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  • An overview of the use of the iron in aquaculture

    Ho, Son Lam; Dang, Tran Tu Tram (2021)
    Iron is a trace element involved in many physiological and biochemical processes of aquatic animals and is necessary for the production and normal functioning of hemoglobin, myoglobin, cytochromes, and many other enzyme systems, maintains the structural integrity of the epithelium and thus suppresses pathogens, iron deficiency induces microcytic anemia in certain fish species, iron-free content in mucus membranes and in other tissues that are one of the first glands to protect the host against infection, iron deficiency can decrease host resistance so that iron supplementation increases host resistance disease. This report not only reviews the iron requirement in fish and crustaceans farming but also its effect on the health status.
  • Environmental assessment of coastal water of Can Gio district - Ho Chi Minh city by sea water quality index

    Nguyen, Hoang Thai; Nguyen, Phi Uy Vu; Bui, Duc Linh; Nguyen, Phi Khanh Phong (2021)
    Assessment of water quality plays an essential role in controlling and monitoring environmental quality for economic development. Based on the monitoring results in 2018-2019, the paper aims to classify the water quality based on SQWI in the coastal waters of Can Gio district, Ho Chi Minh City. Although the SQWI value increased from 35 (in 2018) to 82 (in 2019), the water environment was not considered polluted. However, the results also warn of the pollution level due to high SQWI coliform in Cau Den and Long Hoa in the rainy season.
  • Pollution of total petroleum hydrocarbon in coastal zone Ca Na, Ninh Thuan province

    Le, Trong Dung; Nguyen, Hong Thu; Le, Hung Phu; Phan, Hong Ngoc; Cao, Van Nguyen; Dao, Viet Ha (2021)
    The paper presents the analysis results of total petroleum hydrocarbon (TPH) in the water and sediments of two surveys at 12 stations in the Ca Na sea area in Ninh Thuan province in April 2018 and December 2019. Water samples were extracted by liquid-liquid method with dichloromethane solvent, sediment samples extracted by Soxhlet method, and Dichlorometal. Analysis by gas chromatography with FID detector (GC-FID). The total hydrocarbon content is calculated from the carbon range C9 to C36. The results showed that the concentration of TPH in the water ranged from 1.2 to 32.3µg/l with an average of 11.9±6.2µg/l, nearshore stations in the north (Mui Dinh) have higher concentrations than in the south (Ca Na), the concentration in December 2019 was higher than in April 2018 at most stations. In the sediments, the average TPH content is 4.3µg/gdry, ranging from 1.7-11.0 µg/gdry, showing that the sediment here has not been contaminated with TPH.
  • Composition and antioxidant activity of crude extract from squid Uroteuthis chinensis

    Nguyen, Phuong Anh; Pham, Xuan Ky; Dao, Viet Ha; Phan, Bao Vy; Le, Ho Khanh Hy; Doan, Thi Thiet (2021)
    The antioxidant activities against DPPH free radical of crude extracts using ethyl acetatee and methanol from Uroteuthis Chinensis were studied muscles of, ranged from 13.43% to 41.13%. TLC and FT-IR analysis of several fractions methanol extracts showed the presence of amino acids, peptides, and proteins. SDS-PAGE result of some fractions of methanol extracts described the presence of proteins with a molecular weight of 19-220 kDa. The antioxidant activities of different segments of the Uroteuthis Chinensis were various.
  • Preparation of nanohydroxyapatite from skipjack tuna bone (Katsuwonus pelamis) by alkaline hydrolysis and thermal calcination methods

    Le, Ho Khanh Hy; Dao, Viet Ha; Pham, Xuan Ky; Nguyen, Phuong Anh; Doan, Thi Thiet; Phan, Bao Vy (2021)
    As the main component of bones and teeth, hydroxyapatite (HAp) is considered a vital biomaterial in many fields. Meanwhile, fishbone by-products are abundant sources of HAp. Therefore, this study was conducted to prepare nano HAp from skipjack tuna bone (Katsuwonus pelamis) using alkaline hydrolysis and thermal calcination methods. After pre-treatment of fish bones for removing organic impurities, the bone powders were under alkaline hydrolysis in 1 M NaOH solution at 250o C for 1 hour. This method allows to obtain HAp nanopowders with an average particle size of only 22 nm; whereas, when heating at 600o C for four hours, the calcium formed was on average larger (40 nm) in size than the alkaline hydrolysis product. The HAp nanopowders formed by alkaline hydrolysis had a molar ratio of Ca/P 1.929, higher than that of the calcinated sample (1.848). These Ca/P molar ratios prove that the nano-HAp powders are B-type biological hydroxyapatites confirmed by the FTIR spectrum. In addition, the heavy metal contents of calcium powders are detected within safety limits of regulatory requirements of Vietnam regulations on dietary supplements and functional foods.
  • Hydroxyapatite: physicochemical properties, biological role and marine origin

    Le, Ho Khanh Hy (2021)
    Biomedical materials research aims to find new forms of materials and medical devices, which can able to adapt to the bio-physiological mechanism of the human body, avoid the elimination, therefore helping improve the quality of human life. Hydroxyapatite (HAp) is one of the stable calcium phosphate (CaP) with loBiomedical materials research aims to find new forms of materials and medical devices, which can able to adapt to the bio-physiological mechanism of the human body, avoid the elimination, therefore helping improve the quality of human life. Hydroxyapatite (HAp) is one of the stable calcium phosphate (CaP) with low solubility and Ca/P ratio similar to the Ca/P ratio in bones and teeth (Ca/P = 1.67). These properties allow HAp to be served as bone-regenerating materials or as a drug carrier. Nowadays, most HAp applied materials are products of synthesis processes, but they are still not enough for widespread applications. Therefore, several chemical methods have been developed to obtain natural HAp from marine organisms such as corals, cuttle-bones, seashells, fish scales, fish bones and algae. w solubility and Ca/P ratio similar to the Ca/P ratio in bones and teeth (Ca/P = 1.67). These properties allow HAp to be served as bone-regenerating materials or as a drug carrier. Nowadays, most HAp applied materials are products of synthesis processes, but they are still not enough for widespread applications. Therefore, several chemical methods have been developed to obtain natural HAp from marine organisms such as corals, cuttle-bones, seashells, fish scales, fish bones and algae.
  • Microplastics in three sandy beaches in Khanh Hoa province

    Le, Hung Phu; Pham, Hong Ngoc; Le, Trong Dung; Nguyen, Hong Thu; Dao, Viet Ha (2021)
    Microplastics (MPs) are small plastic debris (< 5 mm) which pose negative impacts to marine ecosystems. This paper investigated microplastic abundance in 0–5 cm and 5–10 cm layers of three sandy beaches in Khanh Hoa province. The results showed that fiber was the most abundant microplastics in the samples, comprising 85% of the total microplastics. Fragment and film were reported with smaller percentages, over 10% and 2%, respectively. In addition, the effect of grain sizes on microplastic abundance in two sediment layers was also observed. At Doc Let and Cam Lam, sediments were mainly of fine grain sizes, microplastic concentrations decreased, when the sample depths increased. On the other hand, at Bach Dang, sediment sizes ranged from medium to coarse sizes, the difference of microplastic levels in two layers was not significant.
  • Estimation of water transport exchange between the East Vietnam Sea and the neighboring seas using a 3D hydrodynamic model

    Trinh, Bich Ngoc; To, Duy Thai; Nguyen, Hong Nam; Duong, Quang Ha (2021)
    The East Vietnam Sea connects the Pacific and Indian Oceans through several interocean straits (SCSTF). A high resolution (4 km) simulation is performed with the three-dimensional regional ocean model SYMPHONIE to provide consistent estimates of the climatological averages and the interannual variability of the water transport exchanged between the East Vietnam Sea and the neighboring seas. The East Sea receives an annual average water transport of 4.45±1.35 Sv, mainly from the Luzon Strait (95%). Less than 5% of the water input comes from the atmosphere, rivers and the Balabac Strait. The East Vietnam Sea laterally releases the total amount of water input, mainly to the Sulu Sea through the Mindoro strait (49%), to the East China Sea via the Taiwan strait (28%) and to the Java Sea through the Karimata strait (22%). The interannual variability of total exchanged water volume is driven by water transport at Luzon and Mindoro straits. ENSO has a significant impact on water transport at Luzon and Mindoro straits.
  • Characteristics of the wind regime in Hon Yen island (Phu Yen province) from analysis of NCEP CFSR dataset (1979-2020)

    Tran, Van Chung; Ngo, Manh Tien; Cao, Van Nguyen (2021)
    The wind data set of 10 m on the sea surface is provided by meteorological data NCEP CFRS corresponding to 42 years (1979–2020), with hourly frequency. The purpose of this paper is to find the most effective numerical method for the Weibull distribution function for the wind regime in Hon Yen waters based on analyzing and comparing the efficiency of 10 (ten) numerical methods, namely, the empirical method of Justus (EMJ), the empirical method of Lysen (EML), the method of moments (MoM), the graphical method (GM), the Mabchour’s method (MMab), the energy pattern factor method (EPFM), the maximum likelihood method (MLM), the modified maximum likelihood method (MMLM), the equivalent energy method (EEM), and the alternative maximum likelihood method (AMLM). According to the analysis results, the EPFM method is best suited for the wind regimes of January, July and December; MLM method is best suited for February, June, August and September wind regimes; The EML method is best suited for the wind regime in March and October and the EMJ method is best suited for November. The AMLM method often results in inaccurate results in forecasting the wind regime in the Hon Yen area.
  • Research on Synop eddy currents (large size) in the East Vietnam Sea

    Pham, Xuan Duong (2021)
    The field survey to determine the size, location, morphology and time of appearance of Synop vortexes in the East Vietnam Sea is not feasible in the current conditions of our country. The East Vietnam Sea stretches over 25 degrees latitude, with the main climate and weather conditions of the tropics, with monsoon and equator, so the possibility of the appearance of Synop vortexes is entirely possible. Indirectly studying the Synopic vortexes of the East Vietnam Sea, using the research model, has also obtained certain results. Recently, a number of ocean circulation models have developed strongly of three-dimensional modeling problems, the models have applied effective calculations on the seas and world oceans of Synopic processes without also describes oceanic spectra ranging from small to global in size, ranging in duration from a few seconds to thousands of years. Using the calculated ROMS (Regional Ocean Modeling System) model, the current field in the East Vietnam Sea appears many different large-sized vortex shapes. There exists a large vortex pattern covering several small internal vortices. The vortex may appear only in the western part of the East Vietnam Sea, or only in the eastern part of the East Vietnam Sea. There exist contiguous double vortices, this double vortex is usually two reversible vortices, the belt of eddies flows continuously in opposite directions from west to east or from east to west. Comparing the research results with other research results published by foreign authors shows that there is a concordance.
  • Assessment on the Occurrence of Anisakid and other Endoparasitic Nematodes Infecting Commercially-Important Fishes at Tayabas Bay

    Ramos, Maribeth H.; Argarin, Trazarah Hanoof E.; Olaivar, Beatriz A. (2020)
    Anisakid nematodes are parasites commonly present in the marine environment. Parasites belonging to the family Anisakidae or the genus Anisakis can cause two different clinical manifestations: gastrointestinal disorders and allergic reactions known as anisakiasis. In this study, we examined 7,126 marine fishes belonging to four different commercially-important fish species; Rastrelliger kanagurta, Sardinella lemuru, Atule mate, and Selar crumenophthalmus for the presence of anisakid and other endoparasitic nematode infection. The fishes caught from Tayabas Bay were bought from three different landing sites from March 2017 to February 2018. The gonads, liver, and stomach of each fish species were incubated for 12-18 hours for rapid isolation and endoparasite evaluation. After the isolation of parasites, anisakid nematodes were fixed in vials with 70% ethanol for morphological analysis under the microscope. Six anisakid groups of genera, including Hysterothylacium, Terranova, Anisakis, Contracaecum, Raphidascaris, and Camallanus, and a non-anisakid group Echinorhynchus were identified. The results showed that the prevalence of anisakid infection in all species was 24.18 %, with a mean intensity of infection of 1.91. Rastrelliger kanagurta (Dalahican), Atule mate, and Selar crumenophthalmus were the most infected with 50.90%, 38.98%, and 30.52% prevalence rate, respectively, followed by Rastrelliger kanagurta (San Francisco) (24.18%) and Sardinella lemuru (7.46%). The collected data suggest that commercially-important fish caught in the Tayabas Bay waters are susceptible to parasitization by larvae of the genus Camallanus followed by Hysterothylacium and Terranova in their visceral organs. The prevalence of anisakid infection was almost similar between female (45.3 %) and male (47.21 %) fishes with a mean intensity of 1.95 & 1.96, respectively. Also, larger fishes were heavily infected with anisakid larvae than small fishes. Thus, the intensity and prevalence of the fish parasite can be used as a biological tag for benchmarking and stock assessment purposes.
  • Estimation of condition factor of Bengal Tongue Sole (Cynoglossus cynoglossus) in the Bay of ‎Bengal, Bangladesh.‎

    Tanjin, Sumaya; Rahman, Md. Ashekur; Uddin, Minhaz; Sarker, Biplob Kumer; Sarmin‎, Most. Shakila; Mawa‎, Zannatul; Rahman‎, Md. Ataur; Rahman, Obaidur; Samad, Md. Abdus; Habib, Kazi Ahsan; et al. (2021-12-31)
    The Bay of Bengal is rich with its biological diversity, which plays an important role in ‎the country's economic and social development. This study describes the condition ‎factor of Cynoglossus cynoglossus in the Bay of Bengal, Bangladesh. Samples were ‎collected from the Bay of Bengal during January to December 2020. Body weight (BW) ‎of fishes were taken by an electric balance with 0.01 g precision, and total length (TL) ‎was measured using a measuring board to the nearest 0.1 cm accuracy. The Fulton’s ‎condition factor was estimated by the equation: KF =100 × (BW/TL3). Total length and ‎body weight ranged from 10.0-38.7 cm (mean ± SD = 24.24 ± 6.30) and 9.1-280.6 g ‎‎(98.44 ± 57.79), respectively. The value of Fulton’s condition factor was observed as ‎‎0.6469 (SD = 0.1148), indicating unstable physiological condition of fish in Bay of ‎Bengal. The outcomes of this study will be helpful for sustainable management of C. cynoglossus in the Bay of Bengal and use as baseline information for further studies.‎
  • Re-discription of Calappa exanthematosa Alcock and Anderson, 1894 (Crustacea: Decapoda: ‎Calappidae) from the coastal waters of Pakistan.‎

    Osmani, Hamid Badar; Naz, Farah; Saher, Noor Us (2021-12-31)
    The box crab Calappa exanthematosa Alcock and Anderson, (1894) re-described ‎from the coastal waters of Pakistan. C. exanthematosa was collected as a bycatch during ‎the shrimp trawling. This species previously synonymised under C. japonica ‎Ortmann, (1892) from the Bay of Bengal, (type locality Japan), since 1937 to till date ‎‎(Galil, 1997; Spiridinov and Apel, 2007). Ng et al., (2011) re-described and illustrated the ‎C exanthematosa after comparison of freshly collected specimen of Calappa japonica ‎from the Gulf of Oman and India and revealed that the both species have resemblance ‎to each other, but few marked differences exist between both species. Current study re-‎described the morphological characteristic of C. exanthematosa from the coastal waters ‎of Pakistan.‎
  • Estimation of growth pattern and form factor of Torpedo scad Megalaspis cordyla (Linnaeus, ‎‎1758) in the Bay of Bengal, Bangladesh.‎

    Sarmin‎, Most. Shakila; Tanjin‎, Sumaya; Rahman‎, Md. Ashekur; Hasan, Md. Rabiul; Sabbir, Wasim; Asadujjaman, Md.; Mondol‎, Md. Rashedul Kabir; Habib‎, Kazi Ahsan; Hossain, Md. Yeamin (2021-12-31)
    The horse mackerel, Megalaspis cordyla is one of the commercially valuable fish species ‎in the Bay of Bengal. This study was defined the growth pattern and form factor (a3.0) of ‎M. cordyla in the Bay of Bengal. Total of 105 specimens were analyzed, caught from ‎the Bay of Bengal during January to December 2020. Total length (TL) was measured ‎by measuring board with 0.01 cm and body weight (BW) was taken by digital balance ‎with 0.01 g accuracy. The TL and BW varied between 16.8 to 41.0 cm and 67.15 to ‎‎544.0 g, respectively. The length-weight relationship (LWR) was significantly related (p < ‎‎0.0001), with r2 value 0.984. The evaluated allometric co-efficient (b) was 2.50 that ‎indicated negative allometric growth (< 3.0) in the Bay of Bengal. The estimated a3.0 was ‎‎0.0102 for M. cordyla in the Bay of Bengal. The assessed a3.0 was varied from 0.0069 to ‎‎0.0182 in worldwide waterbodies. The computed median (0.0102) and 95% confidence ‎limit (0.0099-0.0132) specified that M. cordyla poses the typical torpedo body shape ‎‎‘fusiform’. This study will provide information on growth pattern and form factor as well ‎as body shape alternation between geographic distributions which would be effective for ‎its stock assessment and management in the Bay of Bengal and else-where.‎
  • The first assessment on metal contamination in the critically endangered Sawback Angel Shark ‎‎(Squatina aculeata) from north-eastern Mediterranean.‎

    Turan, Funda; Yola‎, Mehmet Lütfi; Ergenler, Aysegul; Turan, Cemal (2021-12-31)
    A Sawback angel shark (Squatina aculeata) classified as “Critically Endangered” Global ‎Red List by the IUCN (2017) and CITES (2017) is one of the threated elasmobranch ‎groups and the increased pollution in the marine environment negatively impact angel ‎shark species. Despite this, limited information exists about the effects of toxic chemical ‎contamination in angel sharks. Therefore, present study was conducted to elucidate ‎heavy metal accumulation in Squatina aculeata captured from the Iskenderun Bay, ‎North-Eastern Mediterranean by electrochemical technique. Arsenic (As), Mercury (Hg), ‎Copper (Cu), Iron (Fe), Zinc (Zn) and Mangan (Mn) were found by electrochemical ‎analyzer. Among the gill and liver tissue samples of S. aculeata, Fe and Zn were detected ‎as highest concentrations followed by As, Hg, Mn and Cu; Among the muscle tissue of S. ‎aculeata, Fe and Zn were detected as highest followed by Hg, As, Mn and Cu. Average ‎total arsenic contents in S. aculeata was 7.5416±0.6548 μg g-1, which exceeded ‎maximum limit legalized for any kind of food. Similarly, Total mercury average content ‎in S. aculeata was 19.9942±1.6116 μg g -1, which exceeded the proposed limit value ‎which is 0.2-2 μg g-1, confirming that the consumption of S. aculeata is a high risk ‎threating the health of consumer. These results confirmed that the metal contamination ‎in North-Eastern Mediterranean area may pose a potential threat to the sustainability of ‎S. aculeata in marine ecosystem and the concentrations detected is the above the safety ‎limits for angel shark that should be taken into consideration regarding human ‎consumption.‎
  • Winners and losers: Post conflict biodiversity in the stressed ecosystem of Khor al-Zubair, Iraq

    Ali‎, Malik Hassan; Fawzi‎, Nadia Al-Mudaffar; Mohammed‎, Hanaa Hussein; Helmuth, Brian; Dwyer, Amanda M. (2021-12-31)
    A rapid assessment of biodiversity in the immediate wake of civil conflict and other ‎disasters is critical to inform recovery efforts. We report on the first surveys of aquatic ‎biodiversity in Khor Al-Zubair (KAZ) in southern Iraq, following the cessation of recent ‎violence in the region. This site is in the midst of ongoing environmental changes due to ‎climate change and reductions in water flow from the Tigris and Euphrates rivers, which ‎have led to increases in salinity in the KAZ. Monthly surveys of biodiversity were ‎conducted in 2017-2018 and compared to historical data from the site obtained from a ‎literature survey. Results indicate a loss of 80% of species richness, suggesting a ‎fundamental and potential catastrophic decline in species diversity resulting from largely ‎anthropogenic drivers.‎
  • Overview of the old and new IHO Data Protection Schemes

    Kajimura, Toru; Hattori, Tomonori (2022)
    IHO S-63“IHO Data Protection Scheme” is the standard for protecting S-57 ENCs from piracy and unauthorized use. It has been used worldwide. Part 15 of the IHO S-100“Universal Hydrographic Data Model” is the upgraded version of S-63 and will be used for S-100 products, not only for ENCs, in the near future. This article gives comparisons between them and offers some considerations.
  • Presentation of parallels and meridians in the Maritime-domain-awareness (MDA) Situational Indication Linkages, UMISHIRU

    Okano, Hirofumi; Toyosato, Hiroto; Akiyama, Hikaru; Minami, Hiroki; Matsumoto, Yoshihiro (2022)
    The Maritime-domain-awareness (MDA) Situational Indication Linkages, UMISHIRU, operated by the Japan Coast Guard, is a Web-GIS (Geographic Information System) featuring more than 200 items of marine information. Since being upgraded from the former Japan Marine Cadastre in 2019, UMISHIRU has covered global-scale information items, but it can overlay the parallels and meridians to a limited extent on the map. This paper describes a method for beginners to draw parallels and meridians beyond the limited range, and likewise to draw other geographic lines.
  • Presentation of depth information in the Maritime-domain-awareness (MDA) Situational Indication Linkages, UMISHIRU

    Okano, Hirofumi; Ito, Koji; Kamikura, Hideka; Kobayashi, Taiga; Minami, Hiroki (2022)
    When thinking about general use in waters, depth information is one of the necessar y pieces of information. By using a Web-GIS system such as the Maritime-domain-awareness (MDA) situational indication linkages, UMISHIRU, this can be effectively achieved. Unfortunately, the UMISHIRU does not itself have the depth information in. In this paper, we describe how to compile the depth data of the J-EGG500 and ETOPO1 and present the depth information in the UMISHIRU for the beginning UMISHIRU user.
  • Statistical data of sea ice observation in the recent 30 years

    Egawa, Asato; Inazumi, Shinobu; Iizuka, Masashiro (2022)
    Ice information center open every winter at the 1st Regional Coast Guard Headquarters. For safe navigation, we collect and analyze data of sea ice observations from C.G. offices, stations and relative organizations, and offer ice information as sea ice condition charts and navigational warnings. In this report, we summarize observation results of coastal sea ice stations from C.G. offices etc. in the recent 30 years.

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