Transcriptome analysis reveals limited toxic effects of the UV-filter benzophenone-3 (BP-3) on the hermatypic coral Acropora tenuis and its symbiotic dinoflagellates.

This study aimed to investigate the toxic and transcriptomic effects of the ultraviolet filter benzophenone-3 (BP-3) on Acropora tenuis and its symbiotic dinoflagellates while using acetone as a solvent. Seven-day exposure to 50 and 500 µg/L, which is higher than most BP-3 records from coastal waters, did not affect coral colour or dinoflagellate photosynthesis. Differentially expressed genes (DEGs) between seawater and solvent controls were <20 in both corals and dinoflagellates. Eleven coral DEGs were detected after treatment with 50 µg/L BP-3. Fourteen coral DEGs, including several fluorescent protein genes, were detected after treatment with 500 µg/L BP-3. In contrast, no dinoflagellate DEGs were detected in the BP-3 treatment group. These results suggest that the effects of 50-500 µg/L BP-3 on adult A. tenuis and its dinoflagellates are limited. Our experimental methods with lower acetone toxicity provide a basis for establishing standard ecotoxicity tests for corals.

Development of a novel phosphorus recovery system using incinerated sewage sludge ash (ISSA) and phosphorus-selective adsorbent.

Phosphorus is an essential nutrient but faces foreseeable resource depletion. The incinerated sewage sludge ash (ISSA) is a promising source for recovering phosphorus. In this study, we proposed a new system for recovering phosphorus from ISSA. This innovative system uses phosphorus-selective adsorbent to purify phosphorus from the ISSA acid leachate. Laboratory scale batch and column tests were performed to demonstrate the feasibility of the system. Note that >70% of phosphorus in ISSA can be recovered as a high-purity recovery product. The product showed a structure similar to hydroxyapatite (Ca5(PO4)3OH). The total amount of Ca, P, and O in the product was above 90 wt%. The content of trace elements (As, Cd, Cr, and Pb) in the product was below the fertilizer limits, suggesting that the health and environmental risks of using fertilizer in agriculture are negligible. The expected costs of the system were estimated. The reusability of the adsorbent can reduce the operational costs to a satisfactory level. This study provides a practical alternative for recovering phosphorus from ISSA.

Hydroxyl carlactone derivatives are predominant strigolactones in Arabidopsis.

Strigolactones (SLs) regulate important aspects of plant growth and stress responses. Many diverse types of SL occur in plants, but a complete picture of biosynthesis remains unclear. In Arabidopsis thaliana, we have demonstrated that MAX1, a cytochrome P450 monooxygenase, converts carlactone (CL) into carlactonoic acid (CLA) and that LBO, a 2-oxoglutarate-dependent dioxygenase, can convert methyl carlactonoate (MeCLA) into a metabolite called [MeCLA + 16 Da]. In the present study, feeding experiments with deuterated MeCLAs revealed that [MeCLA + 16 Da] is hydroxymethyl carlactonoate (1'-HO-MeCLA). Importantly, this LBO metabolite was detected in plants. Interestingly, other related compounds, methyl 4-hydroxycarlactonoate (4-HO-MeCLA) and methyl 16-hydroxycarlactonoate (16-HO-MeCLA), were also found to accumulate in lbo mutants. 3-HO-, 4-HO-, and 16-HO-CL were detected in plants, but their expected corresponding metabolites, HO-CLAs, were absent in max1 mutants. These results suggest that HO-CL derivatives may be predominant SLs in Arabidopsis, produced through MAX1 and LBO.

Effect of low concentrations of Irgarol 1051 on RGB (R, red; G, green; B, blue) colour values of the hard-coral Acropora tenuis.

Colour change in Acropora tenuis, a representative species of Indo-Pacific hard coral, in response to low concentrations of Irgarol 1051 was examined in the laboratory. Branches of A. tenuis were exposed to 0, 1, and 10µgIrgarol1051/L for 14days, and photographed daily using digital camera. These Irgarol 1051 concentrations were similar to those recorded at a number of sea ports. Red, green and blue (RGB) coral colour values were quantified from the photographs, with black represented by R=G=B=0 and white as R=G=B=255. Exposure to Irgarol 1051 caused RGB values to increase, moving towards the 'white' end of the spectrum as Irgarol 1051 concentration increased. These results suggest that the ambient levels of Irgarol 1051 recorded from port environments could be implicated in coral bleaching, if concentrations over nearby reef ecosystems are similar.

Trace element concentrations in barramundi (Lates calcarifer) collected along the coast of Vietnam.

We determined concentrations of 23 trace elements (TEs), and stable carbon and nitrogen isotope (δ(13)C and δ(15)N) signatures in barramundi (Lates calcarifer) specimens collected along the coast of Vietnam in the Northern (NCZ), Central (CCZ) and Southern (SCZ) zones in the period 2007-2010. A combination of δ(13)C and δ(15)N signatures provided insight into ontogenetic shifts in barramundi foraging choices. There were clear zone-dependent differences in Mn, As, Sr and Tl concentrations; levels of Tl were highest in the NCZ, As in the CCZ, and Mn and Sr in the SCZ. Lowest concentrations of Rb occurred in the NCZ, Bi was lowest in the CCZ, and Cd and Cs were lowest in the SCZ. δ(15)N values significantly increased with increasing Zn, Se, Sn and Cs. Concentrations of TEs in barramundi from Vietnam were below worldwide guidelines for human consumption.

Polychlorinated biphenyl (PCB) concentrations and congener composition in masu salmon from Japan: a study of all 209 PCB congeners by high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS).

We collected two subspecies of masu salmon: Oncorhynchus masou masou from four localities (southern Sea of Japan northward to Hokkaido) and O. masou ishikawae from upstream from Ise Bay close to a heavy industrial area. All 209 PCB congeners were analyzed using HRGC/HRMS. PCA ordination of congener concentrations divided data into three groups: (i) ssp. masou from Hokkaido, (ii) ssp. masou from the other regions and (iii) ssp. ishikawae. The highest ∑ PCB concentration (40.39 ng/wet wt) was in ssp. ishikawae followed by ssp. masou from southern waters; however the TEQdioxin-like PCBs was highest in ssp. masou from southern water (1.96 pg-TEQdioxin-like PCBs/g wet wt.) due to the high proportion of congener #126 in its complement (#126 has the highest toxic equivalency factor among congeners). There is likely a contamination source offshore in the southern Sea of Japan and/or along the migratory route of ssp. masou.

Evaluating Henry's law constant of N-nitrosodimethylamine (NDMA).

N-Nitrosodimethylamine (NDMA), a potential carcinogen, may contaminate the groundwater when the reclaimed wastewater is used for irrigation and groundwater recharge. Henry's law constant is a critical parameter to assess the fate and transport of reclaimed wastewater-borne NDMA in the soil profile. We conducted a laboratory experiment in which the change of NDMA concentration in water exposed to the atmosphere was measured with respect to time and, based on the data, obtained the dimensionless Henry's law constant (K(H)') of NDMA, at 1.0 x 10(-4). The K(H)' suggests that NDMA has a relatively high potential to volatilize in the field where NDMA-containing wastewater is used for irrigation and the volatilization loss may be a significant pathway of NDMA transport. The experiment was based on the two boundary-layer approach of mass transfer at the atmosphere-water interface. It is an expedient method to delineate K(H)' for volatile or semi-volatile compounds present in water at low concentrations.

Leaching risk of N-nitrosodimethylamine (NDMA) in soil receiving reclaimed wastewater.

N-nitrosodimethylamine (NDMA) is a potential carcinogen frequently found in treated wastewater as a byproduct of chlorination. The potential for NDMA to contaminate the groundwater is a significant concern. A solute fate and transport model, Hydrus-1D, was used to evaluate the leaching potential of NDMA under different irrigation practices and soil properties. The results indicate that the risk of NDMA to reach the ground water is slim, when the reclaimed wastewater is applied under the customary conditions for landscape irrigation. The NDMA disappears in the reclaimed wastewater receiving soils rapidly through the microbial degradation and the volatilization processes. The factors that enhance the leaching risk are the soil hydraulic conductivity, the NDMA adsorption constants, and the irrigation intensity. When the hydraulic conductivity of soil is high, the NDMA adsorption constant of soil is low and/or the irrigation intensity is high, the NDMA leaching risk may dramatically increase. To reduce the NDMA leaching risk, it is imperative that the fields be irrigated at the proper volume and frequency and attention be paid to fields with soils having high-hydraulic conductivities and/or low-NDMA adsorption constants.