• 한국수산과학회지
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• 제56권5호
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• pp.684-690
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• 2023

This study was conducted bimonthly from February to December 2021 to reveal the ecology of Sargassum thunbergii in the intertidal zone along the coasts of Korea. Separate surveys on the period of embryo formation were conducted from February 2021 to December 2022. The growth of S. thunbergii began to increase in February, reached a maximum in June, and was at a minimum in October. Air vesicles were formed from February to June, April to August, and February to August on the east, west, and south coasts, respectively. Receptacles were observed from April to June on the east coast, but from April to August on the west and south coasts. The earliest release of embryos was observed in late May 2022 on the south coast, followed by early June on the east and west coasts. The average size of leaves, stems, and air vesicles was maximum on the east coast and minimum on the west coast, whereas leaf and internode intervals were maximum on the west coast and minimum on the east coast. Plant length, biomass, and the number of branches showed maximum values in the south coast and minimum values in the east coast.

• 해양환경안전학회지
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• 제13권4호
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• pp.15-19
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• 2007

2006년 8월 경북 연안의 우렁쉥이 앙식장에서 대량폐사가 발생하였다. 폐사 원인을 규명하기 위하여 폐사 직후 폐사가 발생한 양식장을 대상으로 수질환경 조사와 병리학적 조사를 실시하였으나 특이점을 발견하지 못하였다. 그래서 폐사가 발생하기 직전 동해에 영향을 미친 10호 태풍 '우쿵'이 우렁쉥이 폐사에 영항을 미쳤을 것으로 가정하고 태풍 '우쿵' 통과 전후의 해황 자료를 분석하였다. 태풍 우쿵의 영향을 받기 전인 8월 초 중순 동해 연안은 전반적으로 저층 냉수의 용승으로 인하여 수심 10m 이심에서는 $15^{\circ}C$ 이하의 찬물이 존재하고 있었다. 그 후 매풍 '우쿵'의 영향으로 인한 북풍이 약 5일간 지속되면서 수온이 높은 외측의 표층수가 연안으로 밀려와 침강하는 현상(에크만 효과)이 발생하여 우렁쉥이가 매달려 있는 수심 $10{\sim}20m$의 수은이 일시에 $10^{\circ}C$ 이상 상승하여 약 5일간 지속되었다. 2006년 경북 연안의 양식 우렁쉥이는 장기간 냉수에 적응되어 있다가 태풍 '우쿵'의 영향으로 수온이 급상승함에 따른 수온 스트레스로 인하여 대량폐사된 것으로 추정된다.

• 한국패류학회지
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• 제25권2호
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• pp.93-96
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• 2009

Unexpected mass mortality has been one of the drawbacks in front of the stable production of Japanese scallop (Patinopecten yessoensis) on the Gangwon coasts of the East Sea. The preliminary data from our routine observation revealed that the mortality appeared to be related to variation of water temperature in the farming site and the degree of the mortality was dependent on scallop strain. The present study performed to verify the preliminary findings exhibited that the mortality was closely related to daily temperature variation rather than monthly variation. Daily temperature variation was particularly damageable to the scallop during the temperature elevation period. Scallops from hatchery seeds (Chinese strain) were more tolerant against the temperature variation over those from wild seeds. The hatchery scallop gain of the temperature tolerance was probably due to their larval experience to higher temperature in the hatchery as well as their maternal genetic acclimation to upper temperature extreme of the Chinese environment which was recently found.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 1996년도 수산관련공동학술대회발표요지집
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• pp.299-303
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• 1996

• 한국지형학회지
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• 제25권4호
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• pp.21-35
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• 2018

The distribution and size of sandy beaches along eastern Korea has a close relationship with the presence of granite rocks. In general, elongated and wide beaches with abundant sands are likely to develop along the coasts where granitic basic rocks comprise the dominant geology or where a large amount of sands are supplied by streams from inland granitic rocks. Small sandy beaches, in contrast, appear in non-granitic rocks (i.e., under sedimentary and/or metamorphic geology). Hence, large beaches are observed continuously along the shore of Gangwon-do, of which coasts consist predominantly of granitic geology. Such continuity declines from Samcheok city to Pohang city. The rock of Gyeonbuk-do is commonly known as sedimentary, deposited between the late Triassic and the early Tertiary Periods. Because few sands are supplied from the upstream areas, sandy beaches unlikely develop along the coasts of the province, only showing a sporadic, discontinuous distribution under Bulguksa granite, granitic gneiss, and some volcanic rocks. Erosion was rarely observed in the beaches where granitic rocks are distributed, whereas merely five beaches seemed to have undergone some level of erosion in non-granitic regions. This is presumably because a larger amount of sands than that which had been eroded away was replenished in areas under granitic geology, while under non-granitic geology having a deficit in sands, no large sandy beaches had formed at first.

• 대한원격탐사학회지
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• 제37권1호
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• pp.85-95
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• 2021

Recently, as data mining and artificial neural network techniques are developed, analyzing large amounts of data is proposed to reduce the dimension of the data. In general, empirical orthogonal function (EOF) used to reduce the dimension in the ocean data and recently, Self-organizing maps (SOM) algorithm have been investigated to apply to the ocean field. In this study, both algorithms used the monthly Sea level anomaly (SLA) data from 1993 to 2018 around the East Asia Coasts. There was dominated by the influence of the Kuroshio Extension and eddy kinetic energy. It was able to find the maximum amount of variance of EOF modes. SOM algorithm summarized the characteristic of spatial distributions and periods in EOF mode 1 and 2. It was useful to find the change of SLA variable through the movement of nodes. Node 1 and 5 appeared in the early 2000s and the early 2010s when the sea level was high. On the other hand, node 2 and 6 appeared in the late 1990s and the late 2000s, when the sea level was relatively low. Therefore, it is considered that the application of the SOM algorithm around the East Asia Coasts is well distinguished. In addition, SOM results processed by SLA data, it is able to apply the other climate data to explain more clearly SLA variation mechanisms.

• 한국수산과학회지
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• 제21권6호
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• pp.351-360
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• 1988

Based on historic data of monthly means of sea surface temperatures (SST) for 24 years $(1921\~1944) $ at 23 Korean and Japanese coastal stations in the East Sea (the Japan Sea), we analyzed spatio-temporal characteristics of coastal SST and SST anomalies. The means of SST at Korean coast are higher than those at Japanese coast of the same latitudes, and the annual range of SST at Korean coast are larger than those at Japanese coast. Empirical orthogonal function analysis shows that almost all $(96\%)$ of the SST fluctuations are described by simultaneous seasonal variations. The flurtuations of SST anomalies are small in the Korea Strait and large at the boundaries between the warm and told currents in the basin. The fluctuations of SST anomalies along Korean coast are correlated each other The same is true for SST anomalies along Japanese coast. However, there is only weak correlation between the SST anomalies at Korean coast and those at Japanese coast. Empirical orthogonal function analysis shows that $27\%$ of the coastal SST anomalies in the East Sea are described by simultaneous fluctuations, and $12\%$ of them are described by alternating fluctuations between Korean and Japanese coasts.

• Fisheries and Aquatic Sciences
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• 제24권7호
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• pp.243-259
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• 2021

The spatial and temporal behaviors and fluctuations of the cold water that appeared in the South East Sea and the East Sea coast from 2016 to 2017 were investigated. The water temperature drop was large in the east coast from April to June and the southeast coast from July to September, and the temperature drop period was longer in the southeast coast. The water temperature fluctuated sensitively to the wind direction, and it gradually decreased in the southwest wind but rose as if jumping in the northeast wind. Wind stress and surface water temperature had an inverse correlation, which was larger in Bukhang-Idukseo, and decreased toward the north of Guryongpo. The cold water appeared mainly in Geojedo-Pohang after 1 to 2 days when the southwest wind was strong, but when the wind became weak, it shrank to the Idukseo (Ulgi-Gampo) and extended into the open sea in a tongue shape. Cold water was distributed only in Samcheok-Toseong in mid-May, Idukseo-Guryongpo and Hupo-Jukbyeon-Samcheok from late May to mid-July, and Bukhang-Idukseo in August-September. The intensity of cold water was greatest in mid-August, and the center of cold water descended from the east coast to the southeast coast from spring to summer. The water temperature fluctuation was dominant at the periods of 1 d and 7-21 d. In wavelet spectrum analysis of water temperature and wind, wind speed increase-water temperature decrease showed phase difference of 12 h in 2 d, 18 h in 3 d, 1.5 d in 4-8 d, and 2-3 d in 8-24 d period. The correlation between the two parameters was large in Geojedo and Namhang, Bukhang-Idukseo, Guryongpo-Jukbyeon, and Samcheok-Toseong. Monitoring stations with high correlation in all periods were generally parallel to the monsoon direction.

• ALGAE
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• 제21권1호
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• pp.49-59
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• 2006

A total of twenty one species of marine macro-algae were reported from 460 kms long Orissa coast in the east coast of India. Of these 9 species belongs to Chlorophyta, 2 to Phaeophyta and 10 to Rhodophyta. The low species richness compared with southern and western coasts of India was due to lack of rocky and/or coral substratum. Enteromorpha usneoides and Gelidium divaricatum were reported first from India. Enteromorpha linza, E. clathrata, Colpomenia sinuosa, Dictyota dichotoma, Catenella impudica, Compsopogon aeruginosus and Grateloupia lithophila were the new records for Orissa coast.

• 생명과학회지
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• 제9권3호
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• pp.262-267
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• 1999

Mitochondrial DNA (mtDNA) polymorphism of the blue mussel (Mytilus edulis) species complex sampled from the east coast of Korean was studied using a partial sequence of COIII gene (336 bp). Samples obtained from three localities on the east coast of Korea revealed four haplotypes with two clearly differentiated mitochondrial clades (termed clades B and E), separated by 4.2% of minimum sequence divergence. This pattern indicates no difference between east and south coasts of Korea. According to population genetic theory on evolutionary characteristics of mtDNA, we concluded that mtDNA introgression from M. edulis to M. gallprovincialis might be a source for mtDNA polymorphism found in mussels on the east coast of Korea.