Sediment dredging can cause damage to the marine environment due to mobilization of sediments and contaminants. The effects of dredging and boundary environmental conditions on the concentration of Polycyclic Aromatic Hydrocarbons (PAHs) in water were evaluated during dredging of the Oil Port of Genoa-Multedo (Italy). Results showed that turbidity and PAH concentrations increased in the water during dredging. However, the scenario was complex due to the high number of interacting physical-chemical factors influencing PAH concentrations and transport. Due to these, PAH distribution is different in water, where low-molecular-weight PAHs were predominant (maximum concentration 0.105 μg L−1), and in bottom sediments, where high-molecular-weight PAHs had the highest concentrations (from 299.3 to 1256.5 ng g−1). Moreover, mainly during dredging the PAH concentrations in water were significantly higher inside than outside the port as a consequence of the lower dynamics within the port basin. Turbidity was the main parameter related to PAH concentrations.

Constructed coastal marsh regulates land-born nitrogen (N) loadings through salinity-dependent microbial N transformation processes. A hypothesis that salinity predominantly controls N removal in marsh was tested through incubation in a closed system with added-15NH4+ using sediments collected from five sub-marshes in Shihwa marsh, Korea. Time-course patterns of concentrations and 15N–atom% of soil-N pools were analyzed. Sediments having higher salinity and lower soil organic-C and acid-extractable organic-N exhibited slower rates of N mineralization and immobilization, nitrification, and denitrification. Rates of denitrification were not predicted well by sediment salinity but by its organic-C, indicating heterotrophic denitrification. Denitrification dominated N-loss from this marsh, and nitrogen removal capacity of this marsh was estimated at 337 kg N day−1 (9.9% of the daily N-loadings) considering the current rooting depth of common reeds (1.0 m). We showed that sediment N removal decreases with increasing salinity and can increase with increasing organic-C for heterotrophic denitrification.

Concentrations of selected antibiotic compounds from different groups were measured in sediment samples (14 analytes) and in near-bottom water samples (12 analytes) collected in 2011–2013 from the southern Baltic Sea (Polish coastal zone). Antibiotics were determined at concentration levels of a few to hundreds of ng g−1 d.w. in sediments and ng L−1 in near-bottom waters. The most frequently detected compounds were sulfamethoxazole, trimethoprim, oxytetracycline in sediments and sulfamethoxazole and trimethoprim in near-bottom waters. The occurrence of the identified antibiotics was characterized by spatial and temporal variability. A statistically important correlation was observed between sediment organic matter content and the concentrations of sulfachloropyridazine and oxytetracycline. Risk assessment analyses revealed a potential high risk of sulfamethoxazole contamination in near-bottom waters and of contamination by sulfamethoxazole, trimethoprim and tetracyclines in sediments. Both chemical and risk assessment analyses show that the coastal area of the southern Baltic Sea is highly exposed to antibiotic residues.

The availability of marine habitats maps remains limited due to difficulty and cost of working at sea. Reduced light penetration in the water hampers the use of optical imagery, and acoustic methods require extensive sea-truth activities. Predictive spatial modelling may offer an alternative to produce benthic habitat maps based on complete acoustic coverage of the seafloor together with a comparatively low number of sea truths. This approach was applied to the coralligenous reefs of the Marine Protected Area of Tavolara - Punta Coda Cavallo (NE Sardinia, Italy). Fuzzy clustering, applied to a set of observations made by scuba diving and used as sea truth, allowed recognising five coralligenous habitats, all but one existing within EUNIS (European Nature Information System) types. Variable importance plots showed that the distribution of habitats was driven by distance from coast, depth, and lithotype, and allowed mapping their distribution over the MPA. Congruence between observed and predicted distributions and accuracy of the classification was high. Results allowed calculating the occurrence of the distinct coralligenous habitats in zones with different protection level. The five habitats are unequally protected since the protection regime was established when detailed marine habitat maps were not available. A SWOT (Strengths-Weaknesses-Opportunities-Threats) analysis was performed to identify critical points and potentialities of the method. The method developed proved to be reliable and the results obtained will be useful when modulating on-going and future management actions in the studied area and in other Mediterranean MPAs to develop conservation efforts at basin scale.

This baseline assessment reports on the occurrence, distribution, and sources of emerging organic contaminants (EOCs) in tropical coastal sediments of anthropogenically impacted Klang River estuary, Malaysia. Bisphenol A was the highest concentration detected at 16.84 ng g−1 dry weight, followed by diclofenac (13.88 ng g−1 dry weight) and E1 (12.47 ng g−1 dry weight). Five compounds, namely, amoxicillin, progesterone, diazinon, bisphenol A, and E1, were found in all sampling stations assessed, and other compounds such as primidone, diclofenac, testosterone, E2, and EE2 were ubiquitously present in sediment samples, with percentage of detection range from 89.04% to 98.38%. Organic carbon content and pH were the important factors controlling the fate of targeted compounds in the tropical estuarine sediment. On the basis of the literature from other studies, the sources of EOCs are thought to be from wastewater treatment plants, domestic/medical waste discharge, livestock activities, industrial waste discharge, and agricultural activities.

Andaman and Nicobar islands is one of the major tourism hubs of the World. Most travelers visit these islands for historical attractions, beaches, snorkeling, scuba diving, coral reefs, adventure and recreation. Port Blair is the capital and sole entry/exit point of these islands. The coasts of Port Blair Bay (PBB) and Wandoor Creek (WC) are largely populated due to its services offered to different public/private sectors and for the economic significance. Nevertheless, the global recognition of these islands relies on its healthy ecosystem. Effective management of beaches, bays and their environmental services requires knowledge of coastal water quality. This study assesses the datasets of twenty seawater quality parameters of PBB and WC generated during five years (2011–2015) at eight sites. Multivariate statistical techniques were used for (i) analysis and interpretation of water quality parameters (ii) identification of pollution factors/sources and (iii) understanding spatio-temporal variations valuable for coastal water quality management.

Polydimethylsiloxane (PDMS) based passive water samplers deployed at Normanby Island, Great Barrier Reef (Australia) from 2007 to 2013 were analyzed for halogenated natural products (HNPs). Altogether, 38 samples, typically deployed for 30 days, were studied. Five HNPs (Q1, 2′‑MeO-BDE 68, BC-10, 2,4‑dibromoanisole and 2,4,6‑tribromoanisole) were detected in all samples. Most samples (>90%) featured 2,2′‑diMeO-BB 80, 6‑MeO-BDE 47, 2′,6‑diMeO-BDE 68 and 2,4‑dibromophenol. In addition, tetrabromo‑N‑methylpyrrole (TBMP) was detected in ~80% and Cl6-DBP in ~30% of the samples. Estimated time weighted maximum water concentrations were >150 pg Q1 and 60 pg 2′‑MeO-BDE 68 per L seawater. Typically, the concentrations were varying from year to year. Moreover, time weighted average water concentration estimates did not reveal consistent maximum trend levels within a given year. Additional screening analysis via GC/MS indicated the presence of several polyhalogenated 1′‑methyl‑1,2′‑bipyrroles (PMBPs), 1,1′‑dimethyl‑2,2′‑bipyrroles (PDBPs), and 1‑methylpyrroles (PMPs) along with four brominated N‑methylindoles and several other polyhalogenated compounds at Normanby Island.

The 137Cs activity in surface water of the East China Sea (ECS) was 0.66–1.36 Bq m−3 during May of 2011. The low activities were observed in the Changjiang Estuary and Zhejiang-Fujian coast and high activities were observed in the south offshore and Kuroshio Current pathway, suggesting that the influence from the current system in the ECS. The 134Cs were undetectable (<0.03 Bq m−3) and the contribution of the Fukushima accident to ECS is estimated to be below 3%; hence it is negligible during the investigation period. Using the vertical profiles of 137Cs in the ECS, the mass balance is obtained, which suggests that the oceanic input dominates the 137Cs source in the ECS. 137Cs is potentially useful to trace water mass movement in the ECS. Our study provides comprehensive baseline of 137Cs in the ECS for evaluation of the possible influence of the nuclear power plants in the future.

We comprehensively investigated sedimentary Hg in Yellow and East China Seas (YECSs), which constitute potentially important depocenters for large anthropogenic Hg emissions from mainland China. A large dataset of Al-TOC-Hg concentrations led to an in-depth understanding of sedimentary Hg in the entire YECSs, including distribution and its determinants, source-to-sink, background levels, inventory in flux and budget, and accumulation history. Especially, the net atmospheric Hg flux to the sediments was estimated to be 1.3 × 10−5 g/m2/yr, which corresponded reasonably well to that calculated using a box model. About 21.2 tons of atmospheric Hg (approximately 4% of the total anthropogenic atmospheric Hg emissions from China) were buried annually in the YECS basin. This result implies that most of atmospheric Hg from China is transferred to the surface of the Pacific (including the East/Japan Sea and South China Sea) by the westerlies and, consequently, can play a critical role in open-sea aquatic ecosystems.

The presence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in oceanic ecosystems constitutes an emerging public health risks in the marine environment. In this study, we report for the first time the identification of ESBL (CTX-M)-producing E. coli in wild fishes from a polluted area in the South Atlantic coast of Brazil, where a genomic analysis confirm the presence of livestock and human E. coli lineages belonging to sequence types (STs) ST744 and ST746, which carried clinically relevant resistance genes for human and veterinary antibiotics, and heavy metals. These findings reveal the presence of multidrug-resistant (MDR) bacteria in the gut microbiota of wild fishes living in polluted coastal waters, alerting that microbial contamination by bacteria related directly and indirectly to human or animal activities could affect the safety of the seafood supply, as well as the commercial and recreational use of coastal marine waters.