A new species of the genus Brachytarsophrys,named Brachytarsophrys wenshanensis sp.nov.,has been identified in southeastern Yunnan,China.This new species can be readily distinguished from other known congeners by both...A new species of the genus Brachytarsophrys,named Brachytarsophrys wenshanensis sp.nov.,has been identified in southeastern Yunnan,China.This new species can be readily distinguished from other known congeners by both morphological criterion and molecular analysis of three mitochondrial gene segments:16S,COI,and Cytb.This classification is based on the following morphological characters:(1)medium body size(SVL 83.8–85.1 mm in two adult males);(2)enormous head,with head width nearly 1.2 times the length;(3)tongue pyriform,feebly notched;(4)non-meeting heels;(5)male lacking nuptial pad;(6)tibiotarsal articulation reaching angle of mouth when hindlimbs are extended forward alongside the body;(7)absence of outer metatarsal tubercle,inner metatarsal tubercle elliptic and approximately equal to first toe;(8)rudimentary toe webbing,webbing formula:Ⅰ(2–)–(2^(++))Ⅱ(2^(–))–(3^(++))Ⅲ(2^(½))–(4)Ⅳ(4^(+))–(2^(⅔))V;(9)lateral fringes narrow;(10)dermal ridge or glandular fold on dorsum absent;(11)pectoral glands distinct and irregular,femoral gland small.Our work increases the number of species within the genus Brachytarsophrys to 9.展开更多
The flux of settling particles in the ocean has been widely explored since 1980s due to its important role in biogenic elements cycling,especially in the transport of particulate organic carbon(POC)in the deep sea.How...The flux of settling particles in the ocean has been widely explored since 1980s due to its important role in biogenic elements cycling,especially in the transport of particulate organic carbon(POC)in the deep sea.However,research in the seamount area of the oligotrophic subtropical Northwest Pacific Ocean is lacking.In this work,two sediment traps were deployed at the foot and another two at the hillside of Niulang Guyot from August2017 to July 2018.The magnitude and composition of particle fluxes were measured.The main factors influencing the spatial variations of the fluxes were evaluated.Our results indicated a low particulate flux from Niulang Guyot area in the Northwest Pacific Ocean,reflecting low primary productivity of the oligotrophic ocean.The total mass flux(TMF)decreased from 2.57 g/(m^(2)·a)to 0.56 g/(m^(2)·a)with increasing depth from 600 m to 4850 m.A clear seasonal pattern of TMF was observed,with higher flux in summer than that in winter.The peak flux of 26.52 mg/(m^(2)·d)occurred in August at 600 m,while the lowest value of 0.07 mg/(m^(2)·d)was shown in February at 4850 m.The settling particles at the deep layers had similar biochemical composition,with calcium carbonate(CaCO_(3))accounting for up to 90%,followed by organic matter and opal,characteristics of Carbonate Ocean.The POC flux decreased more rapidly in the twilight layer because of faster decomposition,remineralization,and higher temperature.A small fraction of POC was transported into the deep ocean by biological pump.Particle fluxes were mainly controlled by the calcareous ballasts besides the primary productivity of the surface water.The advection may be another important factor affecting the flux in the seamount area.The combination of settled matters rich in foraminiferal tests with topography and currents may be the reason for regulating the local abundance of benthos on seamounts.Our results will fill in the knowledge gap of sedimentation flux,improve the understanding of ecosystem in Niulang Guyot area,and eventually provide data support for the optimization of regional ecological modeling.展开更多
This research investigated eight stations in Clarion-Clipperton Fracture Zone(CCFZ)in the eastern tropical Pacific in 2017 to study the spatial distribution characteristics of nutrients and chlorophyll a(Chi a)concent...This research investigated eight stations in Clarion-Clipperton Fracture Zone(CCFZ)in the eastern tropical Pacific in 2017 to study the spatial distribution characteristics of nutrients and chlorophyll a(Chi a)concentration,and compared nutrient concentrations and molar ratios with those of other investigations 20 years ago in the same area.The study found that dissolved inorganic nutrient(N,P and Si)concentrations were lowest in the upper layer,and increased from surface to some depths,then they decreased a little to the bottom.N was the limited nutrient factor for the growth of phytoplankton community.Although nutrient concentrations and molar ratios have no obvious changes in 2017 comparing those in 1998-2003,supplemented from the equatorial Pacific,nutrient concentrations in the study area were higher than those in seamounts in the North Pacific and Station ALOHA.Furthermore,this study used Generalized Additive Models(GAMs)to infer the underlying bottom-up factors controlling phytoplankton abundance(Chi a concentration),showing that depth,salinity and PO^-P concentration were major factors controlling the growth of phytoplankton community.Furthermore,this study can provide basic data and theoretical support for the development of polymetallic nodule area and its long-term impact assessment on the environment.展开更多
Resource exploitation in the Clarion-Clipperton Zone(CCZ)is of major research interest worldwide,but its influence on the environment is poorly understood,especially due to the lack of baseline values for metals in th...Resource exploitation in the Clarion-Clipperton Zone(CCZ)is of major research interest worldwide,but its influence on the environment is poorly understood,especially due to the lack of baseline values for metals in the surrounding sediment.This work aimed to establish the baseline values of 17 metals(Ba,Ca,K,Mg,Mn,Na,Ag,As,B,Cd,Co,Cr,Cu,Hg,Ni,Pb,and Zn)using normalization,the cumulative frequency curve method considering a total of 172 samples taken from 8 multitube cores and 1 box sediment core collected in the western CCZ during the COMRA-45 cruise campaign from August to September 2017.The baseline values of the evaluated metals were as follows:1932 mg/kg for Ba,29512 mg/kg for Ca,18150 mg/kg for K,17120 mg/kg for Mg,6747 mg/kg for Mn,28546 mg/kg for Na,0.571 mg/kg for Ag,5.00 mg/kg for As,94.4 mg/kg for B,0.626 mg/kg for Cd,104 mg/kg for Co,76.1 mg/kg for Cr,370 mg/kg for Cu,0.028 mg/kg for Hg,190 mg/kg for Ni,27.5 mg/kg for Pb and 156 mg/kg for Zn.Our findings would fill the baseline value gap in the study area and further improve accuracy of environmental impact assessments on the impact of resource exploitation.展开更多
基金supported by Fundamental Research Fund for Central Universities (SWUKR22014)National Natural Science Foundation of China (NSFC 32170478, 32370478)+2 种基金“Special Fund for Youth Team of Southwest University” (SWU-XJPY202302)Youth Top Talent Program of Chongqing (CQYC 20220510893) to Zhiyong YUANNational Natural Science Foundation of China (NSFC 31900323) to Jinmin CHEN。
文摘A new species of the genus Brachytarsophrys,named Brachytarsophrys wenshanensis sp.nov.,has been identified in southeastern Yunnan,China.This new species can be readily distinguished from other known congeners by both morphological criterion and molecular analysis of three mitochondrial gene segments:16S,COI,and Cytb.This classification is based on the following morphological characters:(1)medium body size(SVL 83.8–85.1 mm in two adult males);(2)enormous head,with head width nearly 1.2 times the length;(3)tongue pyriform,feebly notched;(4)non-meeting heels;(5)male lacking nuptial pad;(6)tibiotarsal articulation reaching angle of mouth when hindlimbs are extended forward alongside the body;(7)absence of outer metatarsal tubercle,inner metatarsal tubercle elliptic and approximately equal to first toe;(8)rudimentary toe webbing,webbing formula:Ⅰ(2–)–(2^(++))Ⅱ(2^(–))–(3^(++))Ⅲ(2^(½))–(4)Ⅳ(4^(+))–(2^(⅔))V;(9)lateral fringes narrow;(10)dermal ridge or glandular fold on dorsum absent;(11)pectoral glands distinct and irregular,femoral gland small.Our work increases the number of species within the genus Brachytarsophrys to 9.
基金The Global Change and Air-sea Interaction II Project under contract Nos GASI-04-HYST-01 and GASI-01-NPACSTsumthe Eastern Pacific Eco-environment Monitoring and Protection Project under contract No.DY135-E2-5-02+1 种基金the Fund of COMRA-45 Cruise under contract No.DY-HC-135-45the Scientific Research Foundation of Third Institute of Oceanography,Ministry of Natural Resources of the People’s Republic of China under contract No.2017014。
文摘The flux of settling particles in the ocean has been widely explored since 1980s due to its important role in biogenic elements cycling,especially in the transport of particulate organic carbon(POC)in the deep sea.However,research in the seamount area of the oligotrophic subtropical Northwest Pacific Ocean is lacking.In this work,two sediment traps were deployed at the foot and another two at the hillside of Niulang Guyot from August2017 to July 2018.The magnitude and composition of particle fluxes were measured.The main factors influencing the spatial variations of the fluxes were evaluated.Our results indicated a low particulate flux from Niulang Guyot area in the Northwest Pacific Ocean,reflecting low primary productivity of the oligotrophic ocean.The total mass flux(TMF)decreased from 2.57 g/(m^(2)·a)to 0.56 g/(m^(2)·a)with increasing depth from 600 m to 4850 m.A clear seasonal pattern of TMF was observed,with higher flux in summer than that in winter.The peak flux of 26.52 mg/(m^(2)·d)occurred in August at 600 m,while the lowest value of 0.07 mg/(m^(2)·d)was shown in February at 4850 m.The settling particles at the deep layers had similar biochemical composition,with calcium carbonate(CaCO_(3))accounting for up to 90%,followed by organic matter and opal,characteristics of Carbonate Ocean.The POC flux decreased more rapidly in the twilight layer because of faster decomposition,remineralization,and higher temperature.A small fraction of POC was transported into the deep ocean by biological pump.Particle fluxes were mainly controlled by the calcareous ballasts besides the primary productivity of the surface water.The advection may be another important factor affecting the flux in the seamount area.The combination of settled matters rich in foraminiferal tests with topography and currents may be the reason for regulating the local abundance of benthos on seamounts.Our results will fill in the knowledge gap of sedimentation flux,improve the understanding of ecosystem in Niulang Guyot area,and eventually provide data support for the optimization of regional ecological modeling.
基金The Eastern Pacific Ecoenvironment Monitoring and Protection Project under contract No.DY135-E2-5-02the Global Change and Air-sea Interaction II under contract No.GASI-01-NPAC-STsumthe Scientific Research Foundation of the Third Institute of Oceanography,Ministry of Natural Resources of China under contract No.2019017.
文摘This research investigated eight stations in Clarion-Clipperton Fracture Zone(CCFZ)in the eastern tropical Pacific in 2017 to study the spatial distribution characteristics of nutrients and chlorophyll a(Chi a)concentration,and compared nutrient concentrations and molar ratios with those of other investigations 20 years ago in the same area.The study found that dissolved inorganic nutrient(N,P and Si)concentrations were lowest in the upper layer,and increased from surface to some depths,then they decreased a little to the bottom.N was the limited nutrient factor for the growth of phytoplankton community.Although nutrient concentrations and molar ratios have no obvious changes in 2017 comparing those in 1998-2003,supplemented from the equatorial Pacific,nutrient concentrations in the study area were higher than those in seamounts in the North Pacific and Station ALOHA.Furthermore,this study used Generalized Additive Models(GAMs)to infer the underlying bottom-up factors controlling phytoplankton abundance(Chi a concentration),showing that depth,salinity and PO^-P concentration were major factors controlling the growth of phytoplankton community.Furthermore,this study can provide basic data and theoretical support for the development of polymetallic nodule area and its long-term impact assessment on the environment.
基金The Eastern Pacific Eco-environment Monitoring and Protection Project under contract No.DY135-E2-5-02the Scientific Research Foundation of Third Institute of Oceanography,Ministry of Natural Resources of China under contract No.2017014+1 种基金the Global Change and Air-Sea InteractionⅡunder contract No.GASI-01-NPAC-STsumthe Fund of COMRA-45 Cruise under contract No.DYHC-135-45。
文摘Resource exploitation in the Clarion-Clipperton Zone(CCZ)is of major research interest worldwide,but its influence on the environment is poorly understood,especially due to the lack of baseline values for metals in the surrounding sediment.This work aimed to establish the baseline values of 17 metals(Ba,Ca,K,Mg,Mn,Na,Ag,As,B,Cd,Co,Cr,Cu,Hg,Ni,Pb,and Zn)using normalization,the cumulative frequency curve method considering a total of 172 samples taken from 8 multitube cores and 1 box sediment core collected in the western CCZ during the COMRA-45 cruise campaign from August to September 2017.The baseline values of the evaluated metals were as follows:1932 mg/kg for Ba,29512 mg/kg for Ca,18150 mg/kg for K,17120 mg/kg for Mg,6747 mg/kg for Mn,28546 mg/kg for Na,0.571 mg/kg for Ag,5.00 mg/kg for As,94.4 mg/kg for B,0.626 mg/kg for Cd,104 mg/kg for Co,76.1 mg/kg for Cr,370 mg/kg for Cu,0.028 mg/kg for Hg,190 mg/kg for Ni,27.5 mg/kg for Pb and 156 mg/kg for Zn.Our findings would fill the baseline value gap in the study area and further improve accuracy of environmental impact assessments on the impact of resource exploitation.