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  • 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.
  • Trial of creating of tidal current grid data for the Akashi Strait

    Muneda, Koji; Tsuchiya, Chikara; Ino, Kohei (2022)
    The Japan Coast Guard Hydrographic and Oceanographic Department has provided data on tidal current, which is one of the ocean currents, as area information (tidal current grid data). In recent years, technologies related to the ocean have advanced, and new information such as detailed water depth data has been acquired. In addition, the mainstream method of providing tidal current grid data is digital, which has a high variety of information usages from printed matter. The Hydrographic and Oceanographic Department is conducting research to create new tidal current grid data corresponding to these. Between 2019 and 2020, the Akashi Strait was examined as part of first trial at creating tidal current grid data.
  • On the tidal current harmonic constants in Ise Bay

    Muneda, Koji (2022)
    The tidal current harmonic constants in Ise Bay are owned by the Japan Coast Guard Hydrographic and Oceanographic Department and is a point-like one created by continuous day and night observation of tidal currents at fixed points. There is a grid-like one created in 2004 based on joint reserch with the Japan Hydrographic Association (2004, 2005a, 2005b). This time, as part of the research to create tidal current grid data, tidal current harmonic constants were created from the current direction and current velocity data observed by the Ise Bay Ocean Short Wave Radar operated by the Nagoya Port and Airport Technical Research Office, Chubu Regional Development Bureau, Ministry of Land, Infrastructure, Transport and Tourism. We examined these tidal current harmonic constants.
  • Optimized observation cycle for the tidal harmonic analysis

    Ino, Kohei; Tsuchiya, Chikara (2022)
    The Japan Coast Guard observes the tidal time series using the Autonomous Ocean Vehicle (AOV) to precisely determine datum levels. As the AOVs utilize solar energy for their observation equipment, interruptions of observation caused by the power shortage due to decrease in the amount of sunshine in the winter becomes an operational issue. In this paper, we investigate whether short observations during interruptions or prolonged observation are effective to obtain reliable tidal harmonic constants. We found that short observations of more than 24 hours during interruptions or observations from the next year on the same date as the interruption make the tidal harmonic constants close to the value calculated from no missing data. The results of this study can be used as index for deciding the implementation of observation in winter or making plans for observation using AOVs.
  • Installation of a seafloor geodetic observation system on the S/V Koyo

    Yoshida, Shigeru (2022)
    The Hydrographic and Oceanographic Department, Japan Coast Guard (JHOD), has installed an acoustic transducer on all of its survey vessels (excluding the S/V Tenyo) to conduct GNSS-Acoustic ranging (GNSS-A) observations. JHOD also installed a seafloor geodetic observation system on the new S/V Koyo(4,000 tons) commissioned in March 2021 to improve the efficiency of its GNSS-A observations. In this article, we report on the outline of the seafloor geodetic observation system installed on the S/V Koyo, the survey method and the resulting relative position between the GNSS antenna and the transducer, and the result of the test observation. The result of the test observation indicated that the horizontal components of the seafloor site position observed by the S/V Koyo agree with the trend of the time series estimated from our regular GNSS-A observations. On the other hand, the vertical component indicated the possibility of a positioning bias, which would necessitate further evaluation by continuing the GNSS-A observations using the S/V Koyo.
  • Trial to visualize the distribution and seasonal variation of ALB-measurable areas estimated from remotely sensed diffused attenuation coefficient data

    Ogawa, Haruka; Yamano, Hiroyuki; Sumiyoshi, Masanao (2022)
    Efficient Airborne Lidar Bathymetry (ALB) surveys involve elaborate prior adjustments and operation planning processes based on a consideration of various relevant conditions. We attempted to visualize the distribution and its seasonal variation of the ALB measurable areas around Japan using a remotely sensed dataset of diffused attenuation coefficients, which represents the optical characteristics of the seawater, to help reduce the burden of the operation planning. The results showed that the maximum measurable depth at a certain spot seasonally varies and, subsequently, the distribution of the measurable areas varies as well. The estimated maximum penetration depths have proved to make a useful index for operation planning, while its future verification is required.
  • Developing the standard operating procedures of ellipsoidally referenced surveys at coastal waters in Japan: trials of bathymetric data processing and verification of their results†

    Okubo, Masaki; Sumiyoshi, Masanao; Ino, Kohei; Kobayashi, Kenta; Tsuchiya, Chikara; Rika, Nozawa; Kurita, Hirokazu; Ogawa, Haruka; Nagano, Katsuyuki; Yamano, Hiroyuki; et al. (2022)
    In recent years, with the spread and improvement in the accuracy of kinematic GNSS positioning, ellipsoidally referenced surveys (ERS) have become practically possible, which in principle do not require tide observations during the bathymetric surveys. In this paper, as the first step of a trial to establish the standard operating procedures for ERS in Japan, we presented the practical operating procedures of bathymetric data processing in ERS and vertical datum model estimation, by using the existing bathymetric data in Tokyo Bay. In this case, the validity of the ERS operating procedures was verified by comparing the depths in the ERS procedures with those in the conventional procedures with tidal reduction.
  • On the calculation of the tide table

    Ino, Kohei; Tsuchiya, Chikara (2022)
    This article reviews the algorithms used for various calculations such as predicting the tidal heights and currents for the tide table, using the tide table, and obtaining tidal harmonic constants.
  • Operation and observations of the Autonomous Ocean Vehicle (AOV.

    Ino, Kohei; Sugiyama, Shinji; Kon, Takahiro; Tsuchiya, Chikara; Nozawa, Rika; Ogahara, Hidemi; Yoshi, Nobuyoshi; Nakayama, Koichiro; Nagakura, Katsumi; Uchimura, Shinobu (2021)
    Japan Coast Guard has been operating the Autonomous Ocean Vehicle (AOV) since 2016 in order to precisely determine datum levels and observe meteorological and oceanographic conditions. In this paper, we report the problems and improvements concerning long-term observation. Moreover, we review the tide level data processing method related to determining datum level precisely and show recent examples of meteorological and oceanographic observation.
  • Installation of seafloor geodetic observation system on the S/V Heiyo.

    Yoshida, Shigeru; Watanabe, Shun-ichi; Hashimoto, Tomohisa; Nakamura, Yuto (2021)
    The Hydrographic and Oceanographic Department, Japan Coast Guard (JHOD) installed an acoustic transducer on the bottoms of the S/V Meiyo (550 tons) in March 2008, the S/V Takuyo (2,400 tons) in February 2010, the S/V Kaiyo (550 tons) in March 2012, and the S/V Shoyo (3,000 tons) in November 2012 and started sailing GNSS-Acoustic (GNSS-A) observations. The JHOD also installed a seafloor geodetic observation system on the New S/V Heiyo (4,000 tons) in January 2020 for more efficient and precise seafloor positioning. In this report, we discuss the outline of the seafloor crustal movement observation system installed in the S/V Heiyo, the position measurement method and the measurement results of the GNSS antenna and the transducer, and the results of the test observation
  • Historical nautical charts published by the Japanese Navy during the Meiji era and owned by domestic and overseas libraries and museums.

    Sato, Satoshi; Yoritaka, Miwako (2021)
    We surveyed the Japanese nautical charts published in the Meiji era in the collections of domestic and overseas libraries and museums in 2019. As a result, we found the following new facts.The Tokyo National Museum has in its holdings the charts exhibited at the first and third National Industrial Exhibitions held in 1877 and 1890. The Leiden University Libraries in Netherlands own two volumes of the Dai-Nippon Kaigan Jissokuzu, the atlas of Japanese nautical charts that the Japanese Hydrographic Office compiled based on its own hydrographic surveys in its founding period.While it is known that the Kyoto University Museum owns many charts that were published in the Meiji era and stamped with “Donated by the Navy”, some documents of the National Archives revealed that these charts were donated by the Japanese Imperial Navy in 1911, upon request from the Kyoto Imperial University.

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