Mercury concentrations were assessed in the sea turtle Lepidochelys olivacea from a nesting colony of Oaxaca, Mexico; 25 female turtles were sampled, a total of 250 eggs were collected during the season 2005–2006. Higher concentrations were found in yolk fraction, while in blood and albumen mean levels were below of 0.0010μgg⁻¹ dry wt. On the basis of one nesting season, the maternal transfer of Hg via eggs-laying was estimated in 2.0±1.1%. According to international norms, the health of this population and its habitats is acceptable for Hg and corresponds to baseline levels of a nearly pristine environment.

We reconstructed the first long-term (∼400years) records of black carbon (BC) deposition flux from three ornithogenic sediment profiles, which were collected from three remote, isolated islets of the Xisha archipelago, South China Sea. The significant correlations between black carbon, organic matter and excess ²¹⁰Pb suggested that black carbon was mainly derived from atmospheric deposition, and further enriched by plant-derived organic matter in sediments. During the past 400years, the BC flux remained relatively low before the onset of 20th century; it started to increase from approximately 1900 AD, and peaked around the 1970s. In the recent 30years, the BC flux seemed to display decreasing trend, very likely due to the change of energy structure and development of pollution control techniques. In comparison with marginal sea regions that are greatly impacted by anthropogenic activities, these pristine Xisha islands were not significantly influenced by black carbon of anthropogenic origin.

The increasing use of nanotechnology highlights the need to understand and clarify the environmental impacts of nanomaterials. In this study, the acute toxicity and oxidative stress of titanium dioxide nanoparticles (nTiO₂) in mature marine abalone (Haliotis diversicolor supertexta) were assessed. No acute effect was found in any of the treatment groups with nTiO₂ concentration gradients ranging from 0.1 to 10mg/L. However, the activity of an antioxidant enzyme superoxide dismutase (SOD) significantly increased in the group that was exposed to 1.0mg/L nTiO₂. The content of a non-enzymatic antioxidant, glutathione (GSH), significantly decreased in the groups with an nTiO₂ concentration ⩾1.0mg/L. The level of lipid peroxidation (LPO) was found to increase as the nTiO₂ dose increased. Furthermore, NO was produced in excess in abalone. These results demonstrated that, although nTiO₂ is not acutely toxic to abalone, it does exert oxidative stress on abalone.

Iron (Fe) plaque formed on mangrove root increased with wastewater discharge, but the extent was species-specific. For Bruguiera gymnorrhiza, Fe plaque concentration was 0.80mgg⁻¹ root d.wt at Day 0 and increased to 4.59, 6.84 and 7.52mgg⁻¹ at Day 75 in the fresh water control (FW), synthetic wastewater with pollutant concentrations five times of municipal sewage (5SW) and double of 5SW (10SW) treatments, respectively; the respective increases in Excoecaria agallocha were from 0.70 to 2.37, 10.73 and 13.21mgg⁻¹. For Acanthus ilicifolius, similar increase was found in 5SW, but all of the plants were dead in 10SW at Day 75. The concentrations of heavy metals and phosphorus immobilized were positively correlated with the amounts of Fe plaque formed, but the regression coefficients varied among species. The performance of mangrove plants in wastewater treatments was related to the Fe plaque formed and its immobilized wastewater-borne pollutants.

The bacterial communities in the anoxic layer of a heavily polluted microbial mat and their growth on hydrocarbons under sulfate-reducing conditions were investigated. Microbial communities were dominated by members of Alphaproteobacteria (27% of the total rRNA), Planctomycetes (21.1%) and sulfate-reducing bacteria (SRB: 17.5%). 16S rRNA cloning revealed sequences beloning to the same bacterial groups with SRB affiliated to the genera Desulfobulbus, Desulfocapsa, Desulfomicrobium, Desulfobacterium and Desulfosarcina/Desulfococcus. The derived enrichment cultures on crude oil, hexadecane and toluene were dominated by SRB. While most SRB sequences of the toluene and hexadecane cultures were related to the sequence of Desulfotignum toluolica, the crude oil enrichment showed a more diverse bacterial community with sequences from the genera Desulfotignum, Desulfobacter, Desulfatibacillus, Desulfosalina, and Desulfococcus. We conclude that the anoxic layer of the studied mats contains a diverse community of anaerobic bacteria, dominated by SRB, some of which are able to grow on hydrocarbons.

In Korea, the new permission criteria for industrial effluents based on Daphnia magna acute toxicity tests will be gradually implemented starting from 2011. Thus, in this study, toxicity assessment and identification using a marine species (Tigriopus japonicus) and the freshwater species (D. magna) was comparatively investigated. Effluent from an acid mine drainage treatment plant showed acute toxicity toward both organisms due to low pH, which was removed by neutralization of the effluent. Additionally, evaluation of the effluent of an electronics company revealed that Cu was attributable to the observed toxicity, and the effluent was more toxic toward T. japonicus than D. magna. Moreover, effluents from a metal plating factory were acutely toxic toward D. magna (6.50 TU), while they were not toxic against T. japonicus. Toxicity identification revealed that the high level of Cl⁻ (12,841mgL⁻¹) was the cause of toxicity. Thus, the effluents had no effect on the marine species, T. japonicus. These findings suggest that a marine species rather than a freshwater species is more desirable for toxicity assessment of industrial effluent discharged into the saltwater, and thus should be considered in the legislation of toxicity-based discharge limits in Korea.

Flow cytometry was used to examine immune responses in haemocytes of the green-lipped mussel Perna viridis under six combinations of oxygen level (1.5mg O₂l⁻¹, 6.0mg O₂l⁻¹) and temperature (20°C, 25°C and 30°C) at 24h, 48h, 96h and 168h. The mussels were then transferred to normoxic condition (6.0mg O₂l⁻¹) at 20°C for further 24h to study their recovery from the combined hypoxic and temperature stress. Esterase (Est), reactive oxygen species (ROS), lysosome content (Lyso) and phagocytosis (Pha) were reduced at high temperatures, whereas hypoxia resulted in higher haemocyte mortality (HM) and reduced phagocytosis. For HM and Pha, changes were observed after being exposed to the stresses for 96h, whereas only a 24h period was required for ROS and Lyso, and a 48h one for Est. Recovery from the stresses was observed for HM and Pha but not other immune responses.

The potential of 2,2′,4,4′-tetrabromodiphenyl ether (BDE47) and its related hydroxylated analogs (2′-HO-BDE28, 6-HO-BDE47, 4′-HO-BDE17, and 4′-HO-BDE49) to modulate estrogen/thyroid/androgen receptor-(ER, TR, AR), mediated responses were investigated by use of reporter gene assays. Exposure to 1 or 10μM, 4′-HO-BDE17 significantly up-regulated expression of Luc, whereas other four chemicals did not induce Luc expression under control of the ER. Anti-estrogenic potency was observed for 4′-HO-BDE17 (IC50=1.14μM)>6-HO-BDE47 (IC50=2.65μM)>2′-HO-BDE28 (IC50=9.49μM)>BDE47 (IC50=21.11μM). No anti-estrogenic effect of 4′-HO-BDE49 was observed. Both 4′-HO-BDE17, 4′-HO-BDE49 resulted in greater responses of Luc expression induced by T3. BDE47, 2′-HO-BDE28, 6-HO-BDE47 did not show any effect on the expression of Luc induced by 5nM T3. 6-HO-BDE47 (IC50=0.34μM)>4′-HO-BDE17 (IC50=1.41μM)>BDE47 (IC50=3.83μM)>2′-HO-BDE28 (IC50=29.22μM) exhibited anti-androgenic potency, while 4′-HO-BDE49 did not show androgenic transcriptional activity.

Entanglement with plastic debris is a major cause of mortality in marine taxa, but the population-level consequences are unknown. Some seabirds collect marine debris for nesting material, which may lead to entanglement. Here we investigate the use of plastics as nesting material by northern gannets Morus bassanus and assess the associated levels of mortality. On average gannet nests contained 469.91g (range 0–1293g) of plastic, equating to an estimated colony total of 18.46 tonnes (range 4.47–42.34tonnes). The majority of nesting material was synthetic rope, which appears to be used preferentially. On average 62.85±26.84 (range minima 33–109) birds were entangled each year, totalling 525 individuals over eight years, the majority of which were nestlings. Although mortality rates are high, they are unlikely to have population-level effects. The use of synthetic fibres as nesting material is a common strategy among seabirds, but the impacts of entanglement warrants further investigation.

In recent years, with the development of society and economy of Qingdao, environment and ecosystem problems, for instance, red ties, become more and more serious in Jiaozhou Bay, China, because of the increasing pollutants discharged into it. In order to solve these problems, an eco-hydrodynamic model is constructed to estimate the marine environmental capacity of nitrogen and phosphorus nutrients in Jiaozhou Bay, whose simulation results are rational for the bay. According to the model, if the target is set to achieve water quality (grade II) in Jiaozhou Bay, the environmental capacity of dissolved inorganic nitrogen and phosphorus in one year are approximately 7800 and 840tons, respectively. Thus our research offers necessary scientific foundation to the total loads control efforts in this area.