The objective of the study is to evaluate the effect of fish cultivation on water quality in fish culture zone (FCZ) and analysed by Principle Component Analysis (PCA). 120 surface water samples were collected from Hong Kong Waters (60 samples in Victoria Harbour and another 60 in Ma Wan FCZ). Significant difference was found in dissolved oxygen (MW: 59.6%; VH: 81.3%), and Escherichia coli (MW: 465CFU/100ml; VH: 162.5CFU/100ml). Three principle components are responsible for water quality variations in the studying sites. The first component included E. coli (0.625) and dissolved oxygen (0.701). The second included E. coli (0.387) and ammonical-nitrogen (0.571). The third included E. coli (0.194) and ammonical-nitrogen (0.287). This framework provides information to assess the relative contribution of eco-aquaculture to nutrient loads and the subsequent risk of eutrophication. To conclude, a rigorous monitoring of water quality is necessary to assess point and nonpoint source pollution. Besides, appropriate remediation techniques should be used to combat water pollution and achieve sustainability.

We examined the synergistic effects of CO2 injection on electro-chlorination in disinfection of plankton and bacteria in simulated ballast water. Chlorination was performed at dosages of 4 and 6ppm with and without CO2 injection on electro-chlorination. Testing was performed in both seawater and brackish water quality as defined by IMO G8 guidelines. CO2 injection notably decreased from the control the number of Artemia franciscana, a brine shrimp, surviving during a 5-day post-treatment incubation (1.8 and 2.3 log10 reduction in seawater and brackish water, respectively at 6ppm TRO+CO2) compared with water electro-chlorinated only (1.2 and 1.3 log10 reduction in seawater and brackish water, respectively at 6ppm TRO). The phytoplankton Tetraselmis suecica, was completely disinfected with no live cell found at >4ppm TRO with and without CO2 addition. The effects of CO2 addition on heterotrophic bacterial growth was not different from electro-chlorination only. Total residual oxidant concentration (TRO) more rapidly declined in electro-chlorination of both marine and brackish waters compared to chlorine+CO2 treated waters, with significantly higher amount of TRO being left in waters treated with the CO2 addition. Total concentration of trihalomethanes (THMs) and haloacetic acids (HAAs) measured at day 0 in brackish water test were found to be 2- to 3-fold higher in 6ppm TRO+CO2-treated water than in 6ppm TRO treated water. The addition of CO2 to electro-chlorination may improve the efficiency of this sterilizing treatment of ballast water, yet the increased production of some disinfection byproducts needs further study.

Particulate matter samples (PM10 and PM2.5) in downtown Nelson, New Zealand were collected from 2006 to 2012. These samples were used to investigate sources of PM10 and PM2.5, and to evaluate long-term trends in PM10 and BC concentrations. Five PM10 and PM2.5 sources were identified using positive matrix factorization: biomass combustion, motor vehicles, secondary sulfate, marine aerosol and soil. Overall, biomass combustion was the dominant contributor to PM10 (48%) and PM2.5 (77%) mass. The biomass combustion factor profile featured arsenic, suggesting that locals were burning copper chrome arsenate-treated timber, an activity that appears to occur throughout New Zealand.Trend analyses on PM10 and black carbon concentrations revealed that both were decreasing year-on-year, at an average rate of 0.5 μg m−3 per year and 100 ng m−3 per year, respectively. This study provides important information for Nelson City Council, who are responsible for managing air quality in Nelson, to effectively manage air quality. This study also shows that relatively simple mitigation measures can instigate decreases in PM and BC concentrations.

The intrinsic features of the temporal evolution of the air pollution are of crucial importance for its reliable modeling. In this regard, Varotsos et al. (2012) suggested that the surface ozone fluctuations at Athens since 1900, exhibit long-range dependence (long-memory), despite its present-day doubling. We herewith establish the long-memory in surface ozone concentrations that assumed in Varotsos et al. (2012), by employing recent analytical tools.

The aim of this study was to assess the levels of heavy metal pollution in the clay/silt fraction (<63μm fraction) of marine sediments from Quintero Bay, Chile. For this, sediment samples were collected from 14 sites from the bay and analyzed for major and minor element determination. The metal concentrations found suggest an anthropogenic origin related with Cu, Se, Mo, As, Sb and Pb. The mineralogical characteristics of the samples were determined by XRD and selected samples were examined by SEM to determine morphological differences. The results showed heavy metal-bearing particles such as Cu, Zn, As and Pb, which are most likely associated with by the copper smelter.

Pacific angel sharks (Squatina californica) are a benthic elasmobranch that occupy intermediate trophic level positions in coastal food webs. Angel sharks’ life history characteristics make them susceptible to accumulating high amounts of contaminants. Four angel sharks were opportunistically captured in southern California and their liver and uterine contents were analyzed for PCBs, DDTs and other pesticides. High DDT:PCB ratios were found in the sharks indicating direct or indirect foraging near a local EPA Superfund Site. Organic contaminants were measured in ovulated eggs, indicating that females are able to maternally offload contaminants. Despite the potential mismatch between ovarian and uterine fecundity, we estimated females to offload approximately 13±5% of their total body load, which represents the upper limit of this capability. Although low in sample size, the initial findings from this study suggest that habitat use might play an important role in contaminant accumulation in this species.

Sea grasses are foundation species for estuarine ecosystems. The available light for sea grasses diminishes rapidly during pollutant spills, effluent releases, disturbances such as intense riverine input, and tidal changes. We studied how sea grasses’ remote-sensing signatures and light-capturing ability respond to short term light alterations. In vivo responses were measured over the entire visible-light spectra to diminishing white-light on whole-living-plants’ spectral reflectance, including 6h of full oceanic-light fluences from 10% to 100%. We analyzed differences by various reflectance indices. We compared the sea grasses species responses of tropical vs. temperate and intertidals (Halodule wrightii, and Zostera marina) vs. subtidal (Thalassia testudinum). Reflectance diminished with decreasing light intensity that coincided with greater accessory pigment stimulation (anthocyanin, carotenoids, xanthins). Chlorophyll a and Chlorophyll b differed significantly among species (Thalassia vs. Halodule). Photosynthetic efficiency diminished at high light intensities. The NDVI index was inadequate to perceive these differences. Our results demonstrate the leaf-level utility of data to remote sensing for mapping sea grass and sea grass stress.

Lindane is an organochlorine pesticide that has been widely used to treat agricultural pests. It is of particular concern because of its toxicity, persistence and tendency to bioaccumulate in terrestrial and aquatic ecosystems. In this context, we investigated the ability of the demosponge Hymeniacidon perlevis to bioremediate lindane polluted seawater during in vitro experimentation. Lindane was extracted by solid-phase micro-extraction (SPME) and determined by gas chromatography–mass spectrometry (GC–MS). Furthermore, we assessed the role exerted in lindane degradation by bacteria isolated from the sponge. Sponges showed low mortality in experimental conditions (lindane concentration 1μg/L) and were able to remove about 50% of the lindane content from seawater in 48h. Bacteria isolated from sponges showed a remarkable remediating capacity (up to 97% of lindane removed after 8-days). A lindane metabolite was identified, 1,3,4,5,6-pentachloro-cyclohexene. The results obtained are a prelude to the development of future strategies for the in situ bioremediation of this pollutant.

Metal pollution has been of great concern in the estuaries in Southern China. In this study, metabolic differences between oysters Crassostrea hongkongensis from clean and metal-polluted sites were characterized using NMR-based metabolomics. We collected oyster samples from one clean (Jiuzhen) and two metal polluted sites (Baijiao and Fugong). The metal concentrations in oyster gills indicated that both the Baijiao and Fugong sites were severely polluted by several metals, including Cr, Ni, Cu, Zn, Ag, Cd and Pb. In particular, Cu and Zn were the major contaminants from the Baijiao and Fugong sites. Compared with those oysters from the clean site (JZ), metal pollution in BJ and FG induced disturbances in osmotic regulation and energy metabolism via different metabolic pathways, as indicated by different metabolic biomarkers. This study demonstrates that NMR-based metabolomics is a useful tool for characterizing metabolic responses induced by metal pollution.

An experiment was carried out on an estuarine mudflat to assess impacts of inorganic nutrients used to fertilize sugar-cane fields on the surrounding aquatic ecosystem, through changes in the nematode community structure. During 118days, nine quadrats each 4m2 were sampled six times after the beginning of fertilizer addition. The fertilizer was introduced weekly in six areas, at two different concentrations (low and high doses), and three areas were used as control. The introduction of nutrients modified key nematode community descriptors. In general, the nematodes were negatively affected over the study period. However, Comesa, Metachromadora, Metalinhomoeus, Spirinia and Terschellingia were considered tolerant, and other genera showed different degrees of sensitivity. Nutrient input also affect the availability and quality of food, changing the nematode trophic structure. The use of inorganic fertilizer should be evaluated with care because of the potential for damage to biological communities of coastal aquatic systems.