• Title/Summary/Keyword: coastal waters

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Sex Reversal Pattern of Wrasse in Jeju Coastal Waters

  • Lee, Young-Don;Kim, Se-Jae
    • Proceedings of the Korean Society of Developmental Biology Conference
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    • 2003.10a
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    • pp.76-76
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    • 2003
  • Eleven wrasse species inhabit the coastal waters of Jeju Island, Korea. They are the target of leisure fishing and are considered good eating. We investigated the distribution of standard length (SL) by sex of wrasse in Jeju coastal waters for Halichores poecilopterus, H. tenuispinis, Pseudolabrus japonicus, and Pteragogus flagellifera. A cross-section of the ovary showed the ovarian cavity and ovarian lamellae containing oocytes. A cross-section of the testis showed many lobules containing spermatogonia and spermatocytes. A cross-section of a gonad undergoing sex reversal showed the regression or reduction of oocytes and some spermatocytes located in the ovarian lamellae. A cross-section of a sex-reversed testis showed the primary structure of the ovary, with spermatocytes distributed in the epithelium of the lamellae, and reformed seminiferous ducts in the basement lamellae. (중략)

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A Study on an Integrated Monitoring and Modeling System for Marine Environment of Coastal Waters (연안해역 환경의 종합 감시 및 모델 체계에 관한 연구)

  • 김광수
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.8 no.1
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    • pp.149-159
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    • 2002
  • Various numerical models that have been developed for marine environments and applied to coastal waters in USA were introduced briefly. Inter alia, with regard to an integrated monitoring and modeling system, the main features and outline of system, the system architecture for data management and representation system, and the incorporation of internet based technology were described. An example of application of an integrated system to coastal waters was also presented. The prospective research works to improve the capabilities and to advance the functionality of an integrated monitoring, modeling and management system were suggested to be the instrumentations for various monitoring parameters, the new development and/or advancement of various numerical models, the relevant internet based technologies. etc..

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AStudy on the Fine Structure of the Marine Diatoms of Korean Coastal Waters-Genus Thalassiosira 1. (한국연안역의 부유성 규조류의 미세구조에 관한 연구 Thalassiosira 속 1.)

  • 이진환;유광일
    • 한국해양학회지
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    • v.21 no.3
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    • pp.184-192
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    • 1986
  • A study on the fine structure of the marine diatom has been carried out for taxonomical purpose during the period from Fib. 1982 to Feb. 1986 in Korean coastal waters. Fine structure of small Thalassiosira (Bacillariophyceae) was studied by means of light and scanning electron microscopy. Firstly, four species of Thalassiosira were identified and described. Of these Thalassiosira weissflogii, T.minima and T.oestrupii var venrickae were new records for Korean coastal waters.

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Morphology and distribution of some marine diatoms, family Rhizosoleniaceae, genus Proboscia, Neocalyptrella, Pseudosolenia, Guinardia, and Dactyliosolen in Korean coastal waters

  • Yun, Suk-Min;Lee, Jin-Hwan
    • ALGAE
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    • v.26 no.4
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    • pp.299-315
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    • 2011
  • The morphology, taxonomy, and distribution of species belonging to the diatom family Rhizosoleniaceae were studied from the marine coastal waters of Korea. Rhizosolenid diatom taxa were collected at 30 sites from September 2008 to February 2010 and were analyzed by light and scanning electron microscopy. We identified 6 rhizosolenid genera, including Rhizosolenia, Proboscia, Pseudosolenia, Neocalyptrella, Guinardia, and Dactyliosolen. We describe 5 genera in this study, except Rhizosolenia. Five genera were compared in detail with congeneric species. Six genera within the family Rhizosoleniaceae were divided into two groups based on morphological diagnostic characters including valve shape, areolae pattern, the shape of external process, and girdle segments in the column. The first group had a conoidal valve and loculate areolae, which comprised Rhizosolenia, Proboscia, Pseudosolenia, and Neocalyptrella, and the second group of Guinardia and Dactyliosolen showed a flat or rounded valve and poroid areolae. Important key diagnostic characters were based on valve shape, areolae pattern on the segment, external process, position of the tube, and the valve margin. D. phuketensis was new to Korean coastal waters.

A Study on the Fine Structure of the Marine Diatoms of Korean Coastal Waters - Genus Thalassiosira 3

  • Lee, Jin-Hwan;Park, Joon-Sang
    • ALGAE
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    • v.23 no.3
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    • pp.187-199
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    • 2008
  • A study on the fine structure of the marine diatom Thalassiosira has been carried out during the periods from January 2007 to March 2008 in Korean coastal waters. As the third series of the Thalassiosira species, a fine structure, description, distribution and taxonomic remarks of the six Thalassiosira species were observed by means of light microscope and scanning electron microscope. The critical features of Thalassiosira species were a shape of external tubes of marginal strutted processes and labiate process. Six species showed each different shape of external tubes, marginal strutted processes and labiate process. The shape of external tube was divided into five types: T shape of Thalassiosira curviseriata, small-rounded shape of T. lundiana, double-layer form and flame shape of T. nordenskioeldii, tulip shape of T. punctigera and tooth-shape of T. tenera. This external character may be able to key character for positive identification of the Thalassiosira species. Of these Thalassiosira lundiana, T. minuscula and T. tenera were new records for Korean coastal waters.

Larval Development of Chthamalus challengeri Hoek (Cirripedia: Thoracica: Chthamalidae) with Keys to Barnacle Larvae of Korean Coastal Waters

  • Chu Lee
    • Animal cells and systems
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    • v.3 no.1
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    • pp.59-68
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    • 1999
  • Chthamalus challengeri Hoek was collected from intertidal rocks to rear the larvae from hatching through nauplius to cyprid in the laboratory. Larval development consists of six nauplius stages and a cyprid. Unilobed labrum with a prominent protuberance and the frontolateral horns folded under the anterior cephalic shield margin are diagnostic features through all nauplius stages. The posterior border of the cephalic shield bears no posterior shield spines in nauplius stages IV-Ⅵ. There is a specific hispid seta in the fourth group of the antennal endopodite. Morphological features such as the cephalic shield, labrum, abdominal process, antennules, antennae and mandibles in all nauplius and cyprid stages are illustrated and described. The numerical setations of the antennule are found to aid in the intraspecific identification of barnacle nauplius stages without dissection. The keys to each stage of the barnacle larvae in Korean coastal waters are provided based on the reared nauplii of seven species: Pollicipes mitella Octomeris sulcata, Chthamalus challengeri, Balanus albicostatus B. trigonus, B. amphitrite, and B. improvisus inhabiting Korean coastal waters.

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A Study on the Fine Structure of the Marine Diatoms of Korean CoastalWaters - Genus Thalassiosira 4

  • Park, Joon-Sang;Jung, Seung-Won;Lee, Jin-Hwan
    • ALGAE
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    • v.24 no.2
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    • pp.67-77
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    • 2009
  • The marine phytoplankton diatom Thalassiosira species are described from the Korean coastal waters, based onobservations of Fine structutre of its frustules. As a fourth series, this study deals with 5 Thlassiosira species (T. decip-iens, T. ecgentrica, T. mala, T. nodulolinmta, and T. proschinae). The most striking features of these species are also theform and position of two processes on frustules. There is a central strutted process on valve face except T. nodvlolin-eata, which has a modified one on its center. The extemal tubes of marginal strutted processes are divided twoforms: "pile" form in T. decipiens and T. proschkinae, "short straw" form in T. eccentrica and T. nodulolineata. T. maladoes not present the extemal tubes in valve margin. The labiate processes are located in valve margin except T.proschkinae, which has it on valve face. Of theae, thrce species (T. mala, T. nodulineata at a final contentration of 5%and T. proschkinae were newly recorded in the coastal waters of Korea.

Newly recorded unarmored dinoflagellates in the family Kareniaceae(Gymnodiniales, Dinophyceae) in brackish and coastal waters of Korea

  • Cho, Minji;Choi, Hojoon;Nam, Seung Won;Kim, Sunju
    • Korean Journal of Environmental Biology
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    • v.39 no.2
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    • pp.236-244
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    • 2021
  • Unarmored dinoflagellates, in the family Kareniaceae, include harmful or toxic bloom-forming species, which are associated with massive fish kills and mortalities of marine organisms worldwide. The occurrence and distribution of the toxigenic species in the family Kareniaceae were investigated in the brackish and coastal waters of Korea between July 2018 and October 2020. During the survey, we collected seven newly recorded species; Karenia papilionacea, Karlodinium digitatum, Karl. veneficum, Karl. zhouanum, Takayama acrotrocha, T. helix, and T. tasmanica. A total of fifteen strains of the seven taxa were successfully established as clonal cultures and examined using LM, SEM, and molecular phylogeny inferred from LSU rDNA sequences. Herein, we present the taxonomic information, morphological features, and molecular phylogenetic positions of the unrecorded dinoflagellate species collected from Korean coastal waters.

Ecosystem-based resource assessment on coastal fisheries of Uljin in East Sea of Korea (한국 동해 울진 연안어업의 생태계 기반 자원평가)

  • Yoon, Sang-Chul;Zhang, Chang-Ik;Seo, Young-Il;Kim, Zang-Geun
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.50 no.4
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    • pp.567-582
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    • 2014
  • Coastal fisheries in Korean waters have highly complexity with a variety of fishing gears, and scale of those fisheries is smaller than that of offshore fisheries. As a result, important spawning and nursery grounds for many species of fish has been destroyed. The pragmatic ecosystem-based approach was developed for the assessment of fisheries resources in Korean waters by Zhang et al. (2009; 2010). As for the species risk index (SRI), common squid caught by coastal gillnet in the Uljin region had the highest risk. As for the fisheries risk index (FRI), coastal gillnet in the Uljin coastal waters had the highest risk. For the common squid which had the highest SRI, resources management strategies must be established such as catch prohibition of length and period with TAC. For the coastal gillnet in the Uljin region which had the highest FRI, it is judged to need management plans for conserving biodiversity as reducing the catch of non-target species and discards. Also to protect existing habitat, illegal fishery should be prohibited, and fishing gears should be designed in the environmental-friendly way considering when fishing gears lost.