The occurrence of 14 polycyclic aromatic hydrocarbons (PAHs) listed by the United States Environmental Protection Agency was investigated in surface seawater of Yangpu Bay, China in November 2013 (winter) and May 2014 (summer). Seventy-two samples were collected from 12 sampling sites. The total concentrations of PAHs in Yangpu Bay showed obvious variations in different seasons, which varied from 582.8 to 2208.3ngL−1 in winter and 952.4 to 1201.7ngL−1 in summer, respectively. Two-ring PAHs accounted for more than 91.6% of total PAHs in winter, and three-ring PAHs were dominant with 81.6% of total PAHs in summer. Molecular indices analyses indicated that the main source of PAHs in Yangpu Bay could be petrogenic contamination. The ecological risk assessment by Risk quotients (RQNCs and RQMPCs) showed a potential ecological risk of PAHs in Yangpu Bay, indicating a close attention should be paid to pollution of PAHs in the coastal area of Yangpu.

The distribution of different forms of phosphorus in surface sediment from 17 sites were investigated by SEDEX method. The sites were divided into three sectors: Santos Channel (SC – influenced by harbour, fertilizers plants and phosphogypsum mountains), São Vicente Channel (SVC– domestic waste) and Santos Bay (SB – sewage outfall). The average percentage of each P fraction of the surface sediments in this region followed the sequence P–Fe (38%)>Porg (27%)>Pexch (13%)>Detrital – P (12%)>Auth – P (10%). Ptotal varied from 3.57 to 74.11μmolg−1 in both seasons. In SVC, Pexch ranged from 13% to 27% and Porg varied from 12% to 56%. These high percentages of Pexch/Ptotal (greater than 20%) may be related to low oxygen resulting from oxygen consumed by intensive organic matter decomposition as well as the salty water that leads to cation and anion flocculation. Also, the possibility of an influence related to the industrial source of Pexch is not ruled out. No significant seasonal differences were found among sites, except for sewage outfall, with changing in the grain size and hence, the P geochemistry. During the summer in the sewage outfall station, Porg represented 37% of Ptotal, which decreased to 13% in the winter. These results suggest that high percentages of organic phosphorus cannot be attributed only to autochthonous and allochthonous organic matter, but also to detergents and/or domestic waste. In contrast, spatial differences among sectors were observed, with the highest values of each fraction associated with sites near industrial and domestic waste activities.

The open top chamber (OTC) method was used in a farmland to study the influence of different levels of O3 concentrations (40 ppb, 80 ppb and 120 ppb) on the enzymatic activity and metabolite contents of the antioxidation system of the winter wheat leaves during the jointing, heading and milk stage. The protective effect of exogenous spermidine (Spd) against the antioxidation of winter wheat under the O3 stress was investigated. With the increasing O3 concentrations and fumigation time, the injuries of the winter wheat leaves were observed to be more serious. For instance, when the O3 concentration reached 120 ppb, the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and nitrate reductase (NR) in the jointing stage decreased by 50.3%, 64.9%, 75.5% and 92.9%, respectively; peroxidase (POD) and glutathione reductase (GR) increased by 45.1% and 80.5%, respectively; the contents of malondialdehyde (MDA), ascorbic acid (AsA) and reduced glutathione (GSH) increased by 314.3%, 8.4% and 31.7%, respectively; and the soluble protein (SP) content decreased by 47.5%. The O3 stress also had significant impact on the contents of proline (Pro), NO3––N and NH4+–N of the winter wheat leaves. During the heading stage, when the O3 concentration was 40 ppb and 80 ppb, the content of Pro was 163.9% and 173.2% higher than that in the control group, respectively. But under 120 ppb, it was decreased by 42.4%. Exogenous application of Spd increased the activities of SOD, POD, CAT, APX and GR, as well as the contents of GSH and SP, but decreased the contents of MDA and AsA. This indicates that Spd is an effective antioxidant to relieve the O3 stress on winter wheat leaves, thereby might be applicable to protect winter wheat from the harm of O3.

In 2010, a massive bloom of the raphidophycean flagellate Chattonella occurred in the Ariake Sea and Tachibana Bay. Bloom dynamics and hydrographical conditions were examined by field survey. The development and decline of the bloom occurred three times in Tachibana Bay. First and third bloom developments synchronized with precipitation, and the second bloom developed in synchronization with a salinity decrease which occurred in relation to an increase of river discharge from the Chikugo River which takes several days to flow from the Ariake Sea. These results imply that the bloom was transported with the low salinity water from the Ariake Sea to Tachibana Bay. During blooms along the northern coast of Shimabara Peninsula, the predominant phytoplankton species changed from Chattonella to Skeletonema. Low salinity water intrusion induced an interregional difference of the Chattonella and Skeletonema bloom spatially-differentiated by the salinity in the Ariake Sea and Tachibana Bay.

Microplastics provide a mechanism for the long-range transport of hydrophobic chemical contaminants to remote coastal and marine locations. In this study, plastic resin pellets were collected from Zhengmingsi Beach and Dongshan Beach in China. The collected pellets were analyzed for PAHs, PCBs, HCHs, DDTs, chlordane, heptachlor, endosulfan, aldrin, dieldrin and endrin. The total concentration of PCBs ranged from 34.7–213.7ngg−1 and from 21.5–323.2ngg−1 in plastic resin pellets for Zhengmingsi Beach and Dongshan Beach respectively. The highest concentrations of PCBs were observed for congeners 44, 110, 138, 155 and 200. The total concentration of PAHs ranged from 136.3–1586.9ngg−1 and from 397.6–2384.2ngg−1 in the plastic pellets, whereas DDTs concentration ranged from 1.2–101.5ngg−1 and from 1.5–127.0ngg−1 for the two beaches. The elevated concentrations of pollutants appear to be related to extensive industrial development, agricultural activity and the use of coal in the area.

The concentrations of As, Sb, Hg, Pb, Cd, and Ba in the surface and core sediments of the oil and gas producing region of the Beibu Gulf were measured by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Atomic Fluorescence Spectrometry (AFS), and the spatial distribution and historical trends of these elements are discussed. The results show that the concentrations of these elements are highest near the platforms. The results of Enrichment Factor (EF) and Potential Ecological Risk Index (PERI) also reveal significantly higher enrichment around the platforms, which imply that the offshore petroleum production was the cause of the unusual distribution and severe enrichment of these elements in the study area. The environment around the platforms was highly laden with toxic elements, thereby representing a very high ecological risk to the environment of the study area.

Sediment samples were taken from six sampling sites in Bramble Bay, Queensland, Australia between February and November in 2012. They were analysed for a range of heavy metals including Al, Fe, Mn, Ti, Ce, Th, U, V, Cr, Co, Ni, Cu, Zn, As, Cd, Sb, Te, Hg, Tl and Pb. Fraction analysis, Enrichment Factors and Principal Component Analysis–Absolute Principal Component Scores (PCA–APCS) were carried out in order to assess metal pollution, potential bioavailability and source apportionment. Cr and Ni exceeded the Australian Interim Sediment Quality Guidelines at some sampling sites, while Hg was found to be the most enriched metal. Fraction analysis identified increased weak acid soluble Hg and Cd during the sampling period. Source apportionment via PCA–APCS found four sources of metals pollution, namely, marine sediments, shipping, antifouling coatings and a mixed source. These sources need to be considered in any metal pollution control measure within Bramble Bay.

Ocean acidification and pollution coexist to exert combined effects on the functions and services of marine ecosystems. Ocean acidification can increase the biotoxicity of heavy metals by altering their speciation and bioavailability. Marine pollutants, such as heavy metals and oils, could decrease the photosynthesis rate and increase the respiration rate of marine organisms as a result of biotoxicity and eutrophication, facilitating ocean acidification to varying degrees. Here we review the complex interactions between ocean acidification and pollution in the context of linkage of multiple stressors to marine ecosystems. The synthesized information shows that pollution-affected respiration acidifies coastal oceans more than the uptake of anthropogenic carbon dioxide. Coastal regions are more vulnerable to the negative impact of ocean acidification due to large influxes of pollutants from terrestrial ecosystems. Ocean acidification and pollution facilitate each other, and thus coastal environmental protection from pollution has a large potential for mitigating acidification risk.

Organochlorine pesticides and PCB (POPs) concentrations were determined in the blood and eggs of green and hawksbill turtles. We compared concentrations between species, analyzed the relationship between turtle size and the POPs concentrations and the relationship between the concentrations in the blood of the nesting turtles and their eggs. We expected higher concentrations in the hawksbill turtle because of its higher trophic level, but concentrations were not higher in all the cases. Significant differences were found in δ-HCH blood concentrations. Lindane, heptachlor epoxide and PCB 101 concentrations were significantly higher in the hawksbill eggs. The relationship between the size of the turtles and the POP concentrations in the eggs of the hawksbills showed a negative correlation. No correlation was found between the size of the female and concentrations in the blood. In eggs, only the hawksbill turtles exhibited negative correlation in the concentration of mirex and PCB 44 and size.

Dissolved organic nitrogen (DON) is an important nutrient in the aquatic environment. This study examined the influence of DON addition on the adsorption, absorption, and distribution in macromolecular forms of environmentally deleterious trace metal (Ni) in Prorocentrum donghaiense and Skeletonema costatum over eight days. Ni adsorption and absorption of two species increased with the addition of urea, while Ni adsorption and absorption of two species in the presence of humic substances (HS) decreased. Meanwhile, Ni adsorption and absorption of P. donghaiense were higher than that of S. costatum. Furthermore, Ni contents in the protein fraction of the cells, both in P. donghaiense and S. costatum, were increased with both urea and HS addition. Thus, urea and HS input could impact Ni biogeochemistry and bioavailability, and then affect the biodynamics thereafter.