Virgin polyvinyl chloride (PVC) particles were exposed to heat, ultraviolet B (UVB) and solar radiation either in artificial seawater or in air for different periods of time. The surface and chemical properties of fresh and degraded particle surfaces were determined via image analysis using scanning electron micrographs, a Brunauer-Emmett-Teller (BET) specific surface area analyzer and infrared spectroscopy. Thermal and UVB degradation resulted in unique PVC morphologies. In addition, the increased presences of functional groups were evident as dehydrochlorination and oxidation during the degradation process, which altered the chemical properties of PVC. In contrast, under solar exposure with or without seawater, unevenness to the surface was noted that seems to originate from degradation of the PVC surface; in addition, no new functional groups were found. This suggests that the chemical properties of PVC are stable over extended periods in the marine environment.

To examine the impacts of estuarine mixing on the dispersion of polycyclic aromatic hydrocarbons (PAHs), seasonal variations in the vertical distribution of dissolved PAHs in the Humen River mouth of the Pearl River Estuary, which is a tide-dominated estuary, were thoroughly examined. An analysis of the vertical distribution of the concentration, composition and sources of PAHs indicates enhanced mixing of PAHs in January relative to June, which is strongly related to seasonal variations in the magnitude of estuarine mixing. Furthermore, the vertical distribution of PAHs initially indicated an increase and then a decrease from the surface layer to the bottom layer. In general, estuarine mixing promotes the vertical dispersion of PAHs, causing a more even PAHs distribution, while salinity stratification can trap PAHs, resulting in higher PAHs concentrations. Our study indicates that salinity variability stimulates significant dynamic effects regarding the dispersion of PAHs within estuarine environments.

The atmospheric concentrations of volatile organic compounds (VOCs) generated by surface slicks during an oil spill have not been extensively studied. We modeled oil transport and fate, air emissions, and atmospheric dispersion of VOCs from a hypothetical deepwater well blowout in De Soto Canyon of the Gulf of Mexico assuming no intervention and use of SubSea Dispersant Injection (SSDI) at the source during three week-long periods representing different atmospheric mixing conditions. Spatially varying time histories of atmospheric VOCs within ~2 km from the release site were estimated. As compared to the no-intervention case, SSDI dispersed the discharged oil over a larger water volume at depth and enhanced VOC dissolution and biodegradation, thereby reducing both the total mass of VOCs released to the atmosphere and the concentration of VOCs within 2 km from the release site. Atmospheric conditions also influenced the VOC concentrations, although to a lesser degree than SSDI.

The spatial and seasonal distribution of trace elements (TEs) (n=16) in surficial sediment were examined along the Hooghly River Estuary (~175km), India. A synchronous elevation of majority of TEs concentration (mgkg⁻¹) was encountered during monsoon with the following descending order: Al (67070); Fe (31300); Cd (5.73); Cr (71.17); Cu (29.09); Mn (658.74); Ni (35.89). An overall low and homogeneous concentration of total Hg (THg=17.85±4.98ngg⁻¹) was recorded in which methyl mercury (MeHg) shared minor fraction (8–31%) of the THg. Sediment pollution indices, viz. geo-accumulation index (Igₑₒ) and enrichment factor (EF) for Cd (Igₑₒ=1.92–3.67; EF=13.83–31.17) and Ba (Igₑₒ=0.79–5.03; EF=5.79–108.94) suggested high contamination from anthropogenic sources. From factor analysis it was inferred that TEs primarily originated from lithogenic sources. This study would provide the latest benchmark of TE pollution along with the first record of MeHg in this fluvial system which recommends reliable monitoring to safeguard geochemical health of this stressed environment.

Seawater and brackish water desalination has been a practical approach to mitigating the global fresh water scarcity. Current large-scale desalination installations worldwide can complementarily augment the global fresh water supplies, and their capacities are steadily increasing year-on-year. Despite substantial technological advance, desalination processes are deemed energy-intensive and considerable sources of CO₂ emission, leading to the urgent need for innovative low carbon desalination platforms. This paper provides a comprehensive review on innovations in membrane processes and membrane materials for low carbon desalination. In this paper, working principles, intrinsic attributes, technical challenges, and recent advances in membrane materials of the membrane-based desalination processes, exclusively including commercialised reverse osmosis (RO) and emerging forward osmosis (FO), membrane distillation (MD), electrodialysis (ED), and capacitive deionisation (CDI), are thoroughly analysed to shed light on the prospect of low carbon desalination.

We report a mortality event of Red Phalaropes (Phalaropus fulicarius) that occurred from October to November 2016 on the north coast of British Columbia, Canada. All individuals were severely underweight and showing signs of physiological stress. The guts of all carcasses contained ingested plastics (100%, n = 9). Distribution modelling from pelagic bird surveys (1990–2010) indicated that Red Phalaropes are not typically found in the study area during fall months. Ocean conditions during fall 2016 were unusually warm, coinciding with reduced upwelling in the study area. eBird records since 1980 indicated Red Phalaropes are observed closer to shore during periods associated with reduced upwelling. These results suggest that distribution shifts of Red Phalaropes closer to shore, where plastic debris occurs in higher concentrations, may lead phalaropes to feed on plastic debris while in a weakened state, resulting in a combination of two adverse circumstances.

Here we investigate microplastics contamination on beaches of four islands of the Lesser Antilles (Anguilla, St. Barthélemy, St. Eustatius and St. Martin/Maarten). These islands are close to the North Atlantic subtropical gyre, which contains high levels of microplastics. On average 261 ± 6 microplastics/kg of dry sand were found, with a maximum of 620 ± 96 microplastics on Grandes Cayes, Saint Martin. The vast majority of these microplastics (>95%) were fibers. Levels of microplastics differed among islands, with significantly lower levels found in St. Eustatius compared to the other Islands. No difference in microplastic levels was found between windward and leeward beaches. Our research provides a detailed study on microplastics on beaches in the Lesser Antilles. These results are important in developing a deeper understanding of the extent of the microplastic challenge within the Caribbean region, a hotspot of biodiversity.

Bryozoa is a phylum of aquatic invertebrates widely distributed around the world, including harbor areas. They have association to artificial structures as main mechanism of dispersal, including ships, which facilitates their introduction to new environments. The detection of exotic species is important to prevent new introductions and to propose management strategies of marine areas. Thus, after analyzing and discussing local and global criteria of exotic species, an account of exotic bryozoans from Brazil is presented, including 12 classified as exotic (six established and six detected) and 17 classified as potentially exotic (cryptogenic). Three species have been reported causing economic or environmental impacts worldwide. Of those, Membraniporopsis tubigera is known to cause economic impacts on the Brazilian coast. Hull fouling is the main dispersal mechanism for exotic bryozoans. The lacking of reliable data did not allow inferring on the exotic status on some fouling bryozoan species in Brazil.

With INDESO, Indonesia has implemented a system for the monitoring and management of its tuna resources. Despite increasing catch, very few is known about the dynamics and real abundance of tuna species in the Indonesian waters and adjacent oceanic regions. The SEAPODYM model was implemented in an operational chain of production for the Indonesian region to simulate tuna spatial dynamics in realtime. This challenging objective imposed developing a global scale model at coarse resolution to provide initial and boundaries conditions of the regional model. A parameter optimization approach was used to provide the best solution fitting several hundreds of thousand catch observations, over a long historical simulation at coarse resolution. Then downscaling method and regional modelling at high resolution (1/12°x day) were validated to produce realtime and forecast on a weekly basis. The architecture of this application, the approach for its parameterization and some key results are presented and discussed.

Understanding the natural variability and its influence on the performance of marine biotic indices used for the health assessment of marine ecosystem is the prime concern. This study addresses the seasonal variability of univariate and multimetric indices by using macrobenthic data collected from three intertidal habitats for two years (July 2013–July 2015). The univariate indices viz., abundance, richness, Shannon index and ES (100) showed strong seasonal variability. For the multimetric indices, the seasonal variability was low and appeared site specific. W-statistics, AMBI and M-AMBI showed highest constancy whilst BENTIX and BOPA exhibited wide - ranging. A general tendency could be inferred as majority of indices showed improvement in benthic quality (poor - moderate and good - high) from turbulent monsoon to stable dry period. The results are discussed concerning possible consequences especially related to the benthic community and biotic indices in intertidal habitats under the influence of sewage discharge and monsoonal effects.