One of the main challenges of bioremediation is to define efficient protocols having a low environmental impact. We have investigated the effect of three treatments in oily-seawater after a real oil-spill occurred in the Gulf of Taranto (Italy). Biostimulation with inorganic nutrients allowed the biodegradation of the 73±2.4% of hydrocarbons, bioaugmentation with a selected hydrocarbonoclastic consortium consisting of Alcanivorax borkumensis, Alcanivorax dieselolei, Marinobacter hydrocarbonoclasticus, Cycloclasticus sp. 78-ME and Thalassolituus oleivorans degraded 79±3.2%, while the addition of nutrients and a washing agent has allowed the degradation of the 69±2.6%. On the other hand, microbial community was severely affected by the addition of the washing agent and the same product seemed to inhibit the growth of the majority of strains composing the selected consortium at the tested concentration. The use of dispersant should be accurately evaluated also considering its effect on the principal actors of biodegradation.

Offshore petroleum exploration has increased the risks of oil spills in coastal tropical and subtropical habitats. Monitoring tools are needed to assess and protect environmental health. We determined baseline values of antioxidant biomarkers (CAT, SOD, GPx, GST, MDA) for five ecologically relevant species in a subtropical system in southern Brazil. Regional baseline levels are compared with literature data as a basis to eventually test their efficacy as post-spill monitoring tools. Differences in the antioxidant response among species, contamination, and seasons were tested using univariate and multivariate analyses. The bivalves Anomalocardia flexuosa and Crassostrea rhizophorae and the catfish Genidens genidens emerge as suitable sentinel species. Seasonality is the main factor accounting for biomarkers variability, and not background contamination level. However, interactions between season and contamination level are also significant, indicating that biomarkers respond to complex environmental settings, a fact that needs to be fully understood for designing proper monitoring programs.

We have investigated the distribution of a heavy oil residue in the coastal sediments of the Gulf of Mexico. The amount of the contamination was determined by high-temperature pyrolysis coupled with the Gas Chromatography–Mass Spectrometry (GCMS) of air-dried sediments. The pyrolysis products contain straight-chain saturated and unsaturated hydrocarbons, such as dodecane and 1-dodecene, resulting in a very characteristic pattern of double peaks in the GCMS. Hydrocarbons containing 8 to 23 carbon atoms were detected in the pyrolysis products. Using thermal pyrolysis we have found that the sediment samples collected along Texas, Louisiana, and Mississippi shores contain no detectable traces of oil residue, but most of the samples collected along Alabama and Florida shores contain ~200ppm of heavy oil residue.

We investigated the applicability of Nile Red (NR), a fluorescent dye, for microplastic analysis, and determined the optimal staining conditions. Five mg/L NR solution in n-hexane effectively stained plastics, and they were easily recognized in green fluorescence. The NR staining method was successfully applied to micro-sized polyethylene, polypropylene, polystyrene, polycarbonate, polyurethane, and poly(ethylene-vinyl acetate), except for polyvinylchloride, polyamide and polyester. The recovery rate of polyethylene (100–300μm) spiked to pretreated natural sand was 98% in the NR stating method, which was not significantly (p<0.05) different with FT-IR identification. The NR staining method was suitable for discriminating fragmented polypropylene particles from large numbers of sand particles in laboratory weathering test samples. The method is straightforward and quick for identifying and quantifying polymer particles in the laboratory controlled samples. Further studies, however, are necessary to investigate the application of NR staining to field samples with organic remnants.

A bacterial consortium was selected in the presence of Cu from sediment samples taken from Sepetiba Bay, Brazil, which is a site historically contaminated by metals. Bacteria were exposed to 0, 1, 6, 12.5, 25 and 50μg·mL−1 Cu, Pb and Cu+Pb for 11days of bioassay. Results showed Alcanivorax dominance (81%) and cell counts of 108cells·mL−1. However, a reduction in dehydrogenase activity was observed from the fifth day of exposure for all Cu, Pb, and Cu+Pb concentrations tested. Esterase activity tended to increase, indicating higher energy demand to complete the bacterial lifecycle. Pb concentrations in the filtered culture medium (0.2μm) were below the detection limit, indicating biosorption, whereas concentrations of Cu were close to the tested concentrations, indicative of efflux. Results suggest the need for biomarkers, such as esterase and dehydrogenase enzymatic activity, in the assessment of resistance and tolerance of communities previously exposed to stressors.

Mangroves provide vital climate change mitigation and adaptation (CCMA) ecosystem services (ES), yet have suffered extensive tropics-wide declines. To mitigate losses, rehabilitation is high on the conservation agenda. However, the relative functionality and ES delivery of rehabilitated mangroves in different intertidal locations is rarely assessed. In a case study from Panay Island, Philippines, using field- and satellite-derived methods, we assess carbon stocks and coastal protection potential of rehabilitated low-intertidal seafront and mid- to upper-intertidal abandoned (leased) fishpond areas, against reference natural mangroves. Due to large sizes and appropriate site conditions, targeted abandoned fishpond reversion to former mangrove was found to be favourable for enhancing CCMA in the coastal zone. In a municipality-specific case study, 96.7% of abandoned fishponds with high potential for effective greenbelt rehabilitation had favourable tenure status for reversion. These findings have implications for coastal zone management in Asia in the face of climate change.

This study provides first-time estimates of direct fuel inputs and greenhouse gas emissions produced by the trawl fishing fleet operating off southeastern and southern Brazil. Analyzed data comprised vessel characteristics, landings, fishing areas and trawling duration of 10,144 fishing operations monitored in Santa Catarina State from 2003 to 2011. Three main fishing strategies were differentiated: ‘shrimp trawling’, ‘slope trawling’ and ‘pair trawling’. Jointly these operations burned over 141.5millionl of diesel to land 342.3millionkg of fish and shellfish. Annually, 0.36–0.48l were consumed for every kg of catch landed. Because all fishing strategies relied on multispecific catches to raise total incomes, estimates of fuel use intensity were generally low but increased 316–1025% if only nominal targets were considered. In nine years, trawling operations emitted 104.07GgC to the atmosphere, between 36,800–49,500tons CO2 per year.

This study focused on the feasibility of the treatment of heavy metals-contaminated sediments from Gabes harbor (Tunisia) using enhanced electrokinetic process. It presented a laboratory short-time electrokinetic experiment. The enhancing agents, as citric, acetic acids and sodium dodecyl sulfate (SDS) were used regarding their low environmental hazard. The electrokinetic cell was specially designed in order to elaborate two experiments at the same time. This paper is composed of three parts. The first part introduces the characterization of Gabes sediments. The second part describes the design of laboratory electrokinetic cell and the followed methods. The third part is dedicated to the results analysis. Treatment efficiency revealed that more than 80% of lead was removed from Gabes marine sediments. The reduction of cooper concentration, in sediments after treatment, ranged from 74 to 87%. Despite, the high removal of cadmium that ranged from 58 to 79%, treated sediments presented Cd concentration above the threshold limit.

The Cananéia–Iguape system is located in a Southeastern Brazilian coastal region, acknowledged by UNESCO as Biosphere Reserve of the Atlantic Rainforest. This system underwent important environmental changes due to the opening of the artificial channel of Valo Grande and by past intensive Pb ore mining activities. In view of this scenario, this study evaluated Cu, Pb and Zn availability in sediments from Cananéia–Iguape system, based on the content associated with the main components of the sediments. Moreover, in order to assess local contamination, the metals' contents were compared to Canadian quality guidelines, the past levels of metals preceding the mining activities and background sediment values. Concerning Cu and Zn in a state of chemical remobilization, both elements would possibly present no harm to the local communities. However, Pb available content exceeded the comparison values in various sampling sites, suggesting the need of monitoring regarding its bioavailability.

The Yellow River Delta (YRD) is a large region of China with complex pollution sources and a long history of environmental deterioration. Despite this, relatively little data exists on the status of important contaminants of concern in this region. Here, we review the literature on the status of key persistent organic pollutants (POPs) of concern including organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) in the YRD. Sources, source identification methods, and spatial distribution patterns are presented. Additionally, POPs contamination levels reported in the literature were evaluated against popular regulatory limits worldwide to form a basis for overall environmental health. Our review determined that OCPs in the YRD originated mainly from current pesticide use and past agricultural pesticide application. Sources of PAHs included petrochemical inputs, coal fired plants, and wood combustion. PCB levels were impacted by the petrochemical industry as well as waste disposal of PCB containing equipment. OCPs exhibited a spatial distribution pattern that increased along the urban–rural gradient, while the opposite was seen for PAHs and PCBs. Comparisons of POPs contamination levels in the YRD with popular regulatory limits suggest that the extent of PCB contamination all mediums (sediment, soil, water, and biota) exceeded that of PAHs and OCPs. Overall pollution levels in the YRD seem to be in control; however, levels from heavily polluted point sources raise numerous concerns about the ecological health of the region and require more attention from regulatory authorities.