In this study,the occurrence,sources,and ecological risk of microplastics(>60μm)in the surface and bottom seawater were investigated in the Beibu Gulf,the northern South China Sea.The average abundance of micropla...In this study,the occurrence,sources,and ecological risk of microplastics(>60μm)in the surface and bottom seawater were investigated in the Beibu Gulf,the northern South China Sea.The average abundance of microplastics in surface and bottom waters was 1.35±0.93 and 0.79±0.50 items/m~3,respectively.Microplastics in both surface and bottom waters were predominantly in the form of fragments,and mostly in green.The composition of microplastics in surface water was primarily poly(methyl methacrylate)(PMA),whereas in bottom water,polyethylene(PE)dominated.Positive matrix factorization(PMF)modeling revealed that the primary sources of microplastics were pipeline abrasion,fishing activities,plastic waste,landfill disposal,transportation,aquaculture,and construction activities.The pollution load index(PLI)indicated that the overall risk of microplastic pollution in the Beibu Gulf was low.Conversely,the polymer hazard index(PHI)for microplastics was relatively high.These data underscore the importance of timely and effective reduction of human-intensive activities contributing to microplastic pollution and provide valuable information for further research in microplastic ecotoxicology and biogeochemistry.展开更多
Hepcidins are small cysteine-rich antimicrobial peptides that play a vital role in immunity against pathogen invasion.Here,a hepcidin(Cshep)from Centropristis striata was described,which is considered as a valuable aq...Hepcidins are small cysteine-rich antimicrobial peptides that play a vital role in immunity against pathogen invasion.Here,a hepcidin(Cshep)from Centropristis striata was described,which is considered as a valuable aquaculture marine species in China.The open reading frame consisted of 273 bp.Eight conserved cysteine residues were identified.Phylogenetic analysis showed that Cshep had a relatively close relationship with the hepcidin from Epinephelus moara.Quantitative real-time PCR analysis demonstrated that Cshep was highly expressed in liver and significantly up-regulated when challenged with Vibrio harveyi.In addition,the synthetic Cshep peptide had a high antimicrobial activity against V.harveyi,but low against other pathogenic bacteria tested in this study.The killing kinetics analysis revealed that Cshep had a fast bactericidal effect on V.harveyi.These results suggested that Cshep may be involved in the immune response of C.striata against V.harveyi infection.展开更多
The tectonic evolution of the Caroline Plate during the Oligocene to Early Miocene was mainly controlled by two fulcrums.The west fulcrum at Palau Island remained fixed during 29-25 Ma as the Ayu Trough rifted and pro...The tectonic evolution of the Caroline Plate during the Oligocene to Early Miocene was mainly controlled by two fulcrums.The west fulcrum at Palau Island remained fixed during 29-25 Ma as the Ayu Trough rifted and produced the abyssal hills parallel to its boundaries,and the Pacific Plate and part of the Caroline Plate subducted to the north.At the northeast corner of the Caroline Plate,the east fulcrum is surrounded by a series of arc seamount chains.These chains resulted from the convergence between the Caroline Plate and the Pacific Plate and crustal softening of the northeastern Caroline Plate induced by the Caroline Hotspot at~25 Ma.This softening of the crust also led to the dysfunction of the east fulcrum,and the west fulcrum migrated south,which caused dextral motion along the Ayu Rift and the development of an en echelon structure.The Yap Trench was a part of the spreading center in the Parece-Vela Rift at~29 Ma.However,sinistral motion along the Parece-Vela Rift at around 20-15 Ma led to the exposure of the subducted Yap Trench and left a triangular region with distinctive geophysical characteristics in the surrounding area.展开更多
基金Supported by the National Natural Science Foundation of China(No.U20A20103)the Scientific Research Fund of the Fourth Institute of Oceanography+1 种基金Guangxi Funding Project(No.304024XM20N0006)the Guangxi Talent Science and Technology Project(No.2019AC17008)。
文摘In this study,the occurrence,sources,and ecological risk of microplastics(>60μm)in the surface and bottom seawater were investigated in the Beibu Gulf,the northern South China Sea.The average abundance of microplastics in surface and bottom waters was 1.35±0.93 and 0.79±0.50 items/m~3,respectively.Microplastics in both surface and bottom waters were predominantly in the form of fragments,and mostly in green.The composition of microplastics in surface water was primarily poly(methyl methacrylate)(PMA),whereas in bottom water,polyethylene(PE)dominated.Positive matrix factorization(PMF)modeling revealed that the primary sources of microplastics were pipeline abrasion,fishing activities,plastic waste,landfill disposal,transportation,aquaculture,and construction activities.The pollution load index(PLI)indicated that the overall risk of microplastic pollution in the Beibu Gulf was low.Conversely,the polymer hazard index(PHI)for microplastics was relatively high.These data underscore the importance of timely and effective reduction of human-intensive activities contributing to microplastic pollution and provide valuable information for further research in microplastic ecotoxicology and biogeochemistry.
基金The Youth Foundation of Guangxi Zhuang Autonomous Region,China under contract No.2018GXNSFBA050032the Innovation Driven Development Foundation of Guangxi under contract Nos AD19245135,AD19245161+1 种基金the Doctoral Research Startup Fund of the Fourth Institute of Oceanography,Ministry of Natural Resources under contract Nos 201803,201806the Fund of Key Laboratory of South China Sea Fishery Resources Exploitation&Utilization,Ministry of Agriculture and Rural Affairs,China under contract No.FREU2016-04。
文摘Hepcidins are small cysteine-rich antimicrobial peptides that play a vital role in immunity against pathogen invasion.Here,a hepcidin(Cshep)from Centropristis striata was described,which is considered as a valuable aquaculture marine species in China.The open reading frame consisted of 273 bp.Eight conserved cysteine residues were identified.Phylogenetic analysis showed that Cshep had a relatively close relationship with the hepcidin from Epinephelus moara.Quantitative real-time PCR analysis demonstrated that Cshep was highly expressed in liver and significantly up-regulated when challenged with Vibrio harveyi.In addition,the synthetic Cshep peptide had a high antimicrobial activity against V.harveyi,but low against other pathogenic bacteria tested in this study.The killing kinetics analysis revealed that Cshep had a fast bactericidal effect on V.harveyi.These results suggested that Cshep may be involved in the immune response of C.striata against V.harveyi infection.
基金supported financially by the Scientific and Technological Innovation Project of Pilot National Laboratory for Marine Science and Technology(Qingdao)(Grant No.2017ASKJ02)the Scientific Research Start Funds Project of the Fourth Institute of Oceanography,Ministry of Natural Resources(Grant No.202007)+3 种基金the National Natural Science Foundation of China(Grant No.U1606401)the National Ocean Bureau Program(Grant No.GASIGEOGE-1)the Aoshan Elite Scientist Plan(Grant No.2015ASTP-0S10)of Pilot National Laboratory for Marine Science and Technology(Qingdao)to Prof.Sanzhong LI and his research groupthe Taishan Scholor Program to Sanzhong LI。
文摘The tectonic evolution of the Caroline Plate during the Oligocene to Early Miocene was mainly controlled by two fulcrums.The west fulcrum at Palau Island remained fixed during 29-25 Ma as the Ayu Trough rifted and produced the abyssal hills parallel to its boundaries,and the Pacific Plate and part of the Caroline Plate subducted to the north.At the northeast corner of the Caroline Plate,the east fulcrum is surrounded by a series of arc seamount chains.These chains resulted from the convergence between the Caroline Plate and the Pacific Plate and crustal softening of the northeastern Caroline Plate induced by the Caroline Hotspot at~25 Ma.This softening of the crust also led to the dysfunction of the east fulcrum,and the west fulcrum migrated south,which caused dextral motion along the Ayu Rift and the development of an en echelon structure.The Yap Trench was a part of the spreading center in the Parece-Vela Rift at~29 Ma.However,sinistral motion along the Parece-Vela Rift at around 20-15 Ma led to the exposure of the subducted Yap Trench and left a triangular region with distinctive geophysical characteristics in the surrounding area.
