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.

A one-year impingement monitoring was conducted at Madras Atomic Power Station (MAPS), Kalpakkam, southeastern coast of India and identified a total of 67 species of marine organisms in the cooling water system. Estimates of total annual impingement contributed about 1.47×106 individuals and 142.5t of biomass. Jellyfish contributed about 6.8×105 individuals and 135.6t of biomass. Crabs, shrimps and fish were the most vulnerable organisms contributing about 4.29×105 individuals, 1.39×105 individuals and 2.16×105 individuals respectively. Commercially important species namely Trichiurus lepturus, Sardinella longiceps and Portunus pelagicus were found to be impinged 1.88% and 0.29% by number and weight of the total biomass respectively. Out of ~327 fish species recorded at Kalpakkam, only about 9.4% of species were impinged at MAPS. Multispecies impingement at MAPS poses the problem of finding the best mitigation options for tropical conditions.

The elastic cellulose-based aerogels (CBAs) with highly porous (99.56%) and low-density (0.0065gcm−1) were prepared using Eichhornia crassipes as cellulose source and polyvinyl alcohol directly as cross-linker via a facile and environment-friendly process. The prepared CBAs exhibited excellent oil/solvent sorption capacities (60.33–152.21gg−1), super-hydrophobicity (water contact angle of 156.7°) as well as remarkable reusability. More importantly, the absorbed oil could be quickly recovered by simple squeezing without significantly structure damage (at least 16 times). All these merits make CBAs very promising materials for oil spillage cleaning.

A next-generation sequencing (NGS) approach, in conjunction with culture-based methods, was used to examine fungal and prokaryotic communities for the presence of potential pathogens in beach sands throughout Portugal. Culture-based fungal enumeration revealed low and variable concentrations of the species targeted (yeasts and dermatophytes), which were underrepresented in the community characterized by NGS targeting the ITS1 region. Conversely, NGS indicated that the potentially pathogenic species Purpureocillium liliacinum comprised nearly the entire fungal community. Culturable fecal indicator bacterial concentrations were low throughout the study and unrelated to communities characterized by NGS. Notably, the prokaryotic communities characterized revealed a considerable abundance of archaea. Results highlight differences in communities between methods in beach sand monitoring but indicate the techniques offer complementary insights. Thus, there is a need to leverage culture-based methods with NGS methods, using a toolbox approach, to determine appropriate targets and metrics for beach sand monitoring to adequately protect public health.

Sediments from the Gulf of Mexico (GOM) and the South China Sea (SCS) were analyzed. The low δ13 C values of pentamethylicosane (PMIs) and fatty acids (−81.3 to −85.2‰) were found in only the S-1 sample collected from the GOM, indicating that methanogenic archaea associated with gas hydrate formation contributed to the sediment organic matter. Principle component analysis of fatty acids suggested that similar microbial biomass was found in the S-1, S-9, O-3 and O-5 samples. However, a comparison of the alkanes, fatty acids, and alcohols indicated that the percentage of n-alkan-2-ols in the S-1 sample from the GOM was the highest, while n-alkanes and n-fatty acids were the highest percentages in other samples from the GOM and SCS. This finding suggests that microbial species or the oxidation/reduction environment of the sample site of S-1 were different from those of the other samples. The present study provides a basis for detecting gas hydrate sites on the seafloor of the SCS.

Nutrient loading is a leading cause of global seagrass decline, triggering shifts from seagrass- to macroalgal-dominance. Within seagrass meadows of Xincun Bay (South China Sea), we found that nutrient loading (due to fish farming) increased sediment microbial biomass and extracellular enzyme activity associated with carbon cycling (polyphenol oxidase, invertase and cellulase), with a corresponding decrease in percent sediment organic carbon (SOC), suggesting that nutrients primed microorganism and stimulated SOC remineralization. Surpisingly, however, the relative contribution of seagrass-derived carbon to bacteria (δ13Cbacteria) increased with nutrient loading, despite popular theory being that microbes switch to consuming macroalgae which are assumed to provide a more labile carbon source. Organic carbon sources of fungi were unaffected by nutrient loading. Overall, this study suggests that nutrient loading changes the relative contribution of seagrass and algal sources to SOC pools, boosting sediment microbial biomass and extracellular enzyme activity, thereby possibly changing seagrass blue carbon.

Surface sediment samples from the coastal zone of Qatar were collected and analyzed to determine the characteristics, and sources of anthropogenic and biogenic hydrocarbons. The main compounds in these surface sediments included n-alkanes, methyl n-alkanoates, diterpenoids, hopanes, steranes, phthalate esters, polycyclic aromatic hydrocarbons (PAHs) and unresolved complex mixture (UCM). Their total concentrations ranged from 18.7±3.7–81.1±7.5ng/g (3.7±0.6–10.4±4.8%) for n-alkanes, 8.3±2.3–51±3.4ng/g (3.0±2.0–5.6±2.0%) for methyl n-alkanoates, 1.8±0.1–10.5±1.0ng/g (1.0±0.5–0.4±0.1%) for diterpenoids, 0.0–79.3±7.4ng/g (0.0–7.9±0.6%) for hopanes, 0.0–32.9±7.9ng/g (0.0–6.5±1.0%) for steranes, 0.7±0.1–36.3±3.4ng/g (0.1±0.1–1.9±3.4%) for phthalates, 0.30±0.2–7.8±0.7ng/g (0.02±0.04–0.42±0.72%) for PAHs, and 38±9–609±57ng/g (38.5±13.4–56.5±13.4%) for UCM. The major sources of these lipids were anthropogenic petroleum residues and plasticizers (80–89%), with lesser amounts from natural higher plants and microbial residues (11–20%). Petroleum residues and plasticizer inputs to the coastal sediments of Qatar likely affect the marine ecosystems and associated species groups as well as shallow coastal nursery and spawning areas.

The “Loy Krathong” festival is a major annual Thai event that includes firework displays. It takes place on the evening of the full moon in the 12th month of the traditional Thai lunar calendar. Since fireworks are widely considered a major source of PAHs, it is considered reasonable to expect a significant increase in PAH levels during this event. The overall PAH profile at the six air quality observatories operated by the Pollution Control Department (PCD), Ministry of Natural Resources and Environment (MNRE), showed that the Kingdom of Thailand's atmosphere was dominated by 5–6-ring PAHs during the firework display period. A significant increase in ΣPAHs (153%) was observed during firework displays. A statistical analysis coupled with the application of diagnostic binary PAH ratios was conducted to determine whether the detected increase in PAH congeners during the festival period was due to firework combustion or whether it was a coincidental effect caused by vehicular exhausts, long-range atmospheric transportation, photolysis and chemical degradation. The average incremental lifetime cancer risk (ILCR) values of adults and children living in Bangkok as estimated by three different TEQs for ingestion, dermal contact, and inhalation exposure pathways were greatly lesser than the US EPA baseline, further highlighting that the cancer risk of bonfire night falls into the ‘‘acceptable level’’ range.

The distribution, sources and bioavailability of polycyclic aromatic hydrocarbons (PAHs) in sediment and sea urchin (Echinometra mathaei) from the intertidal zone of the northern Persian Gulf were investigated. Total PAH concentrations varied from 12.8 to 81.25 and from 16.7 to 35 μgKg−1 dry weight in sediment and Echinometra mathaei, respectively. The PAH concentrations can be classified as low. Source identification and apportionment using diagnostic ratios and principal component analysis demonstrate that the combustion of fossil fuels, road traffic, combustion of natural gas and biomass, and oil spill could be considered as the main sources of PAH contamination. The first PAH biota-sediment accumulation factors (BSAF) data from sediment to Echinometra mathaei in the intertidal zone of the northern Persian Gulf were calculated, indicating accumulation of both lower and higher molecular weight PAHs, with a preferential accumulation of lower molecular weight PAHs.

Surface sediments were collected from the main path of Kuroshio Current (KC) off eastern Taiwan (ETW), and laboratory incubation was conducted for the study of the nutrient exchange at the sediment-water interface. Exchange fluxes of NO3−-N, NO2−-N, NH4+-N, PO43−-P and SiO32−-Si under simulated site condition were −0.0866, 0.00146, 0.0634, −0.00812 and −0.181mmolm−2d−1, respectively. This indicated that sediments in the studied area might act as a source of NO2−-N and NH4+-N and a sink of NO3−-N, PO43−-P and SiO32−-Si. Factors affecting nutrient exchange fluxes were studied by changing incubation conditions. Compared with some coastal areas in China, the main path of KC off ETW showed relatively low nutrient exchange fluxes at the sediment-water interface. It could be inferred that the sediment-water exchange of nutrients in the main path of KC off ETW had little influence on the downstream nutrient transportation by KC year-round based on the results of this research.