Based on a modified trait hierarchy of body-size units, the feasibility for bioassessment of water pollution using body-size distinctness of planktonic ciliates was studied in a semi-enclosed bay, northern China. An annual dataset was collected at five sampling stations within a gradient of heavy metal contaminants. Results showed that: (1) in terms of probability density, the body-size spectra of the ciliates represented significant differences among the five stations; (2) bootstrap average analysis demonstrated a spatial variation in body-size rank patterns in response to pollution stress due to heavy metals; and (3) the average body-size distinctness (Δz+) and variation in body-size distinctness (Λz+), based on the modified trait hierarchy, revealed a clear departure pattern from the expected body-size spectra in areas with pollutants. These results suggest that the body-size diversity measures based on the modified trait hierarchy of the ciliates may be used as a potential indicator of marine pollution.

Bivalve shellfish may accumulate contaminants of public health concern including pathogenic bacteria and viruses. Microbiological monitoring of production areas is based on faecal coliforms in water in the USA and Escherichia coli in bivalve molluscs in the European Union. E. coli is known to reflect contamination with Salmonella enterica but not necessarily with other human pathogens such as enteric viruses. A structured field study was undertaken at three locations in order to investigate the geographical and temporal variability of E. coli and norovirus (NoV). Total norovirus concentration differed significantly by both sampling site and sampling date. A significant correlation was found between total NoV concentration and E. coli concentration by sample, but not with E. coli in seawater. The results have implications for the establishment of sampling plans for NoV in harvesting areas and potentially also for the approach taken to classification based on faecal indicator bacteria.

Cytochrome P450 (CYP) enzymes play important roles in the metabolism of exogenous compounds such as polycyclic aromatic hydrocarbons (PAHs). A novel, full-length CYP gene (CYP4V30) was identified in the oligochaete Thalassodrilides sp. CYP4V30 mRNA expression was studied in worms exposed to PAH-polluted (Σ16PAHs; 37441ng/g dry weight) or unpolluted (Σ16PAHs; 19ng/g dry weight) sediment. CYP4V30 expression was much higher in worms exposed to contaminated sediments than in those exposed to unpolluted sediments at some temperatures (20 and 25°C) and exposure durations (11-fold increase at 20°C, 10-day exposure), but not at 15°C or other exposure durations (P<0.05). CYP4V30 mRNA expression was higher in the middle of the body than in the posterior (P<0.05). The variation in transcriptional response with exposure time, temperature, and body region indicates that these factors should be considered when monitoring marine sediment pollution.

Atmospheric deposition from non-ferrous mining and smelting is one of the dominant sources of heavy metal pollution in soil. Jiyuan City in Henan Province, China produces about 900 000 tonnes of lead annually. Heavy metal soil contamination and elevated blood lead levels (BLLs) of local children in Jiyuan have been reported. This work investigated As, Cd and Pb deposition fluxes over 17 consecutive months at collection sites about 1000 m from a major lead smelter in Jiyuan. Mean As, Cd and Pb deposition fluxes were 17.2, 3.45 and 88.8 mg/m2/(30 d), respectively, lower values occurred from July to September during the traditional rainy season. Decreasing deposition fluxes of Cd and Pb were observed during the 17 month period, while As increased in the same period. Deposition fluxes of As, Cd and Pb of the sites near the smelter were 22.6, 29.2 and 29.4 times of those of a clean background site (0.762, 0.118 and 3.03 mg/m2/(30 d), respectively) far away from the smelter. Annually, the deposition enriches agricultural soil (0–20 cm plow zone) at the sampling sites with 0.805, 0.161 and 4.16 mg/kg As, Cd and Pb, respectively.

The performances of aluminum chloride modified clay (AC-MC), aluminum sulfate modified clay (AS-MC) and polyaluminum chloride modified clay (PAC-MC) in the removal of Aureococcus anophagefferens were compared, and the potential mechanisms were analyzed according to the dispersion medium, suspension pH and clay surface charges. The results showed that AC-MC and AS-MC had better efficiencies in removing A.anophagefferens than PAC-MC. The removal mechanisms of the three modified clays varied. At optimal coagulation conditions, the hydrolysates of AC and AS were mainly monomers, and they transformed into Al(OH)3(am) upon their addition to algae culture, with the primary mechanism being sweep flocculation. The PAC mainly hydrolyzed to the polyaluminum compounds, which remained stable when added to the algae culture, and the flocculation mainly occurred through polyaluminum compounds. The suspension pH significantly influenced the aluminum hydrolysate and affected the flocculation between the modified clay and algae cells.

Marine litter is one of the problems marine ecosystems face at present, coastal habitats and food webs being the most vulnerable as they are closest to the sources of litter. A range of animals (bivalves, free swimming crustaceans and benthic, deposit-feeding animals), of a coastal community of the northern Baltic Sea were exposed to relatively low concentrations of 10μm microbeads. The experiment was carried out as a small scale mesocosm study to mimic natural habitat. The beads were ingested by all animals in all experimental concentrations (5, 50 and 250beadsmL−1). Bivalves (Mytilus trossulus, Macoma balthica) contained significantly higher amounts of beads compared with the other groups. Free-swimming crustaceans ingested more beads compared with the benthic animals that were feeding only on the sediment surface. Ingestion of the beads was concluded to be the result of particle concentration, feeding mode and the encounter rate in a patchy environment.

Measurements of 16 polycyclic aromatic hydrocarbon (PAH) congeners (particles and vapour) have been made at three sites over a distance of 230 km on the Red Sea coast of Saudi Arabia. The data have been pooled with an earlier dataset from three sites in the city of Jeddah, with one urban site common to both studies. The concentrations and congener profiles are broadly similar for the two measurement campaigns at the common site. Coefficients of Divergence have been calculated and show more substantial differences between the sites within the city of Jeddah than are found between the sites to the north of the city which emphasises the strong concentration gradients within Jeddah in comparison to those found in the atmosphere of the coastal sites to the north of the city. A sub-set of data corresponding to days on which the air mass travelled from the northwest parallel with the Red Sea coast, hence linking the three sites, showed a progressive reduction in concentrations as the air mass travelled towards the southeast, which is attributed to emissions from a large source area to the northwest of the sampling sites and either atmospheric dilution or chemical reaction accounting for a progressive reduction in concentrations with advection of the air mass. The congener profile is very similar to that identified in earlier work relating to oil refinery emissions and is consistent with the major petrochemical installation at Yanbu contributing substantial emissions to the atmosphere which are advected to downwind sites.

A study of the efficiency of hydrodynamic cavitation and separation was carried out to evaluate an innovative, environmentally safe and acceptable system for ballast water treatment for reducing the risk of introducing non-native species worldwide. Mesocosm experiments were performed to assess the morphological changes and viability of zooplankton (copepods), Artemia salina cysts, and the growth potential of marine bacteria after the hydrodynamic cavitation treatment with a different number of cycles. Our preliminary results confirmed the significant efficiency of the treatment since more than 98% of the copepods and A. salina cysts were damaged, in comparison with the initial population. The efficiency increased with the number of the hydrodynamic cavitation cycles, or in combination with a separation technique for cysts. There was also a significant decrease in bacterial abundance and growth rate, compared to the initial number and growth potential.

Stable isotope analyses of the abundant infaunal polychaete Hediste diversicolor, recognised as an indicator of sewage pollution, support the hypothesis that nutrient enrichment promotes surface deposit feeding, over suspension feeding and predation. At sewage-polluted sites in three estuaries in SE England Hediste mainly consumed microphytobenthos, sediment organic matter and filamentous macroalgae Ulva spp. At cleaner sites Hediste relied more on suspension feeding and consumption of Spartina anglica. There were no consistent differences in Hediste densities between the polluted and cleaner sites, probably because of increased densities at the cleaner sites too, facilitated by the planting of Spartina and nitrogen enrichment there too, including from agricultural run-off. Increased nutrient enrichment and the artificial availability of Spartina have probably increased densities of, and deposit-feeding by, Hediste in the past half-century and contributed indirectly to saltmarsh losses, since deposit-feeding by Hediste has been implicated in recent saltmarsh erosion in SE England.