Lipid and fatty acid (FA) composition and selected oxidative stress parameters of freshwater clams (Dipolodon chilensis), from a sewage-polluted (SMA) and a clean site, were compared. Trophic markers FA were analyzed in clams and sediment. Saturated FA (SAFA), and bacteria and sewage markers were abundant in SMA sediments, while diatom markers were 50% lower. Proportions of SAFA, branched FA, 20:5n−3 (EPA) and 22:6n−3 (DHA) were higher in SMA clams. Chronic exposure of D. chilensis to increasing eutrophication affected its lipid and FA composition. The increase in EPA and DHA proportions could be an adaptive response, which increases stress resistance but could also lead to higher susceptibility to lipid peroxidation TBARS, lipofuscins (20-fold) and GSH concentrations were higher in SMA clams. FA markers indicated terrestrial plant detritus and bacteria are important items in D. chilensis diet. Anthropogenic input in their food could be traced using specific FA as trophic markers.

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in the sediment from the Hormuz strait, Persian Gulf. The sum of 16 PAHs (ΣPAH) concentrations varied from 72.17 to 277.77ngg−1 dry weight, with an average value of 131.20±59.29ngg−1 dry weight. An ecological risk assessment of PAHs, indicated that adverse biological effects caused by acenaphthene and acenaphthylene occasionally may take place in the sediment of Hormuz strait. PAH source identification showed that the PAHs in the sediments come from pyrogenic and mixed origin. Based on classification of pollution levels, sediments from Hormuz strait could be considered as low to moderately polluted with PAHs.

To investigate the effects of Spartina alterniflora on heavy metals pollution of intertidal sediments, sediment cores of a S. alterniflora salt marsh and a mudflat in Bohai Bay, China were analyzed. The results showed that S. alterniflora caused higher total C and P, but lower bulk density and electrical conductivity. The levels of Cd, Cu and Pb were higher in S. alterniflora sediment. Both Cd and Zn were higher than the probable effect level at both sites, indicating their toxicological importance. The geo-accumulation and potential ecological risk indexes revealed higher metal contamination in S. alterniflora sediment. Multivariate analysis implied that anthropogenic activities altered mobility and bioavailability of heavy metals. The percentage of mobile heavy metals was higher in S. alterniflora sediment, indicating improvement of conversion from the immobilized fraction to the mobilized fraction. These findings indicate that S. alterniflora may facilitate accumulation of heavy metals and increase their bioavailability and mobility.

In this study, the bioremediation potentials of two seaweeds (Sargassum hemiphyllum and S. henslowianum) against pollution in a coastal mariculture area of Shenzhen, South China, were investigated by comparing the growth, nutrient bioaccumulation capacity of plants from the seaweed bed (control site) with plants from the fish farm. Results indicated that both species are potential candidates for bioremediation in the fish farm areas in terms of their high growth rates and high bioaccumulation capacities on inorganic nutrients. Both Sargassum spp. contain high levels of crude protein (11.7–14.0%) and crude fat (2.2–2.7%), suggesting high nutritional values. The S. hemiphyllum may serve as a good aquaculture fodder with high nutritional compositions and low heavy metal contents. However, heavy metals (Cr, Pb and Cd) of S. henslowianum exceed the maximum allowable concentrations as aquatic feed, which restricts its fodder application. In general, the results of this study may contribute to the marine pollution bioremediation in the coastal areas of South China, especially in mariculture zones.

Sediment quality has been assessed within the Avilés estuary, an important industrial area in the NW of Spain. The study started with a geochemical characterization of the superficial sediments that revealed some anomalous metal(oid)s concentrations in sensitive areas such as beaches or dunes. These data were studied by means of multivariate statistical techniques and enrichment factors calculation to evaluate the correlations and geochemical origin within the different elements. A novel approach using the combination of enrichment factors with a sequential application of factor analysis, clustering and kriging was essential to identify the possible sources of pollution. The collected information suggested that Cd (strongly correlated with Zn and Pb) was the potentially toxic element most widely distributed and problematic. Furthermore, particulate emissions from Zn metallurgy, as well as dust generated by the mineral loading and stockpile activities in the port were identified as the most important sources of pollution.

X-ray fluorescence scanners, such as the Itrax™ Core Scanner (Itrax) (Cox Analytical Systems, Mölndal, Sweden), provide high-resolution geochemical data within several hours. However, the semi-quantitative nature of these analysers has hampered their use to study pollution. This study explores Itrax’s capabilities to detect trace metals, such as Hg and Cd, in the Ría de Pontevedra harbour (NW Spain). A set of Itrax detection levels were proposed for each metal after comparison with quantitative measurements obtained from Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and Vapour Atomic Absorption Spectrometry (CVAAS) analyses. These quantitative data obtained after a sequential extraction were used to evaluate pollutant bioavailability and to determine metal pollution levels exhibiting Hg pollution. The reliability of inc/coh and Br/Cl ratios to assess the total organic matter variability was also evaluated. The results indicated that the Itrax is an efficient and fast option to monitor contamination, thereby avoiding laborious discrete analyses and reducing analytical cost and time.

In this paper, a Monte Carlo simulation based two-stage adaptive resonance theory mapping (MC-TSAM) model was developed to classify a given site into distinguished zones representing different levels of offshore Oil Spill Vulnerability Index (OSVI). It consisted of an adaptive resonance theory (ART) module, an ART Mapping module, and a centroid determination module. Monte Carlo simulation was integrated with the TSAM approach to address uncertainties that widely exist in site conditions. The applicability of the proposed model was validated by classifying a large coastal area, which was surrounded by potential oil spill sources, based on 12 features. Statistical analysis of the results indicated that the classification process was affected by multiple features instead of one single feature. The classification results also provided the least or desired number of zones which can sufficiently represent the levels of offshore OSVI in an area under uncertainty and complexity, saving time and budget in spill monitoring and response.

Coastal lagoons are ecotones between continents and the sea. Coastal lagoons of Western Greece, subjected to different human pressures, were classified into four different types based on their hydromorphological characteristics and monitored over a three year period for their biotic and abiotic features. Six ecological indices based on water quality parameters (TSI-Chl-a, TSI-TP, TRIX), benthic macrophytes (E-MaQI, EEI-c) and an integrated index TWQI, were applied to assess the ecological status of studied lagoons under real conditions. The trophic status ranged from oligotrophic to hypertrophic according to the index applied. The ecological quality of transitional water ecosystems can be better assessed by using indices based on benthic macrophytes as changes in abundance and diversity of sensitive and tolerant species are the first evidence of incoming eutrophication. The multi-parametric index TWQI can be considered appropriate for the ecological assessment of these ecosystems due to its robustness and the simple application procedure.

Superficial sediments from Lenga estuary in the VIII region of central Chile were analysed for Polychlorinated Biphenyls (PCBs) and Hexachlorobenzene (HCB). Organic carbon (OC) analysis was also performed and the statistical correlations (Pearson correlations) between compounds were also tested. Results showed the total PCB concentrations (ngg−1d.w.) fluctuated from ∼20 to 10,000. These levels are higher than those reported in other coastal sediments of the world. The PCB profile was dominated by middle to highly chlorinated congeners (6-Cl=40% and 7-Cl=30%). HCB concentrations (ngg−1d.w.), were lower than the PCBs and, fluctuated between 1 (at L1) and 870 (at L4). OC values ranged from 1% (L1) to 7% (L4) showing a significant positive correlations between OC% and PCBs (r=0.86; p<0.05) and for HCB (r=0.71). These results are an important contribution to knowledge of levels of POPs levels in coastal Chilean environments.

Reactivation and chemical modification were used to obtain modified activated carbons with different pore structure and surface chemical properties. The samples were characterized by nitrogen absorption–desorption, Fourier transform infrared spectroscopy and the Bothem method. Using mercury chloride as the target pollutant, the Hg2+ adsorption ability of samples was investigated. The results show that the Hg2+ adsorption capacity of samples increased significantly with increases in micropores and acidic functional groups and that the adsorption process was exothermic. Different models and thermodynamic parameters were evaluated to establish the mechanisms. It was concluded that the adsorption occurred through a monolayer mechanism by a two-speed process involving both rapid adsorption and slow adsorption. The adsorption rate was determined by chemical reaction.