• Title/Summary/Keyword: ocean environment

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Histological Study of Oculocutaneous Albinism in the Korean Bitterling, Acheilognathus signifer (Osteichthyes; Cyprinidae) (묵납자루, Acheilognathus signifer의 Oculocutaneous Albinism에 대한 조직학적 연구)

  • Oh, Min-Ki;Park, Jong-Young;You, Min-Jeong;Kang, Eon-Jong;Yang, Sang-Geun;Kim, Eung-Oh;Jo, Yong-Cheol;Park, In-Seok;Kim, Chi-Hong;Ishinabe, Toshihiro
    • Korean Journal of Ichthyology
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    • v.20 no.3
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    • pp.167-172
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    • 2008
  • The Korean bitterling, Acheilognathus signifer (Osteichthyes Cyprinidae), is an endemic and endangered species in Korea. During developmental stages, a small number of oculocutaneous albinism (with colorless body and eyeballs) were observed in the species. In order to investigate histological differences between normal and albinic bitterling, the dorsal skin and choroid-retina of the eyes were taken. The skin and eyes of normal and albino bitterling were similar in structure except for the presence or density of pigment cells. In normal bitterling, the epidermal melanocytes and dermal melanophores were abundantly developed in both the skin and epidermis of the eyes. But in the albino, the dorsal skin had few melanins, and the pigment cells over the choroid-retina pigment epithelium and iris of the eye were very small.

Temporal Variation and Identification of a Centric Diatom, Stephanodiscus spp. during Winter-spring Blooms in the Yeongsan River (영산강 동계 조류 대발생 기간의 규조류 Stephanodiscus spp. 출현양상과 형태적 분류)

  • Jeong, Byungkwan;Kim, Yongjae;Jung, Seung Won;Lee, Hakyoung;Shin, Yongsik
    • Korean Journal of Ecology and Environment
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    • v.47 no.4
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    • pp.273-281
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    • 2014
  • We conducted the weekly monitoring (December 2012~April 2013) to evaluate the temporal variation and identification of Stephanodiscus spp. that are generally dominant during winter in the Yeongsan River. Phytoplankton species were identified and counted using the optical microscope and scanning electron microscope (SEM). Phytoplankton in the river were grouped into 6 classes (bacillariophyceae, chlorophyceae, cryptophyceae, cyanophyceae, dinophyceae, euglenophyceae), 30 genus and 41 species. Phytoplankton composition showed high abundance of diatoms in winter and Aulacoseira sp., Cyclotella sp. and Stephanodiscus spp. were dominant. Among the species, Stephanodiscus spp. was relatively abundant compared to other diatom species. Stephanodiscus spp. appeared from December 2012 to April 2013 and their abundance peaked in January. Abundance of diatoms especially peaked ($21,080cells\;mL^{-1}$) in January 15, 2013 when Stephanodiscus spp. also bloomed ($20,560cells\;mL^{-1}$). The abundances of Stephanodiscus spp. were gradually decreased from March and reached as low as $60cells\;mL^{-1}$ in April 26. Cyclostephanos (C. invisitatus), Cyclotella (C. meneghiniana), Discostella (D. pseudostelligera, D. woltereckii) and Stephanodiscus (S. hantzschii, S. minutulus, S. parvus) were classified in the circular diatoms. Abundance of S. hantzschii was extremely high compared to S. minutulus and S. parvus.

A Study on the Designation of the place of Refuge Through the Analysis of Foreign Cases (외국 사례분석을 통한 국내 선박 피난처 지정에 관한 연구)

  • Lee, Chang-Hyun;Kim, Chol-Seong;Yang, Won-Jae;Park, Seong-Hyun;Jeong, Jung-Sik
    • Proceedings of KOSOMES biannual meeting
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    • 2007.11a
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    • pp.169-174
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    • 2007
  • A huge marine accident causes a loss of valuable lives, property and the serious environmental contamination. In the IMO, active discussions about a potential occurrence possibility of marine accidents and appropriate place(place of refuge) to minimize the damage are being developed as appropriate transferring vessels which has a worry of a secondary marine environmental pollution from a previous marine accident Our country has a great potential et marine accidents due to the foreign vessel in distress because there is a huge vessel traffic amounts of the passage since which locate with in the important navigation connects the Asian region. and North America centering around north Pacific Ocean Also, we need the minimize the secondary damage from accident which occurs in domestic ports as transferring safe쇼 place when it is needed In this paper, analyzed and investigated a designated the place of refuge that analyze foreign cases, and will make a efficient and reasonable investigating plan of interior place of refuge.

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Faunal Analysis and Oceanic Environment of the Recent Benthonic Foraminifera from the West and South Sea of korea (한국 서남해에서 산출된 현생저서 유공충의 동물군 분석 및 해양환경 연구)

  • CHEONG, HAE-KYUNG;PAIK, KWANG-HO;PARK, BYONG-KWON
    • 한국해양학회지
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    • v.27 no.2
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    • pp.123-136
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    • 1992
  • As a result of faunal analysis on 50 bottom samples bearing a total of 183 species of the Recent benthonic foraminifers from the West and South Sea of korea, five bioassociations (groups of species) and five biotopes (groups of samples) were discriminated. From the areal distribution of biotopes in combination with bioassociations and the available ecological data of foraminiferal species, five biofacies are recognized: (1) Southern Inner Shelf Biofacies; (2) Southern Coast Biofacies; (3) Northern Middle Shelf Biofacies; (4) Central Middle Shelf Biofacies; and (5) Southern Outer Shelf and Upper Slope Biofacies. The biofacies are defined by a group of sampling stations containing a diagnostic species association and can be related to the major current pasterns and water masses in the West and South Sea of Korea: Southern Inner Shelf Biofacies is related to the Coastal Waters and drainage from China; Southern Coast Biofacies is related to the Coastal Waters and drainage from Korea; Northern Middle Shelf Biofacies is related to the Coastal Waters and Yellow Sea Cold Water, Central Middle Shelf Biofacies is related to the Yellow Sea Warm Current; and Southern Outer Shelf and Upper Slope Biofacies is related to the Tsushima Warm Current.

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Spatial Distribution of Macrobenthos in Sueocheon Stream Estuary at the Nothern Part of Gwangyang Bay, Korea (광양만 북부 수어천 하구역의 여름철 대형저서동물 공간분포)

  • Lim, Hyun-Sig;Choi, Jin-Woo;Choi, Sang-Duk
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.17 no.2
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    • pp.76-86
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    • 2012
  • Macrozoobenthos were collected from 24 sites using small grab ($0.05m^2$) in order to see the spatial distribution of them at Sueocheon stream at the northern part of Gwangyang Bay during summer season when the maximum ecological processes are occurring. A total of 44 species of macrozoobenthos occurred, and their mean density was $789individuals/m^2$. Mollusks was the dominant faunal group accounted for 43.1% and 86.8% of the whole community density and biomass, respectively. Top five dominant species were a molluscan, Corbicula japonica (40.7%), two polychaete worms, Neanthes japonica (19.3%) and Heteromastus filiformis( 8.1%), and two crustaceans, Paranthura japonica (6.9%) and Jaeropsis sp. (6.9%). Species diversity index was very low with mean value of 1.12 and maximum value was recorded at the river mouth. At the upper stream, a brackish water species such as Corbicula japonica showed their maximum population density. The overall distribution of stream macrobenthos showed a rather simple pattern along with salinity and grain size gradients with few brackish water species occurring at coarse sediments in the stream but more diverse faunas inhabiting fine sediments in the river mouth.

Report of East Sea Crossing by Underwater Glider (수중 글라이더를 이용한 동해 횡단 사례 보고)

  • Park, Yo-Sup;Lee, Shin-Je;Lee, Yong-Kuk;Jung, Seom-Kyu;Jang, Nam-Do;Lee, Ha-Woong
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.17 no.2
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    • pp.130-137
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    • 2012
  • The underwater glider using conception of Lagrangian method, is a new observation platform to understand the properties of the ocean vertically. In 2011 March, KORDI made a first successful autonomous trip from Hupo to west coast of Uleungdo piloting Littoral Glider of Alaska Native Technology LLC. The journey considered many environmental variables and route vigilantly selected, the glider covered 177 km horizontally and took approximately 6 days (153 hours). Despite the existence of 1 kt eddy current, Sound velocity sampling was conducted from 5 meters and reaching maximum of 200 meters depth at each dive. It successfully collected sound velocity and temperature profile at every 5 seconds totaling up to 1408 profiles using SVT&P sensor. During the flight it was also a mission to check the diverse modes of the glider i.e. spiral, waypoints, heading, drift and hover could function without a defect in a given situation. These modes were thoroughly monitored and it could be considered that the glider handled it well during the flight. As a result of this test flight, it was evident that the given underwater glider could operate under 2kt current environment with users defined heading and depth, also with the payload up to 5 kg without changing internal buoyancy.

Development of Eggs, Larvae and Juvenile of the Korean Bullhead, Pseudobagrus fulvidraco (Richardson) reared in the laboratory (동자개의 형태발달과 성장특성)

  • Han, Kyung-Nam;Nam, Ki-Bong;Jeong, Choong-Hoon
    • Korean Journal of Ichthyology
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    • v.13 no.1
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    • pp.74-84
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    • 2001
  • The early developmental stages, growth and morphological changes of the Korean bullhead, Pseudobagrus fulvidraco, were studied from a series of reared specimens. Details of the early developmental stages are illustrated with special reference to morphological transformations. Egg and sperm of Korean bullhead were obtained from mature adults under hormonal treatment, fertilized artificially, and incubated in the aquarium. The incubation period of fertilized eggs was 55 to 66 hours at a temperature of 24.9${\pm}$0.34$^{\circ}$. Larvae were fed successively with Artemia salina and Daphnia magna for 2 to 15 days and artificial food after 20 days. Fertilized eggs were adhesive and spherical with a diameter of 2.04mm(n = 100). The mean total length of newly hatched larvae was about 4.92${\pm}$0.33 mm. Mouth opening occurred on one-day-old yolk-sac larvae, and initial feeding was observed on the third day after hatching. The morphological transitions from larvae to juvenile and juvenile to young stages occurred when the fish reached about 17 mm in total length (about 13days after hatching) and about 32 mm in total length (about 30 days after hatching), respectively. Many changes in proportion of body parts to total length were observed at about 7~8 mm and 30~32 mm, corresponding to the transformations from larvae to juvenile and from juvenile to young, respectively. In comparing relative growth of each body part against total length, those characteristics related to head parts showed positive growth in the pre-larval stages, while those concerning mobile abilities showed positive growth in the post-larval stage.

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First Record of a Velvetfish, Cocotropus masudai (Scorpaeniformes: Aploactinidae) from Korea (한국산 풀미역치과 어류 1미기록, Cocotropus masudai)

  • Han, Song Hun;Kim, Maeng Jin;Song, Choon Bok
    • Korean Journal of Ichthyology
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    • v.28 no.2
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    • pp.116-120
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    • 2016
  • A specimen of Cocotropus masudai (41.2 mm in standard length), belonging to the family Aploactinidae, was firstly collected from the eastern coastal waters of Jejudo Island, Korea by using a fish trap in July 2011. This species is characterized by having the following morphological traits: XII, 9 dorsal fin rays; I, 8 anal fin rays; 12 pectoral fin rays; I, 3 pelvic fin rays; five preopecular spines; five sensory pores present on lower jaw and isthmus tip beyond fifth sensory pore. This species is similar to C. izuensis except for the number of preopercular spines (five in C. izuensis vs. four in C. masudai) and the anterior position of the isthmus (well beyond the fifth lower jaw sensory pore vs. the tip mostly reaching to the pore). In Korea, C. masudai can be easily distinguished from the Erisphex pottii in having the dorsal fin with nine soft rays (vs. 10~14 for Erisphex pottii), anal fin with seven soft rays (vs. 10~13) and pelvic fin with three soft rays (vs. two). We propose new Korean names, "Dot-chi-sok" and "Dot-chi" for the genus and species, respectively.

Study on the Manufacturing of Leather-like Material using Leather and Textile Scrap (피혁 및 섬유 제조공정 폐기물을 활용한 피혁 대체 소재의 제조에 관한 연구)

  • Kim, Won-Ju;Ko, Jae-Yong;Heo, Jong-Soom
    • Journal of the Korea Organic Resources Recycling Association
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    • v.8 no.4
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    • pp.93-99
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    • 2000
  • Treatment of shaving scrap, a chrome containing solid scrap generated by leather manufacturing process, has been so far depended on mainly incineration, soil landfill and ocean dumping, which give bad impact on environment and cause pollution. Shaving scrap generates from the mechanical work for controlling the final thickness of leather and its main components are collagen protein and pan of chromium compound. For the purpose of reusing this leather waste as resources, researches in connection with collagen fiber recovery, gelable protein recovery and liquid fertilizer is being speedily progressed. In the experiment, shaving scrap went through wet pulverizing treatment by physical and chemical methods. Then, making the leather sheet evenly, it is mixed with natural latex and every kind of binding materials in the container, and the mixtures were passed through experimental hydraulic press machine and applied to Fourdrinier machine respectively. Lastly, a test for fading out physical strength and properties of multiple-purpose of leather-like material was performed on a continuous leather sheet prepared by the experiment. In result, the physical strength and properties of leather-like material showed noticeable differences according to mixing ratio of binding materials, beating methods and the Ends of binding materials selected, and generally tear strength was the weakest property among others. Also, by the pilot scale experiment in sequence, it was possible to manufacture recycled goods made of soft and hard types of leather-like material with various performances.

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A Study on the Improvement of Marine Pollution and Marine Litter Managements in Korea (우리나라 해양오염 및 해양폐기물관리 개선에 관한 연구)

  • Park, Kwang-Ha;Kwon, Young-Du;Kim, Jong-Sung
    • Journal of the Korea Organic Resources Recycling Association
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    • v.21 no.4
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    • pp.33-43
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    • 2013
  • That occur in the ocean and the efficient management of marine litter on marine pollution oil spill response one step further strategies are needed. Marine pollution accidents occurred in 2011, a total of 287 and was found in runoff 369 kL, respectively compared to the previous year decreased by 13% and 39%. Average amount of marine materials during 5-years represent the oil flow of 310.5 kL (heavy fuel oil of 106.0 kL, diesel of 178.9 kL, oily bilge water of 22.3 kL, other oil of 7.7 kL) and the waste of 62.3 tons, the hazardous and noxious substances (HNS) was 510.6 kL. Marine emissions in 2011 by type of waste that a total amount of dumping 3,972 $m^3$, and livestock manure 795 $m^3$(20%), waste water 1,431 $m^3$(36%), sewage sludge 887 $m^3$(22%), wastewater sludge, 813 $m^3$(21%), manure 5 $m^3$(0.1%), other 41 $m^3$(0.9%), respectively. The concept of marine waste and needs to be more clearly defined. Integrated management of hazardous chemicals according to the incident management system should be established. To remove of coastal pollution, response officer needs korean coast response system. Like the marine pollution response, coastal pollution response systems also require step response.