A fouling study was conducted in coastal waters southwest of the East China Sea between December 2013 and November 2014. A total of 84 species of fouling organisms belonging to 69 genera, 49 families, and 10 phyla wer...A fouling study was conducted in coastal waters southwest of the East China Sea between December 2013 and November 2014. A total of 84 species of fouling organisms belonging to 69 genera, 49 families, and 10 phyla were recorded over the entire year. The community composition was dominated by coastal warm-water species belonging to typical subtropical inner bay communities. The prosperous stage of settlement lasted from April to September, and the adhesion strength of the fouling organisms was the highest in summer. Sessile suspension feeders constituted the main core of settlement for the fouling community. Amphibalanus reticulatus was the most dominant and representative species of fouling organism, and other dominant species included Caprella equilibra, Ectopleura crocea, Anthopleura nigrescens, Stylochus ijimai, Spirobranchus kraussii, Crassostrea angulata, Perna viridis, Jassa falcata, Stenothoe valida, Sphaerozius nitidus, and Biflustra grandicella. The individuals in the fouling community showed a mutual dependence or constraint relationship due to competition for settlement space and food, and they exhibited a particular spatiotemporal distribution in accordance with adaptation to environmental factors. Temperature was the most important environmental factor determining the geographic distribution of fouling organisms. The temperature characteristics of species essentially reflect the differences in the fouling community composition in various climate zones. The species number, settlement stage, and settlement rate of fouling organisms are closely related to water temperature. Local natural environmental conditions（salinity, water currents, light, etc.） as well as human activity（such as aquaculture production） are all important factors affecting the settlement of fouling organisms.展开更多
Hole-drilling method is a commonly used method for measuring residual stress. The calibration coefficients in ASTM E837-13 a would cause large errors due to the plasticity deformation of materials. In the study, calib...Hole-drilling method is a commonly used method for measuring residual stress. The calibration coefficients in ASTM E837-13 a would cause large errors due to the plasticity deformation of materials. In the study, calibration coefficients were modified in the plasticity deformation stage based on the distortion energy theory. The calibration experiment of calibration coefficients was simulated by the finite element model, and the plasticity modification formulas of 7075 aluminum alloy were obtained. From the results of uniaxial tensile loading test, the measuring errors of high residual stress are significantly reduced from-4.071%～53.440% to-5.140% ～ 0.609% after the plasticity modification. This work provides an effective way to expand the application of hole-drilling method.展开更多
Field investigations of marine macrobenthos were conducted at ten sites in the Bering Sea in July 2010. Altogether 90 species of macrobenthos belonging to 59 families and 78 genera were identified. Among them, 41 poly...Field investigations of marine macrobenthos were conducted at ten sites in the Bering Sea in July 2010. Altogether 90 species of macrobenthos belonging to 59 families and 78 genera were identified. Among them, 41 polychaetes, 16 mollusks, 23 crustaceans, three echinoderms, two cnidarians, one nemertean, one priapulid, two sipunculids, and one echiuran were identified. The average density and biomass of total macrobenthos were 984 ind./m2 and 1207.1 g/ma of wet weight, respectively. The predominant species in the study area were Scoloplos armiger, Eudorella pacifica, Ophiura sarsii, Heteromastus filiformis, Ennucula tenuis, and Harpiniopsis vadiculus by abundance, while the predominant species in this area was Echinarachnius parma by biomass. Hierarchical cluster analysis （Bray-Curtis similarity measure） revealed that two impor- tant benthic assemblages in the study area were CommunityA and Community B. CommunityA was stable and Community B was unstable, as shown by the Abundance/Biomass Comparisons （ABC） approach. The macrobenthic community structure in the shelf of the Bering Sea was characterized by its high abundance and biomass, high productivity but great heterogeneity.展开更多
Seagrasses are one of the most productive ecosystems in coastal areas and support a wide variety of associated fauna. The tropical Indo-Pacific region is considered to have the highest diversity of seagrass plant spec...Seagrasses are one of the most productive ecosystems in coastal areas and support a wide variety of associated fauna. The tropical Indo-Pacific region is considered to have the highest diversity of seagrass plant species and the largest distribution areas of seagrass, yet the seagrass macrofauna in this region are poorly understood. To help fill this gap in our knowledge, an ecological survey was conducted to describe the abundance and diversity of benthic macrofauna from tropical seagrass beds and to determine between-station variations within a transect and between-site variations in macrofaunal abundance, taxa richness and community structure. Benthic macrofaunal samples associated with seagrass beds were collected with a core sampler on the east coast of North Sulawesi in May 2014 and on the west coast in October 2015. A total of 149 species from 14 higher taxa was collected. The most species-rich groups were polychaetes（56 species, 26% of total individual numbers）, decapods（20 species, 9% of total numbers） and amphipods（18 species, 35% of total numbers）. Between-station variations within a transect displayed different patterns between the east coast and the west coast. On the east coast, there were marked variations in abundance between stations within a transect for the macrofauna and amphipod assemblages. Both taxa richness and abundance varied with station for the macrofauna and polychaete assemblages on the west coast, resulting from the heterogeneity of the substrate along a transect. One-way ANOSIM together with MDS ordination indicated that macrofaunal community structure in seagrasses differed significantly between the east coast and the west coast, corresponding with the division of seagrasses into two broad categories of habitats, i.e.,mangrove-seagrass-reef continuum and seagrass-reef continuum. Compared with other studies in tropical areas,the abundance and diversity of benthic macrofauna in the present study were moderate. The reason for the two markedly distinct macrofaunal communities might be attributed to multiple factors, including sediment pattern,seagrass structure and temporal changes.展开更多
Field sampling of the macrobenthos from 23 stations in the Chukchi Sea was conducted during the 4th CHI- NARE （Chinese National Arctic Research Expeditions, July-August, 2010）. We identified a total of 140 species o...Field sampling of the macrobenthos from 23 stations in the Chukchi Sea was conducted during the 4th CHI- NARE （Chinese National Arctic Research Expeditions, July-August, 2010）. We identified a total of 140 species of macrozoobenthos belonging to nine phyla, which were dominated by polychaetes （66）, crustaceans （30）, and mollusks （25）, followed by echinoderms （9） and others （ten others, including four cnidarians, one oligochaete, one sipuncula, one priapulida, two bryozoans, and one urochordata）. The dominant species were Aphelochaeta pacifica, Heteromastus filiformis, Nephtys ciliata, Nephtys caeca, Scoletoma fragilis, Golfingia margaritacea, Nuculana pernula, Macoma calcarea, Ennucula tenuis, Macoma inquinata, Musculus discors, Echinarachnius parma, and Ophiura sarsii, so there were more cold-eurythermal boreal immigrants than trulyArctic species （endemics）. The average density and biomass （mean ± SD across all stations） of the total macrozoobenthos were （916 ± 907） ind/m2 and （902.9 ± 1227.7） g/m2 （wet weight）, respectively. Relatively high density and biomass were observed in the samples from the northeastern and southern Chukchi Sea. The spatial variation of benthic communities in the study sea area was relatively large; this spatial heteroge- neity has led to high diversity and a patchy distribution pattern in the community structure. Compared to the 1st CHINARE （July-August, 1999）, this investigation revealed different degrees of decreases in the average taxa numbers and the average density, abundance, and biodiversity in the area over the recent decade, which might be associated with global warming, human activities, and sea ice variations.展开更多
Mediomastus is a common genus around the world, and Chinese specimens used to be identified as M. californiensis Hartman. In this study, 118 Mediomastus specimens collected from four localities along the southeast coa...Mediomastus is a common genus around the world, and Chinese specimens used to be identified as M. californiensis Hartman. In this study, 118 Mediomastus specimens collected from four localities along the southeast coast of China were examined. They belonged to an unknown species. We treat them as a new species, described herein. The new species is characterized as follows： （1） chaetigers 1-9 biannulate with chaetal fascicles at midsegment, thereafter multiannulate with chaetal fascicles posterior to midsegment; （2） parapodial ridges on posterior abdomen; （3） possession of bilimbate capillary chaetae on chaetigers 1-4; （4） thoracic hooks with long, straight shaft, hood length about 3-5 times width; （5） abdominal hooks shorter, with developed shoulder and distinct constriction, markedly different from those in thorax; （6） unique staining pattern with methyl green. The present study indicated that Mediomastus species inhabiting Chinese waters might be misidentified as M. californiensis, and that Mediomastus chinensis sp. nov. is widely distributed along the southeast coast of China.展开更多
Due to its unique geological location, the Bering Sea is an ideal place to investigate the water exchange and ecosystem connectivity of the Pacific Ocean–Arctic Ocean and subarctic–Arctic region. Based on a number o...Due to its unique geological location, the Bering Sea is an ideal place to investigate the water exchange and ecosystem connectivity of the Pacific Ocean–Arctic Ocean and subarctic–Arctic region. Based on a number of summer surveys（July to September, 2010, 2012 and 2014）, macrobenthic communities and their spatial-temporal patterns are exhibited for the majority of the Bering Sea（53°59′–64°36′N）. The results show that the macrobenthic communities were dominated by northern cold-water species and immigrant eurythermic species, and the communities assumed a dispersed and patchy distribution pattern. Polychaetes（Scoloplos armiger）, crustaceans（Ceradocus capensis） and sea urchins（Echinarachnius parma） were the main dominant groups in the shallow shelves; the sea star（Ctenodiscus crispatus） and the brittle star（Ophiura sarsii） were the main dominant groups in the continental slope; whereas small polychaetes（Prionospio malmgreni） dominated the basin area. Sediment type, water depth, and currents were the major factors affecting the structure and spatial distribution of the macrobenthic communities. Compared with other seas, the shallow areas of the Bering Sea showed an extremely high-standing biomass. In particular, the northern shelf area（north of St. Lawrence Islands and west of 170°W）,which is primarily controlled by Anadyr Water, is an undersea oasis. In contrast, a deficiency in the downward transport of particulate organic carbon has resulted in a desert-like seabed in the basin area. By comparing our results to previous studies, we found that macrobenthic communities of the Bering Sea have undergone significant structural changes in recent decades, resulting in a decrease in abundance and an increase in biomass.In addition, populations of amphipods and bivalves in the northern shelves have decreased significantly and have been gradually replaced by other species. These changes might be associated with advanced seasonal ice melting,changes in organic carbon input, and global warming, indicating that large-scale ecosystem changes have been occurring in the Bering Sea.展开更多
基金The National Natural Science Foundation of China under contract Nos 41176102 and 41306116
文摘A fouling study was conducted in coastal waters southwest of the East China Sea between December 2013 and November 2014. A total of 84 species of fouling organisms belonging to 69 genera, 49 families, and 10 phyla were recorded over the entire year. The community composition was dominated by coastal warm-water species belonging to typical subtropical inner bay communities. The prosperous stage of settlement lasted from April to September, and the adhesion strength of the fouling organisms was the highest in summer. Sessile suspension feeders constituted the main core of settlement for the fouling community. Amphibalanus reticulatus was the most dominant and representative species of fouling organism, and other dominant species included Caprella equilibra, Ectopleura crocea, Anthopleura nigrescens, Stylochus ijimai, Spirobranchus kraussii, Crassostrea angulata, Perna viridis, Jassa falcata, Stenothoe valida, Sphaerozius nitidus, and Biflustra grandicella. The individuals in the fouling community showed a mutual dependence or constraint relationship due to competition for settlement space and food, and they exhibited a particular spatiotemporal distribution in accordance with adaptation to environmental factors. Temperature was the most important environmental factor determining the geographic distribution of fouling organisms. The temperature characteristics of species essentially reflect the differences in the fouling community composition in various climate zones. The species number, settlement stage, and settlement rate of fouling organisms are closely related to water temperature. Local natural environmental conditions（salinity, water currents, light, etc.） as well as human activity（such as aquaculture production） are all important factors affecting the settlement of fouling organisms.
基金supported by the Natural Science Foundation of Fujian Provinceof China(No.2018J01082)the China Scholarship Council(No.201806315006)the National Natural Science Foundation of China(No.51305371)
文摘Hole-drilling method is a commonly used method for measuring residual stress. The calibration coefficients in ASTM E837-13 a would cause large errors due to the plasticity deformation of materials. In the study, calibration coefficients were modified in the plasticity deformation stage based on the distortion energy theory. The calibration experiment of calibration coefficients was simulated by the finite element model, and the plasticity modification formulas of 7075 aluminum alloy were obtained. From the results of uniaxial tensile loading test, the measuring errors of high residual stress are significantly reduced from-4.071%～53.440% to-5.140% ～ 0.609% after the plasticity modification. This work provides an effective way to expand the application of hole-drilling method.
基金The China Action Plan of the International Polar Yearthe Public Science and Technology Research Funds Projects of Ocean under contract No.201105022-2+1 种基金the National Natural Science Foundation of China under contract Nos 41306115 and 41306116the Polar Science Strategic Research Foundation of China under contract No.20140309
文摘Field investigations of marine macrobenthos were conducted at ten sites in the Bering Sea in July 2010. Altogether 90 species of macrobenthos belonging to 59 families and 78 genera were identified. Among them, 41 polychaetes, 16 mollusks, 23 crustaceans, three echinoderms, two cnidarians, one nemertean, one priapulid, two sipunculids, and one echiuran were identified. The average density and biomass of total macrobenthos were 984 ind./m2 and 1207.1 g/ma of wet weight, respectively. The predominant species in the study area were Scoloplos armiger, Eudorella pacifica, Ophiura sarsii, Heteromastus filiformis, Ennucula tenuis, and Harpiniopsis vadiculus by abundance, while the predominant species in this area was Echinarachnius parma by biomass. Hierarchical cluster analysis （Bray-Curtis similarity measure） revealed that two impor- tant benthic assemblages in the study area were CommunityA and Community B. CommunityA was stable and Community B was unstable, as shown by the Abundance/Biomass Comparisons （ABC） approach. The macrobenthic community structure in the shelf of the Bering Sea was characterized by its high abundance and biomass, high productivity but great heterogeneity.
基金China-Indonesia Maritime Cooperation Fund Project“China-Indonesia Bitung Joint Marine Ecological Station Establishment”the Scientific Research Foundation of Third Institute of Oceanography,SOA under contract No.2011034
文摘Seagrasses are one of the most productive ecosystems in coastal areas and support a wide variety of associated fauna. The tropical Indo-Pacific region is considered to have the highest diversity of seagrass plant species and the largest distribution areas of seagrass, yet the seagrass macrofauna in this region are poorly understood. To help fill this gap in our knowledge, an ecological survey was conducted to describe the abundance and diversity of benthic macrofauna from tropical seagrass beds and to determine between-station variations within a transect and between-site variations in macrofaunal abundance, taxa richness and community structure. Benthic macrofaunal samples associated with seagrass beds were collected with a core sampler on the east coast of North Sulawesi in May 2014 and on the west coast in October 2015. A total of 149 species from 14 higher taxa was collected. The most species-rich groups were polychaetes（56 species, 26% of total individual numbers）, decapods（20 species, 9% of total numbers） and amphipods（18 species, 35% of total numbers）. Between-station variations within a transect displayed different patterns between the east coast and the west coast. On the east coast, there were marked variations in abundance between stations within a transect for the macrofauna and amphipod assemblages. Both taxa richness and abundance varied with station for the macrofauna and polychaete assemblages on the west coast, resulting from the heterogeneity of the substrate along a transect. One-way ANOSIM together with MDS ordination indicated that macrofaunal community structure in seagrasses differed significantly between the east coast and the west coast, corresponding with the division of seagrasses into two broad categories of habitats, i.e.,mangrove-seagrass-reef continuum and seagrass-reef continuum. Compared with other studies in tropical areas,the abundance and diversity of benthic macrofauna in the present study were moderate. The reason for the two markedly distinct macrofaunal communities might be attributed to multiple factors, including sediment pattern,seagrass structure and temporal changes.
基金The National Natural Science Foundation of China under contract Nos 41306116 and 41306115the Basic Research Funds of the Third Institute of Oceanography,State Oceanic Administration under contract No.HSK 2013006+2 种基金the Projects of Chinese Polar Scientific Research under contract No.CHINARE2012-2015the Marine Nonprofit Industry Special Research Project Fund under contract No.201105022-2the Polar Science Strategic Research Foundation of China under contract No.20140309
文摘Field sampling of the macrobenthos from 23 stations in the Chukchi Sea was conducted during the 4th CHI- NARE （Chinese National Arctic Research Expeditions, July-August, 2010）. We identified a total of 140 species of macrozoobenthos belonging to nine phyla, which were dominated by polychaetes （66）, crustaceans （30）, and mollusks （25）, followed by echinoderms （9） and others （ten others, including four cnidarians, one oligochaete, one sipuncula, one priapulida, two bryozoans, and one urochordata）. The dominant species were Aphelochaeta pacifica, Heteromastus filiformis, Nephtys ciliata, Nephtys caeca, Scoletoma fragilis, Golfingia margaritacea, Nuculana pernula, Macoma calcarea, Ennucula tenuis, Macoma inquinata, Musculus discors, Echinarachnius parma, and Ophiura sarsii, so there were more cold-eurythermal boreal immigrants than trulyArctic species （endemics）. The average density and biomass （mean ± SD across all stations） of the total macrozoobenthos were （916 ± 907） ind/m2 and （902.9 ± 1227.7） g/m2 （wet weight）, respectively. Relatively high density and biomass were observed in the samples from the northeastern and southern Chukchi Sea. The spatial variation of benthic communities in the study sea area was relatively large; this spatial heteroge- neity has led to high diversity and a patchy distribution pattern in the community structure. Compared to the 1st CHINARE （July-August, 1999）, this investigation revealed different degrees of decreases in the average taxa numbers and the average density, abundance, and biodiversity in the area over the recent decade, which might be associated with global warming, human activities, and sea ice variations.
基金The Public Science and Technology Research Funds Projects of Ocean under contract No.201505004
文摘Mediomastus is a common genus around the world, and Chinese specimens used to be identified as M. californiensis Hartman. In this study, 118 Mediomastus specimens collected from four localities along the southeast coast of China were examined. They belonged to an unknown species. We treat them as a new species, described herein. The new species is characterized as follows： （1） chaetigers 1-9 biannulate with chaetal fascicles at midsegment, thereafter multiannulate with chaetal fascicles posterior to midsegment; （2） parapodial ridges on posterior abdomen; （3） possession of bilimbate capillary chaetae on chaetigers 1-4; （4） thoracic hooks with long, straight shaft, hood length about 3-5 times width; （5） abdominal hooks shorter, with developed shoulder and distinct constriction, markedly different from those in thorax; （6） unique staining pattern with methyl green. The present study indicated that Mediomastus species inhabiting Chinese waters might be misidentified as M. californiensis, and that Mediomastus chinensis sp. nov. is widely distributed along the southeast coast of China.
基金The National Natural Science Foundation of China under contract Nos 41306116 and 41506217the Chinese Polar Environment Comprehensive Investigation and Assessment Programs under contract Nos CHINARE 04-03,03-05 and 03-02+1 种基金the Polar Science Strategic Research Foundation of China under contract No.20140309the Scientific Research Foundation of Third Institute of Oceanography,SOA under contract No.2016011
文摘Due to its unique geological location, the Bering Sea is an ideal place to investigate the water exchange and ecosystem connectivity of the Pacific Ocean–Arctic Ocean and subarctic–Arctic region. Based on a number of summer surveys（July to September, 2010, 2012 and 2014）, macrobenthic communities and their spatial-temporal patterns are exhibited for the majority of the Bering Sea（53°59′–64°36′N）. The results show that the macrobenthic communities were dominated by northern cold-water species and immigrant eurythermic species, and the communities assumed a dispersed and patchy distribution pattern. Polychaetes（Scoloplos armiger）, crustaceans（Ceradocus capensis） and sea urchins（Echinarachnius parma） were the main dominant groups in the shallow shelves; the sea star（Ctenodiscus crispatus） and the brittle star（Ophiura sarsii） were the main dominant groups in the continental slope; whereas small polychaetes（Prionospio malmgreni） dominated the basin area. Sediment type, water depth, and currents were the major factors affecting the structure and spatial distribution of the macrobenthic communities. Compared with other seas, the shallow areas of the Bering Sea showed an extremely high-standing biomass. In particular, the northern shelf area（north of St. Lawrence Islands and west of 170°W）,which is primarily controlled by Anadyr Water, is an undersea oasis. In contrast, a deficiency in the downward transport of particulate organic carbon has resulted in a desert-like seabed in the basin area. By comparing our results to previous studies, we found that macrobenthic communities of the Bering Sea have undergone significant structural changes in recent decades, resulting in a decrease in abundance and an increase in biomass.In addition, populations of amphipods and bivalves in the northern shelves have decreased significantly and have been gradually replaced by other species. These changes might be associated with advanced seasonal ice melting,changes in organic carbon input, and global warming, indicating that large-scale ecosystem changes have been occurring in the Bering Sea.
