Air-quality forecasting is difficult because air quality time series are heterogeneous, consisting of one-dimension series data and multi-dimension panel data. Therefore, a hybrid forecasting model with both linear and nonlinear models may be appropriate to represent the complex behavior of a heterogeneous time series data set. In this paper, a new hybrid-Garch (Generalized Autoregressive Conditional Heteroskedasticity) methodology is proposed in order to integrate the individual forecasting models of the ARIMA (Autoregressive Integrated Moving Average) and SVM(Support Vector Machine). The hybrid-Garch approach for time series prediction is tested by 10-day hourly PM2.5 concentrations data including linear and non-linear, in Shenzhen, China. Empirical results from six station data sets indicate that: 1) the PM2.5 concentrations of Shenzhen experiences a regular fluctuation during the 24 h of the whole day with the peak value in working hours due to factory and vehicle emissions. 2) Spatial difference of PM2.5 concentrations is not noticeable because of the geographical and meteorological conditions. 3) The proposed hybrid model generates a more reliable and accurate forecast capability. 4) The proposed hybrid model analyses the time series data with possibly conditional heteroscedasticity characteristics and estimates the variance for the volatility of the PM2.5 concentrations.

This study investigates living benthic foraminiferal assemblages as bio-indicators of anthropogenic activities in a coastal area within the Gulf of Palermo (Sicily, Italy), affected by industrial and urban activities, and evaluates the environmental quality through the calibration of a Tolerant Species index (%TSstd).Sediments from 6 stations were sampled along a bathymetric transect from the coast to offshore. Sediment grain size, TOC, major, minor and trace elements and polycyclic aromatic hydrocarbons (PAHs) were compared to benthic foraminiferal assemblages and species at each station.Diversity and density of benthic foraminiferal assemblages were not affected by the presence of pollutants, while tolerant species increased with organic (TOC and PAHs) or chemical (As and Pb) concentrations. Moreover, the calibration of the %TSstd formula to >125μm foraminiferal assemblage, gives a detailed description of environmental quality along the transect, representing a good and sensitive tool to evaluate marine coastal environment.

Seawater samples from 50 sites in the BS and YS were collected to investigate the spatial distribution of 7 OPs. Concentrations of the total OPs (ƩOPs) in the BS and YS ranged from 8.12ngL−1 to 98.04ngL−1 with a geometric mean (GM) of 23.70ngL−1. Tris(1-chloro-2-propyl) phosphate (TCPP) was the dominant compound, followed by tris(2-chloroethyl) phosphate (TCEP) and triphenylphosphine oxide (TPPO). The ƩOPs together with the most commonly detected individual OPs (TCPP, TCEP, tris(1,3-dichloro-2-propyl) phosphate (TDCPP), tri-iso-butyl phosphate (TiBP), triphenyl phosphate (TPhP), and TPPO) tended to decrease from nearshore to offshore and from the surface to the bottom seawaters, indicating major land-based sources. Furthermore, the Yellow Sea Cold Water Mass (YSCWM), Changjiang Diluted Water (CDW), Taiwan Warm Current (TaWC), and Subei Coastal Water (SCW) influenced the horizontal and vertical distributions of the OPs in the study area.

There is a critical knowledge gap regarding the impacts of seismic air gun signals on the physiology of adult crustaceans. We conducted four controlled field experiments to examine the impact of seismic acoustic signals on spiny lobster, Jasus edwardsii. Seismic air gun exposure suppressed total haemocyte count (THC) for up to 120days post-exposure, suggesting a chronic negative impact of immune competency. THC levels after 365days post-exposure, were elevated two fold, potentially indicating an immune response to infection. Haemolymph refractive index was reduced after 120days post exposure in one experiment, suggesting a chronic impairment of nutritional condition. There was no effect of air gun exposure on 24 haemolymph biochemical parameters, hepatopancreas index or survival. Collectively these results indicate that the biochemical haematological homeostasis of J. edwardsii is reasonably resilient to seismic acoustic signals, however, air gun exposure may negatively influence the lobster's nutritional condition and immunological capacity.

We investigated the distribution of 17 individual per- and polyfluoroalkyl substances (PFASs) in 42 surface water samples collected from the East and South China Seas (7.0–36.0°N, 110.0°N–123.0°E). Concentrations of 7 individual PFASs, including perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluoropentanoic acid (PFPA), perfluorohexanoate (PFHxA), perfluoroheptanoate (PFHpA), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonamide (FOSA), were quantified in the East China Sea, but only concentrations of PFOA and FOSA were quantified in the South China Sea. The total concentrations of the 17 PFASs ranged from 181 to 2658pg/L in the East China Sea and from 62 to 494pg/L in the South China Sea. We also show that river fluxes and ocean currents had a strong influence on the distribution of PFASs in the East China Sea. Using ArcGIS 10.1, we show how ocean currents control the spatial distribution of PFOA in the central South China Sea.

A dust storm was observed at the Semi-Arid Climate and Environment observatory of Lanzhou University (SACOL) using a dual-wavelength lidar and an aethalometer from 16 March to 22 March 2010. After the arrival of the dust storm, the lidar backscattered signal increased suddenly, the volume depolarization ratio ranged from 0.2 to 0.4. The dust aerosol was detected mainly in a layer below 2.5 km altitude. A higher attenuated backscatter coefficient (0.005–0.02 km−1/sr) was distributed in a lower layer (below 2.5 km) during the dust storm. The evolution of the dust storm was also clearly revealed by the integrated particle backscatter coefficient (BE). Particles in the coarse mode are predominant during the dust storm because Ångström exponent mainly ranged from 0.5 to 1.0. An aethalometer was used to measure the aerosol absorption coefficient as well as aerosol mass concentration. The average mass concentration of aerosol was 1.3 μg/m3 during the dust free period but increased to 1.8 μg/m3 during the dust storm, so the dust aerosol apparently played an important role. The main absorptive particle was black carbon during the dust free period. In addition, the peaks of dust aerosol concentration mainly occurred at around 08:00 and 20:00 (Beijing Time), one reason was that the increase of wind speed result in more dust particles blown up into the atmosphere in the neighborhood of SACOL and another reason was that the boundary layer convection was undeveloped in the morning and the temperature inversion appeared easily in the evening. The trend of the aerosol absorption coefficient was similar to that of mass concentration, and the aerosol absorption coefficient significantly increased during the dust storm.

Hainan Island is the second largest island and one of the most famous tourist destinations in China, but sediment contamination by trace metals in coastal areas is a major issue. However, full-scale risk assessments of trace metal-polluted coastal sediments are lacking. In this study, coastal surface sediments from 474 geographical locations covering almost the entire island were collected to identify risk-related variables. Controlling factors and possible sources of trace metals were identified, and the toxicity effects were carefully evaluated. Our results suggest that trace-metal pollution in coastal sediments, which was mainly caused by Pb, Zn and Cu emissions, has primarily resulted from industrial sewage and shipping activities and has threatened the offshore ecosystem of Hainan Island and warrants extensive consideration. This is the first study that has systematically investigated trace metal-polluted coastal sediments throughout the entirety of Hainan Island and provides solid evidence for sustainable marine management in the region.

Yalujiang River is a famous border river between China and North Korea. In this study, 22 sample sites (seawater and sediments) were investigated to determine the concentrations of nutrients (dissolved inorganic nitrogen and soluble reactive phosphorus) and trace elements (Hg, As, Pb, Cu, Cd, Cr, and Zn) during the flood season (August). Generally, the concentration of nutrients were higher in the entrance of the estuary than that in the downstream region and the trophic index ranged from moderate to high production, indicating a potential eutrophication risk. With the exception of Cd, the mean concentrations of most metals attained the first level of seawater quality. Sediment pollution assessment was undertaken using contamination factor (CF) and geoaccumulation index (Igeo). The CF values of the seven trace elements were in the following order: Cd>Hg>Pb>As>Cu>Zn>Cr. Both CF and Igeo values indicated the elevated Cd and Hg concentrations in the region. Cluster analysis indicated that the sources of Cu, Cd, Cr, and Zn were mainly derived from copper mine and coastal industrial effluents, whereas Pb, Hg, and As were mainly from vehicle emissions and oil combustion. This study could provide a basis for the sustainable management of the marine ecosystem in this region.

The source of anthropogenic nutrient and its spatial extent in three fringing reefs with differing human population gradients in Kenya were investigated using stable isotope approaches. Nutrient concentrations and nitrate-δ15N in seepage water indicated that population density and tourism contributed greatly to the extent of nutrient loading to adjacent reefs. Although water-column nutrient analyses did not show any significant difference among the reefs, higher δ15N and N contents in macrophytes showed terrestrial nutrients affected primary producers in onshore areas in Nyali and Bamburi reefs, but were mitigated by offshore water intrusion especially at Nyali. On the offshore reef flat, where the same species of macroalgae were not available, complementary use of δ15N in sedimentary organic matter suggested inputs of nutrients originated from the urban city of Mombasa. If population increases in the future, nutrient conditions in the shallower reef, Vipingo, may be dramatically degraded due to lower water exchange ratio.

The particulate material was fractionated into 5 size classes (>90μ, 50–90μ, 6–50μ, 1–6μ, and <1μ). DOP was analysed as easily (DOPh, DOPpa) and less easily hydrolysable compounds (DOPox). Based on Vmax, 94% of the high affinity AP activity was due to <50μ cells and 77% to <1μ cells. 83% of the low affinity activity was due to >90μ cells. The high affinity activities were negatively correlated with DOP for the <50μ classes. These correlations came mostly from DOPox. They were more significant when NO3+NO2 concentrations were high, when DIP concentrations were low and when N/P ratio was >10. At lower N/P ratios, AP was more significantly correlated with DIP. The low affinity activities showed significant negative correlation with DIP and with DOP and DOPox for the >90μ class. The inhibition of AP activities by DOPox may originate from stable compounds interfering with DIP for the control of AP synthesis.