Information standardization for typical toxic and harmful algae in China's coastal waters——a case study of Karenia mikimotoi

To assist the researches of toxic and harmful algae and provide government workers with judgment basis for decision-making related events,we established a biological information management system for toxic and harmful algae in China’s of fshore to assist relevant research.In this study,Karenia mikimotoi was studied as a typical toxic and harmful algae species,and the basic biological information and biogeographic distribution information of K.mikimotoi were systematically studied and collected.In the part of basic biological information,the name,toxin,and molecular characteristic sequence of K.mikimotoi were sorted out by literature searching and website browsing.Through experimental means,the relevant information of morphological identifi cation,pigment composition,and lipid composition were obtained.In the part of biogeographic distribution information,this study sorted out the information of K.mikimotoi,analyzed the characteristics of its occurrence,and completed the standardized construction of biogeographic distribution information.Through the collation of basic biological information and biogeographic distribution information of K.mikimotoi,the standardization of related information was completed,which provided template and method reference for information collection of other toxic and harmful algae species,which was benefi cial to the database analysis and design.

The“harmful algae and algal toxins in coastal waters of China:investigation and database”project

The“harmful algae and algal toxins in coastal waters of China:investigation and database”project(HAATC)is funded(US$2.3 million)by the Ministry of Science and Technology of China for 60 months starting on the 1st Jan 2019.Since the 1990s,national projects and other related work have greatly improved harmful algal bloom(HAB)research in China.However,the existing research on HABs is often limited to specific sea areas or specific algal bloom disasters,which is insufficient for understanding the long-term evolution of HAB occurrence under the influence of intensified human activity and global change.The HAATC project intends to determine the overall distribution of marine harmful microalgae and macroalgae,and marine algal toxins(in phytoplankton and shellfish)through a large-scale investigation in the coastal waters of China and continuous investigation in key sea areas.It also aims to observe biotic and abiotic processes during harmful red tides and green tides,and establish an open database and query platform of HABs in China.The research consortium,led by chief scientist Prof.Tian YAN,includes approximately 100 scientists and students.More than 2 years of work have shown the increased distribution of HAB species(including cysts)and algal toxins in China’s coastal waters,the increased occurrence of macroalgae blooms(mainly by Ulva prolifera and Sargassum horneri)in the Southern Yellow Sea,increased amount of causative species being identified due to the use of molecular technologies in taxonomy,and new records of algal toxins such as azaspiracid,cycloimines and neurotoxinsβ-N-methylamino-l-alanine have been detected,which complicates the research in algal toxins and toxicology.Eventually,the project will provide systematic basic data and techniques for the rapid and accurate identification of harmful algae species to support the research,monitoring,and control of harmful algal blooms,as well as seafood safety management in China.

Detection of Phaeocystis globosa using sandwich hybridization integrated with nuclease protection assay(NPA-SH)

Phaeocystis globosa Scherffel is one of the common harmful algae species in coastal waters of the southeastern China.In this study,sandwich hybridization integrated with nuclease protection assay(NPA-SH)was used to qualitatively and quantitatively detect P. globosa.Results showed that this method had good applicability and validity in analyzing the samples from laboratory cultures and from fields.The linear regression equation for P.globosa was obtained,and the lowest detection number of cells was 1.8×104 c...

Environmental characteristics of annual pico/nanophytoplankton blooms along the Qinhuangdao Coast

Blooms of some pico/nanophytoplankton have occurred frequently along the Qinhuangdao coast since 2009, and it is necessary to identify the critical environmental factors inducing them. In this study, variations in the physical and nutrient characteristics of the seawater were analyzed following the development of local blooms in 2013. The local environmental characteristics were also compared with those of the Changjiang River estuary, China, and the Long Island estuaries in the USA, which are also prone to blooms of special algal species. In Qinhuangdao the local water temperature varied seasonally and rose above 15°C in 2013 early summer, coincident with the water discoloration. The salinity was more than 28 with a variation range of <3 throughout the year. Our results suggest that the physical conditions of the Qinhuangdao coastal area were suitable for the explosive proliferation of certain pico/nanophytoplankton, e.g. Aureococcus anophageff erens. The water supporting the bloom was not in a condition of serious eutrophication, but there were relatively high concentrations of reduced nitrogen(especially ammonium), which acted as an important nitrogen source for the pico/nanophytoplankton bloom. There was also a large gap between total nitrogen(TN) and dissolved inorganic nitrogen(DIN). Although the phosphate concentration was relatively low, there was no evidence of phosphorus limitation to the growth of pico/nanophytoplankton during bloom events.

Characterization of Amphidinium(Amphidiniales,Dinophyceae)species from the China Sea based on morphological,molecular,and pigment data

Amphidinium species are amongst the most abundant benthic dinoflagellates in marine intertidal sandy ecosystems.Some of them are able to produce a variety of bioactive compounds that can have both harmful effects and pharmaceutical potentials.The diversity of Amphidinium in shallow waters along the Chinese coast was investigated by isolating single cells from sand,coral,and macroalgal samples collected from 2012 to 2020.Their morphologies were subjected to examination using light microscopy(LM)and scanning electron microscopy(SEM).A total of 74 Amphidinium strains were morphologically identified,belonging to 11 species:A.carterae,A.gibbosum,A.operculatum,A.massartii,A.cf.massartii,A.fijiensis,A.pseudomassartii,A.steinii,A.thermaeum,A.theodori,A.tomasii,as well as an undefined species.The last seven species have not been previously reported in Chinese waters.Amphidinium carterae subcladesⅠ,Ⅱ,andⅣwere found in the South China Sea,while subcladeⅢwas only found in the Yellow Sea.Threadlike body scales were observed on the surface of subcladesⅢ and Ⅳ,supporting the idea that A.carterae might contain several different species.Large subunit ribosomal RNA(LSU rRNA)sequencesbased phylogeny revealed two groups(GroupsⅠandⅡ)within Amphidinium,which is consistent with the relative position of sulcus(in touch with cingulum or not).In addition,large differences in morphology and molecular phylogeny between A.operculatum(the type species of Amphidinium)and other species,suggest that a subdivision of Amphidinium might be needed.The pigment profiles of all available strains were analyzed by high performance liquid chromatography(HPLC).Eleven pigments,including peridinin,diadinoxanthin,diatoxanthin,pheophorbide(and pheophorbide a),antheraxanthin,β-carotene,and four different chlorophylls were detected.The high pheophorbide/pheophorbide a ratio in Amphidinium implies that it may be a good candidate as a natural source of photosensitizers,a well-known anticancer drug.

Ecological distribution of harmful epiphytic Oscillatoriales in Alexandria coast,Egypt,with special reference to DNA identification

Objective:To identify the potentially harmful epiphytic Oscillatoriales species and follow up their distribution along Alexandria coast.Methods:Samples were collected bimonthly from April 2009 to February 2010 at three sites along Alexandria coast.Both morphological and molecular analyses were used for identifying the dominant species.Results:Five species belonging to two families were identified;Oscillatoria acutissima,Oscillatoria nigroviridis,Oscillatoria sp.,Lyngbya majuscule and Phormidium formosum.Their cell density ranged from 10^(3)to 126×10^(3)filament g^(-1)fresh weight macroalgae.The morphological study of the dominant species,Oscillatoria sp.(Oscillatoria sp.W1)showed much similarity with Planktothrix agardhii with no heterocysts and akinetes,while molecular ananlysis(16S rDNA)clustered the species in the same group with Anabaena sp.Conclusions:The 16S rDNA genes are not suitable for identifying Oscillatoriales during the present study and another molecular method should be used instead.

Risk associated with toxic blooms of marine phytoplankton functional groups on Artemia franciscana

Objective:To study mortality of copepod Artemia franciscana against the occurrence of harmful marine algae and possible toxicological changes exhibited by binary and tertiary combinations of these harmful algae toxins.Methods:Tweenty four hours acute toxicity assays were performed with selected concentrations of Alexandrium minutum,Prorocentrum lima and Nitzschia N1c1 living cells.Additionally,the results were analyzed using the median-effect/combination index(CI)-isobologram equation to assess possible changes in the toxic effect induced by phytoplankton functional groups.Results:Biotoxin equivalent values obtained by immunodetection were(2.12±0.10),(8.60±1.30)and(4.32±1.67)pg/cell for saxitoxin,okadaic acid and domoic acid,respectively.The 24-h LC_(50) values estimated to saxitoxin and okadaic acid equivalents were 4.06 and 6.27μg/L,significantly below the value obtained for Nitzschia N1c1,which was established at 467.33μg/L.CI analysis applied on phytoplankton assemblages showed that both ternary mixture as the binary combinations exhibited antagonic action on toxic effects in Artemia nauplii,which were significantly lower than the toxic effect exhibited by each species studied.Conclusions:These results show that,although these harmful algae represent a serious risk to estuarine zooplankton community,the presence of phytoplankton functional groups within the same bloom can reduce the potential risk compared to the expected risk when each of the phytoplankton groups are evaluated individually.