Cometabolic degradation is currently an effective and extensively way to remove high molecular weight polycyclic aromatic hydrocarbons(HMW-PAHs).Unfortunately,due to low bio-accessibility and high biotoxicity,the come...Cometabolic degradation is currently an effective and extensively way to remove high molecular weight polycyclic aromatic hydrocarbons(HMW-PAHs).Unfortunately,due to low bio-accessibility and high biotoxicity,the cometabolic degradation rate of HMW-PAHs is limited.Glycine-β-cyclodextrin(GCD)was obtained through amino modification ofβ-cyclodextrin(BCD)and added to cometabolic system of phenanthrene(PHE)and pyrene(PYR)to assist PYR biodegradation.Results show that the addition of GCD(100 mg/L)effectively improved the removal rate of PYR(20 mg/L)by 42.3%.GCD appeared to increase the bio-accessibility and reduce the biotoxicity of PHE and PYR,and then promoted the growth of Pseudomonas stutzeri DJP1 and stimulated the elevation of dehydrogenase(DHA)and catechol 12 dioxygenase(C12O)activities.The phthalate metabolic pathway was accelerated,which improved the cometabolic degradation.This study provided a new reference for the cometabolic degradation of HMW-PAHs.展开更多
This study analyzed the impact of land-based contaminants and tertiary industrial structure on economic development in the selected Bohai Bay area,China.Based on panel data spanning 2011-2020,a vector autoregressive(V...This study analyzed the impact of land-based contaminants and tertiary industrial structure on economic development in the selected Bohai Bay area,China.Based on panel data spanning 2011-2020,a vector autoregressive(VAR)model is used to analyze and forecast the short-run and long-run relationships between three industrial structures,pollutant discharge,and economic development.The results showed that the environmental index had a long-term cointegration relationship with the industrial structure economic index.Per capital chemical oxygen demand(PCOD)and per capita ammonia nitrogen(PNH_(3)N)had a positive impact on delta per capita GDP(dPGDP),while per capita solid waste(PSW),the secondary industry rate(SIR)and delta tertiary industry(dTIR)had a negative impact on dPGDP.The VAR model under this coupling system had stability and credibility.The impulse response results showed that the short-term effect of the coupling system on dPGDP was basically consistent with the Granger causality test results.In addition,variance decomposition was used in this study to predict the long-term impact of the coupling system in the next ten periods(i.e.,ten years).It was found that dTIR had a great impact on dPGDP,with a contribution rate as high as 74.35%in the tenth period,followed by the contribution rate of PCOD up to 3.94%,while the long-term contribution rates of PSW,SIR and PNH3N were all less than 1%.The results show that the government should support the development of the tertiary industry to maintain the vitality of economic development and prevent environmental deterioration.展开更多
Chlorophyll-a(Chl-a)concentration is a primary indicator for marine environmental monitoring.The spatio-temporal variations of sea surface Chl-a concentration in the Yellow Sea(YS)and the East China Sea(ECS)in 2001-20...Chlorophyll-a(Chl-a)concentration is a primary indicator for marine environmental monitoring.The spatio-temporal variations of sea surface Chl-a concentration in the Yellow Sea(YS)and the East China Sea(ECS)in 2001-2020 were investigated by reconstructing the MODIS Level 3 products with the data interpolation empirical orthogonal function(DINEOF)method.The reconstructed results by interpolating the combined MODIS daily+8-day datasets were found better than those merely by interpolating daily or 8-day data.Chl-a concentration in the YS and the ECS reached its maximum in spring,with blooms occurring,decreased in summer and autumn,and increased in late autumn and early winter.By performing empirical orthogonal function(EOF)decomposition of the reconstructed data fields and correlation analysis with several potential environmental factors,we found that the sea surface temperature(SST)plays a significant role in the seasonal variation of Chl a,especially during spring and summer.The increase of SST in spring and the upper-layer nutrients mixed up during the last winter might favor the occurrence of spring blooms.The high sea surface temperature(SST)throughout the summer would strengthen the vertical stratification and prevent nutrients supply from deep water,resulting in low surface Chl-a concentrations.The sea surface Chl-a concentration in the YS was found decreased significantly from 2012 to 2020,which was possibly related to the Pacific Decadal Oscillation(PDO).展开更多
The wave-induced liquefaction of seabed is responsible for causing damage to marine structures.Particle composition and consolidation degree are the key factors affecting the pore water pressure response and liquefact...The wave-induced liquefaction of seabed is responsible for causing damage to marine structures.Particle composition and consolidation degree are the key factors affecting the pore water pressure response and liquefaction behavior of the seabed under wave action.The present study conducted wave flume experiments on silt and silty fine sand beds with varying particle compositions.Furthermore,a comprehensive analysis of the differences and underlying reasons for liquefaction behavior in two different types of soil was conducted from both macroscopic and microscopic perspectives.The experimental results indicate that the silt bed necessitates a lower wave load intensity to attain the liquefaction state in comparison to the silty fine sand bed.Additionally,the duration and development depth of liquefaction are greater in the silt bed.The dissimilarity in liquefaction behavior between the two types of soil can be attributed to the variation in their permeability and plastic deformation capacity.The permeability coefficient and compression modulus of silt are lower than those of silty fine sand.Consequently,silt is more prone to the accumulation of pore pressure and subsequent liquefaction under external loading.Prior research has demonstrated that silt beds with varying consolidation degrees exhibit distinct initial failure modes.Specifically,a dense bed undergoes shear failure,whereas a loose bed experiences initial liquefaction failure.This study utilized discrete element simulation to examine the microscopic mechanisms that underlie this phenomenon.展开更多
Temporal and spatial heterogeneity identifications of marine environment and its changes have great significances in marine spatial planning and offshore pollution control.In this study,considering the integration of ...Temporal and spatial heterogeneity identifications of marine environment and its changes have great significances in marine spatial planning and offshore pollution control.In this study,considering the integration of marine ecological environment and sea-land interaction,we built a spatialized evaluation model named Marine Environment Change Spatial Assessment(MECSA)to quantify the marine environment status and changes.In MECSA,we applied the geospatial model and the pressure-state-response(PSR)model for processing and integrating evaluation indicators.A case study in the Laizhou Bay showed that the marine environment quality was generally in a declining state from 2009 to 2015.In 2015,the Marine Environment Index(MEI)had decreased by 0.1 compared with 2009,although the two years all reached a‘Good'level.The spatial MEI layers of the two years showed a same distribution:the southwestern part was in poorer status,with a fan ring shape gradually getting better to the northeast.The Marine Organisms Response Index(MORI)contributed the most to the MEI.Therefore,future marine environmental assessment and spatial planning should focus on the identification the marine environment with its changes from the perspective of spatial heterogeneity and systemicity.Based on single indicators and comprehensive evaluation results,we can propose spatially targeted policies and recommendations scientifically.展开更多
Laboratory tests were conducted to study the effects of curing time, cement ratio and seawater pressure on cement soil deterioration formed at simulative marine soft clay sites. Deterioration depth was determined on t...Laboratory tests were conducted to study the effects of curing time, cement ratio and seawater pressure on cement soil deterioration formed at simulative marine soft clay sites. Deterioration depth was determined on the basis of characteristics of penetration resistance and penetration depth curves, and the deterioration depth of cement soil with the cement ratio of 7%, reached 31.8 mm after 720 d. Results of research indicated that deterioration extended quickly under seawater environment and the deterioration depth increased with the prolonging curing time. In addition, the water pressure could speed up deterioration. With the increase of cement content, the strength of cement soil increased obviously. At the same time, the deterioration depth decreased significantly. The concentration of calcium ion in the cement stabilized soil increased with the increase of depth, while that of magnesium ion gradually decreased. The variations were consistent with energy dispersive spectrometer(EDS)analysis results, and the calcium concentration with depth was in a good consistency with strength distribution at long term. The results showed that the deterioration became more serious with the curing time, and it was related to calcium leaching.展开更多
Marine ecosystem services are the benefits which people obtain from the marine ecosystem,including provisioning services,regulating services,cultural services and supporting services. The human species,while buffered ...Marine ecosystem services are the benefits which people obtain from the marine ecosystem,including provisioning services,regulating services,cultural services and supporting services. The human species,while buffered against environmental changes by culture and technology,is fundamentally dependent on the flow of ecosystem services. Marine ecosystem services become increasingly valuable as the terrestrial resources become scarce. The value of marine ecosystem services is the monetary flow of ecosystem services on specific temporal and spatial scales,which often changes due to the variation of the goods prices,yields and the status of marine exploitation. Sensitivity analysis is to study the relationship between the value of marine ecosystem services and the main factors which affect it. Uncertainty analysis based on varying prices,yields and status of marine exploitation was carried out. Through uncertainty analysis,a more credible value range instead of a fixed value of marine ecosystem services was obtained in this study. Moreover,sensitivity analysis of the marine ecosystem services value revealed the relative importance of different factors.展开更多
Complex hydrocultural conditions in the estuary affect the migration and transformation of mercury.Using two voyages in July and October 2018,Dissolved Gaseous Mercury(DGM)and Reactive Mercury(RHg)were determined to e...Complex hydrocultural conditions in the estuary affect the migration and transformation of mercury.Using two voyages in July and October 2018,Dissolved Gaseous Mercury(DGM)and Reactive Mercury(RHg)were determined to explore the source,transformation and influence of DGM content in the adjacent waters of Yangtze River Estuary in summer and autumn.The results showed the contents of DGM and RHg in summer were higher than those in autumn,and both of them were higher than those in open sea.In summer and autumn,the Yangtze River brought a higher concentration of DGM,and different flow direction and runoff resulted in differences in the high value region of the surface.The emergence of low-oxygen zones in summer was conducive to the production of DGM.In autumn,windy weather allowed seawater disturbances to promote the release of mercury from the underlying sediments,especially in shallow sea in northwest.RHg showed a higher concentration in the offshore than in the open sea in summer,but there was no such trend in autumn,reflecting the influence of less runoff input.DGM is the main product of RHg reduction,and there was a significant positive correlation between DGM and RHg in summer(r=0.356,P<0.05),while the correlation between DGM and RHg was not significant in autumn due to the influence of light intensity,wind speed and nutrients.The exchange flux of mercury in the adjacent waters of the Yangtze River Estuary was higher than that in the open sea.There was no significant difference of the release flux of mercury in summer and autumn.This article highlighted that the input of mercury from the Yangtze River runoff promotes the release of mercury in seawater,and the hypoxic zone caused by eutrophication is conducive to the production of DGM.展开更多
The knowledge of the existence,distribution and fate of polycyclic aromatic hydrocarbons(PAHs)and substituted polycyclic aromatic hydrocarbons(SPAHs)in wastewater treatment plants(WWTPs)was vital for reducing their co...The knowledge of the existence,distribution and fate of polycyclic aromatic hydrocarbons(PAHs)and substituted polycyclic aromatic hydrocarbons(SPAHs)in wastewater treatment plants(WWTPs)was vital for reducing their concentrations entering the aquatic environment.The concentrations of 13 SPAHs and 16 PAHs were all determined in a WWTP with styrene butadiene rubber(SBR)in partnership with the moving bed biofilm reactor(MBBR)process.SPAHs presented a higher concentration lever than PAHs in nearly all samples.The total removal efficiencies of PAHs and SPAHs ranged from 64.0%to 71.36%and 78.4%to 79.7%,respectively.The total yearly loads of PAHs(43.0 kg)and SPAHs(73.0 kg)were mainly reduced by the primary and SBR/MBBR biological treatment stages.The tertiary treatment stage had a minor contribution to target compounds removal.According to a synthesis and improvement fate model,we found that the dominant processes changed as the chemical octanol water partition coefficient(K_(ow))increased.But the seasonal variations of experimental removal efficiencies were more obvious than that of predicted data.In the primary sedimentation tank,dissolution in the aqueous phase and sorption to sludge/particulate matter were controlling processes for the removal of PAHs and SPAHs.The sorption to sludge and biodegradation were the principal removal mechanisms during the SBR/MBBR biological treatment process.The contribution of volatilization to removal was always insignificant.Furthermore,the basic physicochemical properties and operating parameters influenced the fate of PAHs and SPAHs in the WWTP.展开更多
Endophytic bacteria are promising bacterial fertilizers to improve plant growth under adverse environment.For ecological remediation of coastal wetlands,it was necessary to investigate the effect and interaction of en...Endophytic bacteria are promising bacterial fertilizers to improve plant growth under adverse environment.For ecological remediation of coastal wetlands,it was necessary to investigate the effect and interaction of endophytes on halophytes under saline-alkali stress.In this study,an endophytic bacterium strain HK1 isolated from halophytes was selected to infect Suaeda glauca under pH(7 and 8)and salinity gradient(150,300 and 450mmolL^(-1)).Strain HK1 was identified as Pantoea ananatis and it had ability to fix nitrogen,dissolve inorganic phosphorus and produce indole-3-aceticacid(IAA).The results showed that strain HK1 could promote the growth of S.glauca seedings when the salinity was less than 300mmolL^(-1),in view of longer shoot length and heavier fresh weight.The infected plants could produce more proline to decrease the permeability of cells,which content increased by 26.2%–61.1%compared to the non-infected group.Moreover,the oxidative stress of infected plants was relieved with the malondialdehyde(MDA)content decreased by 16.8%–32.9%,and the peroxidase(POD)activity and catalase(CAT)activity increased by 100%–500%and 6.2%–71.4%,respectively.Statistical analysis revealed that increasing proline content and enhancing CAT and POD activities were the main pathways to alleviate saline-alkali stress by strain HK1 infection,and the latter might be more important.This study illustrated that endophytic bacteria could promote the growth of halophytes by regulation of osmotic substances and strengthening antioxidant activities.This finding would be helpful for the bioremediation of coastal soil.展开更多
The long-distance movement of turbidity currents in submarine canyons can transport large amounts of sediment to deep-sea plains.Previous studies show obvious differences in the turbidity current velocities derived fr...The long-distance movement of turbidity currents in submarine canyons can transport large amounts of sediment to deep-sea plains.Previous studies show obvious differences in the turbidity current velocities derived from the multiple cables damage events ranging from 5.9 to 28.0 m/s and those of field observations between 0.15 and 7.2 m/s.Therefore,questions remain regarding whether a turbid fluid in an undersea environment can flow through a submarine canyon for a long distance at a high speed.A new model based on weakly stable sediment is proposed(proposed failure propagation model for weakly stable sediments,WS S-PFP model for short)to explain the high-speed and long-range motion of turbidity currents in submarine canyons through the combination of laboratory tests and numerical analogs.The model is based on two mechanisms:1)the original turbidity current triggers the destabilization of the weakly stable sediment bed and promotes the destabilization and transport of the soft sediment in the downstream direction and 2)the excitation wave that forms when the original turbidity current moves into the canyon leads to the destabilization and transport of the weakly stable sediment in the downstream direction.The proposed model will provide dynamic process interpretation for the study of deep-sea deposition,pollutant transport,and optical cable damage.展开更多
The resuspension of marine sediments plays a key role in the biogeochemical cycle and marine ecology system.Internal solitary waves are considered to be important driving forces of the resuspension of bottom sediments...The resuspension of marine sediments plays a key role in the biogeochemical cycle and marine ecology system.Internal solitary waves are considered to be important driving forces of the resuspension of bottom sediments.In this paper,the movement of turbidity currents,the generation and the effects on the bottom bed of internal solitary waves and excitation waves are studied by flume tests and numerical simulations,and the sediment resuspension are analyzed.The results show that the excitation wave can lead to the resuspension of the bottom sediments under all the conditions,while the internal solitary wave can lead to the resuspension of the sediment only under some special conditions,such as high amplitude or large underwater slope.Under the experimental conditions,the change in the near-bottom velocity caused by the excitation wave is close to three times that of the internal solitary wave.展开更多
The characteristics of the bacterial community structure in aerosols of different particle sizes over northern Chinese marginal seas and the northwestern Pacific Ocean in autumn were analyzed using high-throughput seq...The characteristics of the bacterial community structure in aerosols of different particle sizes over northern Chinese marginal seas and the northwestern Pacific Ocean in autumn were analyzed using high-throughput sequencing and the quantitative real-time PCR method based on 16S rRNA genes.Combined with environmental factors and air mass sources,the bacterial abundance,community diversity,composition and structural characteristics in aerosols were studied,which might provide a scientific evaluation for a comprehensive understanding of the characteristics,long-distance transmission and ecological effects of aerosols from coastal waters to the distant ocean(northwestern Pacific Ocean).At the junction of the South Yellow Sea and the East China Sea,the bacterial abundance in the aerosols was substantially affected by transmission of continental air masses and was higher than those in other samples,and the bacterial abundance in coarse particle(>2.1μm)samples was significantly higher than that in fine particle(<2.1μm)samples(P<0.05).In contrast,aerosols collected at the northwestern Pacific Ocean(NWP5 site)were less affected by transmissions of continental air masses,and their bacterial abundance in coarse particle samples was significantly lower than that in fine particle samples.Significant differences in the richness and diversity of bacterial communities were observed among all samples(P<0.05).The differences in the bacterial community in different sea areas were greater than those in the same sample with different particle sizes(P>0.05).Among the environmental factors examined,a significant negative correlation was observed between bacterial community richness and temperature(P<0.05),and the bacterial community diversity was significantly positively correlated with the concentration of K^(+)(P<0.05).Canonical correspondence analysis showed that temperature,NH_(4)^(+) concentration and SO_(4)^(2−) concentration exerted significant effects on bacterial community structures(P<0.01)in aerosols of different particle sizes over northern Chinese marginal seas and the northwestern Pacific Ocean.展开更多
Mitochondrial cytochrome b (Cytb), one of the few proteins encoded by the mitochondrial DNA, plays an important role in transferring electrons. As a mitochondrial gene, it has been widely used for phylogenetic analysi...Mitochondrial cytochrome b (Cytb), one of the few proteins encoded by the mitochondrial DNA, plays an important role in transferring electrons. As a mitochondrial gene, it has been widely used for phylogenetic analysis. Previously, a 949-bp fragment of the coding gene and mRNA editing were characterized from Prorocentrum donghaiense, which might prove useful for resolving P. donghaiense from closely related species. However, the full-length coding region has not been characterized. In this study, we used rapid amplification of cDNA ends (RACE) to obtain full-length, 1 124 bp cDNA. Cytb transcript contained a standard initiation codon ATG, but did not have a recognizable stop codon. Homology comparison showed that the P. donghaiense Cytb had a high sequence identity to Cytb sequences from other dinoflagellate species. Phylogenetic analysis placed Cytb from P. donghaiense in the clade of dinoflagellates and it clustered together strongly with that from P. minimum. Based on the full-length sequence, we inferred 32 editing events at different positions, accounting for 2.93% of the Cytb gene. 34.4% (11) of the changes were A to G, 25% (8) were T to C, and 25% (8) were C to U, with smaller proportions of G to C and G to A edits (9.4% (3) and 6.2% (2), respectively). The expression level of the Cytb transcript was quantified by real-time PCR with a TaqMan probe at different times during the whole growth phase. The average Cytb transcript was present at 39.27±7.46 copies of cDNA per cell during the whole growth cycle, and the expression of Cytb was relatively stable over the different phases. These results deepen our understanding of the structure and characteristics of Cytb in P. donghaiense, and confirmed that Cytb in P. donghaiense is a candidate reference gene for studying the expression of other genes.展开更多
Microorganisms in sediments are critical to marine ecosystems.The microbial communities in marine sediments of the Bohai Sea(BS)and Yellow Sea(YS),the eastern Chinese marginal seas,were uncovered in employing the meta...Microorganisms in sediments are critical to marine ecosystems.The microbial communities in marine sediments of the Bohai Sea(BS)and Yellow Sea(YS),the eastern Chinese marginal seas,were uncovered in employing the metagenomic approach.In addition,the taxonomic and functional compositions of microbes were compared among various sediment core depths.Results showing the compositions,diversities,and functions of the microbial communities showed no significant variations with sea areas,and significant seasonal variations was observed in station 3500-7 only on functions of the microbial communities.Moreover,the compositions,diversities,and functions of the microbial communities changed noticeably in different sediment depths in close correlation with physical and chemical properties of sediments.However,the large fraction of the variation in functional communities remained unexplained.From bioinformatic analysis of the metagenomic data,the carbon-metabolismrelated genes such as glycosyl transferase(GT),glycoside hydrolase(GH),and carbohydrate esterase(CE)genes were rich in the microbial community,especially in the top sediment depth.Additionally,in this N-polluted habitat,nitrification and anaerobic ammonia oxidation(anammox)were dominant in the top sediment depth,whereas dissimilatory nitrate reduction to ammonium(DNRA)and denitrification were dominant in the middle and bottom depth,respectively.Further identification of possible biogeochemical links suggested that Gammaproteobacteria,Alphaproteobacteria,Nitrospirae,Nitrospinae,Chloroflexi,and Methanomicrobia might promote effective circulation of carbon and nitrogen cycling.This study expanded our knowledge about the structure and functional potential of microbial communities associated with different sediment depth,and provided further comprehensive information on element cycles in marine environments.展开更多
This paper examines the simplification strategy of retaining only the nonhydrostatic effect of local acceleration in a three-dimensional fully nonhydrostatic model regarding the submesoscale wave phenomenon in the oce...This paper examines the simplification strategy of retaining only the nonhydrostatic effect of local acceleration in a three-dimensional fully nonhydrostatic model regarding the submesoscale wave phenomenon in the ocean.Elaborate scale analysis of the vertical component of the Reynold-averaged Navier-Stokes(RANS)equation was performed,confirming the rationalization of this simplification.Then,the simplification was implemented in a RANS equation-based nonhydrostatic model NHWAVE(nonhydrostatic WAVE)to make a simplified nonhydrostatic model.Numerical examples were taken to test its performance,including surface sinusoidal waves propagating on an idealized East China Sea topography,tidally induced internal lee waves and small-scale solitary waves.The results show that in a considerably wide range of nonlinear strengths,the simplified nonhydrostatic model can obtain similar results as those in the fully nonhydrostatic model,even for smaller-scale solitary waves.Nonlinearity influences the applicability of the simplification.The stronger the nonlinearity is,the worse the simplified model describes the nonhydrostatic phenomenon.In general,the simplified nonhydrostatic model can simulate surface waves better than internal waves.Improvement of computational efficiency in the simplified nonhydrostatic model is reasonable,reducing the central processing unit time duration in the fully nonhydrostatic model by 16.4%–20.6%.The specially designed algorithm based on the simplified nonhydrostatic equation can remarkably reduce the computational time.展开更多
Copepods are among the most abundant and successful metazoans in the marine ecosystem. However, genomic resources related to fundamental cellular processes are still limited in this particular group of crustaceans. Ri...Copepods are among the most abundant and successful metazoans in the marine ecosystem. However, genomic resources related to fundamental cellular processes are still limited in this particular group of crustaceans. Ribosomal proteins are the building blocks of ribosomes, the primary site for protein synthesis. In this study, we characterized and analyzed the c DNAs of cytoplasmic ribosomal proteins(c RPs) of two calanoid copepods, P seudodiaptomus poplesia and A cartia pacifi ca. We obtained 79 c RP c DNAs from P. poplesia and 67 from A. pacifi ca by c DNA library construction/sequencing and rapid amplifi cation of c DNA ends. Analysis of the nucleic acid composition showed that the copepod c RP-encoding genes had higher GC content in the protein-coding regions(CDSs) than in the untranslated regions(UTRs), and single nucleotide repeats(>3 repeats) were common, with "A" repeats being the most frequent, especially in the CDSs. The 3′-UTRs of the c RP genes were signifi cantly longer than the 5′-UTRs. Codon usage analysis showed that the third positions of the codons were dominated by C or G. The deduced amino acid sequences of the c RPs contained high proportions of positively charged residues and had high p I values. This is the fi rst report of a complete set of c RP-encoding genes from copepods. Our results shed light on the characteristics of c RPs in copepods, and provide fundamental data for further studies of protein synthesis in copepods. The copepod c RP information revealed in this study indicates that additional comparisons and analysis should be performed on different taxonomic categories such as orders and families.展开更多
Spatial heterogeneity or“patchiness”of plankton distributions in the ocean has always been an attractive and challenging scientific issue to oceanographers.We focused on the accumulation and dynamic mechanism of the...Spatial heterogeneity or“patchiness”of plankton distributions in the ocean has always been an attractive and challenging scientific issue to oceanographers.We focused on the accumulation and dynamic mechanism of the Acetes chinensis in the Lianyungang nearshore licensed fishing area.The Lagrangian frame approaches including the Lagrangian coherent structures theory,Lagrangian residual current,and Lagrangian particle-tracking model were applied to find the transport pathways and aggregation characteristics of Acetes chinensis.There exist some material transport pathways for Acetes chinensis passing through the licensed fishing area,and Acetes chinensis is easy to accumulate in the licensed fishing area.The main mechanism forming this distribution pattern is the local circulation induced by the nonlinear interaction of topography and tidal flow.Both the Lagrangian coherent structure analysis and the particle trajectory tracking indicate that Acetes chinensis in the licensed fishing area come from the nearshore estuary.This work contributed to the adjustment of licensed fishing area and the efficient utilization of fishery resources.展开更多
The production of toxic sulfides is a common environmental problem in mariculture.Therefore,the effective inhibition of sulfidogens is the key to prevent sulfides production.In this study,the possibility and mechanism...The production of toxic sulfides is a common environmental problem in mariculture.Therefore,the effective inhibition of sulfidogens is the key to prevent sulfides production.In this study,the possibility and mechanism of nitrate(NO_(3)^(−))inhibiting the activity of the sulfate-reducing microbiota(SRM)from mariculture sediments was investigated.The results showed that 1,3,and 5 mmol L^(−1)NO_(3)^(−)continuously inhibited sulfide production for 1-3 d.As NO_(3)^(−) dosage increased to 7 mmol L^(−1),the duration of inhibition increased to 6 days.Denitrifying product NO_(2)^(−)heavily inhibited the activity of dissimilar sulfate reductase gene(dsrB)by 3 orders,which was the main reason that the sulfate-reducing activity was inhibited.The SRM structure changed significantly with the dosage of NO_(3)^(−),while the abundance of sulfidogens Desulfovibrio species increased due to their capability of detoxifying nitrite through nitrite reductase.Hence,sulfidogens Desulfovibrio species are more adaptable to a high nitrate/nitrite environment,and the traditional control strategies by dosing nitrate/nitrite should be paid more attention to.The findings will serve as helpful guidelines for sulfate-reducing microbiota in the habitat of mariculture to reduce their generation of poisonous sulfide.展开更多
The microscopic characterization of isolated bubbles in gassy soil plays an important role in the macroscopic physical properties of sediments and is a key factor in the study of geological hazards in gas-bearing stra...The microscopic characterization of isolated bubbles in gassy soil plays an important role in the macroscopic physical properties of sediments and is a key factor in the study of geological hazards in gas-bearing strata.Based on the box-counting method and the pore fractal features in porous media,a fractal model of bubble microstructure parameters in gassy soil under different gas con-tents and vertical load conditions is established by using an industrial X-ray CT scanning system.The results show that the fractal di-mension of bubbles in the sample is correlated with the volume fraction of bubbles,and it is also restricted by the vertical load.The three-dimensional fractal dimension of the sample is about 1 larger than the average two-dimensional fractal dimension of all the slices from the same sample.The uniform porous media fractal model is used to test the equivalent diameter,and the results show that the variation of the measured pore diameter ratio is jointly restricted by the volume fraction and the vertical load.In addition,the measured self-similarity interval of the bubble area distribution is tested by the porous media fractal capillary bundle model,and the fitting curve of measured pore area ratio in a small loading range is obtained in this paper.展开更多
基金Supported by the National Natural Science Foundation of China(No.51979255)。
文摘Cometabolic degradation is currently an effective and extensively way to remove high molecular weight polycyclic aromatic hydrocarbons(HMW-PAHs).Unfortunately,due to low bio-accessibility and high biotoxicity,the cometabolic degradation rate of HMW-PAHs is limited.Glycine-β-cyclodextrin(GCD)was obtained through amino modification ofβ-cyclodextrin(BCD)and added to cometabolic system of phenanthrene(PHE)and pyrene(PYR)to assist PYR biodegradation.Results show that the addition of GCD(100 mg/L)effectively improved the removal rate of PYR(20 mg/L)by 42.3%.GCD appeared to increase the bio-accessibility and reduce the biotoxicity of PHE and PYR,and then promoted the growth of Pseudomonas stutzeri DJP1 and stimulated the elevation of dehydrogenase(DHA)and catechol 12 dioxygenase(C12O)activities.The phthalate metabolic pathway was accelerated,which improved the cometabolic degradation.This study provided a new reference for the cometabolic degradation of HMW-PAHs.
基金supported by the research funds for Coupling Research on Industrial Upgrade and Environmental Management in the Bohai Rim-Technique,methodology,and Environmental Economic Policies(No.42076221).
文摘This study analyzed the impact of land-based contaminants and tertiary industrial structure on economic development in the selected Bohai Bay area,China.Based on panel data spanning 2011-2020,a vector autoregressive(VAR)model is used to analyze and forecast the short-run and long-run relationships between three industrial structures,pollutant discharge,and economic development.The results showed that the environmental index had a long-term cointegration relationship with the industrial structure economic index.Per capital chemical oxygen demand(PCOD)and per capita ammonia nitrogen(PNH_(3)N)had a positive impact on delta per capita GDP(dPGDP),while per capita solid waste(PSW),the secondary industry rate(SIR)and delta tertiary industry(dTIR)had a negative impact on dPGDP.The VAR model under this coupling system had stability and credibility.The impulse response results showed that the short-term effect of the coupling system on dPGDP was basically consistent with the Granger causality test results.In addition,variance decomposition was used in this study to predict the long-term impact of the coupling system in the next ten periods(i.e.,ten years).It was found that dTIR had a great impact on dPGDP,with a contribution rate as high as 74.35%in the tenth period,followed by the contribution rate of PCOD up to 3.94%,while the long-term contribution rates of PSW,SIR and PNH3N were all less than 1%.The results show that the government should support the development of the tertiary industry to maintain the vitality of economic development and prevent environmental deterioration.
基金Supported by the Fundamental Research Funds for the Central Universities(Nos.202341017,202313024)。
文摘Chlorophyll-a(Chl-a)concentration is a primary indicator for marine environmental monitoring.The spatio-temporal variations of sea surface Chl-a concentration in the Yellow Sea(YS)and the East China Sea(ECS)in 2001-2020 were investigated by reconstructing the MODIS Level 3 products with the data interpolation empirical orthogonal function(DINEOF)method.The reconstructed results by interpolating the combined MODIS daily+8-day datasets were found better than those merely by interpolating daily or 8-day data.Chl-a concentration in the YS and the ECS reached its maximum in spring,with blooms occurring,decreased in summer and autumn,and increased in late autumn and early winter.By performing empirical orthogonal function(EOF)decomposition of the reconstructed data fields and correlation analysis with several potential environmental factors,we found that the sea surface temperature(SST)plays a significant role in the seasonal variation of Chl a,especially during spring and summer.The increase of SST in spring and the upper-layer nutrients mixed up during the last winter might favor the occurrence of spring blooms.The high sea surface temperature(SST)throughout the summer would strengthen the vertical stratification and prevent nutrients supply from deep water,resulting in low surface Chl-a concentrations.The sea surface Chl-a concentration in the YS was found decreased significantly from 2012 to 2020,which was possibly related to the Pacific Decadal Oscillation(PDO).
基金The National Natural Science Foundation of China under contract No.41976049the Opening Foundation of Marine Ecological Restoration and Smart Ocean Engineering Research Center of Hebei Province under contract No.HBMESO2306。
文摘The wave-induced liquefaction of seabed is responsible for causing damage to marine structures.Particle composition and consolidation degree are the key factors affecting the pore water pressure response and liquefaction behavior of the seabed under wave action.The present study conducted wave flume experiments on silt and silty fine sand beds with varying particle compositions.Furthermore,a comprehensive analysis of the differences and underlying reasons for liquefaction behavior in two different types of soil was conducted from both macroscopic and microscopic perspectives.The experimental results indicate that the silt bed necessitates a lower wave load intensity to attain the liquefaction state in comparison to the silty fine sand bed.Additionally,the duration and development depth of liquefaction are greater in the silt bed.The dissimilarity in liquefaction behavior between the two types of soil can be attributed to the variation in their permeability and plastic deformation capacity.The permeability coefficient and compression modulus of silt are lower than those of silty fine sand.Consequently,silt is more prone to the accumulation of pore pressure and subsequent liquefaction under external loading.Prior research has demonstrated that silt beds with varying consolidation degrees exhibit distinct initial failure modes.Specifically,a dense bed undergoes shear failure,whereas a loose bed experiences initial liquefaction failure.This study utilized discrete element simulation to examine the microscopic mechanisms that underlie this phenomenon.
基金surported by the Public Science and Technology Research Funds Projects of Ocean(No.201505001)。
文摘Temporal and spatial heterogeneity identifications of marine environment and its changes have great significances in marine spatial planning and offshore pollution control.In this study,considering the integration of marine ecological environment and sea-land interaction,we built a spatialized evaluation model named Marine Environment Change Spatial Assessment(MECSA)to quantify the marine environment status and changes.In MECSA,we applied the geospatial model and the pressure-state-response(PSR)model for processing and integrating evaluation indicators.A case study in the Laizhou Bay showed that the marine environment quality was generally in a declining state from 2009 to 2015.In 2015,the Marine Environment Index(MEI)had decreased by 0.1 compared with 2009,although the two years all reached a‘Good'level.The spatial MEI layers of the two years showed a same distribution:the southwestern part was in poorer status,with a fan ring shape gradually getting better to the northeast.The Marine Organisms Response Index(MORI)contributed the most to the MEI.Therefore,future marine environmental assessment and spatial planning should focus on the identification the marine environment with its changes from the perspective of spatial heterogeneity and systemicity.Based on single indicators and comprehensive evaluation results,we can propose spatially targeted policies and recommendations scientifically.
基金Supported by the National Natural Science Foundation of China(No.50779062)
文摘Laboratory tests were conducted to study the effects of curing time, cement ratio and seawater pressure on cement soil deterioration formed at simulative marine soft clay sites. Deterioration depth was determined on the basis of characteristics of penetration resistance and penetration depth curves, and the deterioration depth of cement soil with the cement ratio of 7%, reached 31.8 mm after 720 d. Results of research indicated that deterioration extended quickly under seawater environment and the deterioration depth increased with the prolonging curing time. In addition, the water pressure could speed up deterioration. With the increase of cement content, the strength of cement soil increased obviously. At the same time, the deterioration depth decreased significantly. The concentration of calcium ion in the cement stabilized soil increased with the increase of depth, while that of magnesium ion gradually decreased. The variations were consistent with energy dispersive spectrometer(EDS)analysis results, and the calcium concentration with depth was in a good consistency with strength distribution at long term. The results showed that the deterioration became more serious with the curing time, and it was related to calcium leaching.
基金funded by the Marine Public Welfare Pro-ject of China (Nos. 200705029, 200805080)the National Basic Research Program of China (No. 2002CB412406)SOA-funded Program (No. 908-02-04-03)
文摘Marine ecosystem services are the benefits which people obtain from the marine ecosystem,including provisioning services,regulating services,cultural services and supporting services. The human species,while buffered against environmental changes by culture and technology,is fundamentally dependent on the flow of ecosystem services. Marine ecosystem services become increasingly valuable as the terrestrial resources become scarce. The value of marine ecosystem services is the monetary flow of ecosystem services on specific temporal and spatial scales,which often changes due to the variation of the goods prices,yields and the status of marine exploitation. Sensitivity analysis is to study the relationship between the value of marine ecosystem services and the main factors which affect it. Uncertainty analysis based on varying prices,yields and status of marine exploitation was carried out. Through uncertainty analysis,a more credible value range instead of a fixed value of marine ecosystem services was obtained in this study. Moreover,sensitivity analysis of the marine ecosystem services value revealed the relative importance of different factors.
基金the National Natural Science Foundation of China(Nos.41506128,40806045 and 41749903)the Oceanographic Research Vessel Sharing Plan(No.NORC2018-06-25)。
文摘Complex hydrocultural conditions in the estuary affect the migration and transformation of mercury.Using two voyages in July and October 2018,Dissolved Gaseous Mercury(DGM)and Reactive Mercury(RHg)were determined to explore the source,transformation and influence of DGM content in the adjacent waters of Yangtze River Estuary in summer and autumn.The results showed the contents of DGM and RHg in summer were higher than those in autumn,and both of them were higher than those in open sea.In summer and autumn,the Yangtze River brought a higher concentration of DGM,and different flow direction and runoff resulted in differences in the high value region of the surface.The emergence of low-oxygen zones in summer was conducive to the production of DGM.In autumn,windy weather allowed seawater disturbances to promote the release of mercury from the underlying sediments,especially in shallow sea in northwest.RHg showed a higher concentration in the offshore than in the open sea in summer,but there was no such trend in autumn,reflecting the influence of less runoff input.DGM is the main product of RHg reduction,and there was a significant positive correlation between DGM and RHg in summer(r=0.356,P<0.05),while the correlation between DGM and RHg was not significant in autumn due to the influence of light intensity,wind speed and nutrients.The exchange flux of mercury in the adjacent waters of the Yangtze River Estuary was higher than that in the open sea.There was no significant difference of the release flux of mercury in summer and autumn.This article highlighted that the input of mercury from the Yangtze River runoff promotes the release of mercury in seawater,and the hypoxic zone caused by eutrophication is conducive to the production of DGM.
基金This work was supported by the National Natural Science Foundation of China(No.51979255).
文摘The knowledge of the existence,distribution and fate of polycyclic aromatic hydrocarbons(PAHs)and substituted polycyclic aromatic hydrocarbons(SPAHs)in wastewater treatment plants(WWTPs)was vital for reducing their concentrations entering the aquatic environment.The concentrations of 13 SPAHs and 16 PAHs were all determined in a WWTP with styrene butadiene rubber(SBR)in partnership with the moving bed biofilm reactor(MBBR)process.SPAHs presented a higher concentration lever than PAHs in nearly all samples.The total removal efficiencies of PAHs and SPAHs ranged from 64.0%to 71.36%and 78.4%to 79.7%,respectively.The total yearly loads of PAHs(43.0 kg)and SPAHs(73.0 kg)were mainly reduced by the primary and SBR/MBBR biological treatment stages.The tertiary treatment stage had a minor contribution to target compounds removal.According to a synthesis and improvement fate model,we found that the dominant processes changed as the chemical octanol water partition coefficient(K_(ow))increased.But the seasonal variations of experimental removal efficiencies were more obvious than that of predicted data.In the primary sedimentation tank,dissolution in the aqueous phase and sorption to sludge/particulate matter were controlling processes for the removal of PAHs and SPAHs.The sorption to sludge and biodegradation were the principal removal mechanisms during the SBR/MBBR biological treatment process.The contribution of volatilization to removal was always insignificant.Furthermore,the basic physicochemical properties and operating parameters influenced the fate of PAHs and SPAHs in the WWTP.
基金supported by the Shandong Province’s Natural Science Foundation(No.ZR2019MD033).
文摘Endophytic bacteria are promising bacterial fertilizers to improve plant growth under adverse environment.For ecological remediation of coastal wetlands,it was necessary to investigate the effect and interaction of endophytes on halophytes under saline-alkali stress.In this study,an endophytic bacterium strain HK1 isolated from halophytes was selected to infect Suaeda glauca under pH(7 and 8)and salinity gradient(150,300 and 450mmolL^(-1)).Strain HK1 was identified as Pantoea ananatis and it had ability to fix nitrogen,dissolve inorganic phosphorus and produce indole-3-aceticacid(IAA).The results showed that strain HK1 could promote the growth of S.glauca seedings when the salinity was less than 300mmolL^(-1),in view of longer shoot length and heavier fresh weight.The infected plants could produce more proline to decrease the permeability of cells,which content increased by 26.2%–61.1%compared to the non-infected group.Moreover,the oxidative stress of infected plants was relieved with the malondialdehyde(MDA)content decreased by 16.8%–32.9%,and the peroxidase(POD)activity and catalase(CAT)activity increased by 100%–500%and 6.2%–71.4%,respectively.Statistical analysis revealed that increasing proline content and enhancing CAT and POD activities were the main pathways to alleviate saline-alkali stress by strain HK1 infection,and the latter might be more important.This study illustrated that endophytic bacteria could promote the growth of halophytes by regulation of osmotic substances and strengthening antioxidant activities.This finding would be helpful for the bioremediation of coastal soil.
基金Supported by the National Natural Science Foundation of China(Nos.42206055,41976049)the Taishan Scholar Project of Shandong Province(No.TS20190913)the Fundamental Research Funds for the Central Universities(No.202061028)。
文摘The long-distance movement of turbidity currents in submarine canyons can transport large amounts of sediment to deep-sea plains.Previous studies show obvious differences in the turbidity current velocities derived from the multiple cables damage events ranging from 5.9 to 28.0 m/s and those of field observations between 0.15 and 7.2 m/s.Therefore,questions remain regarding whether a turbid fluid in an undersea environment can flow through a submarine canyon for a long distance at a high speed.A new model based on weakly stable sediment is proposed(proposed failure propagation model for weakly stable sediments,WS S-PFP model for short)to explain the high-speed and long-range motion of turbidity currents in submarine canyons through the combination of laboratory tests and numerical analogs.The model is based on two mechanisms:1)the original turbidity current triggers the destabilization of the weakly stable sediment bed and promotes the destabilization and transport of the soft sediment in the downstream direction and 2)the excitation wave that forms when the original turbidity current moves into the canyon leads to the destabilization and transport of the weakly stable sediment in the downstream direction.The proposed model will provide dynamic process interpretation for the study of deep-sea deposition,pollutant transport,and optical cable damage.
基金The research was supported by the National Natural Science Foundation of China(Nos.42206055,41976049,41720104001)the Taishan Scholar Project of Shandong Province(No.TS20190913)the Fundamental Research Funds for the Central Universities(No.202061028).
文摘The resuspension of marine sediments plays a key role in the biogeochemical cycle and marine ecology system.Internal solitary waves are considered to be important driving forces of the resuspension of bottom sediments.In this paper,the movement of turbidity currents,the generation and the effects on the bottom bed of internal solitary waves and excitation waves are studied by flume tests and numerical simulations,and the sediment resuspension are analyzed.The results show that the excitation wave can lead to the resuspension of the bottom sediments under all the conditions,while the internal solitary wave can lead to the resuspension of the sediment only under some special conditions,such as high amplitude or large underwater slope.Under the experimental conditions,the change in the near-bottom velocity caused by the excitation wave is close to three times that of the internal solitary wave.
基金supported by grants from the National Natural Science Foundation of China(No.41775148)the Fundamental Research Funds for the Central Universities(No.201762006)the Shandong Provincial Natural Science Foundation,China(No.ZR2016CB47)。
文摘The characteristics of the bacterial community structure in aerosols of different particle sizes over northern Chinese marginal seas and the northwestern Pacific Ocean in autumn were analyzed using high-throughput sequencing and the quantitative real-time PCR method based on 16S rRNA genes.Combined with environmental factors and air mass sources,the bacterial abundance,community diversity,composition and structural characteristics in aerosols were studied,which might provide a scientific evaluation for a comprehensive understanding of the characteristics,long-distance transmission and ecological effects of aerosols from coastal waters to the distant ocean(northwestern Pacific Ocean).At the junction of the South Yellow Sea and the East China Sea,the bacterial abundance in the aerosols was substantially affected by transmission of continental air masses and was higher than those in other samples,and the bacterial abundance in coarse particle(>2.1μm)samples was significantly higher than that in fine particle(<2.1μm)samples(P<0.05).In contrast,aerosols collected at the northwestern Pacific Ocean(NWP5 site)were less affected by transmissions of continental air masses,and their bacterial abundance in coarse particle samples was significantly lower than that in fine particle samples.Significant differences in the richness and diversity of bacterial communities were observed among all samples(P<0.05).The differences in the bacterial community in different sea areas were greater than those in the same sample with different particle sizes(P>0.05).Among the environmental factors examined,a significant negative correlation was observed between bacterial community richness and temperature(P<0.05),and the bacterial community diversity was significantly positively correlated with the concentration of K^(+)(P<0.05).Canonical correspondence analysis showed that temperature,NH_(4)^(+) concentration and SO_(4)^(2−) concentration exerted significant effects on bacterial community structures(P<0.01)in aerosols of different particle sizes over northern Chinese marginal seas and the northwestern Pacific Ocean.
基金Supported by the National Natural Science Foundation of China (Nos.40406028, 40706044)
文摘Mitochondrial cytochrome b (Cytb), one of the few proteins encoded by the mitochondrial DNA, plays an important role in transferring electrons. As a mitochondrial gene, it has been widely used for phylogenetic analysis. Previously, a 949-bp fragment of the coding gene and mRNA editing were characterized from Prorocentrum donghaiense, which might prove useful for resolving P. donghaiense from closely related species. However, the full-length coding region has not been characterized. In this study, we used rapid amplification of cDNA ends (RACE) to obtain full-length, 1 124 bp cDNA. Cytb transcript contained a standard initiation codon ATG, but did not have a recognizable stop codon. Homology comparison showed that the P. donghaiense Cytb had a high sequence identity to Cytb sequences from other dinoflagellate species. Phylogenetic analysis placed Cytb from P. donghaiense in the clade of dinoflagellates and it clustered together strongly with that from P. minimum. Based on the full-length sequence, we inferred 32 editing events at different positions, accounting for 2.93% of the Cytb gene. 34.4% (11) of the changes were A to G, 25% (8) were T to C, and 25% (8) were C to U, with smaller proportions of G to C and G to A edits (9.4% (3) and 6.2% (2), respectively). The expression level of the Cytb transcript was quantified by real-time PCR with a TaqMan probe at different times during the whole growth phase. The average Cytb transcript was present at 39.27±7.46 copies of cDNA per cell during the whole growth cycle, and the expression of Cytb was relatively stable over the different phases. These results deepen our understanding of the structure and characteristics of Cytb in P. donghaiense, and confirmed that Cytb in P. donghaiense is a candidate reference gene for studying the expression of other genes.
基金Supported by the National Natural Science Foundation of China (Nos.42130410,41620104001,41976133)the Fundamental Research Funds for the Central Universities (No.202061013)。
文摘Microorganisms in sediments are critical to marine ecosystems.The microbial communities in marine sediments of the Bohai Sea(BS)and Yellow Sea(YS),the eastern Chinese marginal seas,were uncovered in employing the metagenomic approach.In addition,the taxonomic and functional compositions of microbes were compared among various sediment core depths.Results showing the compositions,diversities,and functions of the microbial communities showed no significant variations with sea areas,and significant seasonal variations was observed in station 3500-7 only on functions of the microbial communities.Moreover,the compositions,diversities,and functions of the microbial communities changed noticeably in different sediment depths in close correlation with physical and chemical properties of sediments.However,the large fraction of the variation in functional communities remained unexplained.From bioinformatic analysis of the metagenomic data,the carbon-metabolismrelated genes such as glycosyl transferase(GT),glycoside hydrolase(GH),and carbohydrate esterase(CE)genes were rich in the microbial community,especially in the top sediment depth.Additionally,in this N-polluted habitat,nitrification and anaerobic ammonia oxidation(anammox)were dominant in the top sediment depth,whereas dissimilatory nitrate reduction to ammonium(DNRA)and denitrification were dominant in the middle and bottom depth,respectively.Further identification of possible biogeochemical links suggested that Gammaproteobacteria,Alphaproteobacteria,Nitrospirae,Nitrospinae,Chloroflexi,and Methanomicrobia might promote effective circulation of carbon and nitrogen cycling.This study expanded our knowledge about the structure and functional potential of microbial communities associated with different sediment depth,and provided further comprehensive information on element cycles in marine environments.
基金The National Natural Science Foundation of China under contract No.41676003.
文摘This paper examines the simplification strategy of retaining only the nonhydrostatic effect of local acceleration in a three-dimensional fully nonhydrostatic model regarding the submesoscale wave phenomenon in the ocean.Elaborate scale analysis of the vertical component of the Reynold-averaged Navier-Stokes(RANS)equation was performed,confirming the rationalization of this simplification.Then,the simplification was implemented in a RANS equation-based nonhydrostatic model NHWAVE(nonhydrostatic WAVE)to make a simplified nonhydrostatic model.Numerical examples were taken to test its performance,including surface sinusoidal waves propagating on an idealized East China Sea topography,tidally induced internal lee waves and small-scale solitary waves.The results show that in a considerably wide range of nonlinear strengths,the simplified nonhydrostatic model can obtain similar results as those in the fully nonhydrostatic model,even for smaller-scale solitary waves.Nonlinearity influences the applicability of the simplification.The stronger the nonlinearity is,the worse the simplified model describes the nonhydrostatic phenomenon.In general,the simplified nonhydrostatic model can simulate surface waves better than internal waves.Improvement of computational efficiency in the simplified nonhydrostatic model is reasonable,reducing the central processing unit time duration in the fully nonhydrostatic model by 16.4%–20.6%.The specially designed algorithm based on the simplified nonhydrostatic equation can remarkably reduce the computational time.
基金Supported by the National Natural Science Foundation of China(Nos.31372509,41328009)the National Science Foundation for Young Scientists of China(No.41106095)
文摘Copepods are among the most abundant and successful metazoans in the marine ecosystem. However, genomic resources related to fundamental cellular processes are still limited in this particular group of crustaceans. Ribosomal proteins are the building blocks of ribosomes, the primary site for protein synthesis. In this study, we characterized and analyzed the c DNAs of cytoplasmic ribosomal proteins(c RPs) of two calanoid copepods, P seudodiaptomus poplesia and A cartia pacifi ca. We obtained 79 c RP c DNAs from P. poplesia and 67 from A. pacifi ca by c DNA library construction/sequencing and rapid amplifi cation of c DNA ends. Analysis of the nucleic acid composition showed that the copepod c RP-encoding genes had higher GC content in the protein-coding regions(CDSs) than in the untranslated regions(UTRs), and single nucleotide repeats(>3 repeats) were common, with "A" repeats being the most frequent, especially in the CDSs. The 3′-UTRs of the c RP genes were signifi cantly longer than the 5′-UTRs. Codon usage analysis showed that the third positions of the codons were dominated by C or G. The deduced amino acid sequences of the c RPs contained high proportions of positively charged residues and had high p I values. This is the fi rst report of a complete set of c RP-encoding genes from copepods. Our results shed light on the characteristics of c RPs in copepods, and provide fundamental data for further studies of protein synthesis in copepods. The copepod c RP information revealed in this study indicates that additional comparisons and analysis should be performed on different taxonomic categories such as orders and families.
基金the National Natural Science Foundation of China(No.31802297)。
文摘Spatial heterogeneity or“patchiness”of plankton distributions in the ocean has always been an attractive and challenging scientific issue to oceanographers.We focused on the accumulation and dynamic mechanism of the Acetes chinensis in the Lianyungang nearshore licensed fishing area.The Lagrangian frame approaches including the Lagrangian coherent structures theory,Lagrangian residual current,and Lagrangian particle-tracking model were applied to find the transport pathways and aggregation characteristics of Acetes chinensis.There exist some material transport pathways for Acetes chinensis passing through the licensed fishing area,and Acetes chinensis is easy to accumulate in the licensed fishing area.The main mechanism forming this distribution pattern is the local circulation induced by the nonlinear interaction of topography and tidal flow.Both the Lagrangian coherent structure analysis and the particle trajectory tracking indicate that Acetes chinensis in the licensed fishing area come from the nearshore estuary.This work contributed to the adjustment of licensed fishing area and the efficient utilization of fishery resources.
基金supported by the National Natural Science Foundation of China(No.41977315)the Fundamental Research Funds for the Central Universities of China(No.201964004).
文摘The production of toxic sulfides is a common environmental problem in mariculture.Therefore,the effective inhibition of sulfidogens is the key to prevent sulfides production.In this study,the possibility and mechanism of nitrate(NO_(3)^(−))inhibiting the activity of the sulfate-reducing microbiota(SRM)from mariculture sediments was investigated.The results showed that 1,3,and 5 mmol L^(−1)NO_(3)^(−)continuously inhibited sulfide production for 1-3 d.As NO_(3)^(−) dosage increased to 7 mmol L^(−1),the duration of inhibition increased to 6 days.Denitrifying product NO_(2)^(−)heavily inhibited the activity of dissimilar sulfate reductase gene(dsrB)by 3 orders,which was the main reason that the sulfate-reducing activity was inhibited.The SRM structure changed significantly with the dosage of NO_(3)^(−),while the abundance of sulfidogens Desulfovibrio species increased due to their capability of detoxifying nitrite through nitrite reductase.Hence,sulfidogens Desulfovibrio species are more adaptable to a high nitrate/nitrite environment,and the traditional control strategies by dosing nitrate/nitrite should be paid more attention to.The findings will serve as helpful guidelines for sulfate-reducing microbiota in the habitat of mariculture to reduce their generation of poisonous sulfide.
基金supported by the Open Research Fund Program of State Key Laboratory of Hydroscience and Engineering(No.sk lhse-2022-D-03)the National Natural Science Foundation of China(Nos.U2006213,42277139)the Taishan Scholars Program(No.tsqn202306297).
文摘The microscopic characterization of isolated bubbles in gassy soil plays an important role in the macroscopic physical properties of sediments and is a key factor in the study of geological hazards in gas-bearing strata.Based on the box-counting method and the pore fractal features in porous media,a fractal model of bubble microstructure parameters in gassy soil under different gas con-tents and vertical load conditions is established by using an industrial X-ray CT scanning system.The results show that the fractal di-mension of bubbles in the sample is correlated with the volume fraction of bubbles,and it is also restricted by the vertical load.The three-dimensional fractal dimension of the sample is about 1 larger than the average two-dimensional fractal dimension of all the slices from the same sample.The uniform porous media fractal model is used to test the equivalent diameter,and the results show that the variation of the measured pore diameter ratio is jointly restricted by the volume fraction and the vertical load.In addition,the measured self-similarity interval of the bubble area distribution is tested by the porous media fractal capillary bundle model,and the fitting curve of measured pore area ratio in a small loading range is obtained in this paper.
