Displaying publications 1 - 20 of 203 in total

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  1. Liu B, Lu Y, Deng H, Huang H, Wei N, Jiang Y, et al.
    Sci Total Environ, 2023 Sep 01;889:164173.
    PMID: 37201824 DOI: 10.1016/j.scitotenv.2023.164173
    Microplastic (MP) pollution is a serious global environmental problem, particularly in marine ecosystems. However, the pollution patterns of MPs in the ocean and atmosphere, particularly the sea-air interrelationship, remain unclear. Therefore, the abundance, distribution patterns, and sources of MPs in the seawater and atmosphere of the South China Sea (SCS) were comparatively investigated. The results showed that MPs were prevalent in the SCS with an average abundance of 103.4 ± 98.3 items/m3 in the seawater and 4.62 ± 3.60 items/100 m3 in the atmosphere. The spatial analysis indicated that the pollution patterns of seawater MPs were mainly determined by land-based discharge and sea surface currents, whereas atmospheric MPs were predominantly determined by air parcel trajectory and wind conditions. The highest MP abundance of 490 items/m3 in seawater was found at a station near Vietnam with current vortices. However, the highest MP abundance of 14.6 items/100 m3 in the atmosphere was found in air parcels with low-speed southerly winds from Malaysia. Similar MP compositions (e.g., polyethylene terephthalate, polystyrene, and polyethylene) were observed in the two environmental compartments. Furthermore, similar MP characteristics (e.g., shape, color, and size) in the seawater and atmosphere of the same region suggested a close relationship between the MPs in the two compartments. For this purpose, cluster analysis and calculation of the MP diversity integrated index were performed. The results showed an obvious dispersion between the two compartment clusters and a higher diversity integrated index of MPs in seawater than in the atmosphere, thus implying higher compositional diversity and more complex sources of MPs in seawater relative to the atmosphere. These findings deepen our understanding of MP fate and patterns in the semi-enclosed marginal sea environment and highlight the potential interrelationship of MPs in the air-sea system.
    Matched MeSH terms: Seawater
  2. Huang Y, Li J, Xu Y, Xu W, Cheng Z, Liu J, et al.
    Mar Pollut Bull, 2014 Mar 15;80(1-2):194-9.
    PMID: 24462236 DOI: 10.1016/j.marpolbul.2014.01.007
    Nineteen pairs of air and seawater samples collected from the equatorial Indian Ocean onboard the Shiyan I from 4/2011 to 5/2011 were analyzed for PCBs and HCB. Gaseous concentrations of ∑(ICES)PCBs (ICES: International Council for the Exploration of the Seas) and HCB were lower than previous data over the study area. Air samples collected near the coast had higher levels of PCBs relative to those collected in the open ocean, which may be influenced by proximity to source regions and air mass origins. Dissolved concentrations of ∑(ICES)PCBs and HCB were 1.4-14 pg L⁻¹ and 0.94-13 pg L⁻¹, with the highest concentrations in the sample collected from Strait of Malacca. Fugacity fractions suggest volatilization of PCBs and HCB from the seawater to air during the cruise, with fluxes of 0.45-34 ng m⁻² d⁻¹ and 0.36-18 ng m⁻² d⁻¹, respectively.
    Matched MeSH terms: Seawater/chemistry
  3. Kura NU, Ramli MF, Ibrahim S, Sulaiman WN, Aris AZ, Tanko AI, et al.
    Environ Sci Pollut Res Int, 2015 Jan;22(2):1512-33.
    PMID: 25163562 DOI: 10.1007/s11356-014-3444-0
    In this work, the DRASTIC and GALDIT models were employed to determine the groundwater vulnerability to contamination from anthropogenic activities and seawater intrusion in Kapas Island. In addition, the work also utilized sensitivity analysis to evaluate the influence of each individual parameter used in developing the final models. Based on these effects and variation indices of the said parameters, new effective weights were determined and were used to create modified DRASTIC and GALDIT models. The final DRASTIC model classified the island into five vulnerability classes: no risk (110-140), low (140-160), moderate (160-180), high (180-200), and very high (>200), covering 4, 26, 59, 4, and 7 % of the island, respectively. Likewise, for seawater intrusion, the modified GALDIT model delineates the island into four vulnerability classes: very low (<90), low (90-110), moderate (110-130), and high (>130) covering 39, 33, 18, and 9 % of the island, respectively. Both models show that the areas that are likely to be affected by anthropogenic pollution and seawater intrusion are within the alluvial deposit at the western part of the island. Pearson correlation was used to verify the reliability of the two models in predicting their respective contaminants. The correlation matrix showed a good relationship between DRASTIC model and nitrate (r = 0.58). In a similar development, the correlation also reveals a very strong negative relationship between GALDIT model and seawater contaminant indicator (resistivity Ωm) values (r = -0.86) suggesting that the model predicts more than 86 % of seawater intrusion. In order to facilitate management strategy, suitable areas for artificial recharge were identified through modeling. The result suggested some areas within the alluvial deposit at the western part of the island as suitable for artificial recharge. This work can serve as a guide for a full vulnerability assessment to anthropogenic pollution and seawater intrusion in small islands and will help policy maker and manager with understanding needed to ensure sustainability of the island's aquifer.
    Matched MeSH terms: Seawater/analysis*
  4. Corrado R, Lacorata G, Palatella L, Santoleri R, Zambianchi E
    Sci Rep, 2017 04 11;7:46291.
    PMID: 28397797 DOI: 10.1038/srep46291
    The multi-scale and nonlinear nature of the ocean dynamics dramatically affects the spreading of matter, like pollutants, marine litter, etc., of physical and chemical seawater properties, and the biological connectivity inside and among different basins. Based on the Finite-Scale Lyapunov Exponent analysis of the largest available near-surface Lagrangian data set from the Global Drifter Program, our results show that, despite the large variety of flow features, relative dispersion can ultimately be described by a few parameters common to all ocean sub-basins, at least in terms of order of magnitude. This provides valuable information to undertake Lagrangian dispersion studies by means of models and/or of observational data. Moreover, our results show that the relative dispersion rates measured at submesoscale are significantly higher than for large-scale dynamics. Auxiliary analysis of high resolution GPS-tracked drifter hourly data as well as of the drogued/undrogued status of the buoys is provided in support of our conclusions. A possible application of our study, concerning reverse drifter motion and error growth analysis, is proposed relatively to the case of the missing Malaysia Airlines MH370 aircraft.
    Matched MeSH terms: Seawater
  5. Yap CK, Shahbazi A, Zakaria MP
    Bull Environ Contam Toxicol, 2012 Dec;89(6):1205-10.
    PMID: 23052577 DOI: 10.1007/s00128-012-0838-x
    In this study, the ranges of pollutants found in the soft tissues of Perna viridis collected from Kg. Masai and Kg. Sg. Melayu, both located in the Straits of Johore, were 0.85-1.58 μg/g dry weight (dw) for Cd, 5.52-12.2 μg/g dw for Cu, 5.66-8.93 μg/g dw for Ni and 63.4-72.3 μg/g dw for Zn, and 36.4-244 ng/g dry weight for ∑PAHs. Significantly (p < 0.05) higher concentrations of Cd, Cu, Ni, Zn and ∑PAHs in the mussels were found in the water of a seaport site at Kg. Masai than a non-seaport site at Kg. Sg. Melayu population. The ratios of low molecular weight/high molecular weight hydrocarbons (2.94-3.42) and fluoranthene/pyrene (0.43-0.45) in mussels from both sites indicated the origin of the PAHs to be mainly petrogenic. This study has demonstrated the utility of using the soft tissues of P. viridis as a biomonitor of PAH contamination and bioavailability in the coastal waters of Peninsular Malaysia.
    Matched MeSH terms: Seawater/chemistry
  6. Isobe T, Takada H, Kanai M, Tsutsumi S, Isobe KO, Boonyatumanond R, et al.
    Environ Monit Assess, 2007 Dec;135(1-3):423-40.
    PMID: 17370135
    A comprehensive monitoring survey for polycyclic aromatic hydrocarbons (PAHs) and phenolic endocrine disrupting chemicals (EDCs) utilizing mussels as sentinel organisms was conducted in South and Southeast Asia as a part of the Asian Mussel Watch project. Green mussel (Perna viridis) samples collected from a total of 48 locations in India, Indonesia, Singapore, Malaysia, Thailand, Cambodia, Vietnam, and the Philippines during 1994-1999 were analyzed for PAHs, EDCs including nonylphenol (NP), octylphenol (OP) and bisphenol A (BPA), and linear alkylbenzenes (LABs) as molecular markers for sewage. Concentrations of NP ranged from 18 to 643 ng/g-dry tissue. The highest levels of NP in Malaysia, Singapore, the Philippines, and Indonesia were comparable to those observed in Tokyo Bay. Elevated concentrations of EDCs were not observed in Vietnam and Cambodia, probably due to the lower extent of industrialization in these regions. No consistent relationship between concentrations of phenolic EDCs and LABs were found, suggesting that sewage is not a major source of EDCs. Concentrations of PAHs ranged from 11 to 1,133 ng/g-dry, which were categorized as "low to moderate" levels of pollution. The ratio of methylphenanthrenes to phenanthrene (MP/P ratio) was >1.0 in 20 out of 25 locations, indicating extensive input of petrogenic PAHs. This study provides a bench-mark for data on the distribution of anthropogenic contaminants in this region, which is essential in evaluating temporal and spatial variation and effect of future regulatory measures.
    Matched MeSH terms: Seawater/chemistry
  7. Asnor Azrin Sabuti, Che Abd Rahim Mohamed, Zaharudin Ahmad
    MyJurnal
    Various environmental samples (seawater, TSS, sediment, rainwater and fly ash) from eight different stations near Kapar coastal area were analyzed. The 210 Po activity concentrations in liquid samples (seawater and rainwater) varied between 0.34 ± 0.03 mBq L-1 to 22.44 ± 0.53 mBq L-1 . Whereas the concentrations in particulate samples (TSS, sediment and fly ash) varied between 43.79 ± 2.31 Bqkg-1 to 364.48 ± 5.43 Bqkg-1 . Results also showed the radioactivity in Kapar coastal is higher than most of Malaysian coast, reaching a factor of seven. This condition is mainly due to the operation of a coal-fired power plant nearby. This study also clarify the variability of 210 Po in environment was strongly influenced from rainfall events especially during wet seasons.
    Matched MeSH terms: Seawater
  8. Yii, Mei-Wo, Abdul Kadir Ishak, Zaharudin Ahmad
    MyJurnal
    A trial study had been conducted to determine the particulate form of 137 Cs in seawater surrounding East Malaysia. Large volume of seawater was filtered at a flow rate of 15 liters/min through the copper hexacyanoferrates (II) impregnated filters. These filters were ashed and counted using the gamma spectrometry system to determine the dissolved 137 Cs activity. It was found that the particulate form of 137 Cs consists of 20 to 49 % of the total 137 Cs activity concentrations. Some reasonable explanations for higher particulate percentage such as sampling locations, high water flow-rate, and large volume of seawaters were further discussed. It is hope that the result of this study will help to build a better understanding about the usage of impregnated filters to study dissolved 137 Cs activity concentrations.
    Matched MeSH terms: Seawater
  9. Yii, Mei Wo, Zaharuddin Ahmad
    MyJurnal
    The studies of ¹³⁷Cs content in the seawater surrounding Peninsular Malaysia had been carried out as part of the Malaysia Marine Radioactivity Database Project. The results of the measurement will serve as the baseline data and reference level to Malaysia. A numbers of sampling locations, including coastal and offshore at the East Coast (South China Sea) and West Coast (Straits of Malacca) of Peninsular Malaysia had been selected for the study. From each location at the coastal area, water samples were collected from the surface of the seawater. Meanwhile, for the offshore area, water samples have been collected at three different depths. Due to usual low concentration of ¹³⁷Cs in the marine environment, large volumes of seawater were collected and the co precipitation technique was employed to concentrate the ¹³⁷Cs. The activity of ¹³⁷Cs was determined by measuring the peak area under photo peak of the gamma spectrum at 661 keV, which is equivalent to the gamma intensity corrected to the HpGe detection efficiency and percentage of gamma ray abundance of the ¹³⁴Cs. At each study location, there were no significant differences for ¹³⁷Cs activities at 95% confidence interval. The activities of ¹³⁷Cs found to be quite uniformly distributed in the range of 2.33 to 5.00 Bq/m3and 1.76 to 4.76 Bq/m3for the South China Sea and the Straits of Malacca, respectively.
    Matched MeSH terms: Seawater
  10. Tahir D, Shariff M, Syukri F, Yusoff FM
    Vet World, 2018 Mar;11(3):327-331.
    PMID: 29657425 DOI: 10.14202/vetworld.2018.327-331
    Background and Aim: Brown-marbled grouper Epinephelus fuscoguttatus is a premium marine food fish with high demand in Asia. In fish, stress due to environmental changes such as fluctuations in the salinity can result in increased cortisol level. Stress in fish increases susceptibility to diseases ultimately resulting in death. Therefore, the aim of this study was to investigate the salinity tolerance of E. fuscoguttatus and their survival in lower salinities.

    Materials and Methods: In this study, grouper juveniles (92.43±standard error of the mean 0.51 mm) maintained in 31 ppt seawater were transferred into five tanks with seawater diluted to 25, 20, 15, 10, and 5 ppt. The salinity of the control group was not changed and was maintained at 31 ppt. Serum cortisol was measured using ELISA at 0, 30, 60, and 120 min after the fish were transferred to the different concentrations of salinity.

    Results: The survival percentage was recorded for 14 days following the transfer and the results revealed that serum cortisol of fish in a high change in salinity (15, 10, and 5 ppt) was significantly higher than the control group immediately after exposure. At the high salinity change, the cortisol levels gradually decrease at 30 min and 60 min, until no difference in cortisol concentration was observed at 120 min. No mortality was observed in fish exposed to low salinity change (25 and 20 ppt) while in higher salinity change (5 ppt), the survival percentage was 50%.

    Conclusion: The study revealed that the serum cortisol concentration was high initially and continues to decrease to resting cortisol level at 120 min indicating that cortisol hormone is released following acute stress as a primary response in grouper juveniles.

    Matched MeSH terms: Seawater
  11. Hamsawahini K, Sathishkumar P, Ahamad R, Yusoff AR
    Talanta, 2016 Feb 1;148:101-7.
    PMID: 26653429 DOI: 10.1016/j.talanta.2015.10.044
    An effective electrode was developed based on electromembrane extraction (EME) and square wave voltammetry (SWV) for simultaneous separation, pre-concentration and determination of lead (II) (Pb(II)) ions in complex aqueous samples. Electrochemically reduced graphene oxide-graphite reinforced carbon (ErGO-GRC) was utilized in conjunction with the SWV. Pb(II) ions were extracted from an aqueous sample solution into an acidic acceptor phase (1M HCl) in the lumen of the polyvinylidene fluoride (PVDF) membrane bag by the application of voltage of maximum 6 V across the supported liquid membrane (SLM), consisting of organic solvent and di-(2-ethylhexyl)phosphoric acid (D2EHPA). The parameters affecting the EME were optimized for Pb(II) ions. The optimum EME conditions were found to be 20% D2EHPA in 1-octanol impregnated in the wall of PVDF membrane (PVDF17) as the SLM, extraction time of 20 min, pH of sample solution of 8 and a voltage of 5 V. The PVDF-ErGO-GRC electrode system attained enrichment factors of 40 times and 80% of extraction with relative standard deviations (n=5) of 8.3%. Good linearity ranging from 0.25 to 2 nM with coefficients correlation of 0.999 was obtained. The Pb(II) ions detection limit of PVDF-ErGO-GRC electrode was found to be 0.09 nM. The newly developed single setup electrochemical system was applied to complex aqueous samples such as tap, river and sea water to evaluate the feasibility of the method for applications.
    Matched MeSH terms: Seawater
  12. Akyil S, Yusof AM
    J Hazard Mater, 2007 Jun 1;144(1-2):564-9.
    PMID: 17141412
    Concentrations of uranium and thorium in seawater, sediment and some marine species taken from along the coastal areas of Malaysia were determined spectrophotometrically. The uranium and thorium concentrations in seawater were found to vary ranging from 1.80 to 4.1 and 0.14 to 0.88 microg/L, respectively. The concentration of uranium in sediment samples was reported to range from 3.00 to 6.60 microg/g while those of thorium were slightly lower ranging from 0.01 to 0.68 microg/g. The uptake of uranium and thorium in marine species was found to be rather low. Similar variations in total alpha activities in samples were also observed with the total alpha activities relatively lower than the beta activities in most samples.
    Matched MeSH terms: Seawater/analysis
  13. Wu YL, Wang XH, Li YY, Hong HS, Li HY, Yin MD
    Huan Jing Ke Xue, 2009 Sep 15;30(9):2512-9.
    PMID: 19927796
    Polycyclic aromatic hydrocarbons (PAHs) in a sediment core collected from Langkawi Island of the Andaman Sea, Malaysia were determined by GC/MS, the vertical variations of concentration and distributions of PAHs were investigated. In combining with 210Pb-dating, the PAHs sedimentary record in the last 100 years was reconstructed and their possible sources were also discussed. The sigmaPAH concentration ranged from 13.2-60.1 ng x g(-1) in the whole sedimentary section (0-56 cm) with the dominant compounds of phenanthrene, naphthalene and perylene. The sediments contaminated to a lesser extent comparing with the surrounding waters. Before the 1920s, the concentrations of PAHs were considered to be the background level, which was implied from the natural inputs. The historical records of PAHs in the core showed that two distinct peaks which represented the input time of 1960s and 1980s, respectively, inferred that there were some relatively dramatically land-based inputs, and human activities leaded a clear impact to these waters during these periods. Furthermore, PAHs diagnostic ratios indicated that PAHs in the core sediments were mainly of pyrolytic origin (combustion), accompanied with minor petroleum origin. These were related with agriculture, industry, ocean import and export, and shipping activities in the surrounding regions. Meanwhile as the vital communication line, the marine transportation of the Strait of Malacca had influenced the environmental quality of the Andaman Sea. Meanwhile, based on the sedimentary record, PAHs concentrations were found to correlate positively with humanism activities and socioeconomic development (Gross Domestic Production) in the surrounding regions.
    Matched MeSH terms: Seawater/analysis*
  14. S E, G A, A F I, P S G, Y LT
    Environ Res, 2021 06;197:111177.
    PMID: 33864792 DOI: 10.1016/j.envres.2021.111177
    Membrane technology, especially nanofiltration (NF) has great attention to provide an imperative solution for water issues. The membrane is considered to be the heart in the separation plant. Understanding the membrane characteristics could allow predicting and optimizing the membrane performance namely flux, rejection and reduced fouling. The membrane development using biomaterials and nanomaterials provides a remarkable opportunity in the water application. This review focuses on the membrane characteristics of biomaterials and nanomaterials based nanofiltration. In this review, recent researches based on biomaterials and nanomaterials loaded membrane for salt rejection have been analyzed. Membrane fouling depends on the membrane characteristics and this review defined fouling as a ubiquitous bottleneck challenge that hampers the NF blooming applications. Fouling mitigation strategies via membrane modification using biomaterial (chitosan, curcumin and vanillin) and various other nanomaterials are critically reviewed. This review also highlights the membrane cleaning and focuses on concentrates disposal methods with zero liquid discharge system for resource recovery. Finally, the conclusion and future prospects of membrane technology are discussed. From this current review, it is apparent that the biomaterial and various other nanomaterials acquire exclusive properties that facilitate membrane advancement with improved capability for water treatment. Regardless of membrane material developments, still exist considerable difficulties in membrane commercialization. Thus, additional studies related to this field are needed to produce membranes with better performance for large‒scale applications.
    Matched MeSH terms: Seawater
  15. Mustaffa NIH, Latif MT, Wurl O
    Int J Mol Sci, 2021 Jul 10;22(14).
    PMID: 34299033 DOI: 10.3390/ijms22147413
    Climate change has been predicted to influence the marine phytoplankton community and its carbon acquisition strategy. Extracellular carbonic anhydrase (eCA) is a zinc metalloenzyme that catalyses the relatively slow interconversion between HCO3- and CO2. Early results indicated that sub-nanomolar levels of eCA at the sea surface were sufficient to enhance the oceanic uptake rate of CO2 on a global scale by 15%, an addition of 0.37 Pg C year-1. Despite its central role in the marine carbon cycle, only in recent years have new analytical techniques allowed the first quantifications of eCA and its activity in the oceans. This opens up new research areas in the field of marine biogeochemistry and climate change. Light and suitable pH conditions, as well as growth stage, are crucial factors in eCA expression. Previous studies showed that phytoplankton eCA activity and concentrations are affected by environmental stressors such as ocean acidification and UV radiation as well as changing light conditions. For this reason, eCA is suggested as a biochemical indicator in biomonitoring programmes and could be used for future response prediction studies in changing oceans. This review aims to identify the current knowledge and gaps where new research efforts should be focused to better determine the potential feedback of phytoplankton via eCA in the marine carbon cycle in changing oceans.
    Matched MeSH terms: Seawater/analysis*
  16. Hopkins FE, Suntharalingam P, Gehlen M, Andrews O, Archer SD, Bopp L, et al.
    Proc Math Phys Eng Sci, 2020 May;476(2237):20190769.
    PMID: 32518503 DOI: 10.1098/rspa.2019.0769
    Surface ocean biogeochemistry and photochemistry regulate ocean-atmosphere fluxes of trace gases critical for Earth's atmospheric chemistry and climate. The oceanic processes governing these fluxes are often sensitive to the changes in ocean pH (or pCO2) accompanying ocean acidification (OA), with potential for future climate feedbacks. Here, we review current understanding (from observational, experimental and model studies) on the impact of OA on marine sources of key climate-active trace gases, including dimethyl sulfide (DMS), nitrous oxide (N2O), ammonia and halocarbons. We focus on DMS, for which available information is considerably greater than for other trace gases. We highlight OA-sensitive regions such as polar oceans and upwelling systems, and discuss the combined effect of multiple climate stressors (ocean warming and deoxygenation) on trace gas fluxes. To unravel the biological mechanisms responsible for trace gas production, and to detect adaptation, we propose combining process rate measurements of trace gases with longer term experiments using both model organisms in the laboratory and natural planktonic communities in the field. Future ocean observations of trace gases should be routinely accompanied by measurements of two components of the carbonate system to improve our understanding of how in situ carbonate chemistry influences trace gas production. Together, this will lead to improvements in current process model capabilities and more reliable predictions of future global marine trace gas fluxes.
    Matched MeSH terms: Seawater
  17. Chisholm LA, Whittington ID
    Syst Parasitol, 2012 Jun;82(2):167-76.
    PMID: 22581252 DOI: 10.1007/s11230-012-9358-7
    Three new species of Merizocotyle Cerfontaine, 1894 (Monogenea: Monocotylidae) are described from the nasal tissues of stingrays collected off Borneo. Merizocotyle macrostrobus n. sp. is described from the dwarf whipray Himantura walga (Müller & Henle) collected in shallow waters off Sematan, Sarawak, Malaysia. This species can be distinguished from the other members of the genus by the morphology of the sclerotised male copulatory organ, which is long with many twists and loops. The vaginae of this species are also long and looped. Merizocotyle papillae n. sp. is described from the roughnose stingray Pastinachus solocirostris Last, Manjaji & Yearsley collected off Sematan and Mukah, Sarawak, Malaysia. It is distinguished from the other species of Merizocotyle by the morphology of the male copulatory organ, which is a sclerotised tube that expands slightly and then tapers at the distal end, and by the presence of papillae on the dorsal edge of the haptor. Merizocotyle rhadinopeos n. sp. is described from the whitenose whip ray Himantura uarnacoides (Bleeker) collected off Manggar, East Kalimantan, Indonesia. It can be differentiated by the male copulatory organ, which is a short, narrow, curved, sclerotised tube tapering distally, and the path of the ovary, which runs anteriorly to the base of the oötype. We also provide details of new host and/or locality records for M. australensis (Beverley-Burton & Williams, 1989) Chisholm, Wheeler & Beverley-Burton, 1995, M. icopae Beverley-Burton & Williams, 1989 and M. pseudodasybatis (Hargis, 1955) Chisholm, Wheeler & Beverley-Burton, 1995.
    Matched MeSH terms: Seawater
  18. Abdullah AR, Tahir NM, Wei LK
    Bull Environ Contam Toxicol, 1994 Oct;53(4):618-26.
    PMID: 8000192
    Matched MeSH terms: Seawater/analysis*
  19. Segaran TC, Azra MN, Lananan F, Wang Y
    Mar Environ Res, 2023 Jul;189:106015.
    PMID: 37291004 DOI: 10.1016/j.marenvres.2023.106015
    Microbes, or microorganisms, have been the foundation of the biosphere for over 3 billion years and have played an essential role in shaping our planet. The available knowledge on the topic of microbes associated with climate change has the potential to reshape upcoming research trends globally. As climate change impacts the ocean or marine ecosystem, the responses of these "unseen life" will heavily influence the achievement of a sustainable evolutionary environment. The present study aims to identify microbial-related research under changing climate within the marine environment through the mapping of visualized graphs of the available literature. We used scientometric methods to retrieve documents from the Web of Science platform in the Core Collection (WOSCC) database, analyzing a total of 2767 documents based on scientometric indicators. Our findings show that this research area is growing exponentially, with the most influential keywords being "microbial diversity," "bacteria," and "ocean acidification," and the most cited being "microorganism" and "diversity." The identification of influential clusters in the field of marine science provides insight into the hot spots and frontiers of research in this area. Prominent clusters include "coral microbiome," "hypoxic zone," "novel Thermoplasmatota clade," "marine dinoflagellate bloom," and "human health." Analyzing emerging trends and transformative changes in this field can inform the creation of special issues or research topics in selected journals, thus increasing visibility and engagement among the scientific community.
    Matched MeSH terms: Seawater*
  20. Wang Z, Zhang F, Liang Y, Zheng K, Gu C, Zhang W, et al.
    Microbiol Spectr, 2021 10 31;9(2):e0046321.
    PMID: 34643440 DOI: 10.1128/Spectrum.00463-21
    Alteromonas is a ubiquitous, abundant, copiotrophic and phytoplankton-associated marine member of the Gammaproteobacteria with a range extending from tropical waters to polar regions and including hadal zones. Here, we describe a novel Alteromonas phage, ZP6, that was isolated from surface coastal waters of Qingdao, China. ZP6 contains a linear, double-stranded, 38,080-bp DNA molecule with 50.1% G+C content and 47 putative open reading frames (ORFs). Three auxiliary metabolic genes were identified, encoding metal-dependent phosphohydrolase, diaminopurine synthetase, and nucleotide pyrophosphohydrolase. The first two ORFs facilitate the replacement of adenine (A) by diaminopurine (Z) in phage genomes and help phages to evade attack from host restriction enzymes. The nucleotide pyrophosphohydrolase enables the host cells to stop programmed cell death and improves the survival rate of the host in a nutrient-depleted environment. Phylogenetic analysis based on the amino acid sequences of whole genomes and comparative genomic analysis revealed that ZP6 is most closely related to Enhodamvirus but with low similarity (shared genes, <30%, and average nucleotide sequence identity, <65%); it is distinct from other bacteriophages. Together, these results suggest that ZP6 could represent a novel viral genus, here named Mareflavirus. Combining its ability to infect Alteromonas, its harboring of a diaminopurine genome-biosynthetic system, and its representativeness of an understudied viral group, ZP6 could be an important and novel model system for marine virus research. IMPORTANCE Alteromonas is an important symbiotic bacterium of phytoplankton, but research on its bacteriophages is still at an elementary level. Our isolation and genome characterization of a novel Alteromonas podovirus, ZP6, identified a new viral genus of podovirus, namely, Mareflavirus. The ZP6 genome, with a diaminopurine genome-biosynthetic system, is different from those of other isolated Alteromonas phages and will bring new impetus to the development of virus classification and provide important insights into novel viral sequences from metagenomic data sets.
    Matched MeSH terms: Seawater/virology
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