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TBT residual in water had become a noticeable ecological problem for aquatic ecosystems. The river pufferfish (Takifugu obscurus) is a kind of an anadromous fish species and widely distributed in the East China Sea and the Yellow Sea. Because of the water contamination, the pufferfish wild resource had a sudden decline in recent years. Therefore, the study on the response of pufferfish to the TBT exposure may contribute to reveal toxic injury mechanism of T. obscurus under TBT exposure. In this study, the transcriptional library of T. obscurus liver and gill was constructed and sequenced by an improved Illumina HiseqX10 high-throughput sequencing platform under different concentrations of TBT acute stress. The blood cell numbers distinctly decreased after TBT exposure, showing the adverse effects of TBT invasion and self-adjusting ability of the pufferfish. The production of reactive oxygen species increased, demonstrating the oxidation resistance of T. obscurus when exposed to TBT. The obtained data were compared with the genome data of Takifugu rubripes and transcriptional resource database. On this basis, gene function annotation, analysis and classification were carried out by bioinformatics method, and differential genes related to toxic injury function were screened out. Meanwhile, new toxic related genes and related signal pathways were sought to provide new theoretical guidance for the pathogenesis of T. obscurus exposed to TBT. This study not only enriched the transcriptome data of T. obscurus under environmental stress, but also provided a new research method for the response mechanism of T. obscurus under the stimulation of environmental factors.

Microplastics are an emerging hazard in the marine environment, and considered to eventually sink into sediments. An investigation into the long-term variation of microplastic accumulation in sediment cores is essential for understanding the historical trend of this contamination and its response to human activities. In this study, the multidecadal changes of microplastic abundances in two sediment cores from the inner shelf of the East China Sea (ECS) were revealed by two methods, i.e., a visual enumeration method based on scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) and a quantitative method based on microplastic-derived carbon (MPC) abundances. The features of microplastics were determined via SEM-EDS and micro-Fourier transform infrared spectroscopy (μ-FTIR). The results reveal a multidecadal increasing trend of microplastic accumulation in the coastal sediments of the ECS since the 1960s, which may be jointly governed by the release of plastic wastes and oceanographic dynamics. Meanwhile, the breakpoint of the exponential growth of microplastics in the ECS occurs in 2000 AD, which well matches the rapid increasing of plastic production and consumption in China. Further, based on the MPC contents in sediments, the influence of microplastics on the quantitative evaluation of carbon storage in the ECS has been examined for the first time, revealing an insignificant (

Microplastic pollution in marine environments is of particular concern on its risk to the ecosystem. To assess and manage microplastic contaminants, their quantitative detection in environmental samples is a high priority. However, uncertainties of current methods still exist when estimating their abundances, particularly with fine-grained (1 mm) microplastics. This work reports a novel thermoanalytical method for quantifying microplastics by measuring the contents of microplastic-derived carbon (MPC) in samples under the premise of nearly eliminating the limit of their particle appearances. After validating the method via samples with the spiked microplastics, we have conducted a case study on sediment core H43 that spanned 1925-2009 CE from the Yellow Sea for further illustrating the high reliability and practicability of this method for quantifying microplastics in natural samples. Our results have demonstrated that the proposed method may be a promising technique to determine the mass-related concentrations of the total microplastics in marine sediments for evaluating their pollution status and quantitative contribution to marine carbon storage.

Hatchery release of silver carp (Hypophthalmichthys molitrix) is an efficient strategy that has been carried out for years, and its scales expand year by year in the lower reaches of the Yangtze River (LRYR) in China. As the cultured juveniles are released into self-recruiting wild population to increase fisheries resources yields, they may potentially come along with negative impacts such as intra-inter specific completion, loss of genetic diversity and fitness, even causing genetic risk. To assess the relationship between genetic risk and stock enhancement (SE) of the silver carp in the Yangtze River (YR); microsatellite loci amplification, parentage assignment, genetic diversity, genetic differentiation and structure were conducted and testified by the help of eleven fluorescence-labeled microsatellite markers method. Results showed that silver carp populations in the YR had relatively higher genetic diversity (UHe), inbreeding coefficient (Fis), and effective population size (Ne) than breeding stock populations from eight hatcheries. By using the analysis of molecular variance (AMOVA), results showed that the percentage of variance among populations and within populations were 4.15 % and 95.85 %, respectively, which indicated that genetic structure of YR populations possibly had been changed by SE. Therefore, the present study suggests that the large-scale SE possibly resulted in negative genetic impact on silver carp population. Most importantly, an evaluation system in fisheries resource recruitment and genetic risks was established for SE and management.

Anaerobic oxidation of methane (AOM) is one of the most important biogeochemical processes associated with hydrate dissociation and carbon cycling. Though AOM has been extensively investigated, the variations of its microorganisms and lipid biomarkers are still not fully understood. In this study, the porewater geochemical and lipid biomarker evidence for AOM was systematically investigated in the hydrate-bearing system from the Taixinan Basin, the South China Sea, aiming to better expound the vertical variations of AOM-related biomarker signatures and causes of the weak lipid biomarker patterns. Accordingly, the sulfate-methane interface (SMI) depth of 1,000 cmbsf and onset of AOM were determined on the basis of the vertical profiles of porewater parameters. The occurrence of 13C-depleted 2,6,10,15,19-pentamethylicosane (PMI) with the δ13C ratios of −77.7‰ to −131.4‰ near the SMI are in accord with the porewater parameters, despite the absence of archaeol and sn2-hydroxyarchaeol and low abundances of PMI. Meanwhile, the strongly 13C-enriched iso-C15:0 and anteiso-C15:0 fatty acids suggest that non-methane hydrocarbons or oil derivatives are speculated as the probable carbon sources for sulfate-reducing bacteria due to the presence of unresolved complex mixtures (UCMs) and odd–even predominance (OEP) values (about 1.0). The weak in situ signal of AOM-related biomarkers may be attributed to the low-flux methane supply, and dilution effect from the high input of allochthonous and autochthonous organic matters. The great difference in biomarkers between the Taixinan Basin and previously reported sites should be further clarified on the basis of more extensive studies in various AOM-related settings.

Five pyridyl-β-diketones were synthesized by Claisen condensation of ethyl nicotinate with various aryl methyl ketones in benzene in the presence of sodium amide as the base, and then reacted with boron trifluoride diethyl etherate in dichloromethane to afford some new boron difluoride pyridyl-β-diketonate derivatives. The compounds obtained were characterized using FTIR, (1)H NMR, elemental analysis and mass spectrometry. Their optical properties were studied in DMF by UV-vis absorption and fluorescence spectroscopy. The results showed that these boron complexes exhibited intense fluorescence in the blue-green region (420-490 nm) under UV radiation with a relatively high quantum yield. Especially, compounds 4b and 5b displayed much higher quantum yield as compared to compounds 1b, 2b and 3b.

Five diaroylmethanatoboron difluoride derivatives were prepared from aryl methyl ketones via Claisen condensation with aromatic esters and followed by complexation with boron trifluoride etherate. Their structures and spectroscopic properties were studied by elemental analysis, IR, NMR, ESI–MS, UV and fluorescence spectroscopy. The results showed that these boron complexes had strong fluorescent peaks in the 400–500 nm range in chloroform and high quantum yields. The emission peaks for boron complexes containing naphthyl group exhibited considerable red shift as compared to those of containing phenyl group.