Previous studies near historical gold mining districts in Nova Scotia have identified significant enrichment of metal(loid)s in coastal marine sediments. Most of this inventory is buried below biologically active zones, although in some areas arsenic has bioaccumulated in marine biota resulting in localised bivalve shellfish closures. Isaacs Harbour is poised for future industrial development, but before potential impacts are predicted, current marine baseline conditions must be determined. To address this gap, this study established a baseline using surface sediments and biota (mussel and lobster tissues), to provide a broader picture of metal(loid)s in the marine environment. Results confirmed previous studies showing that most sediment metal(loid) concentrations still exceeded Canadian Marine Sediment Quality Guidelines, and also provided evidence of Canadian Food Inspection Agency fish tissue exceedances of arsenic in lobster and lead in mussel tissues indicating that some bioaccumulation of legacy contaminants in marine biota continues to the present day.

The rapid expansion of industry, along with previous pollution events linked to conflicts in the region, have led to a variety of contaminants being inadvertently or deliberately discharged into Kuwait’s marine environment. These include polycyclic aromatic hydrocarbons (PAHs) and trace metals, from the petrochemical industry, and contaminated brine from the region’s desalination industries. The present paper has reviewed over 60 studies that have reported the levels of contaminants, including PAHs, metals and polychlorinated biphenyls (PCBs) present in seawater, sediment and representative marine organisms. Most of the reviewed literature confirmed that while Kuwait’s marine environment has been subjected to a wide array of pollution events, the actual levels of contamination remains relatively low. However, sediment contamination hotspots associated with point sources of industrial contamination, such as originating from the Shuaiba industrial area, do exist at a number of locations around the coast.

In an effort to assess the impact of mercury in the Antarctic Peninsula, we conducted ecotoxicological research in this region during the summer of 2012 and 2013. The objectives were to assess: (a) mercury levels in sediment samples; (b) mercury accumulation in Antarctic seabird feathers: Catharacta lonnbergi (brown skua), Pygoscelis papua (gentoo penguin) and Pygoscelis antarctica (chinstrap penguin); and (c) biomagnification (BMF predator/prey) and biota sediment accumulation (BSAF skuas/sediment) factors. Mercury concentrations in sediment were relatively low. Mercury concentrations were significantly higher in brown skuas and gentoo penguins than in chinstrap penguins (2012), and significantly higher in brown skuas than in both penguins (2013). BMF indicated 2–7.5 times greater mercury levels in brown skuas than in penguins. BSAF values suggested an apparent temporal decrease of 18.2% of this ratio from 2012 to 2013. Long-range environmental transport is the likely route of entry of mercury into the Antarctic Peninsula.

A study on 137Cs, 40K, 226Ra, 228Ra, and 238U was carried out along the EEZ of Qatar. Results serve as the first ever baseline data. The level of 137Cs (mean value 1.6±0.4Bqm−3) in water filters was found to be in the same order of magnitude as reported by others in worldwide marine radioactivity studies. Results are also in agreement with values reported from other Gulf regions. The computed values of sediment–water distribution coefficients Kd, are lower than the values given by IAEA. Measurements were carried out for bottom sediments, biota samples like fish, oyster, sponge, seashell, mangrove, crab, shrimp, starfish, dugong and algae. The ‘concentration factors’ reported for biota samples are below the levels published by IAEA and cause no significant impact on human health for seafood consumers in Qatar.

A challenging aspect of benthic quality indices used for assessing the marine environment has been to compile reliable measures of the species’ sensitivity to disturbances. Sensitivity values and their uncertainties can be calculated, but a problem to cope with is that the results may depend on the actual proportion of samples from disturbed and undisturbed environments.Here we calculated sensitivity values for each species along an artificial disturbance gradient created by bootstrapping varying numbers of samples from disturbed and undisturbed environments. The values were increasing, decreasing, or more or less constant along this gradient. The lowest value with the lowest uncertainty was adopted as the species sensitivity value.Analyses of the uncertainties indicated that the accuracy rather than the precision might be a concern. We suggest a method to exclude species for which the uncertainty is outside predefined limits as a precaution to reduce bias in the environmental status classification.

The mining sector is growing in parallel with societal demands for minerals. One of the most important environmental issues and economic burdens of industrial mining on land is the safe storage of the vast amounts of waste produced. Traditionally, tailings have been stored in land dams, but the lack of land availability, potential risk of dam failure and topography in coastal areas in certain countries results in increasing disposal of tailings into marine systems. This review describes the different submarine tailing disposal methods used in the world in general and in Norway in particular, their impact on the environment (e.g. hyper-sedimentation, toxicity, processes related to changes in grain shape and size, turbidity), current legislation and need for future research. Understanding these impacts on the habitat and biota is essential to assess potential ecosystem changes and to develop best available techniques and robust management plans.

Fiddler crabs Uca rapax were analyzed in three mangrove areas located in both a lagoon and estuarine system in order to study the influence of eutrophication on their population dynamics and production. Populations at the three sites showed a biased sex ratio. Densities were similar at the three sites, but biomass was higher at the lagoon system. Despite biomass being higher at the most eutrophic site, this site exhibited the lowest production. Regarding age structure, the population inhabiting the less eutrophic site mainly comprised younger crabs. The lower production and smaller P/B ratio found in the more eutrophic site were most likely consequences of a high mortality rate and an aged population. Our study evidences the high plasticity of the fiddler crab U. rapax, and confirms secondary production and P/B ratio estimates as useful tools to assess the effects of environmental change.

The aim of this paper was to assess the biological damages in fish caused by various mutagenic agents present in polluted waters of Aliağa Bay. For this purpose, micronuclei (MN) test was performed using peripheral erythrocytes and gill cells of different fish specimens caught from both polluted and relatively clean sites from Aliağa Bay (Turkey). Micronuclei tests is a system of mutagenicity testing used for determining changes in DNA fragments such as micronuclei in the cytoplasm of interphase cells caused by the pollution and chemicals in the environment. Thus, it was attempted to determine whether pollution affected the erythrocytes and gills of fish living in Aliağa Bay at the level of DNA by the means of micronuclei (MN) test. According to the results of present study, frequency of MN was found at high level in polluted site. In conclusion, this study indicates that the micronuclei test gives sensitive results in monitoring the pollution, especially the pollution of harbor, and thus it might be used as standard method in regularly monitoring pollution of coastal ecosystem.

The formation and distribution of oxygen-deficient water mass (ODW) in Jinhae Bay exhibited seasonal patterns similar to those of the summer thermocline, indicating a close mutual relationship, and the influence of ODW formation conditions appeared prominently in the bottom water. The principal factors analysis indicate that dissolved oxygen and NO2 in the bottom water during the time of ODW formation were highly correlated with NH3 and dissolved inorganic phosphorus. The findings clearly illustrate the effects on ODW of seasonal physical and chemical changes. ODW that formed in the bottom water of Jinhae Bay during summer produced high concentrations of nutrients in the bottom water; since the growth of phytoplankton was limited by the strong stratification and low concentrations of dissolved oxygen (<3mg/L) in the bottom layer, these nutrients (especially NH3 and DIP) were retained and accumulated, serving as a major source of nutrients during the dry winter.

Advanced oxidation processes (AOPs) were first proposed in the 1980s for drinking water treatment and later were widely studied for treatment of different wastewaters. During the AOP treatment of wastewater, hydroxyl radicals (OH·) or sulfate radicals (SO₄ ·⁻) are generated in sufficient quantity to remove refractory organic matters, traceable organic contaminants, or certain inorganic pollutants, or to increase wastewater biodegradability as a pre-treatment prior to an ensuing biological treatment. In this paper, we review the fundamental mechanisms of radical generation in different AOPs and select landfill leachate and biologically treated municipal wastewater as model wastewaters to discuss wastewater treatment with different AOPs. Generally, the treatment efficiencies rely heavily upon the selected AOP type, physical and chemical properties of target pollutants, and operating conditions. It would be noted that other mechanisms, besides hydroxyl radical or sulfate radical-based oxidation, may occur during the AOP treatment and contribute to the reduction of target pollutants. Particularly, we summarize recent advances in the AOP treatment of landfill leachate, as well as advanced oxidation of effluent organic matters (EfOM) in biologically treated secondary effluent (BTSE) for water reuse.