This study evaluated the efficiency of Avicennia schaueriana in the implementation of phytoremediation compared with intrinsic bioremediation in mangrove sediments contaminated by total petroleum hydrocarbons (TPHs). The experiment was conducted for 3months at a pilot scale under conditions similar to a mangrove: the dynamics of the tides were simulated, and physical, chemical, microbiological and biogeochemical parameters were monitored. After the 90days, it was found that the phytoremediation was more efficient in the degradation of the TPHs compared to bioremediation, reducing the initial concentration of 32.2–4.2mg/g. A. schaueriana was also more efficient in mediating the degradation of different fractions of hydrocarbons, achieving a removal efficiency of 87%. The microbiological results consisted of a higher growth in the model with the plants, demonstrating the phytostimulation ability of the plants. Finally, the experiment showed that phytoremediation is a promising alternative in mangrove impacted by oil.

We examined persistent organic pollutant and trace element concentrations in eggs of magnificent frigatebirds (Fregata magnificens), a species of conservation concern breeding in the West Indies. Despite that frigatebirds feed at high positions in tropical marine food chains, we detected low levels of most contaminants, suggesting limited contamination of their prey.

Size distribution of oil droplets formed in deep water oil and gas blowouts have strong impact on the fate of the oil in the environment. However, very limited data on droplet distributions from subsurface releases exist. The objective of this study has been to establish a laboratory facility to study droplet size versus release conditions (rates and nozzle diameters), oil properties and injection of dispersants (injection techniques and dispersant types). This paper presents this facility (6m high, 3m wide, containing 40m3 of sea water) and introductory data. Injection of dispersant lowers the interfacial tension between oil and water and cause a significant reduction in droplet size. Most of this data show a good fit to existing Weber scaling equations. Some interesting deviations due to dispersant treatment are further analyzed and used to develop modified algorithms for predicting droplet sizes in a second paper (Johansen et al., 2013).

Forty-three sediment samples were collected from the beaches of Miri City, Sarawak, Malaysia to identify the enrichment of partially leached trace metals (PLTMs) from six different tourist beaches. The samples were analyzed for PLTMs Fe, Mn, Cr, Co, Cu, Ni, Pb, Sr and Zn. The concentration pattern suggest that the southern side of the study area is enriched with Fe (1821–6097μgg−1), Mn (11.57–90.22μgg−1), Cr (51.50–311μgg−1), Ni (18–51μgg−1), Pb (8.81–84.05μgg−1), Sr (25.95–140.49μgg−1) and Zn (12.46–35.04μgg−1). Compared to the eco-toxicological values, Cr>Effects range low (ERL), Lowest effect level (LEL), Severe effect level (SEL); Cu>Unpolluted sediments, ERL, LEL; Pb>Unpolluted sediments and Ni>ERL and LEL. Comparative results with other regions indicate that Co, Cr, Cu, Ni and Zn are higher, indicating an external input rather than natural process.

Many studies have investigated phototoxicity under controlled laboratory conditions, however, few have actually demonstrated it occurring in environmental samples. Here we report on the potential for UK marine coastal waters to demonstrate phototoxicity when tested using the oyster embryo (Crassostrea gigas) bioassay in the presence UV light. Subsurface water, sea surface microlayer samples and subsurface water samples that had been extracted through solid phase extraction (SPE) columns were analysed. Results demonstrated that the majority of samples failed to display any phototoxic potential. However, those collected from Belfast Lough did display an increase in toxicity when bioassays were performed in the presence of UV light when compared to identical samples assayed in the absence of UV light. Analysis of water samples at this location identified known phototoxic PAHs, pyrene and fluoranthene. These findings suggest the need to consider the potential UV light has when determining the toxicity of environmental samples.

The dumping of dredged sediments represents a major stressor for coastal ecosystems. The impact on the ecosystem function is determined by its complexity not easy to assess. In the present study, we evaluated the potential of bacterial community analyses to act as ecological indicators in environmental monitoring programmes. We investigated the functional structure of bacterial communities, applying functional gene arrays (GeoChip4.2). The relationship between functional genes and environmental factors was analysed using distance-based multivariate multiple regression. Apparently, both the function and structure of the bacterial communities are impacted by dumping activities. The bacterial community at the dumping centre displayed a significant reduction of its entire functional diversity compared with that found at a reference site. DDX compounds separated bacterial communities of the dumping site from those of un-impacted sites. Thus, bacterial community analyses show great potential as ecological indicators in environmental monitoring.

In addition to monitoring trends in plastic pollution, multi-species surveys are needed to fully understand the pervasiveness of plastic ingestion. We examined the stomach contents of 20 bird species collected from the coastal waters of the eastern North Pacific, a region known to have high levels of plastic pollution. We observed no evidence of plastic ingestion in Rhinoceros Auklet, Marbled Murrelet, Ancient Murrelet or Pigeon Guillemot, and low levels in Common Murre (2.7% incidence rate). Small sample sizes limit our ability to draw conclusions about population level trends for the remaining fifteen species, though evidence of plastic ingestion was found in Glaucous-Winged Gull and Sooty Shearwater. Documenting levels of plastic ingestion in a wide array of species is necessary to gain a comprehensive understanding about the impacts of plastic pollution. We propose that those working with bird carcasses follow standard protocols to assess the levels of plastic ingestion whenever possible.

We determined total mercury (Hg) distribution in muscle and liver of ten ray species and assessed health risk considering Hg levels in muscle and average consumption of rays in Mexico. Rays were collected from five sites in NW Mexico between March and November 2012. Hg concentrations ranged from 4.465μgg−1 in muscle of the longtail stingray Dasyatis longa to 0.036μgg−1 in liver of the diamond stingray Dasyatis dipterura. Considering all the individuals, Hg in muscle (1.612±1.322μgg−1) was significantly (p<0.05) higher than in liver (0.745±0.616μgg−1). Regarding local health risk assessment, none of the ray species may cause adverse effects on consumers.

The effects of the decline in ocean pH, known as ocean acidification, on marine species are not well understood. To test the effects on embryos and larvae of red king crab, Paralithodes camtschaticus, ovigerous crab and their larvae were held in CO2-acidified (pH 7.7) and control (ambient; pH 8.0) seawater during development. Morphometrics, hatch duration, fecundity, survival, mineral content, and condition were measured. Acidified embryos had 4% larger eyes and 5% smaller yolks, while mean hatch duration was 33% longer and female fecundity was unaffected. Acidified embryos also resulted in 4% longer larvae while acidified larvae had lower survival. Calcium content of both larvae and female carapaces after molting increased by 5% and 19%, respectively. Although ocean acidification may increase larval size and calcium content, the implications of this are unclear and decreased survival is likely to harm red king crab populations.

The influence of seasonal and environmental parameters on the occurrence of bacteria was investigated in two clam species (Venerupis pullastra and Ruditapes philippinarum), water and sediment from the Tagus estuary. Total viable counts (TVC), Escherichia coli, Salmonella spp. and Vibrio spp. were evaluated during one-year. Overall, significant seasonal variations were found in both sampling sites, especially for E. coli and Vibrio spp. levels. In summer, significantly higher Vibrio spp. levels were found in R. philippinarum and sediment samples, but not in V. pullastra clams and water samples. In contrast, significantly higher TVC and E. coli levels were observed in winter months in water and sediment samples. Salmonella spp. was generally isolated when higher levels of E. coli were detected, particularly in R. philippinarum. This study is useful for authorities to develop monitoring strategies for coastal contamination and to estimate human health risks associated with the consumption of bivalves.