The Yellow Sea(YS)and East China Sea(ECS)are highly dynamic marginal seas of the northwestern Pacific Ocean.To gain an in-depth understanding of zooplankton community structure,zooplankton abundance,biovolume,and size...The Yellow Sea(YS)and East China Sea(ECS)are highly dynamic marginal seas of the northwestern Pacific Ocean.To gain an in-depth understanding of zooplankton community structure,zooplankton abundance,biovolume,and size structure in summer 2017 in the YS and ECS were assessed using ZooScan imaging analysis.Zooplankton abundance and biovolume ranged 2.94–1187.14 inds./m^(3)and 3.13–3438.51 mm^(3)/m^(3),respectively.Based on the biovolume data of the categorized size classes of 26 identified taxonomic groups,the zooplankton community was classified into five groups,and each group was coupled with distinctive oceanographic features.Under the influence of the Yellow Sea Cold Water Mass,the Yellow Sea offshore group featured the lowest bottom temperature(10.84±3.42℃)and the most abundant Calanoids(mainly in the 2–3 mm size class).In the Yellow Sea inshore group,Hydrozoans showed the largest biovolume and dominated in the 3–4-mm and>5-mm size classes.The East China Sea offshore group,which was affected by the Kuroshio Branch Current,featured high temperature and salinity,and the lowest bottom dissolved oxygen(2.58±0.5 mg/L).The lowest values of zooplankton abundance and biovolume in the East China Sea offshore group might be attributed to the bottom dissolved oxygen contents.The East China Sea inshore group,which was mainly influenced by the Zhejiang-Fujian Coastal Current and Changjiang Diluted Water,was characterized by high chlorophyll a and the largest biovolume of carnivorous Siphonophores(280.82±303.37 mm^(3)/m^(3)).The Changjiang River estuary offshore group showed the most abundant Cyclopoids,which might be associated with the less turbid water mass in this region.Seawater temperature was considered the most important factor in shaping the size compositions of Calanoids in different groups.展开更多
Harmful algal blooms(HABs) can elicit several negative effects on aquatic environment(such as depleting the oxygen, blocking the sunlight, destroying the habitats of organisms) and life health(including poisoning/kill...Harmful algal blooms(HABs) can elicit several negative effects on aquatic environment(such as depleting the oxygen, blocking the sunlight, destroying the habitats of organisms) and life health(including poisoning/killing marine mammals, birds and human). Among the various control strategies for HABs(physical manipulation needs lots of manpower and expensive equipment, chemicals treatment has some toxic byproduct and high residual, microbial agents only has limited in laboratory research), the coagulation-flocculation of HAB species by modified clay(MC) has been proven to be an effective, lowcost and environmentally friendly method that has been widely applied in the field, particularly in eastern Asia. In order to examine the long-term effects of MC treatment, this study investigated the alternations in seawater of Skeletonema costatum, a high biomass dominant HAB species along the Chinese coast, by comparing the degradation of S. costatum detritus(A1) with the application of MC treatment(A2) and MC treatment in sediment condition(A3). The low dosage of 0.25 g/L MC could efficiently remove 4×108 cells/L of S. costatum cells within 3.5 h(approximately 97% removal). In addition, the results showed that both inorganic and organic nutrients were effectively reduced from seawater by MC particles. Compared to the total nitrogen(TN) and total phosphorus(TP) concentrations in A1 seawater, 44% of TN and 93% of TP in A2 seawater, as well as 72% of TN and 93% of TP in A3 seawater were removed during the onemonth incubation period. Simultaneously, 64% of DISi in A2 and 44% of DISi in A3 significantly decreased( P <0.001). This study demonstrated that MC treatment was able to significantly increase the downward flux of nutrients and delay the release velocity of inorganic nutrient from MC-algae matrix into the overlying seawater, particularly within sediment environment.展开更多
The Jiaozhou Bay is characterized by heavy eutrophication that is associated with intensive anthropogenic activities. Four core sediments from the Jiaozhou Bay are analyzed using bulk technologies, including sedimenta...The Jiaozhou Bay is characterized by heavy eutrophication that is associated with intensive anthropogenic activities. Four core sediments from the Jiaozhou Bay are analyzed using bulk technologies, including sedimentary total organic carbon（TOC）, total nitrogen（TN）, the stable carbon（δ13C） and nitrogen（δ15 N） isotopic composition to obtain the comprehensive understanding of the source and composition of sedimentary organic matter and further shed light on the environmental changes of the Jiaozhou Bay on a centennial time scale.Results suggest that the TOC and TN concentrations increase in the upper core, having indicated a probable eutrophication process since the 1920 s in the inner bay and the 2000 s in the bay mouth. The TOC and TN concentrations outside the bay have also changed since 1916 owing to the variation of terrigenous input.Considering TOC/TN ratio, δ13 C and δ15 N, it can be concluded there is a mixture of terrigenous and marine organic matter sources in the study area. A simple two end-member（terrigenous and marine） mixing model usingδ13 C indicats that 45%–79% of TOC in the Jiaozhou Bay is from the marine source. The environmental changes of the Jiaozhou Bay are recorded by geochemical proxies, which are influenced by the intensive anthropogenic activities（e.g., extensive use of fertilizers, and discharge of sewage） and climate changes（e.g., rainfall）.展开更多
In order to depict the distribution of diatom fossils in surface sediments and to establish a reliable reference data for further paleoenvironmental study in the Changjiang (Yangtze) River estuary and its adjacent wat...In order to depict the distribution of diatom fossils in surface sediments and to establish a reliable reference data for further paleoenvironmental study in the Changjiang (Yangtze) River estuary and its adjacent waters, the diatom fossils from 34 surface sediment samples and their relationship with environmental variables were analyzed by principal component analysis and redundancy correspondence analysis. The diversity and abundance of diatom fossils were analyzed. Some annual average parameters of the overlying water (salinity, temperature, turbidity, dissolved oxygen, depth, dissolved inorganic nitrogen, dissolved inorganic phosphate and dissolved inorganic silicate) were measured at each sampling site. A total of 113 diatom taxa and one silicoflagellate species were identified in the investigation area. Diatom fossils were better preserved in fine sediments. The absolute abundance of diatom fossils did not significantly diff er between inshore and off shore areas, the species diversity decreased from inshore to off shore. This may be because high nutrients and low salinity promoted the growth of more brackish species in coastal waters. The diatom taxa were divided into three groups, on the basis of their response and indication to environmental changes. For example, Actinocyclus ehrenbergii and Cyclotella stylorum were dominant in coastal waters (Group 1 and Group 3) with high nutrients and low salinity;the relative abundances of Paralia sulcata and Podosira stelliger were significantly higher in off shore sites (Group 2, average 39.5%), which were characterized by high salinity and deep water. Four environmental variables (salinity, dissolved inorganic nitrogen, temperature and water depth) explained the composition and distribution of diatom taxa independently ( P< 0.05), this finding can be applied in further paleoenvironmental reconstruction research in this area.展开更多
Ulva prolifera is the causative species of the annually occurring large-scale green tides in China since 2007.Its specific biological features on reproductivity strategies,as well as intra-species genetic diversity,ar...Ulva prolifera is the causative species of the annually occurring large-scale green tides in China since 2007.Its specific biological features on reproductivity strategies,as well as intra-species genetic diversity,are still largely unknown,especially at the genome level,despite their importance in understanding the formation and outbreak of massive green tides.In the present study,the restriction site-associated DNA genotyping approach(2b-RAD)was adopted to identify the genome-wide single-nucleotide polymorphisms(SNPs)of 54 individual thalli including samples collected from Subei Shoal in 2019 and Qingdao coast from 2019 to 2021.SNPs genotype results revealed that most of the thalli in 2019 and 2020 were haploid gametophytes,while only half of the thalli were gametophytes in 2021,indicating flexibility in the reproductive strategies for the formation of the green tides among different years and the dominance of asexual and vegetative reproductive mode for the floating period.Besides,population analysis was conducted,and it revealed a very low genetic diversity among samples from Subei Shoal and the Qingdao coast in the same year and a higher divergence among samples in different years.The results showed the efficiency of 2b-RAD in the exploration of SNPs in U.prolifera and provided the first genome-wide scale evidence for the origin of the large-scale green tides on the Qingdao coast.This study improved our understanding of the reproductive strategy and genetic diversity of the green tide causative species and will help further reveal the biological causes of the green tide in China.展开更多
The mechanisms underlying sex determination and differentiation have long intrigued researchers in the fields of development and evolutionary biology.The roughskin sculpin(Trachidermus fasciatus Heckel),displaying sex...The mechanisms underlying sex determination and differentiation have long intrigued researchers in the fields of development and evolutionary biology.The roughskin sculpin(Trachidermus fasciatus Heckel),displaying sexual dimorphism,provides an ideal model for studying the mechanisms.However,both genetic and genomic information concerning sex determination and differentiation,such as gonadal transcriptome data in roughskin sculpin,are lacking.Here,we present the first gonadal transcriptomes of roughskin sculpin and identify sex-related genes.We identified 8531 differentially expressed genes(DEGs),among them 4065 were upregulated in the ovary and 4466 upregulated in the testis.Several sex-related gene ontology(GO)terms were enriched in ovary-biased genes,including“binding of sperm to zona pellucida”,“egg coat formation”,“positive regulation of acrosome reaction”,“cell division”,and“cell cycle”,while the GO terms such as“spermatogenesis”,“sperm axoneme assembly”,“cilium assembly”,“cilium movement”,and“cilium movement involved in cell motility”were enriched in testis-biased genes.Moreover,six KEGG pathways were significantly enriched in the ovary,whereas only one was enriched in the testis.Of these DEGs,40 sex-related genes were identified,which including 26 testis-biased genes(such as Dmrtb 1,Gsdf,Sox 9 b,Wnt 4 b,Tcp 11 l 2,and Efhb),and 14 ovary-biased genes(such as Cyp 19 a 1 a,Foxh 1,Foxr 1,Gdf 3,Hsd 17 b 12,and Igf 2 bp 3).This gonadal transcript dataset would broaden our understanding of sex determination and differentiation mechanisms in roughskin sculpin,expand the genomic database,support future studies on sex-related gene functions,and facilitate molecular biology research into roughskin sculpin.展开更多
Deep-sea mining activities can potentially release metals,which pose a toxicological threat to deep-sea ecosystems.Nevertheless,due to the remoteness and inaccessibility of the deep-sea biosphere,there is insufficient...Deep-sea mining activities can potentially release metals,which pose a toxicological threat to deep-sea ecosystems.Nevertheless,due to the remoteness and inaccessibility of the deep-sea biosphere,there is insufficient knowledge about the impact of metal exposure on its inhabitants.In this study,deep-sea mussel Gigantidas platifrons,a commonly used deep-sea toxicology model organism,was exposed to manganese(100,1000μg/L)or iron(500,5000μg/L)for 7 d,respectively.Manganese and iron were chosen for their high levels of occurrence within deep-sea deposits.Metal accumulation and a battery of biochemical biomarkers related to antioxidative stress in superoxide dismutase(SOD),catalase(CAT),malondialdehyde(MDA);immune function in alkaline phosphatase(AKP),acid phosphatase(ACP);and energy metabolism in pyruvate kinase(PK)and hexokinase(HK)were assessed in mussel gills.Results showed that deep-sea mussel G.platifrons exhibited a high capacity to accumulate Mn/Fe.In addition,most tested biochemical parameters were altered by metal exposure,demonstrating that metals could induce oxidative stress,suppress the immune system,and affect energy metabolism of deep-sea mussels.The integrated biomarker response(IBR)approach indicated that the exposure to Mn/Fe had a negative impact on deep-sea mussels,and Mn demonstrated a more harmful impact on deep-sea mussels than Fe.Additionally,SOD and CAT biomarkers had the greatest impact on IBR values in Mn treatments,while ACP and HK were most influential for the low-and high-dose Fe groups,respectively.This study represents the first application of the IBR approach to evaluate the toxicity of metals on deep-sea fauna and serves as a crucial framework for risk assessment of deep-sea mining-associated metal exposure.展开更多
Meroplankton play a crucial role in both benthic and pelagic ecosystems.Existing quantitative research on estimating the quantities of meroplankton groups is both underrepresented and inaccurate.To investigate and eva...Meroplankton play a crucial role in both benthic and pelagic ecosystems.Existing quantitative research on estimating the quantities of meroplankton groups is both underrepresented and inaccurate.To investigate and evaluate the influence of varying mesh sizes(505 and 160μm)on the sampling efficiency of meroplankton,we conducted an examination using two commonly used plankton nets during the spring season in the Southern Yellow Sea(SYS).Our study revealed a total of 12 meroplankton groups,with 9 groups identified in the 505-μm mesh nets and 11 groups in the 160-μm mesh nets.The results demonstrated the superior collection efficiency of the 160-μm net compared to the 505-μm net across the majority of meroplankton groups.Furthermore,we focused on exploring the abundance,distribution patterns,and realized niches of meroplankton collected by the two mesh size nets,and observed that the distribution of meroplankton closely resembled the distribution of possible benthic adults in the SYS.Correlation analysis of the six dominant groups collected in the 160-μm mesh nets revealed that seawater temperature and salinity emerged as the key environmental factors driving variations in meroplankton abundance within the SYS.This study also found that a smaller mesh size net does not necessarily capture meroplankton more comprehensively.A comprehensive understanding of the ecological characteristics of meroplankton requires the combination of two types of nets for research.Our research significantly advances our understanding of the quantification,abundance,and distribution of meroplankton,serving as a valuable contribution to the broader landscape of detailed quantitative meroplankton studies.展开更多
A sudden and unprecedented outbreak of molluscan Philine kinglipini occurred in summer 2022 in Jiaozhou Bay,Shandong,China,causing substantial damage to local mariculture industry of the Manila clam Ruditapes philippi...A sudden and unprecedented outbreak of molluscan Philine kinglipini occurred in summer 2022 in Jiaozhou Bay,Shandong,China,causing substantial damage to local mariculture industry of the Manila clam Ruditapes philippinarum.Although P.kinglipini has been found in many coastal regions of China,the molecular research of P.kinglipini has not been extensively studied,making it difficult to accurately identify and track P.kinglipini samples in field using molecular methods.Samples were collected during the outbreak and their morphological features and molecular sequences were analyzed.Results show that the causative species of the outbreak was P.kinglipini.The mitochondrial genome(mt DNA)of P.kinglipini was constructed for the first time,based on which phylogenetic analysis of the mt DNAs of P.kinglipini and related species in the order Cephalaspidea was carried out.As revealed by metabarcoding analysis of 18S rDNA V4,the seasonal change of P.kinglipini and closely related Philine species was striking with peaks between April and August.Therefore,metabarcoding analysis is applicable tool for monitoring the bloom development of P.kinglipini and related species.This study generated for the first time essential molecular marker sequences and mtDNA of P.kinglipini,which provided a reference for future characterization and monitoring of its outbreaks and for phylogenetic analysis of Philine species.展开更多
Cyanea nozakii,a common jellyfish distributed in offshore China,has a complex trophic relationship with other zooplankton groups.However,few studies have reported the predation rates and prey selection patterns of C.n...Cyanea nozakii,a common jellyfish distributed in offshore China,has a complex trophic relationship with other zooplankton groups.However,few studies have reported the predation rates and prey selection patterns of C.nozakii medusae on different prey items.Research is also lacking on the intraguild predation of Aurelia coerulea(another common bloom jellyfish in offshore China)by C.nozakii.To address the knowledge gaps,the clearance rates of C.nozakii for different prey items,including copepods(small<1000μm and large>1000μm),fish larvae,and gelatinous prey(hydromedusae,A.coerulea ephyrae,and chaetognaths),were measured.The influence of predator size on the clearance rate was also determined.Additionally,we examined the intraguild predation of C.nozakii on A.coerulea medusae.The clearance rates of C.nozakii varied widely with prey organisms,being independent of prey concentrations.Gelatinous organisms,except for chaetognaths,were captured with considerably high efficiency,followed by fish larvae and copepods,indicating the preferential prey selection of gelatinous organisms by C.nozakii.The clearance rate increased linearly with the cross-sectional area of C.nozakii.Body size in medusae may,to some extents,underpin their capacity to capture more prey by increasing the encounter rate and capture success through ontogeny.C.nozakii preyed voraciously on A.coerulea in high feeding efficiency,but the clearance rate decreased with increasing A.coerulea(as prey)size.This phenomenon of intraguild predation suggests a speculative hypothesis of potential population regulation of A.coerulea by C.nozakii.The information regarding the feeding ecology of C.nozakii reported in this study is important for understanding plankton dynamics in marine ecosystems with extensive occurrences of this jellyfish.展开更多
Differences among species in prosome length and in species' response to environmental factors do exist. Therefore, it is useful to examine prosome length for different copepod species in variable environments. Sea...Differences among species in prosome length and in species' response to environmental factors do exist. Therefore, it is useful to examine prosome length for different copepod species in variable environments. Seasonal variations in prosome length of four small copepods and their copepodite stages in the Jiaozhou Bay were compared and the relative influence of temperature, salinity, and chlorophyll concentration were examined. Two peaks were found in the mean prosome length of Paracalanus parvus (in early winter and May). For Acartia bifilosa, the maximum values of all copepodites occurred mainly from February to April, and decreased to the bottom in July. Prosome length of Acartia pacifica peaked when it first appeared in June, then reached to the minimum in July. Parvocalanus crassirostris only appeared from late summer to autumn and the mean prosome length showed no clear changes. Correlations of adult prosome length with environmental factors were evaluated. For the four species, temperature was negatively correlated to prosome length except for P. crassirostris. But the different species varied markedly in their responds to temperature. A. bifilosa showed a more definite trend of size variation with temperature than P. parvus and A. pacifica. Correlations of prosome length with salinity were significantly positive for almost all the small copepods. The relationship between chlorophyll concentration and prosome length was complicated for these copepods, but for P. parvus, chlorophyll concentration was also an important affecting factor. Furthermore, investigation needs to be done on food quality for some copepod. These results are essential to estimate the biomass and the production, and to understand these small copepods' population dynamics in this human-affected bay.展开更多
Polar zooplankton are particularly sensitive to climate change, and have been used as rapid-responders to indicate climate-induced changes in the fragile Antarctic ecosystem. DNA barcoding provides an alternative appr...Polar zooplankton are particularly sensitive to climate change, and have been used as rapid-responders to indicate climate-induced changes in the fragile Antarctic ecosystem. DNA barcoding provides an alternative approach for rapid zooplankton species identification. Ninety-four specimens belonging to 32 Antarctic zooplankton species were barcoded to construct a compre- hensive reference library. An 830 to 1 050 base-pair region of the mitochondrial cytochrome c oxidase subunit I （mtCOI） gene was obtained as DNA barcodes. The intraspecific variation of the gene ranged from 0 to 2.6% （p-distance）, with an average of 0.67% （SD=0.67%）. The distance between species within the same genera ranged from 0.1% （Calanus） to 29.3%, with an average of 15.3% （SD=8.4%）. The morphological and genetic similarities between Calanus propinquus and C. simillimus raise new questions about the taxonomic status of C. simillimus. With the exception of the two Calanus species, the intraspecific genetic divergence was much smaller than the interspecific divergence among congeneric species, confirming the existence of a barcode gap for Ant- arctic zooplankton. In addition, species other than Calanus sp. formed a monophyletic group. Therefore, we have confirmed DNA barcoding as an accurate and efficient approach for zooplankton identification in the Antarctic area （except for Hydromedusa, Tu- nicata, and other gelatinous zooplankton）. Indicator vector analysis further confirmed this conclusion. The new primer sets issued here may facilitate the study of Antarctic marine zooplankton species composition by environmental metagenetic analysis.展开更多
Biological CO2 sequestration by microalgae is a promising and environmentally friendly technology applied to sequester CO2. The characteristics of neutral lipid accumulation by two marine oil-rich microalgal strains,n...Biological CO2 sequestration by microalgae is a promising and environmentally friendly technology applied to sequester CO2. The characteristics of neutral lipid accumulation by two marine oil-rich microalgal strains,namely, Isochrysis galbana and Nannochloropsis sp., through CO2 enrichment cultivation were investigated in this study. The optimum culture conditions of the two microalgal strains are 10% CO2 and f medium. The maximum biomass productivity, total lipid content, maximum lipid productivity, carbon content, and CO2 fixation ability of the two microalgal strains were obtained. The corresponding parameters of the two strains were as follows：（（142.42±4.58） g/（m^2·d）,（149.92±1.80） g/（m^2·d））,（（39.95±0.77）%,（37.91±0.58）%）,（（84.47±1.56） g/（m^2·d）,（89.90±1.98） g/（m^2·d））,（（45.98±1.75）%,（46.88±2.01）%）, and（（33.74±1.65） g/（m^2·d）,（34.08±1.32） g/（m^2·d））. Results indicated that the two marine microalgal strains with high CO2 fixation ability are potential strains for marine biodiesel development coupled with CO2 emission reduction.展开更多
Phytoplankton are central components of marine environments,and are major players in the production and respiration budgeting.However,their diversity and distribution patterns are still poorly understood due largely t...Phytoplankton are central components of marine environments,and are major players in the production and respiration budgeting.However,their diversity and distribution patterns are still poorly understood due largely to their small sizes and inconspicuous morphology that have been determined via the application of traditional morphology methods over the past two decades.To better understand the composition and diversity of phytoplankton in Jiaozhou Bay,China,seasonal sampling was carried out in 2019 and samples were analyzed with morphological observations and high-throughput sequencing,from which obvious seasonal variations in phytoplankton composition and proportional abundances were uncovered.Metabarcoding revealed far more diversity and species richness of phytoplankton than morphological observations,especially with respect to dinofl agellates.Diatoms were the most dominant phytoplankton group throughout the year,of which Thalassionema and Skeletonema were co-dominant in the bay.Parasitic dinofl agellates(e.g.Amoebophrya),which is often overlooked in the morphological observations,were in dominance and high diversity in the metabarcoding dataset,thus more attention should be paid to exploring the potential role of parasitic dinofl agellates.Temperature,chlorophyll a,and nutrient levels were the main infl uential factors on the distribution of phytoplankton.This study provided a comprehensive morphological and molecular description of phytoplankton and clearly demonstrated the importance of molecular technology in exploring phytoplankton communities.More-widespread use of molecular technology will facilitate deeper understanding of the ecological importance of the diff erent species.展开更多
This study investigates the composition,abundance,and basic biological parameters of krill in Prydz Bay,Antarctic Peninsula and Amundsen Sea by analyzing samples and environmental data from the Chinese National Antarc...This study investigates the composition,abundance,and basic biological parameters of krill in Prydz Bay,Antarctic Peninsula and Amundsen Sea by analyzing samples and environmental data from the Chinese National Antarctic Research Expeditions conducted between 2009/2010 and 2019/2020.The predominant krill species observed were Euphausia superba,Euphausia crystallorophias,and Thysanoessa macrura.T.macrura,although the most widespread,exhibited the lowest mean abundance 9.96 ind:(1000 m^(-3))and biomass 0.31 g(1000 m^(-3)),predominantly found in low-latitude regions of the Amundsen Sea while E.crystallorophias was most concentrated in polynyas of Prydz Bay.E.superba,with an average abundance of 34.05 ind(1000 m^(-3))and biomass of 11.80 g:(1000 m^(-3)),was mainly distributed in the Antarctic Peninsula and Prydz Bay.This study also identified regional variations in mean body length and frequency distributions of kril.The relationship between krill body length and wet weight followed a power-law pattern.Regional differences were observed in the relationship between krill abundance,biomass,and environmental factors with varying correlations.In the Amundsen Sea,no significant correlation was found between krill abundance and environmental factors.Notably,E.crystallorophias in Prydz Bay demonstrated a significant positive correlation with chlorophyll a concentration,while T.macrura abundance and biomass in the Antarctic Peninsula exhibited a significant negative correlation with ice-free days.The findings contribute valuable regional data on krll distribution,abundance,and biomass in the Southern Ocean,serving as foundational information for the conservation of the Southern Ocean ecosystem and Antarctic krill fishery management on a circumpolar scale.展开更多
To evaluate how the decay of bloom-forming algae affect the coastal dissolved oxygen,a laboratory simulation was conducted in terms of three typical harmful algae,Alexandrium catenella,Prorocentrum donghaiense,and Ske...To evaluate how the decay of bloom-forming algae affect the coastal dissolved oxygen,a laboratory simulation was conducted in terms of three typical harmful algae,Alexandrium catenella,Prorocentrum donghaiense,and Skeletonema costatum.Algae of same biomass(55μg/mL)were conducted in lightproof columns,and the cell density,dissolved oxygen(DO),and ammonia nitrogen of different layers were monitored at certain time series.Results show that the decomposition of algae significantly decreased the DO,and increased the ammonia nitrogen in all layers;and significant deference between different species was observed.The A.catenella treatment showed the lowest DO(average concentration of 3.4 mg/L)and the highest ammonia nitrogen(average concentration of 0.98 mg/L)at the end of test,followed by P.donghaiense;and the S.costatum showed relatively high DO and low ammonia nitrogen due to slow decay rate.Results indicate that decomposition of harmful bloom algae,especially dinoflagellate,would cause significantly DO depletion and toxic ammonia nitrogen increase,which will detrimentally affect both pelagic and benthic ecosystem.展开更多
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 a...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 venefi cum , Margalefi dinium polykrikoides , Prorocentrum donghaiense , P . minimum , Scrippsiella trochoidea , and Heterosigma akashiwo ) using gas chromatography-mass spectrometry in full scan and selected ion monitoring (SIM) modes. Our results show a ubiquitous presence of carbonyl compounds 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 identifi ed 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 identifi ed and quantifi ed 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 confi rmed that trans-2-nonenal could be produced by K . mikimotoi , Karl . venefi cum , 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 dinofl agellate 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 fi shkilling or allelopathy which needs further identifi cation and quantifi cation.展开更多
Harmful algal blooms(HABs)in the Southern Yellow Sea(SYS)have shown a trend of increasing diversity and detrimental ef fects.While the Bohai Sea,East China Sea,and South China Sea have experienced a high incidence of ...Harmful algal blooms(HABs)in the Southern Yellow Sea(SYS)have shown a trend of increasing diversity and detrimental ef fects.While the Bohai Sea,East China Sea,and South China Sea have experienced a high incidence of HABs since the 1980s,the Yellow Sea provides a relatively healthy ecological environment in which fewer HABs have been documented before the 21s t century.Yet largescale blooms of the green macroalga Ulva prolifera(so-called“green tides”)have occurred annually since 2007 in the Yellow Sea.Six people were poisoned and one person died in Lianyungang in 2008 due to ingestion of algal toxins.Moreover,the Yellow Sea experienced co-occurrence of harmful red tides,green tides,and golden tides in 2017.This combination of events,rare worldwide,indicates the potential for further deterioration of the marine environment in the Yellow Sea,which may be related to climate change,aquaculture,and other human activities.Using the SYS as an example,we collected data of the frequency and scale of HABs over the years,as well as that of marine algal toxins,and analyzed the trend in the diversity of HABs in the SYS,to explore the causes and impacts of HABs,as well as the interrelationships among dif ferent types of HABs,including harmful red tides,green tides,and golden tides.We also attempted to improve our understanding of HAB evolution under the influence of global climate change and intensified human activities.展开更多
Lipophilic marine toxins(LMTs)produced by some microalgae in the sea could accumulate in shellfish and pose potential threats to the health of seafood consumers.Phytoplankton and shellfish samples were collected from ...Lipophilic marine toxins(LMTs)produced by some microalgae in the sea could accumulate in shellfish and pose potential threats to the health of seafood consumers.Phytoplankton and shellfish samples were collected from coastal waters of Weihai in Shandong Peninsula,China in autumn,2020,and screened for lipophilic marine toxins and their potential producers using liquid chromatography-tandem mass spectrometry(LC-MS/MS)analysis and high throughput sequencing of partial DNA(V4 region of the 18S rRNA gene)extracted from phytoplankton.Pectenotoxin-2(PTX2),trace amounts of azaspiracid(AZA1 or AZA40),and 13-desmethyl spirolide C(13-DesMe-C)were detected in phytoplankton samples,while PTX2 and gymnodimine(GYM)were detected in shellfish samples.The toxin content in shellfish samples was much lower than the regulatory limit or values reported previously.Results suggest that lipophilic marine toxins should have low risk in coastal waters of Weihai in autumn.Based on the data of high throughput sequencing,the OTUs were assigned to 5 identified species of Alexandrium,including A.ostenfeldii capable of producing 13-DesMe-C and GYM.Two OTUs were found closely related to the toxic species in genus Dinophysis,but it is impossible to assign them to any identified species due to the low resolving power of the V4 region for Dinophysis.The OTUs could not be assigned to any identified species in the genus Azadinium,suggesting the existence of unidentified species in this region.展开更多
Hydantoinase is involved in the production of optically pure amino acids from racemic 5-mono-substituted hydantoins. We measured the D-hydantoinase activity in marine Halomonas sp. YSR-3 and amplified the D-hydantoina...Hydantoinase is involved in the production of optically pure amino acids from racemic 5-mono-substituted hydantoins. We measured the D-hydantoinase activity in marine Halomonas sp. YSR-3 and amplified the D-hydantoinase gene by PCR. The gene was inserted into vector pGM-T and transformed into E. coli TOP10. The positive transformants with the D-hydantoinase gene were sequenced. The sequenced fragment comprises 1 510 base pairs. The D-hydantoinase gene from YSR-3 is 77% similar to that from Pseudomonas entornophila L4 by searching against the NCBI databse. The protein product of the YSR-3 D-hydantoinase gene is 75%, 73%, and 70% similar to those from Pseudomonasfluorescens Pf-5, Marinornonas sp. MED121, and Burkholderia vietnamiensis G4, respectively. The difference of the D-hydantoinase gene between marine Halornonas sp. YSR-3 and other terrestrial organisms is distinct.展开更多
基金the International Science Partnership Program of the Chinese Academy of Sciences(No.133137KYSB20200002)the Laoshan Laboratory(No.LSKJ202204005)+3 种基金the State Key Program of National Natural Science of China(No.42130411)the International Science Partnership Program of the Chinese Academy of Sciences(No.121311KYSB20190029)the Aoshan Science and Technology Innovation Program(No.2016ASKJ02-4)the Taishan Scholars Project(to Song SUN)。
文摘The Yellow Sea(YS)and East China Sea(ECS)are highly dynamic marginal seas of the northwestern Pacific Ocean.To gain an in-depth understanding of zooplankton community structure,zooplankton abundance,biovolume,and size structure in summer 2017 in the YS and ECS were assessed using ZooScan imaging analysis.Zooplankton abundance and biovolume ranged 2.94–1187.14 inds./m^(3)and 3.13–3438.51 mm^(3)/m^(3),respectively.Based on the biovolume data of the categorized size classes of 26 identified taxonomic groups,the zooplankton community was classified into five groups,and each group was coupled with distinctive oceanographic features.Under the influence of the Yellow Sea Cold Water Mass,the Yellow Sea offshore group featured the lowest bottom temperature(10.84±3.42℃)and the most abundant Calanoids(mainly in the 2–3 mm size class).In the Yellow Sea inshore group,Hydrozoans showed the largest biovolume and dominated in the 3–4-mm and>5-mm size classes.The East China Sea offshore group,which was affected by the Kuroshio Branch Current,featured high temperature and salinity,and the lowest bottom dissolved oxygen(2.58±0.5 mg/L).The lowest values of zooplankton abundance and biovolume in the East China Sea offshore group might be attributed to the bottom dissolved oxygen contents.The East China Sea inshore group,which was mainly influenced by the Zhejiang-Fujian Coastal Current and Changjiang Diluted Water,was characterized by high chlorophyll a and the largest biovolume of carnivorous Siphonophores(280.82±303.37 mm^(3)/m^(3)).The Changjiang River estuary offshore group showed the most abundant Cyclopoids,which might be associated with the less turbid water mass in this region.Seawater temperature was considered the most important factor in shaping the size compositions of Calanoids in different groups.
基金Supported by the National Natural Science Foundation of China(No.41276115)the National Basic Research Program of China(973 Program)(No.2010CB428706)the Fund for Creative Research Groups by NSFC(No.41121064)
文摘Harmful algal blooms(HABs) can elicit several negative effects on aquatic environment(such as depleting the oxygen, blocking the sunlight, destroying the habitats of organisms) and life health(including poisoning/killing marine mammals, birds and human). Among the various control strategies for HABs(physical manipulation needs lots of manpower and expensive equipment, chemicals treatment has some toxic byproduct and high residual, microbial agents only has limited in laboratory research), the coagulation-flocculation of HAB species by modified clay(MC) has been proven to be an effective, lowcost and environmentally friendly method that has been widely applied in the field, particularly in eastern Asia. In order to examine the long-term effects of MC treatment, this study investigated the alternations in seawater of Skeletonema costatum, a high biomass dominant HAB species along the Chinese coast, by comparing the degradation of S. costatum detritus(A1) with the application of MC treatment(A2) and MC treatment in sediment condition(A3). The low dosage of 0.25 g/L MC could efficiently remove 4×108 cells/L of S. costatum cells within 3.5 h(approximately 97% removal). In addition, the results showed that both inorganic and organic nutrients were effectively reduced from seawater by MC particles. Compared to the total nitrogen(TN) and total phosphorus(TP) concentrations in A1 seawater, 44% of TN and 93% of TP in A2 seawater, as well as 72% of TN and 93% of TP in A3 seawater were removed during the onemonth incubation period. Simultaneously, 64% of DISi in A2 and 44% of DISi in A3 significantly decreased( P <0.001). This study demonstrated that MC treatment was able to significantly increase the downward flux of nutrients and delay the release velocity of inorganic nutrient from MC-algae matrix into the overlying seawater, particularly within sediment environment.
基金The Joint Fund between Natural Science Foundation of China and Shandong Province under contract No.U1606404the National Basic Research Program(973 Program)of China under contract Nos 2015CB452901 and 2015CB452902+1 种基金the National Key Research and Development Plan Sino-Australian Centre for Healthy Coasts under contract No.2016YFE0101500the Program for Aoshan Excellent Scholars of Qingdao National Laboratory for Marine Science and Technology of China under contract No.2015ASTP-OS13
文摘The Jiaozhou Bay is characterized by heavy eutrophication that is associated with intensive anthropogenic activities. Four core sediments from the Jiaozhou Bay are analyzed using bulk technologies, including sedimentary total organic carbon（TOC）, total nitrogen（TN）, the stable carbon（δ13C） and nitrogen（δ15 N） isotopic composition to obtain the comprehensive understanding of the source and composition of sedimentary organic matter and further shed light on the environmental changes of the Jiaozhou Bay on a centennial time scale.Results suggest that the TOC and TN concentrations increase in the upper core, having indicated a probable eutrophication process since the 1920 s in the inner bay and the 2000 s in the bay mouth. The TOC and TN concentrations outside the bay have also changed since 1916 owing to the variation of terrigenous input.Considering TOC/TN ratio, δ13 C and δ15 N, it can be concluded there is a mixture of terrigenous and marine organic matter sources in the study area. A simple two end-member（terrigenous and marine） mixing model usingδ13 C indicats that 45%–79% of TOC in the Jiaozhou Bay is from the marine source. The environmental changes of the Jiaozhou Bay are recorded by geochemical proxies, which are influenced by the intensive anthropogenic activities（e.g., extensive use of fertilizers, and discharge of sewage） and climate changes（e.g., rainfall）.
基金Supported by the National Natural Science Foundation of China(No.41506142)the NSFC-Shandong Joint Fund for Marine Science Research Centers(No.U1606404)the Sino-Australian Centre for Healthy Coasts of National Key Research and Development Plan(No.2016YFE0101500)
文摘In order to depict the distribution of diatom fossils in surface sediments and to establish a reliable reference data for further paleoenvironmental study in the Changjiang (Yangtze) River estuary and its adjacent waters, the diatom fossils from 34 surface sediment samples and their relationship with environmental variables were analyzed by principal component analysis and redundancy correspondence analysis. The diversity and abundance of diatom fossils were analyzed. Some annual average parameters of the overlying water (salinity, temperature, turbidity, dissolved oxygen, depth, dissolved inorganic nitrogen, dissolved inorganic phosphate and dissolved inorganic silicate) were measured at each sampling site. A total of 113 diatom taxa and one silicoflagellate species were identified in the investigation area. Diatom fossils were better preserved in fine sediments. The absolute abundance of diatom fossils did not significantly diff er between inshore and off shore areas, the species diversity decreased from inshore to off shore. This may be because high nutrients and low salinity promoted the growth of more brackish species in coastal waters. The diatom taxa were divided into three groups, on the basis of their response and indication to environmental changes. For example, Actinocyclus ehrenbergii and Cyclotella stylorum were dominant in coastal waters (Group 1 and Group 3) with high nutrients and low salinity;the relative abundances of Paralia sulcata and Podosira stelliger were significantly higher in off shore sites (Group 2, average 39.5%), which were characterized by high salinity and deep water. Four environmental variables (salinity, dissolved inorganic nitrogen, temperature and water depth) explained the composition and distribution of diatom taxa independently ( P< 0.05), this finding can be applied in further paleoenvironmental reconstruction research in this area.
基金Supported by the Laoshan Laboratory (No.LSKJ202204005)the Mount Tai Scholar Climbing Plan to Song SUNthe Open Fund of CAS Key Laboratory of Marine Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences (No.KLMEES201801)
文摘Ulva prolifera is the causative species of the annually occurring large-scale green tides in China since 2007.Its specific biological features on reproductivity strategies,as well as intra-species genetic diversity,are still largely unknown,especially at the genome level,despite their importance in understanding the formation and outbreak of massive green tides.In the present study,the restriction site-associated DNA genotyping approach(2b-RAD)was adopted to identify the genome-wide single-nucleotide polymorphisms(SNPs)of 54 individual thalli including samples collected from Subei Shoal in 2019 and Qingdao coast from 2019 to 2021.SNPs genotype results revealed that most of the thalli in 2019 and 2020 were haploid gametophytes,while only half of the thalli were gametophytes in 2021,indicating flexibility in the reproductive strategies for the formation of the green tides among different years and the dominance of asexual and vegetative reproductive mode for the floating period.Besides,population analysis was conducted,and it revealed a very low genetic diversity among samples from Subei Shoal and the Qingdao coast in the same year and a higher divergence among samples in different years.The results showed the efficiency of 2b-RAD in the exploration of SNPs in U.prolifera and provided the first genome-wide scale evidence for the origin of the large-scale green tides on the Qingdao coast.This study improved our understanding of the reproductive strategy and genetic diversity of the green tide causative species and will help further reveal the biological causes of the green tide in China.
基金Supported by the National Natural Science Foundation of China(Nos.31972793,31502169)the Key Scientific Research Project in Universities and Colleges in Tianjin(No.2022ZD004)。
文摘The mechanisms underlying sex determination and differentiation have long intrigued researchers in the fields of development and evolutionary biology.The roughskin sculpin(Trachidermus fasciatus Heckel),displaying sexual dimorphism,provides an ideal model for studying the mechanisms.However,both genetic and genomic information concerning sex determination and differentiation,such as gonadal transcriptome data in roughskin sculpin,are lacking.Here,we present the first gonadal transcriptomes of roughskin sculpin and identify sex-related genes.We identified 8531 differentially expressed genes(DEGs),among them 4065 were upregulated in the ovary and 4466 upregulated in the testis.Several sex-related gene ontology(GO)terms were enriched in ovary-biased genes,including“binding of sperm to zona pellucida”,“egg coat formation”,“positive regulation of acrosome reaction”,“cell division”,and“cell cycle”,while the GO terms such as“spermatogenesis”,“sperm axoneme assembly”,“cilium assembly”,“cilium movement”,and“cilium movement involved in cell motility”were enriched in testis-biased genes.Moreover,six KEGG pathways were significantly enriched in the ovary,whereas only one was enriched in the testis.Of these DEGs,40 sex-related genes were identified,which including 26 testis-biased genes(such as Dmrtb 1,Gsdf,Sox 9 b,Wnt 4 b,Tcp 11 l 2,and Efhb),and 14 ovary-biased genes(such as Cyp 19 a 1 a,Foxh 1,Foxr 1,Gdf 3,Hsd 17 b 12,and Igf 2 bp 3).This gonadal transcript dataset would broaden our understanding of sex determination and differentiation mechanisms in roughskin sculpin,expand the genomic database,support future studies on sex-related gene functions,and facilitate molecular biology research into roughskin sculpin.
基金Supported by the Marine S&T Fund of Shandong Province for Qingdao Marine Science and Technology Center(No.2022QNLM030004-1)the National Natural Science Foundation of China(Nos.42276153,42030407)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB42020401)the Key Research Program of Frontier Sciences,CAS(No.ZDBS-LY-DQC032)the National Key R&D Program of China(No.2022YFC2804003)。
文摘Deep-sea mining activities can potentially release metals,which pose a toxicological threat to deep-sea ecosystems.Nevertheless,due to the remoteness and inaccessibility of the deep-sea biosphere,there is insufficient knowledge about the impact of metal exposure on its inhabitants.In this study,deep-sea mussel Gigantidas platifrons,a commonly used deep-sea toxicology model organism,was exposed to manganese(100,1000μg/L)or iron(500,5000μg/L)for 7 d,respectively.Manganese and iron were chosen for their high levels of occurrence within deep-sea deposits.Metal accumulation and a battery of biochemical biomarkers related to antioxidative stress in superoxide dismutase(SOD),catalase(CAT),malondialdehyde(MDA);immune function in alkaline phosphatase(AKP),acid phosphatase(ACP);and energy metabolism in pyruvate kinase(PK)and hexokinase(HK)were assessed in mussel gills.Results showed that deep-sea mussel G.platifrons exhibited a high capacity to accumulate Mn/Fe.In addition,most tested biochemical parameters were altered by metal exposure,demonstrating that metals could induce oxidative stress,suppress the immune system,and affect energy metabolism of deep-sea mussels.The integrated biomarker response(IBR)approach indicated that the exposure to Mn/Fe had a negative impact on deep-sea mussels,and Mn demonstrated a more harmful impact on deep-sea mussels than Fe.Additionally,SOD and CAT biomarkers had the greatest impact on IBR values in Mn treatments,while ACP and HK were most influential for the low-and high-dose Fe groups,respectively.This study represents the first application of the IBR approach to evaluate the toxicity of metals on deep-sea fauna and serves as a crucial framework for risk assessment of deep-sea mining-associated metal exposure.
基金Supported by the Laoshan Laboratory(Nos.LSKJ 202203700,LSKJ 202203704,LSKJ 202204005)the National Natural Science Foundation of China(NSFC)(Nos.42076166,42130411)the NSFC Ship Time Sharing Project(No.42149901)。
文摘Meroplankton play a crucial role in both benthic and pelagic ecosystems.Existing quantitative research on estimating the quantities of meroplankton groups is both underrepresented and inaccurate.To investigate and evaluate the influence of varying mesh sizes(505 and 160μm)on the sampling efficiency of meroplankton,we conducted an examination using two commonly used plankton nets during the spring season in the Southern Yellow Sea(SYS).Our study revealed a total of 12 meroplankton groups,with 9 groups identified in the 505-μm mesh nets and 11 groups in the 160-μm mesh nets.The results demonstrated the superior collection efficiency of the 160-μm net compared to the 505-μm net across the majority of meroplankton groups.Furthermore,we focused on exploring the abundance,distribution patterns,and realized niches of meroplankton collected by the two mesh size nets,and observed that the distribution of meroplankton closely resembled the distribution of possible benthic adults in the SYS.Correlation analysis of the six dominant groups collected in the 160-μm mesh nets revealed that seawater temperature and salinity emerged as the key environmental factors driving variations in meroplankton abundance within the SYS.This study also found that a smaller mesh size net does not necessarily capture meroplankton more comprehensively.A comprehensive understanding of the ecological characteristics of meroplankton requires the combination of two types of nets for research.Our research significantly advances our understanding of the quantification,abundance,and distribution of meroplankton,serving as a valuable contribution to the broader landscape of detailed quantitative meroplankton studies.
基金Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDA22050302,XDB42000000)the Taishan Scholar Project Special Fund(to Nansheng CHEN)the Post-doctoral Program of Qingdao 2021(No.E2KY14101N)。
文摘A sudden and unprecedented outbreak of molluscan Philine kinglipini occurred in summer 2022 in Jiaozhou Bay,Shandong,China,causing substantial damage to local mariculture industry of the Manila clam Ruditapes philippinarum.Although P.kinglipini has been found in many coastal regions of China,the molecular research of P.kinglipini has not been extensively studied,making it difficult to accurately identify and track P.kinglipini samples in field using molecular methods.Samples were collected during the outbreak and their morphological features and molecular sequences were analyzed.Results show that the causative species of the outbreak was P.kinglipini.The mitochondrial genome(mt DNA)of P.kinglipini was constructed for the first time,based on which phylogenetic analysis of the mt DNAs of P.kinglipini and related species in the order Cephalaspidea was carried out.As revealed by metabarcoding analysis of 18S rDNA V4,the seasonal change of P.kinglipini and closely related Philine species was striking with peaks between April and August.Therefore,metabarcoding analysis is applicable tool for monitoring the bloom development of P.kinglipini and related species.This study generated for the first time essential molecular marker sequences and mtDNA of P.kinglipini,which provided a reference for future characterization and monitoring of its outbreaks and for phylogenetic analysis of Philine species.
基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA19060203)the National Natural Science Foundation of China(Nos.42076166,42130411)+4 种基金the Natural Science Foundation of Shandong Province(No.ZR2021QD061)the CAS-CSIRO Project Fund(No.GJHZ1888)the Mount Tai Scholar Climbing Plan to Song SUNthe Innovation Team of Fishery Resources and Ecology in the Yellow Sea and Bohai Sea(No.2020TD01)the Hainan Province Basic and Applied Basic Research Program(Natural Science Field)High-Level Talent Project(No.2019RC353)。
文摘Cyanea nozakii,a common jellyfish distributed in offshore China,has a complex trophic relationship with other zooplankton groups.However,few studies have reported the predation rates and prey selection patterns of C.nozakii medusae on different prey items.Research is also lacking on the intraguild predation of Aurelia coerulea(another common bloom jellyfish in offshore China)by C.nozakii.To address the knowledge gaps,the clearance rates of C.nozakii for different prey items,including copepods(small<1000μm and large>1000μm),fish larvae,and gelatinous prey(hydromedusae,A.coerulea ephyrae,and chaetognaths),were measured.The influence of predator size on the clearance rate was also determined.Additionally,we examined the intraguild predation of C.nozakii on A.coerulea medusae.The clearance rates of C.nozakii varied widely with prey organisms,being independent of prey concentrations.Gelatinous organisms,except for chaetognaths,were captured with considerably high efficiency,followed by fish larvae and copepods,indicating the preferential prey selection of gelatinous organisms by C.nozakii.The clearance rate increased linearly with the cross-sectional area of C.nozakii.Body size in medusae may,to some extents,underpin their capacity to capture more prey by increasing the encounter rate and capture success through ontogeny.C.nozakii preyed voraciously on A.coerulea in high feeding efficiency,but the clearance rate decreased with increasing A.coerulea(as prey)size.This phenomenon of intraguild predation suggests a speculative hypothesis of potential population regulation of A.coerulea by C.nozakii.The information regarding the feeding ecology of C.nozakii reported in this study is important for understanding plankton dynamics in marine ecosystems with extensive occurrences of this jellyfish.
基金Supported by the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW-213-3)the National Basic Research Program of China (973 Program) (No. 2006CB400606)the National Natural Science Foundation of China (No. 40631008)
文摘Differences among species in prosome length and in species' response to environmental factors do exist. Therefore, it is useful to examine prosome length for different copepod species in variable environments. Seasonal variations in prosome length of four small copepods and their copepodite stages in the Jiaozhou Bay were compared and the relative influence of temperature, salinity, and chlorophyll concentration were examined. Two peaks were found in the mean prosome length of Paracalanus parvus (in early winter and May). For Acartia bifilosa, the maximum values of all copepodites occurred mainly from February to April, and decreased to the bottom in July. Prosome length of Acartia pacifica peaked when it first appeared in June, then reached to the minimum in July. Parvocalanus crassirostris only appeared from late summer to autumn and the mean prosome length showed no clear changes. Correlations of adult prosome length with environmental factors were evaluated. For the four species, temperature was negatively correlated to prosome length except for P. crassirostris. But the different species varied markedly in their responds to temperature. A. bifilosa showed a more definite trend of size variation with temperature than P. parvus and A. pacifica. Correlations of prosome length with salinity were significantly positive for almost all the small copepods. The relationship between chlorophyll concentration and prosome length was complicated for these copepods, but for P. parvus, chlorophyll concentration was also an important affecting factor. Furthermore, investigation needs to be done on food quality for some copepod. These results are essential to estimate the biomass and the production, and to understand these small copepods' population dynamics in this human-affected bay.
基金supported by the Chinese Polar Environment Comprehensive Investigation & Assessment Programmes (Grant no.CHINARE2013-01-05)the Institute of Oceanology,Chinese Academy of Sciences (IOCAS) Funding (Grant no.2012IO060102)
文摘Polar zooplankton are particularly sensitive to climate change, and have been used as rapid-responders to indicate climate-induced changes in the fragile Antarctic ecosystem. DNA barcoding provides an alternative approach for rapid zooplankton species identification. Ninety-four specimens belonging to 32 Antarctic zooplankton species were barcoded to construct a compre- hensive reference library. An 830 to 1 050 base-pair region of the mitochondrial cytochrome c oxidase subunit I （mtCOI） gene was obtained as DNA barcodes. The intraspecific variation of the gene ranged from 0 to 2.6% （p-distance）, with an average of 0.67% （SD=0.67%）. The distance between species within the same genera ranged from 0.1% （Calanus） to 29.3%, with an average of 15.3% （SD=8.4%）. The morphological and genetic similarities between Calanus propinquus and C. simillimus raise new questions about the taxonomic status of C. simillimus. With the exception of the two Calanus species, the intraspecific genetic divergence was much smaller than the interspecific divergence among congeneric species, confirming the existence of a barcode gap for Ant- arctic zooplankton. In addition, species other than Calanus sp. formed a monophyletic group. Therefore, we have confirmed DNA barcoding as an accurate and efficient approach for zooplankton identification in the Antarctic area （except for Hydromedusa, Tu- nicata, and other gelatinous zooplankton）. Indicator vector analysis further confirmed this conclusion. The new primer sets issued here may facilitate the study of Antarctic marine zooplankton species composition by environmental metagenetic analysis.
基金The Basic Scientific Fund for National Public Research Institutes of China under contract Nos 2017Q09 and2016Q02the National Natural Science Foundation of China under contract No.41776176+2 种基金the National Key Research and Development Program of China under contract No.2017YFC1404604the Shandong Provincial Natural Science Foundation under contract No.ZR2015PD003the 2012 Taishan Scholar
文摘Biological CO2 sequestration by microalgae is a promising and environmentally friendly technology applied to sequester CO2. The characteristics of neutral lipid accumulation by two marine oil-rich microalgal strains,namely, Isochrysis galbana and Nannochloropsis sp., through CO2 enrichment cultivation were investigated in this study. The optimum culture conditions of the two microalgal strains are 10% CO2 and f medium. The maximum biomass productivity, total lipid content, maximum lipid productivity, carbon content, and CO2 fixation ability of the two microalgal strains were obtained. The corresponding parameters of the two strains were as follows：（（142.42±4.58） g/（m^2·d）,（149.92±1.80） g/（m^2·d））,（（39.95±0.77）%,（37.91±0.58）%）,（（84.47±1.56） g/（m^2·d）,（89.90±1.98） g/（m^2·d））,（（45.98±1.75）%,（46.88±2.01）%）, and（（33.74±1.65） g/（m^2·d）,（34.08±1.32） g/（m^2·d））. Results indicated that the two marine microalgal strains with high CO2 fixation ability are potential strains for marine biodiesel development coupled with CO2 emission reduction.
基金Supported by the National Science Foundation of China(NSFC)(Nos.41876120,41906122,41606128,U1706218)the Science&Technology Basic Resources Investigation Program of China(No.2018FY100200)。
文摘Phytoplankton are central components of marine environments,and are major players in the production and respiration budgeting.However,their diversity and distribution patterns are still poorly understood due largely to their small sizes and inconspicuous morphology that have been determined via the application of traditional morphology methods over the past two decades.To better understand the composition and diversity of phytoplankton in Jiaozhou Bay,China,seasonal sampling was carried out in 2019 and samples were analyzed with morphological observations and high-throughput sequencing,from which obvious seasonal variations in phytoplankton composition and proportional abundances were uncovered.Metabarcoding revealed far more diversity and species richness of phytoplankton than morphological observations,especially with respect to dinofl agellates.Diatoms were the most dominant phytoplankton group throughout the year,of which Thalassionema and Skeletonema were co-dominant in the bay.Parasitic dinofl agellates(e.g.Amoebophrya),which is often overlooked in the morphological observations,were in dominance and high diversity in the metabarcoding dataset,thus more attention should be paid to exploring the potential role of parasitic dinofl agellates.Temperature,chlorophyll a,and nutrient levels were the main infl uential factors on the distribution of phytoplankton.This study provided a comprehensive morphological and molecular description of phytoplankton and clearly demonstrated the importance of molecular technology in exploring phytoplankton communities.More-widespread use of molecular technology will facilitate deeper understanding of the ecological importance of the diff erent species.
基金supported by Marine S&T Fund of Shandong Province for Qingdao Marine Science and Technology Center(Grant no.2022QNLM030002-1)National Natural Science Foundation of China(Grant no.42276238)National Polar Special Program“Impact and Response of Antarctic Seas to Climate Change”(Grant no.IRASCC 01-02-01D)and Taishan Scholars Program.
文摘This study investigates the composition,abundance,and basic biological parameters of krill in Prydz Bay,Antarctic Peninsula and Amundsen Sea by analyzing samples and environmental data from the Chinese National Antarctic Research Expeditions conducted between 2009/2010 and 2019/2020.The predominant krill species observed were Euphausia superba,Euphausia crystallorophias,and Thysanoessa macrura.T.macrura,although the most widespread,exhibited the lowest mean abundance 9.96 ind:(1000 m^(-3))and biomass 0.31 g(1000 m^(-3)),predominantly found in low-latitude regions of the Amundsen Sea while E.crystallorophias was most concentrated in polynyas of Prydz Bay.E.superba,with an average abundance of 34.05 ind(1000 m^(-3))and biomass of 11.80 g:(1000 m^(-3)),was mainly distributed in the Antarctic Peninsula and Prydz Bay.This study also identified regional variations in mean body length and frequency distributions of kril.The relationship between krill body length and wet weight followed a power-law pattern.Regional differences were observed in the relationship between krill abundance,biomass,and environmental factors with varying correlations.In the Amundsen Sea,no significant correlation was found between krill abundance and environmental factors.Notably,E.crystallorophias in Prydz Bay demonstrated a significant positive correlation with chlorophyll a concentration,while T.macrura abundance and biomass in the Antarctic Peninsula exhibited a significant negative correlation with ice-free days.The findings contribute valuable regional data on krll distribution,abundance,and biomass in the Southern Ocean,serving as foundational information for the conservation of the Southern Ocean ecosystem and Antarctic krill fishery management on a circumpolar scale.
基金Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA23050302)the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2018SDKJ050404)+3 种基金the Science&Technology Basic Resources Investigation Program of China(No.2018FY100200)the Sino-Australian Centre for Healthy Coasts(No.2016YFE0101500)the Key Deployment Project of Centre for Ocean Mega-Research of Science,Chinese Academy of Science(No.COMS2019Q05)the NSFC(Nos.41476102,U1406403)。
文摘To evaluate how the decay of bloom-forming algae affect the coastal dissolved oxygen,a laboratory simulation was conducted in terms of three typical harmful algae,Alexandrium catenella,Prorocentrum donghaiense,and Skeletonema costatum.Algae of same biomass(55μg/mL)were conducted in lightproof columns,and the cell density,dissolved oxygen(DO),and ammonia nitrogen of different layers were monitored at certain time series.Results show that the decomposition of algae significantly decreased the DO,and increased the ammonia nitrogen in all layers;and significant deference between different species was observed.The A.catenella treatment showed the lowest DO(average concentration of 3.4 mg/L)and the highest ammonia nitrogen(average concentration of 0.98 mg/L)at the end of test,followed by P.donghaiense;and the S.costatum showed relatively high DO and low ammonia nitrogen due to slow decay rate.Results indicate that decomposition of harmful bloom algae,especially dinoflagellate,would cause significantly DO depletion and toxic ammonia nitrogen increase,which will detrimentally affect both pelagic and benthic ecosystem.
基金Supported by the NSFC-Shandong Joint Fund for Marine Ecology and Environmental Sciences(No.U1606404)the National Natural Science Foundation of China(Nos.41476142,61533011,41606126,41506143)+1 种基金the Scientific and Technological Innovation Project financially supported by Qingdao National Laboratory for Marine Science and Technology(No.2016ASKJ02)the Creative Team Project of the Laboratory for Marine Ecology and Environmental Science,and the Qingdao National Laboratory for Marine Science and Technology(No.LMEES-CTSP-2018-1)
文摘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 venefi cum , Margalefi dinium polykrikoides , Prorocentrum donghaiense , P . minimum , Scrippsiella trochoidea , and Heterosigma akashiwo ) using gas chromatography-mass spectrometry in full scan and selected ion monitoring (SIM) modes. Our results show a ubiquitous presence of carbonyl compounds 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 identifi ed 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 identifi ed and quantifi ed 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 confi rmed that trans-2-nonenal could be produced by K . mikimotoi , Karl . venefi cum , 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 dinofl agellate 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 fi shkilling or allelopathy which needs further identifi cation and quantifi cation.
基金Supported by the Science&Technology Basic Resources Investigation Program of China(No.2018FY100200)the Key Deployment Project of Centre for Ocean Mega-Research of Science,Chinese Academy of Science(No.COMS2019Q05)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA23050302)the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2018SDKJ0504)the Sino-Australian Centre for Healthy Coasts(No.2016YFE0101500)。
文摘Harmful algal blooms(HABs)in the Southern Yellow Sea(SYS)have shown a trend of increasing diversity and detrimental ef fects.While the Bohai Sea,East China Sea,and South China Sea have experienced a high incidence of HABs since the 1980s,the Yellow Sea provides a relatively healthy ecological environment in which fewer HABs have been documented before the 21s t century.Yet largescale blooms of the green macroalga Ulva prolifera(so-called“green tides”)have occurred annually since 2007 in the Yellow Sea.Six people were poisoned and one person died in Lianyungang in 2008 due to ingestion of algal toxins.Moreover,the Yellow Sea experienced co-occurrence of harmful red tides,green tides,and golden tides in 2017.This combination of events,rare worldwide,indicates the potential for further deterioration of the marine environment in the Yellow Sea,which may be related to climate change,aquaculture,and other human activities.Using the SYS as an example,we collected data of the frequency and scale of HABs over the years,as well as that of marine algal toxins,and analyzed the trend in the diversity of HABs in the SYS,to explore the causes and impacts of HABs,as well as the interrelationships among dif ferent types of HABs,including harmful red tides,green tides,and golden tides.We also attempted to improve our understanding of HAB evolution under the influence of global climate change and intensified human activities.
基金Supported by the Pilot National Laboratory for Marine Science and Technology(No.2021QNLM040001-2)the Science and Technology Basic Resources Investigation Program(No.2018FY100200)+2 种基金the National Key R&D Program(No.2017YFC1600701)the CAS-CSIRO BAU project of the Chinese Academy of Sciences(No.GJHZ201973)the National Natural Science Foundation of China(No.42106206)。
文摘Lipophilic marine toxins(LMTs)produced by some microalgae in the sea could accumulate in shellfish and pose potential threats to the health of seafood consumers.Phytoplankton and shellfish samples were collected from coastal waters of Weihai in Shandong Peninsula,China in autumn,2020,and screened for lipophilic marine toxins and their potential producers using liquid chromatography-tandem mass spectrometry(LC-MS/MS)analysis and high throughput sequencing of partial DNA(V4 region of the 18S rRNA gene)extracted from phytoplankton.Pectenotoxin-2(PTX2),trace amounts of azaspiracid(AZA1 or AZA40),and 13-desmethyl spirolide C(13-DesMe-C)were detected in phytoplankton samples,while PTX2 and gymnodimine(GYM)were detected in shellfish samples.The toxin content in shellfish samples was much lower than the regulatory limit or values reported previously.Results suggest that lipophilic marine toxins should have low risk in coastal waters of Weihai in autumn.Based on the data of high throughput sequencing,the OTUs were assigned to 5 identified species of Alexandrium,including A.ostenfeldii capable of producing 13-DesMe-C and GYM.Two OTUs were found closely related to the toxic species in genus Dinophysis,but it is impossible to assign them to any identified species due to the low resolving power of the V4 region for Dinophysis.The OTUs could not be assigned to any identified species in the genus Azadinium,suggesting the existence of unidentified species in this region.
基金Supported by the National Basic Research Program of China (973 Program) (No. 2006AA10A401)the National Natural Science Foundation of China (No. 40376048)
文摘Hydantoinase is involved in the production of optically pure amino acids from racemic 5-mono-substituted hydantoins. We measured the D-hydantoinase activity in marine Halomonas sp. YSR-3 and amplified the D-hydantoinase gene by PCR. The gene was inserted into vector pGM-T and transformed into E. coli TOP10. The positive transformants with the D-hydantoinase gene were sequenced. The sequenced fragment comprises 1 510 base pairs. The D-hydantoinase gene from YSR-3 is 77% similar to that from Pseudomonas entornophila L4 by searching against the NCBI databse. The protein product of the YSR-3 D-hydantoinase gene is 75%, 73%, and 70% similar to those from Pseudomonasfluorescens Pf-5, Marinornonas sp. MED121, and Burkholderia vietnamiensis G4, respectively. The difference of the D-hydantoinase gene between marine Halornonas sp. YSR-3 and other terrestrial organisms is distinct.
