Marine phytoplankton plays a very important role in marine ecology,environment and global climate change,and it is an indicative organism for measuring water quality.The Bohai Sea and the Yellow Sea in China have uniq...Marine phytoplankton plays a very important role in marine ecology,environment and global climate change,and it is an indicative organism for measuring water quality.The Bohai Sea and the Yellow Sea in China have unique geographical locations.Therefore,the characteristics of phytoplankton population distribution in the Bohai Sea and the Yellow Sea are of great significance to the study of marine ecology in China.In this work,the pigment data obtained from the Yellow Sea and Bohai Sea in August 2015 were analyzed by HPLC(High-Performance Liquid Chromatography).Then the pigment data were analyzed statistically by the CHEMTAX software,so that the phytoplankton community structure information was obtained.Results show that in summer 2015,from the perspective of sea area,the biomass of phytoplankton in the surface of Bohai Sea is higher than that in the Yellow Sea,while the phytoplankton biomass in the surface of North Yellow Sea is higher than that in the South.From the perspective of dominant species of phytoplankton,the surface waters of the Yellow Sea and Bohai Sea were dominated by diatoms,prymnesiophytes and chlorophytes,accounting for 55.76%,14.56%and 14.55%respectively.Among them,diatoms accounted for the absolute advantage.展开更多
Paracalanus parvus, Paracalanus crassirostris , and Acartia bifilosa are dominant and widely distributed in the Bohai Sea, and comprise an important part of zooplankton in terms of biomass as well as production rate. ...Paracalanus parvus, Paracalanus crassirostris , and Acartia bifilosa are dominant and widely distributed in the Bohai Sea, and comprise an important part of zooplankton in terms of biomass as well as production rate. In order to understand their seasonal distribution and population dynamics, their stage specific abundance in different months of the year were analyzed based on the never analyzed yet samples collected in 1959. The three species showed clear and remarkable seasonal variation in abundance, which maximized in spring and summer, when they formed high biomass patches or concentrations in the nearshore area. For Paracalanus parvus , two peaks were observed in the annual circle, one in June and the other in September. For Paracalanus crassirostris , one peak occurred in summer and a small one in December. The seasonal pattern of Acartia bifilosa was different in different regions. In Bohai Bay it had a two peak pattern, with the first large peak occurring in May and the second one in October. In Laizhou Bay, a winter peak in December and January could be observed besides the spring one. The number of generations during the reproductive season for the three species was estimated based on the annual cycle in abundance and ambient temperature.展开更多
In order to understand the large-scale spatial distribution characteristics of picoplankton,nanophytoplankton and virio-plankton and their relationship with environmental variables in coastal and offshore waters,flow ...In order to understand the large-scale spatial distribution characteristics of picoplankton,nanophytoplankton and virio-plankton and their relationship with environmental variables in coastal and offshore waters,flow cytometry(FCM) was used to ana-lyze microbial abundance of samples collected in summer from four depths at 36 stations in the North Yellow Sea(NYS).The data revealed spatial heterogeneity in microbial populations in the offshore and near-shore waters of the NYS during the summer.For the surface layer,picoeukaryotes were abundant in the near-shore waters,Synechococcus was abundant in the offshore areas,and bacte-rial and viral abundances were high in the near-shore waters around the Liaodong peninsula.In the near-shore waters,no significant vertical variation of picophytoplankton(0.2-2μm) abundance was found.However,the nanophytoplankton abundance was higher in the upper layers(from the surface to 10 m depth) than in the bottom layer.For the offshore waters,both pico-and nanophytoplankton(2-20μm) abundance decreased sharply with depth in the North Yellow Sea Cold Water Mass(NYSCWM).But,for the vertical dis-tribution of virus and bacteria abundance,no significant variation was observed in both near-shore and offshore waters.Autotrophic microbes were more sensitive to environmental change than heterotrophic microbes and viruses.Viruses showed a positive correla-tion with bacterial abundance,suggesting that the bacteriophage might be prominent for virioplankton(about 0.45μm) in summer in the NYS and that viral abundance might play an important role in microbial loop functions.展开更多
Works concerning zooplankton of freshwaters of the western area of Algeria are only very fragmentary and remain at an embryonic state. Remediating to this situation, it led a study of the biodiversity and zooplanktoni...Works concerning zooplankton of freshwaters of the western area of Algeria are only very fragmentary and remain at an embryonic state. Remediating to this situation, it led a study of the biodiversity and zooplanktonic populations distribution in time and space in the Boughrara dam lake which remains subject to a strong pollution coming essentially from Morocco. The preliminary results of the faunistic analysis of the zooplanktonic populations enabled to highlight an important richness of zoological groups. The CFA （correspondences factorial analysis） and the AHC （ascending hierarchical classification） methods used both enabled to define the species distribution of both open waters and littoral ones, and also to perform existing affinities between them and the state of the used medium. Compared to other barrages, such as those of Bouhanifia and of Sarno, the zooplanktonic populations of both open waters and littoral populations appear to a great extent numerous in rain period. On the quantitative and qualitative level, the zooplanktonic populations strongly suffer from the pollution contamination coming from the Mouillah River especially in summer period. It is time to think about the protection of this fauna which is the second trophic chain link and this intending to preserve the ecosystems in an equilibrium state and to consider the exploitation of natural resources in the realization of an aquacultural farm.展开更多
The influence of sea ice on the species composition and cell density of phytoplankton was investigated in the eastern Bering Sea in spring 2008. Diatoms, particularly pennate diatoms, dominated the phytoplankton commu...The influence of sea ice on the species composition and cell density of phytoplankton was investigated in the eastern Bering Sea in spring 2008. Diatoms, particularly pennate diatoms, dominated the phytoplankton community. The dominant species were Grammonema islandica （Grunow in Van Heurck） Hasle, Fragilariopsis cylindrus （Grunow） Krieger, F. oceanica （Cleve） Hasle, Navicula vanhoeffenii Gran, Thalassiosira antarctica Comber, T. gravida Cleve, T. nordenskioeldii Cleve, and T. rotula Meunier. Phytoplankton cell densities varied from 0.08× 10^4 to 428.8× 10^4 cells/L, with an average of 30.3× 10^4 cells/L. Using cluster analysis, phytoplankton were grouped into three assemblages defined by ice-forming conditions： open wate.r, ice edge, and sea ice assemblages. In spring, when the sea ice melts, the phytoplankton dispersed from the sea ice to the ice edge and even into open waters. Thus, these phytoplankton in the sea ice may serve as a “seed bank” for phytoplankton population succession in the subarctic ecosystem. Moreover, historical studies combined with these results suggest that the sizes of diatom species have become smaller, shifting from microplankton to nannoplankton-dominated communities.展开更多
基金supported by Liao Ning Revitalization Talents Program No. XLYC1807161Dalian High-level Talents Innovation Support Plan No. 2017RQ063+4 种基金Dalian Ocean University “Zhanlan scholar”ProgramThe National Natural Science Foundation of China under contract Nos. 41206013 and 41430963the Public Science and Technology Research Funds Projects of Ocean under contract No. 201205018the National Science and Technology Support Program under contract No. 2014BAB12B02Projects of Institute of Marine Industry Technology of Liaoning Universities
文摘Marine phytoplankton plays a very important role in marine ecology,environment and global climate change,and it is an indicative organism for measuring water quality.The Bohai Sea and the Yellow Sea in China have unique geographical locations.Therefore,the characteristics of phytoplankton population distribution in the Bohai Sea and the Yellow Sea are of great significance to the study of marine ecology in China.In this work,the pigment data obtained from the Yellow Sea and Bohai Sea in August 2015 were analyzed by HPLC(High-Performance Liquid Chromatography).Then the pigment data were analyzed statistically by the CHEMTAX software,so that the phytoplankton community structure information was obtained.Results show that in summer 2015,from the perspective of sea area,the biomass of phytoplankton in the surface of Bohai Sea is higher than that in the Yellow Sea,while the phytoplankton biomass in the surface of North Yellow Sea is higher than that in the South.From the perspective of dominant species of phytoplankton,the surface waters of the Yellow Sea and Bohai Sea were dominated by diatoms,prymnesiophytes and chlorophytes,accounting for 55.76%,14.56%and 14.55%respectively.Among them,diatoms accounted for the absolute advantage.
文摘Paracalanus parvus, Paracalanus crassirostris , and Acartia bifilosa are dominant and widely distributed in the Bohai Sea, and comprise an important part of zooplankton in terms of biomass as well as production rate. In order to understand their seasonal distribution and population dynamics, their stage specific abundance in different months of the year were analyzed based on the never analyzed yet samples collected in 1959. The three species showed clear and remarkable seasonal variation in abundance, which maximized in spring and summer, when they formed high biomass patches or concentrations in the nearshore area. For Paracalanus parvus , two peaks were observed in the annual circle, one in June and the other in September. For Paracalanus crassirostris , one peak occurred in summer and a small one in December. The seasonal pattern of Acartia bifilosa was different in different regions. In Bohai Bay it had a two peak pattern, with the first large peak occurring in May and the second one in October. In Laizhou Bay, a winter peak in December and January could be observed besides the spring one. The number of generations during the reproductive season for the three species was estimated based on the annual cycle in abundance and ambient temperature.
基金supported by the General Oceano-graphic Survey Project(908 Project)the Special Fund forPublic Welfare Industry(Oceanography)(Grant No.20080511)the CAS Hundred Talents Project‘The response mechanism of the typical gulf ecosystem to the environmental changes’
文摘In order to understand the large-scale spatial distribution characteristics of picoplankton,nanophytoplankton and virio-plankton and their relationship with environmental variables in coastal and offshore waters,flow cytometry(FCM) was used to ana-lyze microbial abundance of samples collected in summer from four depths at 36 stations in the North Yellow Sea(NYS).The data revealed spatial heterogeneity in microbial populations in the offshore and near-shore waters of the NYS during the summer.For the surface layer,picoeukaryotes were abundant in the near-shore waters,Synechococcus was abundant in the offshore areas,and bacte-rial and viral abundances were high in the near-shore waters around the Liaodong peninsula.In the near-shore waters,no significant vertical variation of picophytoplankton(0.2-2μm) abundance was found.However,the nanophytoplankton abundance was higher in the upper layers(from the surface to 10 m depth) than in the bottom layer.For the offshore waters,both pico-and nanophytoplankton(2-20μm) abundance decreased sharply with depth in the North Yellow Sea Cold Water Mass(NYSCWM).But,for the vertical dis-tribution of virus and bacteria abundance,no significant variation was observed in both near-shore and offshore waters.Autotrophic microbes were more sensitive to environmental change than heterotrophic microbes and viruses.Viruses showed a positive correla-tion with bacterial abundance,suggesting that the bacteriophage might be prominent for virioplankton(about 0.45μm) in summer in the NYS and that viral abundance might play an important role in microbial loop functions.
文摘Works concerning zooplankton of freshwaters of the western area of Algeria are only very fragmentary and remain at an embryonic state. Remediating to this situation, it led a study of the biodiversity and zooplanktonic populations distribution in time and space in the Boughrara dam lake which remains subject to a strong pollution coming essentially from Morocco. The preliminary results of the faunistic analysis of the zooplanktonic populations enabled to highlight an important richness of zoological groups. The CFA （correspondences factorial analysis） and the AHC （ascending hierarchical classification） methods used both enabled to define the species distribution of both open waters and littoral ones, and also to perform existing affinities between them and the state of the used medium. Compared to other barrages, such as those of Bouhanifia and of Sarno, the zooplanktonic populations of both open waters and littoral populations appear to a great extent numerous in rain period. On the quantitative and qualitative level, the zooplanktonic populations strongly suffer from the pollution contamination coming from the Mouillah River especially in summer period. It is time to think about the protection of this fauna which is the second trophic chain link and this intending to preserve the ecosystems in an equilibrium state and to consider the exploitation of natural resources in the realization of an aquacultural farm.
基金Supported by the National Natural Science Foundation of China(Nos.41276128,41476116)the National Basic Research Program of China(973 Program)(No.2010CB428704)
文摘The influence of sea ice on the species composition and cell density of phytoplankton was investigated in the eastern Bering Sea in spring 2008. Diatoms, particularly pennate diatoms, dominated the phytoplankton community. The dominant species were Grammonema islandica （Grunow in Van Heurck） Hasle, Fragilariopsis cylindrus （Grunow） Krieger, F. oceanica （Cleve） Hasle, Navicula vanhoeffenii Gran, Thalassiosira antarctica Comber, T. gravida Cleve, T. nordenskioeldii Cleve, and T. rotula Meunier. Phytoplankton cell densities varied from 0.08× 10^4 to 428.8× 10^4 cells/L, with an average of 30.3× 10^4 cells/L. Using cluster analysis, phytoplankton were grouped into three assemblages defined by ice-forming conditions： open wate.r, ice edge, and sea ice assemblages. In spring, when the sea ice melts, the phytoplankton dispersed from the sea ice to the ice edge and even into open waters. Thus, these phytoplankton in the sea ice may serve as a “seed bank” for phytoplankton population succession in the subarctic ecosystem. Moreover, historical studies combined with these results suggest that the sizes of diatom species have become smaller, shifting from microplankton to nannoplankton-dominated communities.
