Artificially introduced cordgrass, Spartina alterniflora, rapidly colonized the intertidal flats of the Jiangsu coast, eastern China. The epibenthos on an intertidal flat invaded by S. alterniflorawere studied, to ide...Artificially introduced cordgrass, Spartina alterniflora, rapidly colonized the intertidal flats of the Jiangsu coast, eastern China. The epibenthos on an intertidal flat invaded by S. alterniflorawere studied, to identify how local epibenthos species react to an altered environment. Epibenthic samples and surficial sediment samples were collected along a shore-normal profile in 50 quadrats at ten stations across the Spartina salt marsh; and five control quadrats for a station located on the barren sandy-mud flat. The grain size param- eters of the surficial sediments show that S. alterniflora altered the grain size gradient along the profile of the intertidal zone by trapping fine-grained sediments. Spartina alterniflora could inhabit lower elevation- s than indigenous salt marsh vegetation, thus creating larger areas of finer surficial sediments, which was suitable for not only native epibenthic species but also species which do not exist on the barren sandy-mud flat. Correlation analyses show that the epibenthos were sensitive to sediment grain size and type, on the invaded S. alterniflora salt marsh. Further, there was an interspecific relationship affecting the distribution of epibenthos. The results show that epibenthos preferred ecological niches, within the Spartina salt marsh, even in the same sampling station.展开更多
In order to examine the seasonal and spatial distributions of benthic animals in the intertidal mudflat of the southern Yellow River Delta,field investigations were carried out in 2007 and 2008 and multiple methods we...In order to examine the seasonal and spatial distributions of benthic animals in the intertidal mudflat of the southern Yellow River Delta,field investigations were carried out in 2007 and 2008 and multiple methods were applied.Results showed that,the biomass of macro benthos ranged at 0.75-1151.00 g wet m^(-2) and averaged at 156.31 g wet m^(-2),in which Mactra veneriformis accounted for 75.6%-93.4% of the total macro benthic biomass.More than 90% of macro benthos inhabited in the middle and low tide lines,and higher biomass occurred in early summer and lower in winter.Statistical analysis showed that:1)M.veneriformis growth was primarily favored at higher temperature and lower salinity;2)after long time interaction,benthic bivalve grazers led to patching distributions of Chlorophyll a(Chl a);3)macro benthic biomass positively related with Chl a when the concentration of Chl a was low,but they were negatively related when Chl a concentration was high;and 4)furthermore,the biomass of benthic bivalves peaked in the sediment with median grain size about 0.55 mm,but decreased gradually in coarse or fine sediments.The secondary productivity ranged at 0.37-283.68 g m^(-2)yr^(-1) and averaged at 47.88 g m^(-2) yr^(-1),in which 69.7% was contributed by M.veneriformis It was estimated that primary production was transformed to secondary production at a rate of 6.87%approximately,which implies that there is a local sustainability of high bivalve production.展开更多
A brief review is made on the theory of the Lagrangian residual circulation and inter-tidal transports in a convectively weakly nonlinear system. In the review the emphasis is put on the systematical development of th...A brief review is made on the theory of the Lagrangian residual circulation and inter-tidal transports in a convectively weakly nonlinear system. In the review the emphasis is put on the systematical development of the theory and its weakness of convectively weakly nonlinear approximation. The fundamentals of a Lagrangian tidally-averaged theory on circulation with inter-tidal transport processes have been proposed for a general nonlinear coastal/estuarine system. The Lagrangian residual velocity is strictly de- fined, and it has been verified to be able to embody the velocity field of circulation. A new concept of the concentration for inter- tidal transport processes is presented. The concentration describing the inter-tidal transport processes should be a ＂Lagrangian inter-tidal concentration＂ defined and named, but not the Eulcrian tidally-averaged concentration used traditionally. The circulation described here contains a set of infinite temporal-spatial fields of velocity/concentration, each of which corresponds to a specific value of tidal phases varying continuously over one tidal cycle. When the convectively weakly nonlinear condition（ with a smaller order of eddy diffusion and sources） is approximately satisfied, a set of infinite temporal-spatial fields of velocity/concentration can be reduced to a single one.. the mass transport velocity/the Eulerian tidally averaged concentration as exhibited traditionally.展开更多
Surthce elevation is tile basic data for geo-science. It is difficult to retrieve tidal-flats＇ elevation from a single Re- mote Sensing （RS） image because of the complicated sediment dynanical environment and huge ...Surthce elevation is tile basic data for geo-science. It is difficult to retrieve tidal-flats＇ elevation from a single Re- mote Sensing （RS） image because of the complicated sediment dynanical environment and huge spatial difference in tidal-flats＇ moisture content. A Digital Elevation Model （DEM） construction method for inconstant inter-tidal zone based on high tempo-resolution MODIS data set in a short period is proposed in a ease study on the Dongsha Sandbank of the Jiangsu Radial Tidal Sand-ridges. In the present study, a batch-preprocessing method based on image partition to handle massive MODIS IB images is developed and applied to 8163 scenes of MODIS images. The dataset of short-period and muhi-temporal MODIS images for inter-tidal flats＇ DEM inversion is selected and the usability of MODIS dataset is analyzed. Shorelines of the Dongsha Sandbank are extracted by use of batch supervised classification. In accord with tidal- 0 level forecasted by the Chenjiawu Tidal Gauge Station at the overpass moment of each RS image, DEMs of inter-tidal flats in January and sutmner（Jul, Aug and Sept）, 2003 are built under ArcG1S9.2. Studies show that： （1） The dataset of short-duration and muhi-phase MODIS images can be used to retrieve the historical DEM of tidal-flats at changeful tidal flats. （2） Aualysis on usability of MODIS images from Aqua and Terra indicates that there are more usable and higbquality MODIS images in spring, autumn and winter, but less in summer. Therefore, the period for building inter-tidal fiats＇ DEM is suggested to be one month in spring, autumn and winter and three months in summer.展开更多
Inductively coupled plasma mass spectrometry is used to detect Cdforbenthos in the artificial reef .The results show that： Cd of benthos is varied from0.011μg/L to 0.541 μg/L, and averages 0.188 ± 0.220 μg/L....Inductively coupled plasma mass spectrometry is used to detect Cdforbenthos in the artificial reef .The results show that： Cd of benthos is varied from0.011μg/L to 0.541 μg/L, and averages 0.188 ± 0.220 μg/L. The distribution of Cddecreased in the order： gonads〉 gills〉 muscle in different tissues. The enrichmentregalurity in muscle Cd of different benthos was Oratosquilla, crab, fish, shrimp,ocellatus. Its health risk factor is far less than 1, indicating that Cd hasn’t obvious healthrishks on exposure population.展开更多
Diaspore traits and germination of four non-viviparous mangrove species in Hong Kong,Lumnitzera racemosa(Jack.)Voigt..Heritiera littoralis(Drgand.)Ait.,Excoecaria agallocha L.and Acanthus ilicifolius L.,were investiga...Diaspore traits and germination of four non-viviparous mangrove species in Hong Kong,Lumnitzera racemosa(Jack.)Voigt..Heritiera littoralis(Drgand.)Ait.,Excoecaria agallocha L.and Acanthus ilicifolius L.,were investigated.L.racemosa fruits planted immediately after collection failed to germinate but those stored in wet condition for 35 or 50 d were successfully germinated.This suggested that L.racemosa had endogenous and morphological seed dormancy,with embryos continued to develop during the dormant period.Germination rates of L.racemosa decreased with increasing salinity and no germina-tion was found at salinities over 25 ppt(ppt,parts per thausand).H.littoralis seeds were easily germinated if the fruit coat was artificially removed.Fruit dissection significantly shortened time for root initiation and leaf expansion.E.agallocha and A.ilicifolius seeds were also easy to germinate,initiating roots within 2 and 3 d,respectively.In terms of germination,A.ilicifolius had more tolerance to high salinity than L.racemosa.The four species exhibited three types of adaptation to unstable environments:(1)prolonged diaspore longevity as shown in L.racemosa and H.littoralis;(2)shortened rooting time as in E.agallocha and A.ilicifolius;and(3)produced sinking diaspores in L.racemosa.Diaspore buoyancy was one of the most important factors in determining inter-tidal zonation of non-viviparous mangrove species.Among the four species,L racemosa was distributed in the most seaward zones because its diaspores were sinkers while diaspores of H.littoralis,E.agallocha and A,ilicifolius,more abundant at backshore locations,were floaters.Root initiation was also important in influencing the inter-tidal zonation of the three species whose diaspores were floaters.H.littoralis with the longest rooting time,as compared to E.agallocha and A.ilicifolius,was distributed in the most backshore zone.None of other factors including salinity of seawater,animal predation,diaspore size and seedling dimension could account for inter-tidal zonation of theses pecies.展开更多
By anayses of carbon isotopic composition (δ13C values) of the benthos collected in the Laoshan Bay in August 1993 and February and May 1994, it is found that the main food sources of the benthos can be divided into ...By anayses of carbon isotopic composition (δ13C values) of the benthos collected in the Laoshan Bay in August 1993 and February and May 1994, it is found that the main food sources of the benthos can be divided into four groups in terms of carbon isotope composition: Particulate Organic Matter (POM), benthic diatoms, benthic macroalgae and the organic matter in sediments. The results show that the carbon isotopic composition of the benthic animals has a close relation with that of the food they take in. The Carbon isotopic compositions of benthos may be useful in elucidating their food sources. The carbon isotopic data have confirmed that POM is the main food source of the benthic filter feeders such as bivalves; crustaceans have a wide range of δ13C values, showing their food source has diversity; benthic diatoms are an important fraction of the food for most of gastropods. A preliminary investigation of the benthic-pelagic coupling in that region using the stable carban isotopic tracers has confirmed the importance of POM as a food source for benthos in this region, but the organic matter in sediments and benthic diatoms are also relatively important for a lot of benthic animals. The benthic-pelagic coupling in the Laoshan Bay temperate ecosystem is not so tight as that in ecosystems at higher latitudes such as northeastern water polynya.展开更多
Inter-tidal(subtidal) transport processes in coastal sea depend on the residual motion, turbulent dispersion and relevant sources/sinks. In Feng et al.(2008), an updated Lagrangian inter-tidal transport equation, as w...Inter-tidal(subtidal) transport processes in coastal sea depend on the residual motion, turbulent dispersion and relevant sources/sinks. In Feng et al.(2008), an updated Lagrangian inter-tidal transport equation, as well as new concept of Lagrangian in- ter-tidal concentration(LIC), has been proposed for a general nonlinear shallow water system. In the present study, the LIC is nu- merically applied for the first time to passive tracers in idealized settings and salinity in the Bohai Sea, China. Circulation and tracer motion in the three idealized model seas with different topography or coastline, termed as ‘flat-bottom', ‘stairs' and ‘cape' case, re- spectively, are simulated. The dependence of the LIC on initial tidal phase suggests that the nonlinearities in the stairs and cape cases are stronger than that in the flat-bottom case. Therefore, the ‘flat-bottom' case still meets the convectively weakly nonlinear condi- tion. For the Bohai Sea, the simulation results show that most parts of it still meet the weakly nonlinear condition. However, the de- pendence of the LIS(Lagrangian inter-tidal salinity) on initial tidal phase is significant around the southern headland of the Liaodong Peninsula and near the mouth of the Yellow River. The nonlinearity in the former region is mainly related to the complicated coast- lines, and that in the latter region is due to the presence of the estuarine salinity front.展开更多
Based on the investigation material acquired during the three cruises of the 4 Chinese Antarctic Research Expedition at 19 quantitative dredging stations and 4 trawling stations from the period December 1987 to March ...Based on the investigation material acquired during the three cruises of the 4 Chinese Antarctic Research Expedition at 19 quantitative dredging stations and 4 trawling stations from the period December 1987 to March 1988, this paper studies the quantity of the benthos in Great Wall Bay,the distributive characteristics and variations, and points out that the stock number of the benthos in the bay is extremely large and that there are two large ranged high mass area and 2 - 3 low small-ranged mass area. The instability of the sediments is the cause for the low.mass areas. The warm season is the vigorous reproductive period of the various kinds of the benthos and the monthly variation of the quantity is remarkable.展开更多
Eighteen polycyclic aromatic hydrocarbons(PAHs)were detected in benthos collected onboard the‘Snow Dragon’in the Northern Bering Sea Shelf and Chukchi Sea Shelf during the 6 th Chinese National Arctic Research Exped...Eighteen polycyclic aromatic hydrocarbons(PAHs)were detected in benthos collected onboard the‘Snow Dragon’in the Northern Bering Sea Shelf and Chukchi Sea Shelf during the 6 th Chinese National Arctic Research Expedition(CHINARE 2014).18 PAHs for all biota samples ranged from 34.2 to 128.1 ng/g dry weight(dw),with the highest concentration observed in fish muscle(Boreogadus saida)samples close to St.Lawrence Island.The PAH composition pattern was dominated by the presence of lighter 3 ring(57%)and 2 ring(28%)PAHs,indicating oil-related or petrogenic sources as important origins of PAH contamination.Concentrations of alkyl-PAHs(1-methylnaphthalene and 2-methylnaphthalene)were lower than their parent PAH(naphthalene)in all biological tissue,and their percentage also decreased significantly(p<0.05)compared with those in the corresponding sediment.There were no significant relationships between PAH concentrations and trophic levels,which is possibly due to the combined results of the complex benthic foodweb in the subarctic/Arctic shelf region,as well as a low assimilation/effective metabolism for PAHs.According to toxic potency evaluation results from TCDD toxic equivalents(TEQs)and Ba P-equivalent(Ba PE)values,whelk(Neptunea heros)and starfish(Ctenodiscus crispatus)are two macroinvertebrate species showing relatively higher dioxin-like toxicity and carcinogenic risk.展开更多
One of the oldest published records of benthic fauna was made in 1893 by dredging along transects from soft bottoms, sand and shell debris to rocky bottoms in an archipelago at the Swedish Skagerrak coast. Three of th...One of the oldest published records of benthic fauna was made in 1893 by dredging along transects from soft bottoms, sand and shell debris to rocky bottoms in an archipelago at the Swedish Skagerrak coast. Three of the transects were revisited in 2010 and then fewer taxa were recorded and the shared species between sampling dates at the transects were only between 8% and 12%. The main causes for the drastic changes are suggested to be large-scale eutrophication changing the vegetation composition and variation of climatic factors.展开更多
Benthos are aquatic organisms living at the bottom of water bodies for all or most of their life history.Apart from the settled and moving living,their forms of habitat are mostly attached to the hard substrate like r...Benthos are aquatic organisms living at the bottom of water bodies for all or most of their life history.Apart from the settled and moving living,their forms of habitat are mostly attached to the hard substrate like rocks or soft bases such as mud and sand.In addition,there are benthic species that attach to the plant surfaces or other benthic animals,and inhabit the intertidal zone.In terms of feeding methods,most benthic animals feed on suspended matter and sediment.Most of them are invertebrates and are a complex ecological group.According to the size,they can be divided into macrobenthos and meio-benthos[1].Benthos are an important part of the water ecosystem.Using a typical river(Gaya River)in eastern Jilin Province,this paper analyzed the water quality,the components of benthic organisms and their biological density through sampling surveys of three typical locations in the upper,middle and lower reaches of the Gaya River.In addition,it made a biological evaluation of the water quality of the Gaya River.展开更多
于2022年10月运用环境DNA宏条形码(Environmental DNA metabarcoding,eDNA metabarcoding)技术检测了渤海海峡庙岛群岛海域大型底栖动物群落结构和多样性,比较了环境DNA和传统形态学分类对大型底栖动物的检出效果,探索了影响底栖动物种...于2022年10月运用环境DNA宏条形码(Environmental DNA metabarcoding,eDNA metabarcoding)技术检测了渤海海峡庙岛群岛海域大型底栖动物群落结构和多样性,比较了环境DNA和传统形态学分类对大型底栖动物的检出效果,探索了影响底栖动物种类组成的主要环境因子。结果显示,在庙岛群岛海域16个站位基于18S rDNA宏条形码检测出大型底栖动物12门19纲43目88科110属223个特征序列(Amplicon Sequence Variants,ASVs),环节动物门、扁形动物门和软体动物门为优势类群;基于形态学分类检测出7大门类68个属,主要类群为环节动物和软体动物。上述两种方法所得大型底栖动物种类组成和多样性存在显著差异,环境DNA在门和属水平上能鉴定出更多的种类,Margalef丰富度指数较高,但未能注释出节肢动物甲壳纲。底层水盐度和沉积物粒度参数(中值粒径和偏度)、TOC含量是影响庙岛群岛海域大型底栖动物群落组成的主要环境因子。研究结果表明,环境DNA宏条形码技术作为一种生物多样性监测新方法在大型底栖动物快速监/检测中具有较高的应用潜力,与传统形态学分类相结合能够全面了解区域内海洋底栖动物的种类和生物多样性。展开更多
基金the National Natural Science Foundation of China under contract No. 40476041the State Oceanic Administration of China under contract No. 2010418006
文摘Artificially introduced cordgrass, Spartina alterniflora, rapidly colonized the intertidal flats of the Jiangsu coast, eastern China. The epibenthos on an intertidal flat invaded by S. alterniflorawere studied, to identify how local epibenthos species react to an altered environment. Epibenthic samples and surficial sediment samples were collected along a shore-normal profile in 50 quadrats at ten stations across the Spartina salt marsh; and five control quadrats for a station located on the barren sandy-mud flat. The grain size param- eters of the surficial sediments show that S. alterniflora altered the grain size gradient along the profile of the intertidal zone by trapping fine-grained sediments. Spartina alterniflora could inhabit lower elevation- s than indigenous salt marsh vegetation, thus creating larger areas of finer surficial sediments, which was suitable for not only native epibenthic species but also species which do not exist on the barren sandy-mud flat. Correlation analyses show that the epibenthos were sensitive to sediment grain size and type, on the invaded S. alterniflora salt marsh. Further, there was an interspecific relationship affecting the distribution of epibenthos. The results show that epibenthos preferred ecological niches, within the Spartina salt marsh, even in the same sampling station.
基金supported by the National Natural Science Foundation of China(No.41176064)NSFC-Shandong Joint Fund for Marine Science Research Centers(No.U1406403)
文摘In order to examine the seasonal and spatial distributions of benthic animals in the intertidal mudflat of the southern Yellow River Delta,field investigations were carried out in 2007 and 2008 and multiple methods were applied.Results showed that,the biomass of macro benthos ranged at 0.75-1151.00 g wet m^(-2) and averaged at 156.31 g wet m^(-2),in which Mactra veneriformis accounted for 75.6%-93.4% of the total macro benthic biomass.More than 90% of macro benthos inhabited in the middle and low tide lines,and higher biomass occurred in early summer and lower in winter.Statistical analysis showed that:1)M.veneriformis growth was primarily favored at higher temperature and lower salinity;2)after long time interaction,benthic bivalve grazers led to patching distributions of Chlorophyll a(Chl a);3)macro benthic biomass positively related with Chl a when the concentration of Chl a was low,but they were negatively related when Chl a concentration was high;and 4)furthermore,the biomass of benthic bivalves peaked in the sediment with median grain size about 0.55 mm,but decreased gradually in coarse or fine sediments.The secondary productivity ranged at 0.37-283.68 g m^(-2)yr^(-1) and averaged at 47.88 g m^(-2) yr^(-1),in which 69.7% was contributed by M.veneriformis It was estimated that primary production was transformed to secondary production at a rate of 6.87%approximately,which implies that there is a local sustainability of high bivalve production.
基金The National Key Basic Research Science Foundation ("973"project) of China under contract No. 2002CB412402the National Natu-ral Science Foundation of China under contract No. 40276007the Program for New Century Excellent Talents in University of China NCET-05-0592
文摘A brief review is made on the theory of the Lagrangian residual circulation and inter-tidal transports in a convectively weakly nonlinear system. In the review the emphasis is put on the systematical development of the theory and its weakness of convectively weakly nonlinear approximation. The fundamentals of a Lagrangian tidally-averaged theory on circulation with inter-tidal transport processes have been proposed for a general nonlinear coastal/estuarine system. The Lagrangian residual velocity is strictly de- fined, and it has been verified to be able to embody the velocity field of circulation. A new concept of the concentration for inter- tidal transport processes is presented. The concentration describing the inter-tidal transport processes should be a ＂Lagrangian inter-tidal concentration＂ defined and named, but not the Eulcrian tidally-averaged concentration used traditionally. The circulation described here contains a set of infinite temporal-spatial fields of velocity/concentration, each of which corresponds to a specific value of tidal phases varying continuously over one tidal cycle. When the convectively weakly nonlinear condition（ with a smaller order of eddy diffusion and sources） is approximately satisfied, a set of infinite temporal-spatial fields of velocity/concentration can be reduced to a single one.. the mass transport velocity/the Eulerian tidally averaged concentration as exhibited traditionally.
基金supported by the National Natural Science Foundation of China (Grant Nos .40701117 andJ0630535)
文摘Surthce elevation is tile basic data for geo-science. It is difficult to retrieve tidal-flats＇ elevation from a single Re- mote Sensing （RS） image because of the complicated sediment dynanical environment and huge spatial difference in tidal-flats＇ moisture content. A Digital Elevation Model （DEM） construction method for inconstant inter-tidal zone based on high tempo-resolution MODIS data set in a short period is proposed in a ease study on the Dongsha Sandbank of the Jiangsu Radial Tidal Sand-ridges. In the present study, a batch-preprocessing method based on image partition to handle massive MODIS IB images is developed and applied to 8163 scenes of MODIS images. The dataset of short-period and muhi-temporal MODIS images for inter-tidal flats＇ DEM inversion is selected and the usability of MODIS dataset is analyzed. Shorelines of the Dongsha Sandbank are extracted by use of batch supervised classification. In accord with tidal- 0 level forecasted by the Chenjiawu Tidal Gauge Station at the overpass moment of each RS image, DEMs of inter-tidal flats in January and sutmner（Jul, Aug and Sept）, 2003 are built under ArcG1S9.2. Studies show that： （1） The dataset of short-duration and muhi-phase MODIS images can be used to retrieve the historical DEM of tidal-flats at changeful tidal flats. （2） Aualysis on usability of MODIS images from Aqua and Terra indicates that there are more usable and higbquality MODIS images in spring, autumn and winter, but less in summer. Therefore, the period for building inter-tidal fiats＇ DEM is suggested to be one month in spring, autumn and winter and three months in summer.
基金financially supported by Fishery Bureau of Tianjin Youth Science and Technology Innovation Project(J-2014-08)Tianjin agricultural scientific and technological achievements and to promote the project(201304150)the projects of Seafood aquaculture technology research and demonstration in Artificial reefs(1411)
文摘Inductively coupled plasma mass spectrometry is used to detect Cdforbenthos in the artificial reef .The results show that： Cd of benthos is varied from0.011μg/L to 0.541 μg/L, and averages 0.188 ± 0.220 μg/L. The distribution of Cddecreased in the order： gonads〉 gills〉 muscle in different tissues. The enrichmentregalurity in muscle Cd of different benthos was Oratosquilla, crab, fish, shrimp,ocellatus. Its health risk factor is far less than 1, indicating that Cd hasn’t obvious healthrishks on exposure population.
文摘Diaspore traits and germination of four non-viviparous mangrove species in Hong Kong,Lumnitzera racemosa(Jack.)Voigt..Heritiera littoralis(Drgand.)Ait.,Excoecaria agallocha L.and Acanthus ilicifolius L.,were investigated.L.racemosa fruits planted immediately after collection failed to germinate but those stored in wet condition for 35 or 50 d were successfully germinated.This suggested that L.racemosa had endogenous and morphological seed dormancy,with embryos continued to develop during the dormant period.Germination rates of L.racemosa decreased with increasing salinity and no germina-tion was found at salinities over 25 ppt(ppt,parts per thausand).H.littoralis seeds were easily germinated if the fruit coat was artificially removed.Fruit dissection significantly shortened time for root initiation and leaf expansion.E.agallocha and A.ilicifolius seeds were also easy to germinate,initiating roots within 2 and 3 d,respectively.In terms of germination,A.ilicifolius had more tolerance to high salinity than L.racemosa.The four species exhibited three types of adaptation to unstable environments:(1)prolonged diaspore longevity as shown in L.racemosa and H.littoralis;(2)shortened rooting time as in E.agallocha and A.ilicifolius;and(3)produced sinking diaspores in L.racemosa.Diaspore buoyancy was one of the most important factors in determining inter-tidal zonation of non-viviparous mangrove species.Among the four species,L racemosa was distributed in the most seaward zones because its diaspores were sinkers while diaspores of H.littoralis,E.agallocha and A,ilicifolius,more abundant at backshore locations,were floaters.Root initiation was also important in influencing the inter-tidal zonation of the three species whose diaspores were floaters.H.littoralis with the longest rooting time,as compared to E.agallocha and A.ilicifolius,was distributed in the most backshore zone.None of other factors including salinity of seawater,animal predation,diaspore size and seedling dimension could account for inter-tidal zonation of theses pecies.
基金National Natual Science Foundation of China under contract No.39170172.
文摘By anayses of carbon isotopic composition (δ13C values) of the benthos collected in the Laoshan Bay in August 1993 and February and May 1994, it is found that the main food sources of the benthos can be divided into four groups in terms of carbon isotope composition: Particulate Organic Matter (POM), benthic diatoms, benthic macroalgae and the organic matter in sediments. The results show that the carbon isotopic composition of the benthic animals has a close relation with that of the food they take in. The Carbon isotopic compositions of benthos may be useful in elucidating their food sources. The carbon isotopic data have confirmed that POM is the main food source of the benthic filter feeders such as bivalves; crustaceans have a wide range of δ13C values, showing their food source has diversity; benthic diatoms are an important fraction of the food for most of gastropods. A preliminary investigation of the benthic-pelagic coupling in that region using the stable carban isotopic tracers has confirmed the importance of POM as a food source for benthos in this region, but the organic matter in sediments and benthic diatoms are also relatively important for a lot of benthic animals. The benthic-pelagic coupling in the Laoshan Bay temperate ecosystem is not so tight as that in ecosystems at higher latitudes such as northeastern water polynya.
基金supported by National Basic Research Program of China (No. 2010CB428904)National Science Foundation of China (Nos. 41106006, 40976003)
文摘Inter-tidal(subtidal) transport processes in coastal sea depend on the residual motion, turbulent dispersion and relevant sources/sinks. In Feng et al.(2008), an updated Lagrangian inter-tidal transport equation, as well as new concept of Lagrangian in- ter-tidal concentration(LIC), has been proposed for a general nonlinear shallow water system. In the present study, the LIC is nu- merically applied for the first time to passive tracers in idealized settings and salinity in the Bohai Sea, China. Circulation and tracer motion in the three idealized model seas with different topography or coastline, termed as ‘flat-bottom', ‘stairs' and ‘cape' case, re- spectively, are simulated. The dependence of the LIC on initial tidal phase suggests that the nonlinearities in the stairs and cape cases are stronger than that in the flat-bottom case. Therefore, the ‘flat-bottom' case still meets the convectively weakly nonlinear condi- tion. For the Bohai Sea, the simulation results show that most parts of it still meet the weakly nonlinear condition. However, the de- pendence of the LIS(Lagrangian inter-tidal salinity) on initial tidal phase is significant around the southern headland of the Liaodong Peninsula and near the mouth of the Yellow River. The nonlinearity in the former region is mainly related to the complicated coast- lines, and that in the latter region is due to the presence of the estuarine salinity front.
基金This project was funded by the National Natural Science FoundationState Antarctic Committee
文摘Based on the investigation material acquired during the three cruises of the 4 Chinese Antarctic Research Expedition at 19 quantitative dredging stations and 4 trawling stations from the period December 1987 to March 1988, this paper studies the quantity of the benthos in Great Wall Bay,the distributive characteristics and variations, and points out that the stock number of the benthos in the bay is extremely large and that there are two large ranged high mass area and 2 - 3 low small-ranged mass area. The instability of the sediments is the cause for the low.mass areas. The warm season is the vigorous reproductive period of the various kinds of the benthos and the monthly variation of the quantity is remarkable.
基金supported by the National Natural Science Foundation of China(Nos.41506215,41976211)Shanghai Pujiang Talent Program(No.19PJ1404200)。
文摘Eighteen polycyclic aromatic hydrocarbons(PAHs)were detected in benthos collected onboard the‘Snow Dragon’in the Northern Bering Sea Shelf and Chukchi Sea Shelf during the 6 th Chinese National Arctic Research Expedition(CHINARE 2014).18 PAHs for all biota samples ranged from 34.2 to 128.1 ng/g dry weight(dw),with the highest concentration observed in fish muscle(Boreogadus saida)samples close to St.Lawrence Island.The PAH composition pattern was dominated by the presence of lighter 3 ring(57%)and 2 ring(28%)PAHs,indicating oil-related or petrogenic sources as important origins of PAH contamination.Concentrations of alkyl-PAHs(1-methylnaphthalene and 2-methylnaphthalene)were lower than their parent PAH(naphthalene)in all biological tissue,and their percentage also decreased significantly(p<0.05)compared with those in the corresponding sediment.There were no significant relationships between PAH concentrations and trophic levels,which is possibly due to the combined results of the complex benthic foodweb in the subarctic/Arctic shelf region,as well as a low assimilation/effective metabolism for PAHs.According to toxic potency evaluation results from TCDD toxic equivalents(TEQs)and Ba P-equivalent(Ba PE)values,whelk(Neptunea heros)and starfish(Ctenodiscus crispatus)are two macroinvertebrate species showing relatively higher dioxin-like toxicity and carcinogenic risk.
文摘One of the oldest published records of benthic fauna was made in 1893 by dredging along transects from soft bottoms, sand and shell debris to rocky bottoms in an archipelago at the Swedish Skagerrak coast. Three of the transects were revisited in 2010 and then fewer taxa were recorded and the shared species between sampling dates at the transects were only between 8% and 12%. The main causes for the drastic changes are suggested to be large-scale eutrophication changing the vegetation composition and variation of climatic factors.
文摘Benthos are aquatic organisms living at the bottom of water bodies for all or most of their life history.Apart from the settled and moving living,their forms of habitat are mostly attached to the hard substrate like rocks or soft bases such as mud and sand.In addition,there are benthic species that attach to the plant surfaces or other benthic animals,and inhabit the intertidal zone.In terms of feeding methods,most benthic animals feed on suspended matter and sediment.Most of them are invertebrates and are a complex ecological group.According to the size,they can be divided into macrobenthos and meio-benthos[1].Benthos are an important part of the water ecosystem.Using a typical river(Gaya River)in eastern Jilin Province,this paper analyzed the water quality,the components of benthic organisms and their biological density through sampling surveys of three typical locations in the upper,middle and lower reaches of the Gaya River.In addition,it made a biological evaluation of the water quality of the Gaya River.
文摘针对水下环境复杂性带来的多尺度目标检测挑战,提出了改进算法WPS-YOLOv8。设计了小波池化卷积模块(wavelet pooling convolution,WPConv),该模块通过小波池化技术降低通道压缩后特征图的分辨率,有效抑制了传统下采样过程中产生的频率混叠伪影,提升了特征提取质量和表达能力。提出了局部逐点分组重排卷积模块(partial pointwise group shuffle convolution,PGConv),该模块通过结合局部卷积与逐点卷积,能够在减少信息冗余的同时保持通道间的信息交互,弥补了深度可分离卷积的不足,增强了特征融合效果。提出了ShapeLoss损失函数,综合考虑影响不同尺度目标检测精度的因素,通过集成Shape-IoU和Shape-NWD两种损失测度,有效提升了对多尺度目标的总体检测精度。实验结果显示,相较于YOLOv8,WPS-YOLOv8在URPC2018和UTDAC2020水下数据集上的平均精度均值(mean average precision,mAP)分别提升了8.6和4.4个百分点,展现了其在水下多尺度目标检测中的出色表现。
