Oil from the Exxon Valdez laden with polycyclic aromatic hydrocarbons (PAH) has persisted on some beaches in Prince William Sound, Alaska, >20years after these beaches became contaminated. The degradation rate of the total PAH (TPAH) is estimated at 1% per year. Low oxygen concentrations were found to be the major factor causing oil persistence, and bioremediation through the injection of hydrogen peroxide and nutrients deep into four beaches in PWS were conducted in the summers of 2011 and 2012. It was found that due to the treatment, the TPAH biodegradation rate was between 13% and 70% during summer 2011 and summer 2012. The results also showed high efficiency in the delivery of oxygen and nutrient to the contaminated areas of the beach. However, the approach has an environmental cost associated with it, and stakeholders would need to conduct a rigorous net environmental benefit analysis (NEBA) for pursuing the bioremediation of submerged contaminated sediments, especially in higher latitudes.

A study of suspended particulate matter (SPM) fluxes along with their associated metals, organic matter and carbonates, was conducted off the Mejerda River outlet in May 2011 and in March and July 2012 at depths of 10, 20 and 40m using sediment traps. SPM fluxes are more significant near the Mejerda outlet, especially in winter, but dissipate further offshore. Normalization reveals that the Mejerda is a major source of Pb, Zn, Cd, Cu, Ni, and Co, all of which are the result of human activities. In contrast, Fe, Mn and N are of authigenic origin. The enrichment factor shows that Pb, Zn and especially Cd are the most highly polluting metals off the Mejerda outlet. This confirms the trend observed on the shores of the Mejerda prodelta and is consistent with the type of mining activities conducted in the Mejerda catchment.

The coastal hypersaline system of the Great Barrier Reef (GBR) in the dry season, was investigated for the first time using a 3D baroclinic model. In the shallow coastal embayments, salinity increases to c.a. 1‰ above typical offshore salinity (~35.4‰). This salinity increase is due to high evaporation rates and negligible freshwater input. The hypersalinity drifts longshore north-westward due to south-easterly trade winds and may eventually pass capes or headlands, e.g. Cape Cleveland, where the water is considerably deeper (c.a. 15m). Here, a pronounced thermohaline circulation is predicted to occur which flushes the hypersalinity offshore at velocities of up to 0.08m/s. Flushing time of the coastal embayments is around 2–3weeks. During the dry season early summer, the thermohaline circulation reduces and therefore, flushing times are predicted to be slight longer due to the reduced onshore-offshore density gradient compared to that in the dry season winter period.

Eutrophication is a major ecological crisis in water bodies. This is mainly driven by anthropogenic activities in the catchment that incorporate various nutrients. Input of nutrients can also be driven by atmospheric deposition, which has a large footprint that goes beyond local point source(s). In particular, black carbon (BC) can be a carrier of various nutrients and increase primary productivity in lakes. We need to monitor the input of BC in large water bodies to fully understand its role in driving primary productivity and change in trophic status.

Bacterioplankton communities in a semi-closed bay (Jangmok Bay, South Korea) were analysed using a 16S rDNA multiplex 454 pyrosequencing approach. Diversity and operational taxonomic units of bacterioplankton communities in the Jangmok Bay are highest in cold water seasons and lowest in warm water ones. During cold seasons, α-proteobacteria respond rapidly to pulses of the concentration of inorganic nutrients, while γ-proteobacteria during warm water seasons are the most active type of bacterioplankton resent in the prevailing conditions, which include high dissolved organic carbon, chemical oxygen demand and primary production. Cyanobacteria, a minor group constituting 4.58% of the total bacterioplankton, are more abundant at low temperature. Flavobacteria are more abundant in nutrient-rich conditions and the abundance of this group also demonstrated a delayed decline following summer phytoplankton blooms. The pronounced seasonal oscillations in phosphorus concentration and temperature exert strong selection pressure on bacterioplankton communities.

To better explore the concentration of polycyclic aromatic hydrocarbons (PAHs) in the sediments of the Yangtze River Estuary (YRE), 16 priority PAHs were analyzed based on sampling data obtained in February 2011. The results showed that the total concentrations of PAHs in sediments of the YRE varied from 65.07 to 668.98ng·g−1. The results of toxic equivalent quantities of benzo[a]pyrene and the sediment quality guideline quotient suggested that PAHs had little or no adverse effects on the environment. The cancer risk results showed that the cancer risk at all sites exceeded 10−6, with 73% of sites exceeding 10−4, suggesting that people remain at risk of cancer as a result of their exposure to carcinogenic PAHs. However, the result of hazard index results showed that the non-cancer risks were substantially lower than one, indicating that PAHs in these sediments likely pose little or no adverse health threats to local inhabitants.

This study presents the analysis of the emission, transport, dispersion, and concentration of particulate matter emitted from a large industrial complex dedicated to the manufacture of cement in the town of Malagueño, province of Córdoba (Argentina), using the USEPA's (Environmental Protection Agency) AERMOD model. The model was applied for 224 industrial and background emission sources (8 stacks, 3 limestone quarries, 13 material storage piles, 18 agricultural fields and 182 paved and unpaved segment roads). The application of the model was validated with Total Suspended Particulate matter (TSP) measured at two monitoring sites, where samples were collected for 62 consecutive days in winter. The maximum TSP values obtained at both monitoring sites (748 and 1100 μg m−3) were well above the suggested WHO guidelines. The results obtained showed the impact of this industrial activity on local particulate matter concentrations, from which unpaved industrial roads and stockpiles were the most influential emission sources, directly affecting two of the closest neighborhoods in the area. Future studies will include the accumulation of heavy metals and Polycyclic Aromatic Hydrocarbons in TSP samples, the environmental risk assessment for exposure of the Malagueño population and the source apportionment of these pollutants.

Anthropogenic contaminants reach the marine environment mostly directly from land-based sources, but there are cases in which they are emitted or re-mobilized in the marine environment itself. This paper reviews the literature, with a predominant focus on the European environment, to compile a list of contaminants potentially released into the sea from sea-based sources and provide an overview of their consideration under existing EU regulatory frameworks. The resulting list contains 276 substances and for some of them (22 antifouling biocides, 32 aquaculture medicinal products and 34 warfare agents) concentrations and toxicity data are additionally provided. The EU Marine Strategy Framework Directive Descriptor 8, together with the Water Framework Directive and the Regional Sea Conventions, provides the provisions against pollution of marine waters by chemical substances. This literature review should inform about the current state of knowledge regarding marine contaminant sources and provide support for setting-up of monitoring approaches, including hotspots screening.

To date, most estimates of contaminant fluxes across the sediment/water interface in risk assessments have been done using diffusive flux models. However, the reliability of these is limited as the overall flux from the sediment may have contributions caused by advection and bioturbation. We found through a comparison of modelled fluxes versus measured fluxes, that the methods Benthic Flux Chamber and surface leaching tests in a risk assessment context showed similar magnitude while calculated fluxes deviated at least by a factor of 100 from measured fluxes. This may be explained by the flux contribution in connection with bioturbation. The chamber-measured fluxes of copper were low compared to those of zinc and cobalt, but this is consistent with leaching tests that indicated copper to be more strongly bound. Risk assessments based on total concentrations may be misleading.

A survey of juvenile Asian horseshoe crabs in 2002 on the mudflats along Hong Kong's north-western shoreline abutting Deep Bay identified two species, Tachypleus tridentatus and Carcinoscorpius rotundicauda, and assessed their population characteristics. Since the 2002 survey, there have been significant habitat changes to this natal site for the two species. By employing the same, but expanded, sampling protocol, a further survey was, therefore, conducted twelve years later in 2014. A general population decline was recorded for T. tridentatus whereas for C. rotundicauda there was an increase and its distribution had become more widespread. The distribution patterns of the two species were also shown to have changed. The potential factors that might be responsible for recorded changes in the species' population characteristics between 2002 and 2014 are related to anthropogenic perturbations, including environmental habitat alterations notably the building of a bridge linking Hong Kong to Shenzhen in China.