The ALien Biotic IndEX (ALEX) has been recently proposed to evaluate biological invasions in soft-bottom macro-invertebrate assemblages. The present paper proposes the use of ALEX in sessile assemblages of Mediterranean hard bottom habitats and tests it along gradients of invasion. For five invasive macroalgae a variable number of case studies per each of four habitats were examined from the available data sets. For each case study samples were attributed to four levels of invasion depending on the abundance of the invading macroalgae. Results showed that the application of ALEX to sessile assemblages of hard bottoms allows to qualify the level of invasion along the considered gradients. Moreover, the decline of index values matched the impact of invasion on species number of the assemblages. Results also suggest that the concurrent use of ALEX and indices of benthic quality status can be a valuable tool to assess biopollution in hard bottom habitats.

A growing body of evidence suggests that the jellyfish population in Chinese seas is increasing, and decomposition of jellyfish strongly influences the marine ecosystem. This study investigated the change in water quality during Cyanea nozakii decomposition using simulation experiments. The results demonstrated that the amount of dissolved nutrients released by jellyfish was greater than the amount of particulate nutrients. NH4+ was predominant in the dissolved matter, whereas the particulate matter was dominated by organic nitrogen and inorganic phosphorus. The high N/P ratios demonstrated that jellyfish decomposition may result in high nitrogen loads. The inorganic nutrients released by C. nozakii decomposition were important for primary production. Jellyfish decomposition caused decreases in the pH and oxygen consumption associated with acidification and hypoxia or anoxia; however, sediments partially mitigated the changes in the pH and oxygen. These results imply that jellyfish decomposition can result in potentially detrimental effects on marine environments.

This study provides geochemical data with the aim of identifying and quantifying the main processes occurring in an Acid Mine Drainage (AMD) affected estuary. With that purpose, water samples of the Huelva estuary were collected during a tidal half-cycle and ion–ion plots and geochemical modeling were performed to obtain a general conceptual model. Modeling results indicated that the main processes responsible for the hydrochemical evolution of the waters are: (i) the mixing of acid fluvial water with alkaline ocean water; (ii) precipitation of Fe oxyhydroxysulfates (schwertmannite) and hydroxides (ferrihydrite); (iii) precipitation of Al hydroxysulfates (jurbanite) and hydroxides (amorphous Al(OH)3); (iv) dissolution of calcite; and (v) dissolution of gypsum. All these processes, thermodynamically feasible in the light of their calculated saturation states, were quantified by mass-balance calculations and validated by reaction-path calculations. In addition, sorption processes were deduced by the non-conservative behavior of some elements (e.g., Cu and Zn).

Stabilization of marine dredged sediments contaminated with multi-elements is a challenging task in choosing the appropriate sorbent and application dosage. The present study investigates the possibility of using bauxite residues (Bauxaline® and Bauxsol) as amendment for the treatment of contaminated sediment. A pilot scale experiment was conducted for three months to stabilize trace elements in composted contaminated sediment sample using 5% by-product amendment. The results showed that after 3months of treatment, cationic trace elements were effectively immobilized but increased leaching of anionic pollutants was observed. Increased leaching of anionic pollutants could be limited by addition of higher quantities of amendments. The total content of available pollutants decreased in stabilized sediments but this treatment has no effect on the classification of waste. The leachates were then evaluated for acute toxicity using estuarine rotifers Brachionus plicatilis. Bauxite residues can be inexpensive choices for the stabilization of cationic pollutants in dredged sediments.

Contingency plans are essential in guiding the response to marine oil spills. However, they are written before the pollution event occurs so must contain some degree of assumption and prediction and hence may be unsuitable for a real incident when it occurs. The use of Bayesian networks in ecology, environmental management, oil spill contingency planning and post-incident analysis is reviewed and analysed to establish their suitability for use as real-time environmental decision support systems during an oil spill response. It is demonstrated that Bayesian networks are appropriate for facilitating the re-assessment and re-validation of contingency plans following pollutant release, thus helping ensure that the optimum response strategy is adopted. This can minimise the possibility of sub-optimal response strategies causing additional environmental and socioeconomic damage beyond the original pollution event.

The abundance, composition, and potential sources of marine debris were investigated on remote Alphonse Island, during the austral winter 2013. A total of 4743 items, weighing 142kg, were removed from 1km of windward beach, facing the prevailing southeasterly trade winds. Our study demonstrates the prevalence of plastic debris as a world-wide marine contaminant. Characteristics of the debris suggest it originated primarily from land-based sources. To determine their potential geographic sources we used the Surface Current from Diagnostic model of near-surface ocean currents, forced by satellite sea level and wind data. While preliminary evidence indicated the Southeast Asia to be the main source of the flotsam, the model highlighted Somalia as another potential primary source. Our study concludes that most of the collected debris entered the sea as a result of inadequate waste management and demonstrates how anthropogenic waste can negatively impact even the most remote environments.

Large Eddy Simulation (LES) spectral data and Taylor statistical diffusion theory are used to obtain Eddy diffusivities in a convective boundary layer. The derivation employs a fitting expression obtained from LES data for the vertical peak frequency. The vertical Eddy diffusivities are well behaved and show similar patterns and magnitudes as those derived from experimental spectral peak frequency data. In addition, this new vertical Eddy diffusivity was introduced into an advection diffusion equation which was solved by Generalized Integral Laplace Transform Technique (GILLT) method and validated with observed contaminant concentration data of the Copenhagen experiment. The results of this new approach are shown to agree with the measurements of Copenhagen.

This study measured ambient particle number concentrations (PNC) and the particle number distributions (PND) in the urban area of Porto Alegre, Rio Grande do Sul, Brazil. The samples were analyzed using a NanoScan model 3910 from TSI (diameters between 10 and 420 nm) and were taken from sites with high density of vehicular traffic, including two roadsides, two traffic intersections, one street canyon and one urban background. Association of meteorological variables (temperature, relative humidity, solar radiation, wind direction, and wind speed) on nanoparticle concentrations was examined. The results indicated PNC averages between 4.85×104 cm–3 and 1.80×105 cm–3 for locations affected by vehicular traffic, wherein highest concentrations were observed at sites corresponding to traffic intersections. In addition, all sites studied showed a trimodal average PND, with the modes centered at ~14 nm, ~30 nm, and ~105 nm. PND was dominated by nucleation (44.9%) and Aitken (42.0%) modes being representative at the studied sites of the pollution originating from urban traffic, except at the urban background. Meteorological parameters and synoptic meteorological conditions contributed to the variation in the results between the sampled days in the same location.

Modeled traffic data were used to develop traffic exposure zones (TEZs) such as traffic delay, high volume, and transit routes in the Research Triangle area of North Carolina (USA). on–road air pollution measurements of nitrogen dioxide (NO2), carbon monoxide (CO), carbon dioxide (CO2), black carbon (BC), coarse (PM2.5–10), fine (PM2.5) particulate matter and ultrafine particles (UFPs) were made on routes that encountered these TEZs. Results indicated overall greater traffic pollutant levels in high volume and delay road sections than bus routes or areas of higher signal light density. The combination of delineating roadways into TEZs with highly time resolved on–road measurements demonstrated how pollutant levels can vary within roadways.

To characterize the chemical composition, size distributions, and fractional Fe solubility of atmospheric particles over Asian marginal seas, South Indian Ocean and Australian coast, selected water–soluble inorganic and organic species in aerosols and precipitation, trace metals and soluble Fe in aerosols were analyzed by multi–instruments. Results showed that sea salt and non–sea–salt sulfate (nss–SO42–) were the main components in aerosols. Over Asian marginal seas, Cl– and Na+ were the dominant ions in precipitation, accounting for ˜;72% of the total ions. Both SO42– and NO3– accounted for −26% of the total anions, controlling the acidity of the precipitation. Non–sea–salt Ca2+ (nss–Ca2+) accounted for 6.9% of the total cations, dominating the neutralizing component in rainwater. Observed methane sulfonate (MSA) concentrations and MSA/nss–SO42– increased southward. The concentrations of sea salt were affected by wind speeds, which was mainly accumulated in particle size >10μm. Particle size distributions of nss–SO42– and NH4+ mainly peaked in the fine mode, while NO3– was mainly accumulated in the coarse mode. Oxalate presented a bimodal size distribution pattern in both fine and coarse modes. Based on the air mass back trajectories, enrichment factors and Fe/Al, V/Al ratios, aerosol samples collected over Asian marginal seas could be affected by both long–range transported dust and anthropogenic emissions. Good relationship was found between total dissolved iron and nss–SO42–, indicating that acid processing during long–range transport could play an important role in fractional iron solubility in aerosols. The inverse relationship between atmospheric total Fe and fractional Fe solubility fitted in the global–scale trend. This study implicates that dust and acidic air pollutants from continental sources can interact and affect iron solubility in aerosols in the marine atmosphere. However, due to the small size of samples in this study, more investigations need to be conducted in future.