Standing crop and primary production of benthic microalgae on the tidal flats in Yueqing Bay     

Qiang Hao  Yuming Cai  Xiuren Ning  Chenggang Liu  Xin Peng  Xuexi Tang 《中国海洋大学学报(英文版)》2011,10(2):157-164

The standing stock and primary production of benthic microalgae on tidal flats were measured seasonally at 3 transects (Puqing, Dahengchuang and Puqi) in Yueqing Bay during 2002 2003. The results showed that the integral chlorophyll a (Chl a) concentration in tidal flat mud exhibited a seasonal variation with the order of magnitude: winter (14.0 4.2 mg m-2) > spring (13.0 6.3 mg m-2) > autumn (7.7 5.9 mg m-2) > summer (4.6 3.2 mg m-2). The primary production showed an order of magnitude: spring (270.5 224.9 mgC m-2 d-1)>winter (238.7 225.5 mgC m-2 d-1)>autumn (214.1 56.2 mgC m-2 d-1)>summer (71.6 44.6 mgC m-2 d-1). Both chlorophyll a and primary production showed maximum values in the surface layer of sediment, and decreased rapidly with increasing depth due to sun light limitation. The results of variance analysis indicated that seasonal variation and tidal flat condition affected Chl a greatly, but had no significant effect on primary production. The annual primary production of benthic microalgae on tidal flats in Yueqing Bay was estimated at 16143 tons carbon, which is sufficient to support 1.02×105 tons shellfish production. The environmental factors affecting chlorophyll and primary production on the tidal flats in Yueqing Bay were discussed. By comparing with other bays on China’s coast, it was observed that Yueqing Bay is a region with high benthic microalgae standing crop and primary production, which may be related to the type of its sediment.  相似文献   

Mapping the resting cysts of dinoflagellate Alexandrium catenella along the coast of Qinhuangdao,China     

Tang  Wenjiao  Geng  Huixia  Xi  Yanjuan  Zhang  Qingchun  Tang  Xuexi  Yu  Rencheng 《中国海洋湖沼学报》2022,40(6):2312-2321

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 1 300 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 offer a sound basis for the future monitoring and mitigation of toxic A. catenella blooms and paralytic shellfish poisoning events in this region.

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高立式阻沙网的阻沙效果对比     

马学喜  李生宇  何志辉  王海峰  冯筱  武新成 《中国沙漠》2016,36(4):925-931

设计了高120cm的4种结构HDPE阻沙网：均匀结构阻沙网（a）、大条带上疏下密式阻沙网（b,60cm宽条带）、小条带疏密相间式阻沙网（c,20或10cm宽条带）和中条带上密下疏式阻沙网（d,40cm宽条带）,布设在塔克拉玛干沙漠腹地的垄间平地。阻沙试验结果表明：（1）4种结构阻沙网积沙纵断面的蚀积形态均呈单峰,但积沙宽度和高度不同,3种非均匀结构的阻沙网积沙高度均高于均匀结构阻沙网,积沙高度c> b> d> a。（2）4种结构阻沙网积沙量c> a> b> d,积沙量均集中在下风侧分布,但b和c阻沙网积沙在上风侧的积沙量高于a和d阻沙网。（3）不同结构阻沙网积沙量及其空间分布差异主要与阻沙网结构的特殊风场结构有关。  相似文献   

Identification of the toxic compounds produced by Sargassum thunbergii to red tide microalgae     

���ʾ�  ����  ��ѧ�� 《中国海洋湖沼学报》2012,30(5):778-785

The inhibitory effects of methanol extracts from the tissues of three macroalgal species on the growths of three marine red tide microalgae were assessed under laboratory conditions.Extracts of Sargassum thunbergii(Mertens ex Roth) Kuntz tissue had stronger inhibitory effects than those of either Sargassum pallidum(Turner) C.Agardh or Sargassum kjellmanianum Yendo on the growths of Heterosigma akashiwo(Hada) Hada,Skeletonema costatum(Grev.) Grev,and Prorocentrum micans Ehrenberg.Methanol extracts of S.thunbergii were further divided into petroleum ether,ethyl acetate,butanol,and distilled water phases by liquid-liquid fractionation.The petroleum ether and ethyl acetate fractions had strong algicidal effects on the microalgae.Gas chromatography-mass spectrometry analyses of these two phases identified nine fatty acids,most of which were unsaturated fatty acids.In addition,pure compounds of four of the nine unsaturated fatty acids had effective concentrations below 5 mg/L.Therefore,unsaturated fatty acids are a component of the allelochemicals in S.thunbergii tissue.  相似文献   

Effect of UV-B irradiation on interspecific competition between Ulva pertusa and Grateloupia filicina     

李丽霞  张培玉  赵吉强  周文礼  唐学玺 《中国海洋湖沼学报》2010,28(2):288-294

We report the effect of UV-B irradiation (9.6 kJ m^?2 day^?1) on interspecific competition between two species of macroalgae, Ulva pertusa (U) and Grateloupia filicina (G), in co-culture. Growth of U. pertusa and G. filicina was inhibited by UV-B irradiation in mono-culture and specific growth rate (μ) declined as a result. Interspecific competition between U. pertusa and G. filicina was closely related to the initial weights when co-cultured. When initial ratios of U. pertusa (U) to G. filicina (G) were U:G=1.2:1 and 1:1, U. pertusa was the dominant algae. When the initial U:G ratio was 1:1.2, G. filicina was competitively dominant in the earlier stage, but U. pertusa grew faster, superseding G. filicina in the later stage. At initial ration U:G = 1:1.4, G. filicina was predominant. Under UV-B irradiation, the competitive ability of G. filicina was weakened and the interspecific competitive balance favored U. pertusa, which suggests that G. filicina was more sensitive to UV-B irradiation. We also probed the potential allelopathic effects between the two species, which led to mutual growth inhibition.  相似文献   

Bacterial communities fluctuate in abundance and diversity under simulated oil-contaminated seawater conditions     

LI Xiaohong  YOU Cai  QU Liang  ZHOU Bin  TANG Xuexi  XIAO Hui 《海洋湖沼学报（英文）》2019,(2):615-627

Marine bacteria have recently been identified as a potent solution for petroleum hydrocarbon degradation in response to hazardous oceanic oil spills. In this study, a mesocosm experiment simulating a petroleum spill event was performed to investigate changes in the abundance, structure, and productivity of bacterial communities in response to oil pollution. Cultured heterotrophic bacteria and total bacteria showed a consistent trend involving an immediate decrease in abundance, followed by a slight increase, and a steady low-level thereafter. However, the changing trend of bacterial productivity based on bacterial biomass and bacterial volume showed the opposite trend. In addition, the density of oil-degrading bacteria increased initially, then subsequently declined. The change in the bacterial community structure at day 0 and day 28 were also analyzed by amplified ribosomal DNA restriction analysis (ARDRA), which indicated that the species diversity of the bacterial community changed greatly after oil pollution. Alphaproteobacteria (40.98%) replaced Epsilonproteobacteria (51.10%) as the most abundant class, and Gammaproteobacteria (38.80%) became the second most dominant class in the whole bacterial community. The bacterial communities in oil-contaminated seawater (32 genera) became much more complex than those found in the natural seawater sample (16 genera). The proportion of petroleum-degrading bacteria in the oil-contaminated seawater also increased. In this study, culture-dependent and culture-independent approaches were combined to elucidate changes in both bacterial productivity and community structure. These findings will contribute to a better understanding of the role that bacteria play in material cycling and degradation in response to oil pollution.  相似文献   

Bacterial community succession in response to dissolved organic matter released from live jellyfish     

HAO Wenjin  WICHELS Antje  FUCHS Bernhardt  TANG Xuexi  GERDTS Gunnar 《海洋湖沼学报（英文）》2019,(4):1229-1244

Jellyfish blooms have increased worldwide, and the outbreaks of jellyfish population not only affect the food web structures via voracious predation but also play an important role in the dynamics of nutrients and oxygen in planktonic food webs. However, it remains unclear whether specific carbon compounds released through jellyfish metabolic processes have the potential to shape bacterial community composition. Therefore, in this study, we aimed to investigate the compositional succession of the bacterioplankton community in response to the dissolved organic matter (DOM) released by the live Scyphomedusae Cyanea lamarckii and Chrysaora hysoscella collected from Helgoland Roads of the North Sea. The bacterial community was significantly stimulated by the DOM released form live jellyfish and different dominant phylotypes were observed for these two Scyphomedusae species. Furthermore, the bacterial community structures in the different DOM sources, jellyfish-incubated media, Kabeltonne seawater, and artificial seawater (DOM-free) were significantly different, as revealed by automated ribosomal intergenic spacer analysis fingerprints. Catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH) revealed a rapid species-specific shift in bacterial community composition. Gammaproteobacteria dominated the community instead of the Bacteroidetes community for C. lamarckii, whereas Gammaproteobacteria and Bacteroidetes dominated the community for C. hysoscella. The significant differences in the bacterial community composition and succession indicate that the components of the DOM released by jellyfish might differ with jellyfish species.  相似文献   

Experimental Study on the Interspecific Interactions Between the Two Bloom-Forming Algal Species and the Rotifer Brachionusplicatilis     

XIE Zhihao  XIAO Hui  TANG Xuexi  CAI Hengjiang 《青岛海洋大学学报(英文版)》2009,(2):203-208

The interspecific interactions between the rotifer Brachionus plicatilis and two harmful algal blooms （HAB） species were investigated experimentally by single culture method. B. plicatilis population and the growth of the two algae were compared at different algal cell densities. The results demonstrated that the B. plicatilis obtained sufficient nutrition from Prorocentrum donghaiense to support net population increase. With exposure to 2.5×10^4 cells mL^-1 of P. donghaiense, the number of B. plicatilis increased faster than it did when exposed to other four algal densities （5, 10, 15 and 20 × 10^4 cells mL^-1）, and the increase rate of B. plicatilis population （r） at this algal density was 0.104 ± 0.015 rd^-1. Cell densities of P. donghaiense decreased due to the grazing of B plicatilis. In contrast, Heterosigma akashiwo had an adverse effect on B. plicatilis population and its growth was largely unaffected by rotifer grazing. In this case, B. plicatilis population decreased and H. akashiwo grew at a rate similar to that of the control.  相似文献   

Experimental Study on the Interspecific Interactions Between the Two Bloom-Forming Algal Species and the Rotifer Brachionus plicatilis     

XIE Zhihao）  ）  XIAO Hui）  TANG Xuexi）    CAI Hengjiang） ） Marine Ecology Laboratory  Ocean University of China  Qingdao  P. R. China ） Faculty of Life Science  Biotechnology  Ningbo University  Ningbo  P. R. China 《中国海洋大学学报(英文版)》2009,8(2)

The interspecific interactions between the rotifer Brachionus plicatilis and two harmful algal blooms(HAB) species were investigated experimentally by single culture method. B. plicatilis population and the growth of the two algae were compared at different algal cell densities. The results demonstrated that the B. plicatilis obtained sufficient nutrition from Prorocentrum donghaiense to support net population increase. With exposure to 2.5×104 cells mL-1 of P. donghaiense,the number of B. plicatilis increa...  相似文献   

紫外辐射诱发三角褐指藻自由基伤害的研究   总被引：19，自引：0，他引：19  

唐学玺  杨震  王悠  李永祺 《海洋通报》1999,18(4):93-96

研究了ＵＶ－Ｂ对海洋微藻的影响。研究结果显示紫外辐射（ＵＶ－Ｂ,２８０－３２０ｎｍ）能抑制三角褶指藻的生长,藻细胞经紫外辐射处理后,自由基含量上升,超氧化物歧化酶（Ｓｕｐｅｒｏｘｉｄｅ ｄｉｓｍｕｔａｓｅ,ＳＯＤ）活性下降,而过氧化物酶（Ｐｅｒｏｘｉｄａｓｅ,ＰＯＤ）活性变化不明显。作者认为,紫外辐射诱发自由基对藻细胞形成伤害是紫外线抑制藻细胞生长的主要原因之一）。  相似文献