In recent years, harmful algal blooms(HABs) have occurred frequently along the coast of China, and have been exhibiting succession from diatom- to dinofl agellate-dominated blooms. To examine the eff ects of dif feren...In recent years, harmful algal blooms(HABs) have occurred frequently along the coast of China, and have been exhibiting succession from diatom- to dinofl agellate-dominated blooms. To examine the eff ects of dif ferent diatom and dinofl agellate HABs, the life history parameters of rotifers(B rachionus plicatilis Müller) were measured after exposure to dif ferent concentrations of HAB species. The HAB species examined included a diatom(S keletonema costatum) and four dinofl agellates( Prorocentrum donghaiense, Alexandrium catenella, Prorocentrum lima and Karlodinium venefi cum). Compared with the control treatment(CT), the diatom S. costatum showed no adverse impacts on rotifers. Exposure to dinofl agellates at densities equivalent to those measured in the fi eld resulted in a reduction in all the life history parameters measured. This included a reduction in: lifetime egg production(CT: 20.34 eggs/ind.) reduced to 10.11, 3.22, 4.17, 7.16 eggs/ind., life span(CT: 394.53 h) reduced to 261.11, 162.90, 203.67, 196 h, net reproductive rate(CT: 19.51/ind.) reduced to 3.01, 1.26, 3.53, 5.96/ind., fi nite rate of increase(CT: 1.47/d) reduced to 1.16, 1.03, 1.33, 1.38/d, and intrinsic rate of population increase(CT: 0.39/d) reduced to 0.15, 0.03, 0.28, 0.32/d, for the dinofl agellates P. donghaiense, A. catenella, P. lima and K. venefi cum, respectively. The results showed that the diatom S. costatum had no detrimental consequences on the reproduction and growth of B. plicatilis, however, the four dinofl agellates tested did show adverse ef fects. This suggests that dinofl agellate HABs may suppress microzooplankton, resulting in an increase in algal numbers.展开更多
Algal blooms of haptophyte Phaeocystis globosa have been recorded in the Beibu Gulf,South China Sea(SCS)since 2011.Recent evidence suggests that TypeⅠand TypeⅣare the two dominant genotypes of P.globosa coexisting i...Algal blooms of haptophyte Phaeocystis globosa have been recorded in the Beibu Gulf,South China Sea(SCS)since 2011.Recent evidence suggests that TypeⅠand TypeⅣare the two dominant genotypes of P.globosa coexisting in this area,and their marker pigment profiles,colony sizes,and genetic information differ.Two genotype-specific quantitative polymerase chain reaction(qPCR)assays were used to clarify the distribution and dynamics of P.globosa bloom in the Beibu Gulffrom November 2018 to February 2019.Results show that the patterns of spatial-temporal distribution of TypeⅠand TypeⅣwere similar,the abundance of TypeⅣwas higher than that of TypeⅠduring the algal bloom,and thus TypeⅣcells dominated the P.globosa bloom in winter 2018.The relationships between environmental factors and P.globosa abundance indicated that temperature and nitrate were critical to the distribution and dynamics of P.globosa blooms in this area.The distribution of P.globosa cells in different water masses before the bloom revealed that the westward water via the Qiongzhou Strait,the SCS bottom water,and the current in the northwestern waters of Hainan Island could transport P.globosa cells into the Beibu Gulf serving as the seed sources triggering the intense blooms in the Beibu Gulf.展开更多
Dinoflagellate Alexandrium catenella is a cosmopolitan bloom-forming species with complex life cycle,the formation and germination of resting cysts are critical for its bloom dynamics.In the coastal waters of Qinhuang...Dinoflagellate Alexandrium catenella is a cosmopolitan bloom-forming species with complex life cycle,the formation and germination of resting cysts are critical for its bloom dynamics.In the coastal waters of Qinhuangdao,A.catenella has been identified as the major causative agent for paralytic shellfish poisoning,but there is little knowledge concerning its resting cysts in this region.In this study,three surveys were carried out along the coast of Qinhuangdao from 2020 to 2021 to map the distribution of A.catenella resting cysts,using a quantitative PCR(qPCR)assay specific for A.catenella.The resting cysts were detected in surface sediments during all the three surveys,and their distribution patterns were similar.High abundance of resting cysts(maximum 1300 cysts/g sediment(wet weight))were found in a region(119.62°E-119.99°E,39.67°N-39.98°N)northeast to the coastal waters of Qinhuangdao,where surface sediments were mainly composed of clay and silt(percentage above 50%).Prior to the formation of the A.catenella bloom in March 2021,the abundance of A.catenella vegetative cells in seawater had extremely significant positive correlation with the abundance of resting cysts in surface sediments,reflecting the important role of resting cysts in the initiation of A.catenella blooms.As far as we know,this is the first report on the distribution of A.catenella cysts along the coast of Qinhuangdao.The results will of fer a sound basis for the future monitoring and mitigation of toxic A.catenella blooms and paralytic shellfish poisoning events in this region.展开更多
基金Supported by the Innovation Research Group Program of National Natural Science Foundation of China(No.41121064)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA01020304)
文摘In recent years, harmful algal blooms(HABs) have occurred frequently along the coast of China, and have been exhibiting succession from diatom- to dinofl agellate-dominated blooms. To examine the eff ects of dif ferent diatom and dinofl agellate HABs, the life history parameters of rotifers(B rachionus plicatilis Müller) were measured after exposure to dif ferent concentrations of HAB species. The HAB species examined included a diatom(S keletonema costatum) and four dinofl agellates( Prorocentrum donghaiense, Alexandrium catenella, Prorocentrum lima and Karlodinium venefi cum). Compared with the control treatment(CT), the diatom S. costatum showed no adverse impacts on rotifers. Exposure to dinofl agellates at densities equivalent to those measured in the fi eld resulted in a reduction in all the life history parameters measured. This included a reduction in: lifetime egg production(CT: 20.34 eggs/ind.) reduced to 10.11, 3.22, 4.17, 7.16 eggs/ind., life span(CT: 394.53 h) reduced to 261.11, 162.90, 203.67, 196 h, net reproductive rate(CT: 19.51/ind.) reduced to 3.01, 1.26, 3.53, 5.96/ind., fi nite rate of increase(CT: 1.47/d) reduced to 1.16, 1.03, 1.33, 1.38/d, and intrinsic rate of population increase(CT: 0.39/d) reduced to 0.15, 0.03, 0.28, 0.32/d, for the dinofl agellates P. donghaiense, A. catenella, P. lima and K. venefi cum, respectively. The results showed that the diatom S. costatum had no detrimental consequences on the reproduction and growth of B. plicatilis, however, the four dinofl agellates tested did show adverse ef fects. This suggests that dinofl agellate HABs may suppress microzooplankton, resulting in an increase in algal numbers.
基金Supported by the National Natural Science Foundation of China(Nos.42076140,U20A20104,42076216)the National Key R&D Program of China(No.2017YFC1404304)the National S&T Basic Resources Investigation Program of China(No.2018YF100206)。
文摘Algal blooms of haptophyte Phaeocystis globosa have been recorded in the Beibu Gulf,South China Sea(SCS)since 2011.Recent evidence suggests that TypeⅠand TypeⅣare the two dominant genotypes of P.globosa coexisting in this area,and their marker pigment profiles,colony sizes,and genetic information differ.Two genotype-specific quantitative polymerase chain reaction(qPCR)assays were used to clarify the distribution and dynamics of P.globosa bloom in the Beibu Gulffrom November 2018 to February 2019.Results show that the patterns of spatial-temporal distribution of TypeⅠand TypeⅣwere similar,the abundance of TypeⅣwas higher than that of TypeⅠduring the algal bloom,and thus TypeⅣcells dominated the P.globosa bloom in winter 2018.The relationships between environmental factors and P.globosa abundance indicated that temperature and nitrate were critical to the distribution and dynamics of P.globosa blooms in this area.The distribution of P.globosa cells in different water masses before the bloom revealed that the westward water via the Qiongzhou Strait,the SCS bottom water,and the current in the northwestern waters of Hainan Island could transport P.globosa cells into the Beibu Gulf serving as the seed sources triggering the intense blooms in the Beibu Gulf.
基金Supported by the National S&T Basic Resources Investigation Program of China(No.2018YF100206)the National Key R&D Program of China(Nos.2019YFC1407901,2017YFC1600701)from the Ministry of Science and Technology(MoST)。
文摘Dinoflagellate Alexandrium catenella is a cosmopolitan bloom-forming species with complex life cycle,the formation and germination of resting cysts are critical for its bloom dynamics.In the coastal waters of Qinhuangdao,A.catenella has been identified as the major causative agent for paralytic shellfish poisoning,but there is little knowledge concerning its resting cysts in this region.In this study,three surveys were carried out along the coast of Qinhuangdao from 2020 to 2021 to map the distribution of A.catenella resting cysts,using a quantitative PCR(qPCR)assay specific for A.catenella.The resting cysts were detected in surface sediments during all the three surveys,and their distribution patterns were similar.High abundance of resting cysts(maximum 1300 cysts/g sediment(wet weight))were found in a region(119.62°E-119.99°E,39.67°N-39.98°N)northeast to the coastal waters of Qinhuangdao,where surface sediments were mainly composed of clay and silt(percentage above 50%).Prior to the formation of the A.catenella bloom in March 2021,the abundance of A.catenella vegetative cells in seawater had extremely significant positive correlation with the abundance of resting cysts in surface sediments,reflecting the important role of resting cysts in the initiation of A.catenella blooms.As far as we know,this is the first report on the distribution of A.catenella cysts along the coast of Qinhuangdao.The results will of fer a sound basis for the future monitoring and mitigation of toxic A.catenella blooms and paralytic shellfish poisoning events in this region.
