• Title/Summary/Keyword: MT(Marine Technology)

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Change of Benthic Macroinvertebrates Community Composition Following Summer Precipitation Variance (여름철 집중 강우량 변동에 의한 저서성 대형무척추동물 군집구성의 변화)

  • Hong, Cheol;Kim, Won-Seok;Kim, Jin-Young;Noh, Seong-Yu;Park, Ji-Hyung;Lee, Jae-Kwan;Kwak, Ihn-Sil
    • Korean Journal of Ecology and Environment
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    • v.52 no.4
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    • pp.348-357
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    • 2019
  • To investigate the changes of dominant species of benthic macroinvertebrates following summer precipitation variance, we surveyed twenty five sites of the main Seomjin River in May and September in 2014 and 2015. The temperature, precipitation, water quality factors and substrate composition, water depth and flow velocity, which are important factors in benthos habitat environment, were collected and measured. There is not much difference of the cumulative precipitation (CP) between 2014 (2,322.1 mm) and 2015 (2,371.0 mm) in May. However CP in september was decreased by more than half in 2015 (3,726.1 mm) than 2014 (7,678.2 mm). Due to washing effect by summer precipitation, total number of species and individuals for benthic macroinvertebrates were higher in May than in September. Chironomidae spp. and Choroterpes altioculus were dominated in May, Ecdyonurus levis, Ecdyonurus kibunensis were dominated in September. As a result of correlation analysis between community indices and environment factors, it was found that there is a significant correlation with flow velocity and substrate compositions. According to the results of cluster analysis and PCA based on environment fators and dominant species of benthic macroinvertebrates in Seomjin River, it was divided into four groups following CP and MT. Ecdyonurus levis and Ecdyonurus kibunensis reflect the effect of the decrease in summer precipitation.

Morphological and Genetic Stock Identification of Todarodes pacificus in Korean Waters (한국 주변해역에 서식하는 살오징어(Todarodes pacificus)의 형태 및 유전학적 계군분석)

  • Kim, Jeong-Yun;Yoon, Moon-Geun;Moon, Chang-Ho;Kang, Chang-Keun;Choi, Kwang Ho;Lee, Chung Il
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.18 no.3
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    • pp.131-141
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    • 2013
  • Stock identification of Todarodes pacificus collected in the East Sea, Yellow Sea and East China Sea during the period from September to December in 2011 was analyzed by morphometric characters and mitochondrial DNA (mtDNA) cytochrome oxidase subunit I (COI) gene nucleotide variations. Frequency distributions of mantle length was analyzed by morphological method with measuring size of T. pacificus. Then each stock was estimated to confirm their maturation for mean mantle length comparing with mean mature mantle length 20-22 cm. According to morphologic stock identification, it is estimated that the northern part of East Sea is categorized as summer stock and the rest parts, including mid /southern part of the East Sea, northern part of the East China Sea and northern part of the West Sea were autumn stock. For genetic analysis, a total 49 haplotypes were defined by 33 variable nucleotide sites. From the extensive haplotype diversity, limited nucleotide diversity and star-like shape of haplotype network, T. pacificus appears to have undergone rapid population expansion from an ancestral population with a small effective population size. Although pair-wise Fst estimates which represent genetic difference among groups were low, there are relatively remarkable difference of Fst between middle and southern part of the East Sea. Although middle part of the East Sea and southern part of the East Sea were situated at the East Sea, genetically separated groups were appeared.

Molecular Phylogeny of Two Species of Hexagrammidae (Greenlings) Inferred from Mitochondrial Cytochrome b Gene (쥐노래미과 어류 2종의 미토콘드리아 Cytochrome b 유전자의 분자계통)

  • Jung, Sang-Oun;Lee, Young-Mi;Hur, Jun-Wook;Im, Soo-Yeon;Lee, Jae-Seong;Park, In-Seok
    • Korean Journal of Environmental Biology
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    • v.24 no.2 s.62
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    • pp.112-118
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    • 2006
  • We report mitochondrial cytochrome b (cyt b) genes from greenling Hexagrammos otakii (Jordan et Starks) and spotty belly greenling, H. agrammus (Temminck et Schlegel) within Hexagrammidae, two species of aquaculture importance. Of 489 bp of the cytochrome b gene, a little variation occurred between species (96% similarity). The pairwise distance (0.0342) between greenling and spotty belly greenling in term of the Neighbor-joining method indicated that two species was close in molecular phylogenetic consideration. These findings are applicable to aquaculture, fisheries genetics and molecular phylogenetics in the genus Hexagrammos.

A Natural Hybrid of Intergeneric Mating between a Female Pungtungia herzi and a Male Pseudorasbora parva (Cypriniformes: Cyprinidae)

  • Kim, Keun-Yong;Ko, Myeong-Hun;Cho, Sung Jang;Kim, Woo-Jin;Son, Min Ho;Bang, In-Chul
    • Fisheries and Aquatic Sciences
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    • v.18 no.1
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    • pp.99-107
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    • 2015
  • A natural hybrid of a probable intergeneric mating between the striped shiner Pungtungia herzi and the stone morocco Pseudorasbora parva (Cypriniformes: Cyprinidae) was captured in the Geumho River, a tributary of the Nakdong River basin in Korea. Morphological characters and DNA sequences were analyzed to verify its hybrid state and identify the parentage of its parent species. The hybrid exhibited a phenotypic intermediacy between the two parent species in the number of vertebrae and the mouth shape. Out of 1,488 base pair (bp) positions of the nuclear recombination activating gene 1 gene (rag1), which has a biparental mode of inheritance, 41-bp substitutions were detected between the two parent species, whereas an electropherogram of the hybrid displayed polymorphic double peaks at all of the base positions, along with one additional one, strongly indicating its hybrid state. Meanwhile, sequence comparison of the mitochondrial cytochrome b gene (mt-cyb) (1,140 bp), which has a maternal mode of inheritance, showed only 5-22-bp differences (97.6-99.5% identities) between the hybrid and Pu. herzi, but as many as 158-168-bp differences (85.2-86.1% identities) between the hybrid and Ps. parva, clearly indicating Pu. herzi as the maternal species. Thus, combined analyses of independent data sets (i.e., morphology and nuclear and mitochondrial DNA sequences) offered convincing evidence for the hybrid state of a naturally occurring hybrid resulting from intergeneric mating between a female Pu. herzi and a male Ps. parva.

Occurrence of longtail tuna (Thunnus tonggol) juvenile in Korean waters (백다랑어 (Thunnus tonggol) 치어의 국내 출현)

  • Yoon, Sang Chul;Choi, Kwang Ho;Jeong, Yeon Kyu;Lee, Dong Woo;Ryu, Jung Hwa
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.49 no.4
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    • pp.500-504
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    • 2013
  • A total of 24 juvenile specimens of Thunnus tonggol (5.45~7.26mm in total length) of the Sombridae were collected from the southeast sea of Jeju Island during 26~30 July, 2013. Twenty-four specimens identified T. tonggol have melanophores distributed on the 1st dorsal-fin rays, the dorsal of head and vetral side. Three individulas were identified using mitochondrial DNA cytochrome oxidase submit 1 (CO1) sequences (452 base pairs). All were identified as T. tonggol, their mtCO1 sequences being consistent with those of Thunnus tonggol (d=0.000), followed by Thunnus albacares (d=0.002) and Thunnus obesus (d=0.007).

Genetic Structure and Phylogenetic Relationship of Red Spotted Grouper (Epinephelus akaara) Based on the Haplotypes and Polymorphisms of Mitochondrial COI Gene Sequences (미토콘드리아 COI 유전자 서열의 다형성과 반수체형에 근거한 한국산 붉바리(Epinephelus akaara)의 유전적 구조와 계통 유연관계)

  • Han, Sang-Hyun;Lee, Young-Don;Baek, Hae-Ja;Oh, Hong-Shik;Noh, Choong Hwan
    • Journal of Life Science
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    • v.24 no.6
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    • pp.626-632
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    • 2014
  • The genetic structure and phylogenetic relationship were investigated in Korean red spotted grouper populations using the nucleotide sequence polymorphisms of the mitochondrial DNA (mtDNA) cytochrome c oxidase subunit I (COI) gene. The COI gene was sequenced showed 99.1-99.8% identity with the EF607565 sequence previously reported. A total of twenty haplotypes were found, and the Korean population showed nineteen haplotypes. Among those, Hap_03 and Hap_08 showed Jeju-do and China-specific COI sequences, respectively. However, Hap_07 had twelve COI sequences from South Korea and records from Hong Kong and Taiwan. Neighbor-joining (NJ) trees constructed from the phylogenetic analyses based on the polymorphisms of the COI haplotypes showed a monophyletic branching pattern within the genus Epinephelus. This indicated that the red spotted grouper populations had evolved from common maternal ancestors. In addition, the Hap_08, which had the COI sequence recorded only from China Sea, was found in the middle of the NJ tree nearby Hap_07 and showed a close relationship with Hap_07. This indicates that Chinese red spotted grouper is also maternally related to other populations in East Asia. Consequently, East Asian red spotted grouper populations are maternally related, as well as sharing the same evolutionary history, and are still affected by the East Asian ocean current (Kuroshio). These findings help to explain the genetic structure and phylogenetic relationship of red spotted grouper and also contribute to research on artificial breeding and industrialization.

Offshore CCS Plant Technology for 3Mt-CO2 Storage (연간 300만톤급 온실가스 감축을 위한 해양 CCS 플랜트 기술)

  • Huh, Cheol;Kang, Seong-Gil;Lee, Keum-Suk;Park, Young-Gyu
    • Transactions of the KSME C: Technology and Education
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    • v.1 no.1
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    • pp.123-128
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    • 2013
  • Carbon dioxide Capture and Storage (CCS) is one of the key players in greenhouse gas (GHG) reduction portfolio for mitigating climate change. CCS makes it possible not only to reduce a huge amount of carbon dioxide directly from coal power plant but also to maintain the carbon concentrated-energy infrastructure. The objective of the present paper is to review and introduce R&D progress and large scale demonstration plan focused on marine geological storage in Republic of Korea.

Compositions and pollution characteristics of total suspended particles (TSP) at 1100 Site of Mt. Halla (한라산 1100 고지 총부유분진(TSP)의 조성 및 오염 특성)

  • Kim, Won-Hyung;Kang, Chang-Hee;Jung, Duk-Sang;Go, Hui-Jeong;Lee, Won
    • Analytical Science and Technology
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    • v.21 no.4
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    • pp.304-315
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    • 2008
  • The total suspended particles (TSP) collected at the 1100 site of Mt. Halla have shown higher compositions for the anthropogenic components followed by marine and soil originated ones. The concentrations of the soil originated nss-$Ca^{2+}$, Al, Fe, Ca components have been increased in spring, and the anthropogenic $NH{_4}^+$, $K^+$, nss-$SO{_4}^{2-}$ components showed high concentrations in June. Meanwhile, the concentration of $NO{_3}^-$ as same as nss-$Ca^{2+}$ was higher in spring. It's likely due to the influence of its long-range transport from China. Compared to the non-Asian Dust periods, the concentrations of nss-$Ca^{2+}$, Al, Ca, and Fe have been increased 7.2~9.5 times in Asian Dust storm periods, and those of nss-$SO{_4}^{2-}$ and $NO{_3}^-$ were 1.3 and 3.8 times, respectively. From the factor analysis, the TSP compositions were influenced mainly by anthropogenic emission sources, followed by oceanic and soil sources. The backward trajectory analysis has shown that the concentrations of the anthropogenic and soil components were increased when the air parcels had been moved into Jeju island via China in a northwesterly wind.

New Record of the Brassy Trevally, Caranx papuensis (Carangidae, Perciformes) in Jeju Island of Korea (한국 제주 연안에서 채집된 전갱이과(Carangdiae) 어류, Caranx papuensis의 첫 기록)

  • Hyeon-Jeong Kim;Do-Hyun Oh;Jin-Koo Kim
    • Korean Journal of Ichthyology
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    • v.36 no.2
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    • pp.199-206
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    • 2024
  • A single specimen belonging to the family Carangidae was first collected by angling in Seogwi-dong, Seogwipo-si, Jeju-do on 16 October 2023. This individual was identified as Caranx papuensis Alleyne & MacLeay based on morphological traits as following: lateral line gently curving below the first dorsal fin, presence of scaleless area on the thorax, and gill rakers 26. A total of 619 base pairs sequences of the mitochondrial DNA cytochrome c oxidase subunit I region was analyzed, and we found it closely matched to the Japanese C. papuensis (K2P distance=0.54%). We propose its new Korean name "Hwang-jul-jeon-gang-i" based on a yellow band along the lateral line.

A New Species of the Genus Bryocamptus (Copepoda, Harpacticoida, Canthocamptidae) from Alpine Wetlands at Jeju Island, Korea

  • Lee, Jimin;Chang, Cheon Young
    • Animal Systematics, Evolution and Diversity
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    • v.32 no.3
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    • pp.219-229
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    • 2016
  • Material of a Bryocamptus species, formerly reported as B. umiatensis Wilson, 1958 from Sakhalin and South Korea, is here recognized as a distinct new species. Specimens of both sexes were recently obtained from an alpine wetland, Sumeunmulbaengdui, located in the Hallasan National Park, Korea, and newly registered as a Ramsar Wetland in 2015. The new species, B. jejuensis n. sp., differs from the type population of B. umiatensis from Alaska by the smooth margin of the anal operculum in both sexes, the peculiarly modified terminal seta on the distal endopodal segment of the male leg 3, the sword-like spinous seta on the distal endopodal segment of the male leg 4, and the presence of a setule row on the inner distal margin of the caudal rami in the female. Both sexes of the new species are described in detail with particular reference to the male characters. A revised key to the seven species of the genus Bryocamptus Chappuis, 1929 occurring in Korean waters is provided.