Hypoxia often intensifies with rising dissolved CO2, but the concurrent effects of hypoxia and acidification on bivalves are largely unknown. In this study, immune responses of hemocytes in the mussel Mytilus coruscus were examined under six combinations of pH (7.3, 7.7 and 8.1) and dissolved oxygen (DO) concentrations (2mgL−1, 6mgL−1) for 72h. Generally, total hemocyte account, phagocytosis, esterase and lysosomal content were reduced under low DO and pH conditions, whereas hemocyte mortality and reactive oxygen species production increased under low DO and pH. Both hypoxia and low pH have negative effects on mussels, but the effects of pH are not as strong as DO. Moreover, significant interactions between DO and pH occurred. However, acidification generally doesn't aggravate the effects induced by hypoxia. Acidification and hypoxia may increase disease risk and impact the aquaculture of this species.

Interaction between environmental degradation and economic growth is a growing matter of interest among policymakers. This paper examines the trilateral association between SO2 and NO2 emission, inequality in energy intensity, and economic growth by using simultaneous-equation panel data models for a panel of 139 Indian cities over the period 2001–2013. Our results indicate that there is evidence of feedback hypothesis between NO2 and SO2 emissions and economic growth, economic growth and inequality in energy intensity, and NO2 and SO2 emissions and inequality in energy intensity. The results also verified the existence of Environmental Kuznets curve for both of the pollutants. These results are of interest to environmental and economic policymakers as these can help in coming up with economic policies to ensure environmental sustainability and an inclusive economic growth.

We developed the stir bar sorptive extraction (SBSE)–gas chromatography–mass spectrometry (GC–MS) method to detect 15 kinds of PAEs in seawater. The stir bars (20mm in length and 1mm in film thickness) coated with 150μL of polydimethylsiloxane (PDMS) were found to demonstrate the optimal extraction of PAEs. The optimal conditions were as follows: extraction time of 2h, extraction temperature of 25°C, sodium chloride of 5%, methanol of 10%, analytical time of 50min, and methanol–acetonitrile (4:1) as the solvent. SBSE–GC–MS revealed that under the set temperature, the chromatographic peaks of all 15 PAEs can appear with complete separation. The detection limit ranged from 0.07μg/L to 5.71μg/L, whereas the limit of quantification ranged from 0.023μg/L to 193μg/L, and the correlation coefficients between the chromatographic peak area and concentration of the PAEs were greater than 0.92.

From 2011 to 2013, we conducted a full sanitary survey of pollution sources in proximity to a designated shellfish growing area in Korea, and their impact on the sea area therein. From this area, 836 seawater samples and 93 oyster samples were examined to evaluate their bacteriological quality. There were 483 potential pollution sources in the drainage area of the Jaranman-Saryangdo area, including 38 sources discharging water. It demonstrates that while many pollution sources have been identified, no significant impact occurred within the designated shellfish growing area. Variations in fecal coliform (FC) levels in seawater were closely related to rainfall. The FC levels of seawater and oysters from the designated area met the regulation limits set by various countries. Our study indicates that the oysters produced in this area are apparently safe for raw consumption based on their bacterial quality.

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.

Concentrations of total mercury (THg) were measured in coastal marine sediments near a former chlor-alkali plant in Chaleur Bay, New Brunswick. The chlor-alkali plant has been a local point source of THg since operation began in 1963. Historical THg contamination of marine sediments and biota has been widely reported. No baseline assessment has been conducted following plant closure in 2008. Surface (0–2cm) oxidized marine sediments were sampled along a single 5.2km transect radiating from the former plant and analysed for THg. THg concentrations ranged from 0.04–0.28μgg−1. Some localised THg concentrations exceeded Canadian marine sediment quality guidelines (n=4), but all samples (n=14) were significantly lower than previous studies conducted during plant operation. Plant closure (source control) and natural sediment recovery likely responsible for attenuating THg concentrations, but burial in deeper anoxic sediments may increase bioavilability of Hg that could pose ecological risks to marine biota.

Following the Deepwater Horizon oil spill, the spilled Macondo oil was severely weathered during its transport within the deep-sea plume as discrete particles, which were subsequently deposited on the seafloor. The Macondo oil deposited in deep-sea sediments was distinguished from ambient (background) hydrocarbons and naturally-seeped and genetically-similar oils in the Mississippi Canyon region using a forensic method based upon a systematic, multi-year study of 724 deep-sea sediment cores collected in late 2010 and 2011. The method relied upon: (1) chemical fingerprinting of the distinct features of the wax-rich, severely-weathered Macondo oil; (2) hydrocarbon concentrations, considering a core's proximity to the Macondo well or to known or apparent natural oil seeps, and also vertically within a core; and (3) results from proximal cores and flocculent material from core supernatants and slurp gun filters. The results presented herein establish the geographic extent of “fingerprintable” Macondo oil recognized on the seafloor in 2010/2011.

The presence of antibiotics in animal manure represents a significant concern with respect to the introduction of antibiotic residues to the environment and the development of antibiotic-resistant pathogens. In this review, we have (1) compiled reported detections of antibiotics in poultry litter, swine manure, and cattle manure; and (2) discussed the treatment of antibiotics during conventional agricultural waste management practices. The most reported antibiotics in animal manure were fluoroquinolones, sulfonamides, and tetracyclines, all of which the World Health Organization has listed as critically important for human health. Relatively high treatment efficiencies were observed for antibiotics in composting, anaerobic digestion, and aerobic/anaerobic lagooning. Interestingly, active management of compost piles did not demonstrate a significant increase in antibiotic degradation; however, low- and high-intensity compost systems exhibited high treatment efficiencies for most antibiotics. Anaerobic digestion was not effective for some key antibiotics, including lincosamides and select sulfonamides and fluoroquinolones. Given the potential for energy recovery during anaerobic digestion of agricultural waste, efforts to optimize antibiotic degradation represent an important area for future research. Lagoons also exhibited fairly high levels of antibiotic treatment, especially for aerobic systems; however, the operational costs/complexity of these systems inhibit utilization at the full-scale. No overall trends in antibiotic treatment efficiency during these three agricultural waste management practices were observed. Finally, we posit that increased efforts to include analysis of antibiotic residues in animal manure in national surveillance programs will provide important information to address concerns over the continued use of antimicrobials in animal feeding operations.

Organochlorines (OCs), such as pesticides and polychlorinated biphenyls (PCBs), are persistent, toxic and widely distributed through atmospheric transport and ocean currents. Few studies have been conducted on OCs in sea turtles, especially on the coast of Brazil. Chelonia mydas is the largest hard-shell sea turtle and is found tropical and subtropical regions in all oceans. The aim of the present study was to determine the occurrence of OCs in the green sea turtle (C. mydas). Fat, liver, kidney and muscle samples were collected from 27 juveniles found on the beach of the city of Ubatuba on the northern coast of the state of São Paulo, Brazil. OCs were extracted with organic solvents and the extract was purified with concentrated acid. Gas chromatography-mass spectrometry and electron capture detection were used for the identification and quantification of PCBs and pesticides, respectively. No organochlorine pesticides were detected in any of the samples. Concentrations of total PCBs in wet weight were <1.6 to 48.9ng/g in fat tissue, <1.6 to 17.4ng/g in liver tissue and <1.6 to 37.7ng/g in kidney tissue. The low levels found are mainly related to diet, as the green sea turtle is basically herbivorous and lower PCB contamination compared to other regions.

Adding fertiliser to sediments is an established way of studying the effects of eutrophication but a lack of consistent methodology, reporting on enrichment levels, or guidance on application rates precludes rigorous synthesis and meta-analysis. We developed a simple enrichment technique then applied it to 28 sites across an intertidal sandflat. Fertiliser application rates of 150 and 600gNm−2 resulted in pore water ammonium concentrations respectively 1–110 and 4–580×ambient, with greater elevations observed in deeper (5–7cm) than surface (0–2cm) sediments. These enrichment levels were similar to eutrophic estuaries and were maintained for at least seven weeks. The high between-site variability could be partially explained by the sedimentary environment and macrofaunal community (42%), but only at the high application rate. We suggest future enrichment studies should be conducted in situ across large environmental gradients to incorporate real world complexity and increase generality of conclusions.