Tetepare Island in the Solomon Islands is the largest uninhabited island in the South Pacific and supports seagrass beds inside fringing reefs along its coastline. We monitored the diversity and abundance of seagrass species on Tetepare and nearby sparsely-populated Rendova Island over a 12 year period, 4 years before and up to 8 years after a major earthquake and tsunami event in January 2010. Both seagrass cover and diversity declined after the tsunami and had not reached pre-Tsunami levels after 8 years. Seagrass cover declined the fastest at sites on Rendova, closest to the epicentre, declining from 50% to <10% cover within 12 months of the earthquake. At sites within the Tetepare MPA, seagrass cover took longer to decline and dropped from an average of 50% to <10% within 2 years and became dominated by Halophila ovalis. Species richness declined from 9 to 4 species with some species such as Syringodium isoetifolium disappearing from monitoring sites. Community-based monitoring was an effective method of documenting long term changes in seagrass cover and long-term monitoring is required to determine if seagrass beds are permanently altered or return to pre-tsunami conditions.

The distribution of 14 ARGs, intI1, and 16S rDNA were analysed in 4 wastewater treatment plants (WWTPs), 2 effluent receiving areas (ERAs), and Hangzhou Bay (HZB). The results showed that each integrated WWTP (IWWTP) received higher abundance of ARGs than pharmaceutical WWTPs (PWWTPs), and IWWTPs removed ARGs more efficiently than PWWTPs. The WWTP effluents greatly contributed to the ARGs pollution in the water environments of the ERAs and HZB, and the total abundance of the ARGs displayed a distance decay pattern. In coastal sediments, more ARGs were accumulated in remote sites. The correlation analysis showed that the occurrence of ARGs was more related to 16S rDNA and intI1 in the WWTPs. Three macrolides resistance genes (ermB, mphA, and vatB) had strong correlations with 16S rDNA and intI1 in all the sample groups. Our study clearly reveals the link between land WWTPs discharge and emerging pollution of ARGs in coastal environments.

Microplastics are causing serious environmental threats worldwide. To evaluate the current state of microplastics pollution, 28 sediment samples were examined for microplastics and plastic debris contamination along Silver Beach, Southern India. Visual identification followed by FT-IR spectroscopy was used to estimate the overall distribution and characterization of plastic debris. The results reveal that white-colored (44%) and irregularly-shaped (82%) plastics are prevalent in the study area. Moreover, the dominant polymer in the study area is polyvinyl chloride (79%) followed by polyethylene (14%) and nylon (7%). Based on size fractions, mesoplastics are widely distributed in the beach sediments (65%), followed by microplastics (18%) and macroplastics (17%). The regional sources of plastic debris are tourism and fishing activities followed by storm water runoff through the Gadilam river and wave-induced deposition through high tides. Strict policy measures need to be implemented in recreational beaches like Silver beach to reduce plastic pollution.

We report the ratios of minor (K/Ca, Na/Ca, P/Ca, S/Ca) and trace elements (Al/Ca, Ba/Ca, Fe/Ca, Mn/Ca and Zn/Ca) in skeletons of five Arctic echinoderm species representing three classes: Asteroidea, Ophiuroidea, Crinoidea. We found that skeletons of Arctic echinoderms show a unique, species-specific trace element composition that may suggest that incorporation of elements into the skeleton is biologically controlled by the organism. On the other hand, the concentration of some minor elements in skeletal parts exhibit patterns that are consistent with elemental concentrations in seawater, indicating that formation of echinoderm skeletons is environmentally controlled. Seawater is the main source of ions and compounds needed for skeletal formation and maintaining similar concentrations most likely reduces the biological cost related to selective uptake of ions. Additionally, Al, Ba, Fe, Mg and Mn showed station specific variation in elemental concentration which again suggests that accumulation of metals can be shaped by environmental concentrations.

PURPOSE OF REVIEW: The objective of this review is to provide a closer check on the recent development in the thermal hydrolysis (TH) of wastewater sludge for anaerobic digestion performance enhancement with the focuses on the solubilization of sludge and macromolecules, organic micropollutants removal, TH-AD integration, and TH process (THP) energy balances. RECENT FINDINGS: The recent research has developed improved understanding of the thermal hydrolysis mechanisms of proteins, carbohydrates, and lipid components of sludge and the characteristics of soluble COD in TH-treated sludge. Studies showed that TH treatment can partially remove micropollutants, but it has limited impact on the bioavailability of those compounds. For the THP and AD integration, the post TH and intermediate TH treatment have been introduced as two alternatives of the TH pretreatment, which have demonstrated the ability to achieve higher methane yields and VSS reduction. TH is a well-established technology for anaerobic digestion performance enhancement due to its ability to improve digestion loading rate, sludge biodegradability, and sludge dewaterability. The recent studies elucidated the mechanisms of sludge TH, characteristics, and biodegradability of hydrolysis products, fate of nutrient and micropollutants in sludge TH, and the effect of AD-TH integration on methane production and VS reduction. Future work in sludge TH is still needed to reveal the mechanisms of production of refractory organics during TH treatment, optimize the design and operation of the ITHP-AD and AD-PsTHP processes, and improve the energy efficiency of TH-AD processes through energy reduction and recovery.

The aim of the present study was to evaluate the presence and potential toxic effects of plastic fragments (<400 μm) of polyethylene and polypropylene on the Pacific oyster Crassostrea gigas. Oysters were exposed to environmentally relevant concentrations (0, 0.008, 10, 100 μg of particles/L) during 10 days, followed by a depuration period of 10 days in clean seawater. Effects of microplastics were evaluated on the clearance rate of organisms, tissue alteration, antioxidant defense, immune alteration and DNA damage. Detection and quantification of microplastics in oyster's tissues (digestive gland, gills and other tissues) and biodeposits using infrared microscopy were also conducted. Microplastics were detected in oyster's biodeposits following exposure to all tested concentrations: 0.003, 0.006 and 0.05 particles/mg of biodeposits in oysters exposed to 0.008, 10 and 100 μg of particles/L, respectively. No significant modulation of biological markers was measured in organisms exposed to microplastics in environmentally relevant conditions.

The Deepwater Horizon oil spill released millions of barrels of crude oil into the Gulf of Mexico, and saw widespread use of the chemical dispersant Corexit. We assessed the role of traits, such as cell size, cell wall, motility, and mixotrophy on the growth and photosynthetic response of 15 phytoplankton taxa to oil and Corexit. We collected growth and photosynthetic data on five algal cultures. These responses could be separated into resistant (Tetraselmis astigmatica, Ochromonas sp., Heterocapsa pygmaea) and sensitive (Micromonas pusilla, Prorocentrum minimum). We combined this data with 10 species previously studied and found that cell size is most important in determining the biomass response to oil, whereas motility/mixotrophy is more important in the dispersed oil. Our analysis accounted for a third of the variance observed, so further work is needed to identify other factors that contribute to oil resistance.

Forty-one bottom sediment samples were collected from three cores at the mouth of Wadi Haramel, Wadi Antar, Wadi Dumaygh, north of Al-Wajh, Red Sea, Saudi Arabia, to evaluate the levels of heavy metal contamination, using the enrichment factor (EF), geoaccumulation index (Igeo), contamination factor (Cf), soil pollution index (SPI), and multivariate statistical analysis (hierarchical cluster analysis and principal component analysis). Fe, Al, Pb, Mn, Cu, Ni, Co, Cd, Sr, V, Hg, and Total Organic Matter (TOM%) were quantified by Atomic Absorption Spectrophotometer. The vertical distribution of the heavy metals concentrations increased upwards indicating high heavy metals input. The results of enrichment factor and soil pollution index calculations indicate a strong anthropogenic supply of Cd and Sr (SPI = 1.10, 2.70, EF = 18.25, 17.99 respectively) while Cu and Ni show moderate anthropogenic input from urban, industrial activities and some new projects in the northern coast of Saudi Arabia.

Microplastics (MP) in the marine environment are widely reported. However, MP occurrence in some geographical areas such as from Small Island Developing States (SIDS) is missing. The main aim of this study was to assess MP levels in the urban coastal environment of Suva, the capital of the Republic of Fiji. Microplastics were measured from surface water, sediments and fish gastrointestinal tracts (GI) from three sites adjacent to Suva. In addition, an evaluation on the contribution from the local sewage treatment plant to MP levels was undertaken. In general, low levels of MP in water and sediments were detected, but significant differences were observed among sites. The sewage treatment plant was shown to contribute to MP levels in sediment but not in water. Species ingestion of MP was high and associated with MP in sediments. Fibres and fragments were the predominant type of MP, and fifteen different polymers were detected, with higher percentages of polyethylene, latex and polypropylene. In conclusion, MP were found in Suva coastal environment and these MP were associated to land based human activities.

Bacteria play an important role in ecological processes in oil contaminated marine sediments. In this work, bacterial diversity studies with surface sediment samples from the NW Gulf of Mexico were performed, two from continental shelf and two from upper slope. The bacterial communities seem significantly influenced by depth, distance from the shoreline, temperature, dissolved oxygen and aluminum. The most abundant Phylum was Proteobacteria, Class Gammaproteobacteria. However, Class Deltaproteobacteria, Order Desulfuromonadales predominated in continental shelf and Order Alteromonadales (Gammaproteobacteria) prevailed in the upper slope sediments. Many potential hydrocarbon degrading bacterial genera were identified, 71 of the assigned genera were associated to hydrocarbon degradation processes. The genera Desulfobulbus and Haliea were confined to continental inner-shelf, while Shewanella and Fusibacter were mostly detected in deeper sediments. The occurrence and abundance of putative hydrocarbon degrading bacteria in this area, could be indicative of an impacted zone caused by the presence hydrocarbons in the environment.