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1.
Harmful algal blooms(HABs),caused by the overgrowth of certain phytoplankton species,have negative effects on marine environments and coastal fisheries.In addition to cell-counting methods using phytoplankton nets,a hydroacoustic technique based on acoustic backscattering has been proposed for the detection of phytoplankton blooms.However,little is known of the acoustic properties of HAB species.In this study,as essential data to support this technique,we measured the acoustic properties of two HAB species,Akashiwo sanguinea and Alexandrium affine,which occur in the South Sea off the coast of Korea.Due to the small size of the target,we used ultrasound for the measurements.Experiments were conducted under laboratory and field conditions.In the laboratory experiment,the acoustic signal received from each species was directly proportional to the cell abundance.We derived a relationship between the cell abundance and acoustic signal received for each species.The measured signals were compared to predictions of a fluid sphere scattering model.When A.sanguinea blooms appeared at an abundance greater than 3 500 cells/mL,the acoustic signals varied with cell abundance,showing a good correlation.These results confirm that acoustic measurements can be used to detect HAB species. 相似文献
2.
Carbonyl compounds,especially polyunsaturated aldehydes(PUAs),are increasingly reported as teratogenic to grazers and deleterious to phytoplankton.While PUAs have been considered to be mainly produced by diatoms after cell wounding,little is known about whether microalgae other than diatoms,particularly harmful algal bloom(HAB)-forming species,produce carbonyl compounds.In this study,we analyzed the carbonyl compounds from eight common HAB-forming species(Akashiwo sanguinea,Karenia mikimotoi,Karlodinium veneficum,Margalefidinium polykrikoides,Prorocentrum donghaiense,P.minimum,Scrippsiella trochoidea,and Heterosig,ma akashiwo)using gas chromatography-mass spectrometry in full scan and selected ion monitoring(SIM)modes.Our results show a ubiquitous presence of carbonyl colmpounds in both dissolved and particulate forms in all species we examined.In the full scan mode,133 chromatographic peaks were detected from 51 samples altogether.Both the varieties of carbonyl compounds and their quantities were algal species dependent,although most of the carbonyl compounds could not be fully identified according to the mass spectral database only due to the unavailability of enough standards for all analytes.Aided with nine standards in SIM mode,we further identified and quantified all nine aldehydes(2-methyl-2-pentenal,trans-2-nonenal,cis-6-nonenal,2,6-dimethyl-5-heptenal,trans-2-hexenal,trans-2-decenal,2,4-heptadienal,trans-trans-2,4-octadienal,and trans-trans-2,4-decadienal).Four of these nine aldehydes were detected in particulate form,which confirmed that trans-2-nonenal could be produced by K.mikimotoi,Karl.veneficum,P.donghaiense,P.minimum,S.trochoidea,and H.akashiwo,2,4-heptadienal and trans-trans-2,4-decadienal by A.sanguinea,M.polykrikoides,and S.trochoidea,and trans,trans-2,4-octadienal by S.trochoidea,respectively.We proved that some dinoflagellate and raphidophyte species could contribute to the pool of carbonyl compounds including PUAs in a marine ecosystem.Some carbonyl compounds,particularly those in high cell quota and/or dissolved concentration,may be related to fishkilling or allelopathy which needs further identification and quantification. 相似文献
3.
A bloom of the dinoflagellate Scrippsiella trochoidea was detected for the first time in inner Tolo Harbor,Hong Kong in 2 000. Water samples were collected at eight stations along a transect passing through a red tide patch for microscopic analysis of phytoplankton composition and high-performance liquid chromatography(HPLC) analysis of phytoplankton pigments. During the bloom,the density of dinoflagellates was 1.1×106 cells L-1 within the patch and 8.6×105 cells L-1 outside the patch where the phytoplankto... 相似文献
4.
《中国海洋湖沼学报》2021,(4)
The dinoflagellates Alexandrium pacificum and Prorocentrum donghaiense are two wellknown harmful algal blooms(HABs)-forming species,both were usually found in the same sea areas in form of HABs in China.To date,there is no mechanistic model that can fully explain the occurrence of P.donghaiense blooms with A.pacificum.We found that different strains of P.donghaiense had different intrinsic growth rates of 0.107-0.215/d,and these strains exhibited different responses to the allelopathic action from A.pacificum.Some strains of P.donghaiense could grow well despite some degrees of inhibition in a short period,suggesting the two algal species P.donghaiense and A.pacificum could coexist,even if A.pacificum was allelopathic.Our findings may advance the understanding of phenotypes in P.donghaiense and provide a potential mechanism involved in the coexistence of P.donghaiense and A.pacificum in the same area. 相似文献
5.
浮游植物物候能够反映浮游植物的生长变化与湖泊生态系统的变化,水温、营养盐浓度等因素对物候有重要影响。太湖富营养化程度较高,水温的影响作用日趋显著,物候与水温关系的研究对理解、控制和改善太湖生态系统具有重要意义。本研究利用2003—2018年MODIS遥感数据计算浮游植物物候指标和湖泊水表温度（Temperature of Water Surface,LSWT）,通过分析太湖浮游植物物候时空变化特点探究了不同区域的物候特征,并结合LSWT揭示了浮游植物物候对LSWT变化的响应关系。结果表明：① 不同浮游植物物候指标具有不同空间分布特点,水华发生次数、峰值叶绿素a（Chla）浓度和水华总持续时间呈现由西部沿岸向湖心区递减的趋势;浮游植物生长开始时间和峰值Chla发生时间分布复杂但在沿岸区域相对较早;② 太湖可被划分为4种具有不同物候特征的区域,Ⅰ类区域主要位于贡湖湾、东部沿岸以及太湖中部开阔水域,该区Chla浓度范围为50~60 μg/L,且波动平缓,水华发生次数最少、开始最晚、持续时间最短;Ⅱ类区域主要分布于太湖西部沿岸,Chla浓度范围为50~90 μg/L且变化剧烈,该区水华发生次数最多、开始最早、持续时间最长;Ⅲ和Ⅳ类属于过渡区域,前者主要分布于梅梁湾、竺山湾及入湾口,后者主要位于南部沿岸以及太湖中部;③ 浮游植物物候对LSWT变化的响应受营养水平影响,当营养水平较高时,浮游植物的生长受LSWT的促进作用显著,LSWT年际变化的升高趋势对浮游植生长物候提前、生物量增加的影响明显,反之,则LSWT变化对浮游植物生长的影响减弱。 相似文献
6.
7.
INTRODUCTIONRedtidecanadverselyaffectcoastalfisheriesbycausingthedeathofculturedfishandshrimporproducingtoxinsthatcanbeaccumulatedthroughfoodchains (Anderson ,1 989) .Phytoplanktonisoftenthemaincomponentofmanyredtides.AlongthecoastofJiaozhouBay ,P .R .China,theredtideismainlyformedbyadinoflagellate ,Scrippdiellatrochoidea ,duringsummer (JulytoSep tember)andthecelldensitycanreach 9.98× 1 0 7cells ml (Zou ,unpublisheddata) .Manyresearcherssuggestedthatredtideofphytoplanktonmightresultf… 相似文献
8.
Niu Zhuang Guan Weibing Wang Jinxiu Yuan Yongquan Kong Fanzhou Liu Chao Zhang Qingchun Yu Rencheng 《中国海洋湖沼学报》2022,40(6):2385-2400
Journal of Oceanology and Limnology - Algal blooms of haptophyte Phaeocystis globosa have been recorded in the Beibu Gulf, South China Sea (SCS) since 2011. Recent evidence suggests that Type I and... 相似文献
9.
Resting cysts are an important part of the life cycle for many harmful algal bloom-forming dinoflagellates, and play vital roles in the recurrence and geographical spread of harmful algal blooms. Numerous factors have been suggested to regulate the formation of resting cysts, although only a few have been proven to be significant. Cyst formation can be induced by adverse environmental conditions such as drastic changes in temperature, light, salinity, and nutrient levels, and by biological interactions. In this study, we evaluated the ability of an artificial factor(fine sand particles) to enhance the formation of resting cysts. Fine sand particles were added to cultures of dinoflagellates that are known to produce cysts. The addition of fine sand particles significantly increased both the production rate and final yield of cysts in cultures of S crippsiella trochoidea, Biecheleria brevisulcata, and Levanderina fissa(= Gymnodinium fissum, Gyrodinium instriatum, Gyr odinium uncatenum). The largest increase in the final yield(107-fold) of cysts as a result of sand addition was in S. trochoidea. However, addition of fine sand particles did not induce cyst formation, or barely af fected cyst formation, in A kashiwo san guinea, Cochlodinium polykrikoides and Pheopolykrikos hartmannii, which are also known to be cyst-producing species. We speculated that addition of sand significantly increased the chances of cell collision, which triggered cyst formation. However, further research is required to test this idea. Importantly, our findings indicate that the addition of fine sand particles is a useful method to obtain a large quantity of cysts in a short time for laboratory studies or tests; for example, if a cyst viability test is being used to assess the eff ectiveness of ships' ballast water treatment. 相似文献
10.
《中国海洋湖沼学报》2017,(4)
Fixatives are traditionally used in marine ecosystem research.The bias introduced by fixatives on the dimensions of plankton cells may lead to an overestimation or underestimation of the carbon biomass.To determine the impact of traditional fixatives on dinoflagellates during short-and long-term fixation,we analyzed the degree of change in three bloom-forming dinoflagellates(Prorocentrum micans,Scrippsiella trochoidea and Noctiluca scintillans) brought about by Lugol's iodine solution(hereafter Lugol's) and formalin.The fixation effects were species-specific.P.micans cell volume showed no significant change following long-term preservation,and S.trochoidea swelled by approximately 8.06% in Lugol's and by 20.97% in formalin as a percentage of the live cell volume,respectively.N.scintillans shrank significantly in both fixatives.The volume change due to formalin in N.scintillans was not concentration-dependent,whereas the volume shrinkage of N.scintillans cells fixed with Lugol's at a concentration of 2% was nearly six-fold that in cells fixed with Lugol's at a concentration of 0.6%-0.8%.To better estimate the volume of N.scintillans fixed in formalin at a concentration of 5%,we suggest that the conversion relationship was as follows:volume of live cell=volume of intact fixed cell/0.61.Apart from size change,damage induced by fixatives on N.scintillans was obvious.Lugol's is not a suitable fixative for N.scintillans due to high frequency of broken cells.Accurate carbon biomass estimate of N.scintillans should be performed on live samples.These findings help to improve the estimate of phytoplankton cell volume and carbon biomass in marine ecosystem. 相似文献
11.
NEW TAXA OF EUGLENOPHYTA FROM CHINA 总被引：1，自引：0，他引：1
施之新 《中国海洋湖沼学报》1995,13(4):348-353
Eight new taxa of Euglenophyta are described in this paper. They were collected from severalprovinces in China and respectively named Euglena allorgei var. exsulcata. E pisciformis var. globosa, E.tortiliS, Lepocinclis glabra var. papillata, Phacus pisiformis, Ph.strombuliformis,Ph.trimarginatus var.truncatus and Astasia angusta. 相似文献
12.
Phaeocystis globosa Scherffel, a harmful microalga, and its production of dimethylsulfoniopropionate
The production of dimethylsulfoniopropionate (DMSP) and its cleavage products (DMS) are well studied in phytoplankton worldwide. However, less is known about their sources, distributions, and impacts in the coast of China. We examined the production of DMSP and DMS in Phaeocystis globosa Scherffel and other benthic macroalgae from the South China coast in relation to environmental conditions. P. globosa was a harmful marine microalgal species and its bloom took place in the eutrophic waters along the South China Sea frequently. It also produced high content of DMSP at different growth stages, with the highest concentration usually observed in the stationary period. Moreover, the production of DMSP in P. globosa was significantly affected by salinity and temperature with the highest contents associated with high salinity (e.g. 40) and low temperature (e.g. 20°C). In field benthic macroalgae, there was also a marked difference in the DMSP of various species or different samples of the same species. Chlorophyll a contents were also determined for each macroalgal species. The highest chlorophyll a (238.7 ng/g fresh weight) was recorded in Chlorophyta Ulva lactuca at Guishan Island (Zhuhai), while the lowest value (1.5 ng/g fresh weight) was found in Rhodophyta Gracilaria tenuistipitata in Zhanjiang. Further correlation analysis indicated that there was no significant relationship between the content of DMSP and chl-a in macroalgae samples (P > 0.05). All the results suggested that the production of DMSP in marine algae was not only species- and stage-related, but also greatly affected by various environmental factors. 相似文献
13.
We investigated the allelopathic properties of Alexandrium tamarense (Laboar) Balech on the growth of Prorocentrum donghaiense Lu, Chattonella marina (Subrahmanyan) Hara et Chihara and Heterosigma akashiwo (Hada) Hada in a laboratory experiment. We examined the growth of A. tamarense, C. marina, P. donghaiense and H. Akashiwo in co-cultures and the effect of filtrates from A. tamarense cultures in various growth phases, on the three harmful algal bloom (HAB)-forming algae. In co-cultures with A. tamarense, both C. marina and H. akashiwo were dramatically suppressed at high cell densities; in contrast, the growth of P. donghaiense varied in different inoculative ratios of A. tamarense and P. donghaiense. When the ratio was 1:1 (P. donghaiense: A. tamarense), growth of P. donghaiense was inhibited considerably, while the growth of P. donghaiense was almost the same as that of the control when the ratio was 9:1. The growth difference of P. donghaiense, C. marina and H. akashiwo when co-cultured with A. tamarense indicated that the allelopathic effect may be one of the important factors in algal competition and phytoplankton succession
involving A. tamarense. In addition, the filtrate from A. tamarense culture had negative impacts on these three HAB algae, and such inhibition varied with different growth phases of A. tamarense in parallel with reported values of PSP toxin content in Alexandrium cells. This implied that PSP toxin was possibly involved in allelopathy of A. tamarense. However, the rapid decomposition and inactivation of PSP toxin above pH 7 weakened this possibility. Further studies on
the allelochemicals responsible for the allelopathy of A. tamarense need to be carried out in future. 相似文献
14.
The toxicity of seven major HAB (harmful algal bloom) species/strains, Prorocentrum donghaiense, Phaeocystis globosa, Prorocentrum micans, Alexandrium tamarense (AT-6, non-PSP producer), Alexandrium lusitanicum, Alexandrum tamarense (ATHK) and Heterosigma akashiwo were studied against rotifer Brachionus plicatilis under laboratory conditions. The results show that P. donghaiense, P. globosa, P. micans, A. tamarense (AT-6), or A. lusitanicum could maintain the individual survival and reproduction, as well as the population increase of the rotifer, but the individual reproduction would decrease when exposed to these five algae at higher densities for nine days; H. akashiwo could decrease the individual survival and reproduction, as well as population increase of the rotifer, which is similar to that of the starvation group, indicating that starvation might be its one lethal factor except for the algal toxins; A. tamarense (ATHK) has strong lethal effect on the rotifer with 48h LC50 at 800 cells/mL. The experiment on ingestion ability indicated by gut pigment change shows that P.donghaiense, P. globosa, P. micans, A. tamarense (AT-6) and A. lusitanicum can be taken by the rotifers as food, but A. tamarense (ATHK) or H. akashiwo can be ingested by the rotifers. The results indicate that all the indexes of individual survival and reproduction, population increase, gut pigment change of the rotifers are good and convenient to be used to reflect the toxicities of HAB species. Therefore, rotifer is suggested as one of the toxicity testing organisms in detecting the toxicity of harmful algae. 相似文献
15.
Wei Huang Xuyu Zhu Quanzhen Chen Qing He Yibo Liao Ping Du Peng Zhang Jiangning Zeng 《中国海洋大学学报(英文版)》2013,12(4):577-588
With the rapid development of economy and increase of population in the drainage areas, the nutrient loading has increased dramatically in the Changjiang estuary and adjacent coastal waters. To properly assess the impact of nutrient enrichment on phytoplankton community, seasonal microcosm experiments were conducted during August 2010–July 2011 in the coastal waters of Zhejiang Province. The results of the present study indicated that the chl a concentration, cell abundance, diversity indices, species composition and community succession of the phytoplankton varied significantly with different N/P ratios and seasons. Higher growth was observed in the 64:1 (spring), 32:1 (summer), 16:1 (autumn) and 128:1, 256:1 (winter) treatments, respectively. The values of Shannon-Wiener index (H′) and Pielou evenness index (J) were lower in the 8:1 and 16:1 treatments in autumn test, while H′ value was higher in the 128:1 and 8:1 treatments in winter test. A definite community succession order from diatoms to dinoflagellates was observed in the autumn and winter tests, while the diatoms dominated the community throughout the culture in the spring and summer tests. 相似文献
16.
Anthropogenic nutrient discharge poses widespread threats to coastal ecosystems and has increased environmental gradients from coast to sea. Bacterioplankton play crucial roles in coastal biogeochemical cycling, and a variety of factors af fect bacterial community diversity and structure. We used 16 S r RNA gene pyrosequencing to investigate the spatial variation in bacterial community composition(BCC) across five sites on a coast-of fshore gradient in the East China Sea. Overall, bacterial alpha-diversity did not diff er across sites, except that richness and phylogenetic diversity were lower in the of fshore sites, and the highest alpha-diversity was found in the most landward site, with Chl-abeing the main factor. BCCs generally clustered into coastal and of fshore groups. Chl-a explained 12.3% of the variation in BCCs, more than that explained by either the physicochemical(5.7%) or spatial(8.5%) variables. Nutrients(particularly nitrate and phosphate), along with phytoplankton abundance, were more important than other physicochemical factors, co-explaining 20.0% of the variation in BCCs. Additionally, a series of discriminant families(primarily affiliated with Gammaproteobacteria and Alphaproteobacteria), whose relative abundances correlated with Chl-a, DIN, and phosphate concentrations, were identified, implying their potential to indicate phytoplankton blooms and nutrient enrichment in this marine ecosystem. This study provides insight into bacterioplankton response patterns along a coast-of fshore gradient, with phytoplankton abundance increasing in the of fshore sites. Time-series sampling across multiple transects should be performed to determine the seasonal and spatial patterns in bacterial diversity and community structure along this gradient. 相似文献
17.
《中国海洋湖沼学报》2014,(6)
We present results on the effect of modified clay on cyst formation of Scrippsiella trochoidea in harmful algal bloom(HAB).Modified clay(in concentration of 0,0.1,0.5,and 1.0 g/L) were added to cultures,and observations were made on cysts of 5.trochoidea under controlled laboratory conditions.Results indicate that the removal rate of algal cells reached 97.7%at the clay concentration of 1.0 g/L.The cyst formation rate increased from 4.6%to 24.6%when the concentration of clay was increased from 0to 1.0 g/L.Two cyst metamorphs were observed:spinal calcareous cysts and smooth noncalcareous ones.The proportion of the spinal cysts decreased from 76.9%to 24.1%when clay concentration increased from0 to 1.0 g/L.In addition,modified clay affected cyst germination.The germination rate decreased with the increases in the clay concentrations.Non-calcareous cysts had a lower germination rate with a longer germination time.We conclude that modified clay could depress algal cell multiplication and promote formation of temporal cysts of 5.trochoidea,which may help in controlling HAB outbreaks. 相似文献
18.
We present results on the effect of modified clay on cyst formation of Scrippsiella trochoidea in harmful algal bloom （HAB）. Modified clay （in concentration of 0, 0.1, 0.5, and 1.0 g/L） were added to cultures, and observations were made on cysts of S. trochoidea under controlled laboratory conditions. Results indicate that the removal rate of algal cells reached 97.7% at the clay concentration of 1.0 g/L. The cyst formation rate increased from 4.6% to 24.6% when the concentration of clay was increased from 0 to 1.0 g/L. Two cyst metamorphs were observed： spinal calcareous cysts and smooth noncalcareous ones. The proportion of the spinal cysts decreased from 76.9% to 24.1% when clay concentration increased from 0 to 1.0 g/L. In addition, modified clay affected cyst germination. The germination rate decreased with the increases in the clay concentrations. Non-calcareous cysts had a lower germination rate with a longer germination time. We conclude that modified clay could depress algal cell multiplication and promote formation of temporal cysts of S. trochoidea, which may help in controlling HAB outbreaks. 相似文献
19.
Dynamics of phytoplankton communities in the Jiangdong Reservoir of Jiulong River,Fujian, South China 总被引：2，自引：0，他引：2
Phytoplankton blooms occurring in the Jiangdong Reservoir of Jiulong River, Fujian Province, South China, are a potential source of contamination of the drinking water of Xiamen （Amoy） City. To understand the main factors governing phytoplankton composition and succession, we sampled phytoplankton and measured environmental parameters in the reservoir, weekly or biweekly from Jan. 2010 to Feb. 2012. We identified 123 species of phytoplankton from 7 phyla and 74 genera. The major phyla were Chlorophyta, Bacillariophyta, Cryptophyta, Cyanophyta, and Dinophyta. The main trend in the succession of phytoplankton was from prevalence of Cryptophyta-Bacillariophyta communities to those of Chlorophyta-Cyanophyta. High cell concentrations of Cryptophyta, predominantly Komma caudate, Cryptomonas marssonii, and Cryptomonas erosa, were present in winter, associated with low river discharge and cold water. Bacillariophyta, primarily Cyclotella meneghiniana, Aulacoseira granulata, and Aulacoseira granulata var. angustissima, dominated in early spring, coinciding with high turbulence and low irradiance. During early summer and autumn, Chlorophyta, comprising Scenedesmus quadricauda, Dictyosphaerium ehrenbergianum, and Pandorina sp. were prevalent during conditions of warmer water temperatures and low turbulence. Cyanophyta, with dominance ofPseudanabaena mucicola, Merismopedia tenuissima and Raphidiopsis sp. increased throughout the summer, coinciding with higher water temperatures and lower nutrient concentrations. Dinophyta content was occasionally high during winter and summer. Peridiniopsis penardii （Dinophyta） bloomed during winter 2009, with a persistently high biomass recorded into early spring. Canonical correspondence analysis indicated that phytoplankton communities were influenced by river discharge, irradiance, water temperature, and nutrient concentrations. 相似文献
20.
Pigment characterization for the 2011 bloom in Qinhuangdao implicated "brown tide" events in China 总被引：6，自引：0，他引：6
A large-scale bloom occurred from May to June in 2011 in sea area near Qinhuangdao of the Bohai Sea, leading to huge damage of the scallop culture industry. Similar blooms have been observed in this region for three years. The causative species of the bloom, which dominated the phytoplankton community with the maximum cell density around 109 cell/L, could not be identified with morphological features due to the small cell size (~2 mm). A pigment analytical method was then adopted to analyze the pigment profile of the phytoplankton samples collected from the blooming sea area. It was found that pico-sized (<2 mm), nano-sized (2-20 mm), and bulk phytoplankton samples had similar pigment profile, representing the pigment signature of the bloom-causative species. The major pigments detected included 19-butanoyloxyfucoxanthin (But-fuco), fucoxanthin (Fuco), diadinoxanthin (Diad) and chlorophyll a (Chl a), and high content of But-fuco was the most significant characteristics of the phytoplankton samples. Based on the pigment composition and content, the bloom-causative species could be tentatively identified as pelagophyte, "type 8" group of haptophyte, or silicoflagellate. Some unique features of the bloom, such as the extremely high cell density, small-sized and But-fuco containing cells, occurring in early summer, and the feeding-cessation effects on scallops, suggest it be a "brown tide" event similar to those reported in the east coast of the United States of America. The recurrent "brown tide" events and their dramatic impacts on the shellfish mariculture industry in Qinhuangdao need close attention in the coming years. 相似文献