine their origin to the environment.

Fluorescence microscopy is an important step in visual identification of microplastics and is used to highlight white and transparent plastics that are otherwise easily missed or misidentified. Investigators using fluorescence must proceed with caution, however, as fluorescence photobleaching can significantly reduce the fluorescence output of samples within experimentally relevant time frames. We report on the photobleaching rate and subsequent lack of fluorescence recovery of five common plastics. Our results reveal statistically different photobleaching rates across plastic types. In the best-case scenario of low illumination intensity and a robust plastic, initial fluorescence intensity decayed by 10% in just 11(3) s and by 33% in 230(40) s. In all cases, fluorescence failed to recover more than 13(8)% in 3 h. These results indicate that significant bleaching can occur while searching a sample for plastics to identify and that the lack of recovery can compromise samples for further study.

The discharge of petroleum hydrocarbons (PHs; ~10,000tons annually) into the Bohai Sea, a shallow inland sea in China, presents a serious threat to the marine environment. To evaluate the effects of PHs pollution and estimate the corresponding environmental capacity, we have developed a genetic algorithm-based coupled hydrodynamic/transport for simulating PHs concentration evolution and distribution from July 2006 to October 2007, with the predicted values being in good agreement with monitoring results. Importantly, the mean PHs concentrations and seasonal concentration variations were primarily determined by external loading, i.e., currents were shown to drive PHs transport, reconfigure local PHs patterns, and increase PHs concentration in water masses, even at large distances from discharge sources. The developed model could realistically simulate PHs distribution and evolution, thus being a useful tool for estimating the seasonal environmental capacity of PHs.

In the present study, the spatial distributions and vertical variations of PFASs in the sediments of the Dalian Bay were investigated. The total concentrations of PFASs (∑PFASs) in surface sediments of Dalian Bay ranged from 1.49 to 2.66ngg⁻¹ dw. The predominant PFASs in surface sediments were PFOA, PFBS and PFBA with the concentration ranges of 0.50 to 0.95, 0.21 to 0.94, and 0.035 to 0.32ngg⁻¹ dw, respectively. For the two sediment cores, ∑PFASs ranged from 1.20 to 2.00 and from 1.37 to 2.06ngg⁻¹ dw, respectively. There was a maximum ∑PFASs concentration value near the surface. In general, ∑PFASs gradually decreased with increasing sampling depth after reaching the maximum. PFOA, PFBS and PFBA were also the predominant PFASs in the two sediment cores. It is recommended that the monitoring and risk assessment of short-chain PFAS should be taken into consideration, and further researches are needed to understand the transportation and fate of these chemicals in the aquatic environment.

We compared the performance of abundance- and biomass-based M-AMBI in the 13 major Italian lagoons, using a benthic dataset constituted by 208 sampling sites. The relative importance of ecological groups changed when using abundance or biomass, sometimes leading to an improved ecological status classification. Being biomass more ecologically relevant than abundance, the adoption of a biomass-based index may better describe the ecological status of lagoons, where the community is naturally disturbed and dominated by tolerant and opportunist species.