• 한국해양학회지
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• v.20 no.3
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• pp.1-5
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• 1985

Seasonal variations of heat content in the neighbouring seas of Korea are estimated from the bimonthly normals of seawater temperature in the upper 300m for 15 years (1961~1975) at 192 stations. The heat is seasonally stored mainly in the upper 100m layer in the East Sea and in the whole water column in the West and South Seas of Korea. The annual range of heat content changes in the West Sea is almost the same as that in the East Sea. The annual phase of heat content variation lags behind that of sea surface temperature variation by one to three months. Due to the seasonal advections of heat by currents and winds, the annual amplitude of heat storage rate in the neighbouring seas of Korea is much larger than that of incoming radiation.

• The Korean Journal of Zoology
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• v.31 no.4
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• pp.327-333
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• 1988

계절에 따른 초파리 집단내 역위다형 현상의 변동상을 알기 위하여 전주근교의 과수원에서 1983년 1월부터 11월까지 격월로 여섯번 채집한 집단 표본을 분석하였다. 총 1071마리에서 얻은 15개형의 역위는 모두 편동원체역위(paracentric inversion)였으며, 이 중 7개형은 세계형91위(cosmopolitan inversion)였고, 나머지 8개형은 지역형역위(endemic inversion)였다. 개체당 역위의 평균 보유수는 0.639이고 역위를 보유한 개체의 빈도는 0.465였다. 7개의 세계형역위에 대한 표본집단을 분석한 결과 격월 집단간에서 유의한 차이를 보이는 반면 1월과 1 1월 표본간에서는 그 성황이 오히려 비숫해짐으로서 집단내 총역위빈도는 주기적으로 변동하고 있음이 암시된다. 역위와 환경변수와의 다중상관분석에서는 기온, 습도, 강수량이 역위빈도에 유의한 영향을 미치는 것으로 나타났고 역위 중 In(2L)t가 상기한 환경변수 모두에 대하여 유의한 상관관계를 보인 반면, In(3R)C와 In(3R)P는 어느 것과도 상관성을 보이지 않았다. 염색체내 그리고 염색체간의 연관 또는 조합의 검정결과 연관불평형혈상을 1월, 5월, 그리고 7월 표본의 제3염색체에서, 그리고 비균일조합은 1월과 7월 표본에서 역시 제3염색체에서만 산출 되었다. Seasonal changes of inversion frequencies in Chonju 0. melanogaster populations were studied. A total of 1071 males were collected six times with ho months intewal from January through November in 1983. to analyse diploid sets of chromosomes carried by males, each male was mated to several virgin females homoBvgous for cytologically standard sequence in all chromo-somes. From each mating, more than seven FL larvae were selected in random and tested to find chromosomal aberrations. In the present study, 15 different inversions were found and identified to be paracentric only In both second and third chromosomes; seven were cosmopolitan and the rest eight endemic types. The average frequency of inversions was 0.465 and the mean number of inversions carried by a single male was 0.639. The linkage disequilibria were detected between the leK and right arms of third chromosomes from the samples of January, May and Julv, Whereas nonrandom associations appeared also in the third chromosomes only in January and Julv samples. In multiple regression analysis among frequencies of inversions and environ-mental variables it appeared that mean temperature, relative humidity and total precipitation for a month skipped over 30 days before collected affect to change to frequencies of particular inver-sions. With respect to the behavior of inversions in the present samples, it is suggested, with the Friedman's analysis of variance by ranks of inversion frequency orders, that the frequencies of inversions change cyclically year to year.

• Korean Journal of Ichthyology
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• v.9 no.2
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• pp.235-243
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• 1997

The seasonal changes in species composition of fishes in Kwangyang Bay were determined using bimonthly samples with a bottom trawl at five stations from February to December 1990. A total of 32 families 54 species, 9,497 individuals, and 65,838.2g of fishes were collected. Leiognathus nuchalis occupied 64.9% of the total number of individuals. L. nuchalis and Konosirus punctatus occupied 28.8% and 22.3% of the total biomass, respectively. The number of species, the number of individuals and the biomass were lowest in February. More than 20 species occurred during the period when the water temperature was higher than $12^{\circ}C$. The number of individuals was the highest in October. The biomass was the highest in April. The community structure of fish in Kwangyang Bay showed the seasonal variation according to Leiognathus nuchalis and Konosirus punctatus.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.29 no.1
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• pp.56-76
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• 2024

We for the first time made a successful longest continuous sectional observation in the East Sea by an underwater glider during 95 days from September 18 to December 21 2020 in the Korea along the 106 Line (129.1 °E ~ 131.5 °E at 37.9 °N) of the regular shipboard measurements by the National Institute of Fishery Science (NIFS) and obtained twelve hydrographic sections with high spatiotemporal resolution. The glider was deployed at 129.1 °E in September 18 and conducted 88-days flight from September 19 to December 15 2020, yielding twelve hydrographic sections, and then recovered at 129.2 °E in December 21 after the last 6 days virtual mooring operation. During the total traveled distance of 2550 km, the estimated deviation from the predetermined zonal path had an average RMS distance of 262 m. Based on these high-resolution long-term glider measurements, we conducted a comparative study with the bi-monthly NIFS measurements in terms of spatial and temporal resolutions, and found distinguished features. One is that spatial features of sub-mesoscale such as sub-mesoscale frontal structure and intensified thermocline were detected only in the glider measurements, mainly due to glider's high spatial resolution. The other is the detection of intramonthly variations from the weekly time series of temperature and salinity, which were extracted from glider's continuous sections. Lastly, there were deviations and bias in measurements from both platforms. We argued these deviations in terms of the time scale of variation, the spatial scale of fixed-point observation, and the calibration status of CTD devices of both platforms.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.5
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• pp.439-458
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• 2013

Temporal and spatial variations of water quality were investigated in the Cheonsu Bay of Yellow Sea, Korea from 2010 to 2011. Water samples were collected at 16 stations and physicochemical parameters were analyzed including water temperature, salinity, suspended solids (SS), chemical oxygen demand (COD), dissolved oxygen (DO), Chlorophyll a and nutrients. Spatial distribution patterns of all survey items were not clear among stations but the bimonthly variations were distinct except the bottom water of the suspended solids. The trend analysis by principal component analysis (PCA) during 2 years revealed the significant variations in water quality in the study area. Spatial water qualities were discriminated into 3 clusters by PCA; station cluster in the surface water 1, 2~11, and 12~16, the bottom water 1, 2~7, and 8~16. Annual bimonthly water qualities were clearly discriminated into 3 clusters by PCA. But tend of cluster in the surface and bottom water was difference, period most of the research was low in nutrient. Ecology-based water quality criteria was a good level of grade II. Bimonthly results are shown as III grade(normal) at June and August, II grade(good) at October and December and I grade for February and April. Water quality was showed by the input of fresh water same as those of Kyoungin coastal area, Asan coastal area, Gunsan coastal and Mokpo coastal area in the Cheonsu.

• Korean Journal of Environmental Biology
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• v.22
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• pp.11-29
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• 2004

This study was conducted bimonthly from June 2001 to June 2003 to investigate the seasonal variation of the zooplankton community in Gwangyang Bay, Zooplankton were collected at 9 stations using a NORPAC net from surface layer. The zooplankton community consisted of 47 taxa and the mean abundance was 6,205 inds. $m^{-3}$ during the survey period. The maximum abundance was observed to be 20,060 inds. $m^{-3}$ in June 2002 and the minimum in August 2001 with 630 inds. $m^{-3}$. Copepods were the predominant constituent, wihich comprised 4.6~84.1% (mean 38.2%) of the total zooplankton abundance. Dominant species of copepods were Acartia omorii, Acartia erythraea, Centropages abdominalis, Paracalanus parvus. Paracalanus parvus dominated from June 2001 to December 2002. A red tide causative dinoflagellate, Noetiluca scintillans, dominated from June 2002 to February 2003, Acartia omorii and Centropages abdominalis dominated in winter and spring seasons. While, Acartia erythraea dominated in summer and fall seasons. In June and August, Cladocerans and Cirriped larvae dominated. The abundance of zooplankton according to the tidal cycle showed considerable fluctuations with a range of 2,768~15,856 inds. $m^{-3}$ $(\risingdotseq$ 5.7 times).

• 한국지구과학회:학술대회논문집
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• 2010.04a
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• pp.122-123
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• 2010

2000~2009년 동안 격월로 관측한 수온 관측 자료를 분석하여 표층 수온이 10년 동안 약 $1{\sim}1.9^{\circ}C$ 상승하는 경향을 관찰하였다. 상승폭이 해역마다 약간의 차이를 보이고 있는데 부산해역은 약 $1.5^{\circ}C$, 여수해역은 약 $1.7^{\circ}C$, 제주북부에서도 약 $1.7^{\circ}C$의 상승폭을 보임으로서 남해 동쪽보다는 서쪽해역의 상승폭이 약간 높게 나타났다. 남해 연안수의 평균 수온이 증가하는 추세경향으로 미루어 볼 때 남해 수온전선이 약해지게 되어 결과적으로 연안쪽으로 밀릴 것으로 추정된다. 제주도 모슬포는 약 $1.9^{\circ}C$ 가 상승하였으며 제주도 성산포는 2004~2009년 동안 약 $1.2^{\circ}C$ 상승하는 추세를 보였다. 이와 같은 수온의 변동성은 조위관측소에서 관측된 수온에서도 확인할 수 있는데 부산은 $0.2^{\circ}C$/8년, 여수 $0.4^{\circ}C$/10년, 제주북부는 $1.5^{\circ}C$/10년, 모슬포와 성산포는 $1^{\circ}C$/6년, 서귀포는 $1.7^{\circ}C$/8년 상승폭을 보인다. 조위관측소의 수온 상승폭보다 한국연안해류조사의 수온 상승폭이 약간 높게 나타나고 있는데 이는 관측소의 위치가 해안가에 있는 반면 연안해류조사는 선박을 이용하여 외해쪽에서 수온을 관측하기 때문에 고온 고염의 대마난류(Tsushima Warm Current) 영향을 더 많이 받았기 때문으로 볼 수 있다. 해수의 수온 상승 현상은 증가율이 약간 낮기는 하지만 50m 수심에서도 나타나고 있다. 부산해역, 여수해역, 제주북부 해역은 모두 약 $1.2^{\circ}C$의 상승폭을 보였으며, 제주도 성산포는 약 $1.1^{\circ}C$인 반면, 모슬포 해역에서는 약 $1.5^{\circ}C$로 상승추이가 크게 나타났다. 이와 같이 남해 연안수가 표층과 저층에서 동반 상승했다는 것은 대마난류의 세력이 강해졌다는 것을 보여주는 지시자(indicator)로서 최근 제주도와 남부지방의 기후온난화와 관련이 있을 것으로 추정된다. 하지만 상승률은 관측기간이 길어질수록 작아지는 경향이 있기 때문에 남해의 물리적 특성 변화를 보다 명확히 규명하기 위해서는 좀 더 장기적인 자료가 필요하다.

• Korean Journal of Environmental Biology
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• v.19 no.1
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• pp.25-36
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• 2001

Precent study has been carried out to clarify the ecological characteristics of Tintinnina community, during the period from March,1998 to January, 1999 at twelve stations in lower Seomjin river system. During the surveyed period, a total of 56 species were identified. Seasonal variation of number of species occurred was varied: 43 species during spring season, 21 species during summer season, 27 species during autumn season, 20 species during winter season. Total abundance of Tintinnina ranged from 0 to 170,134 indiv./㎥. The abundance was high in March and low in September. Among 22 dominant species, 18 species (81.8%) were Tintinnopsis genus. The relationships between environmental factors and Tintinnina community were as follows; 11 species (Tintinnopsis rara, T. angulata, T. sp. 1, T. sp. 4, T. sp. 5, T. sp. 8, T. sp. 9, Stenosemella pacifica, S. steini, Codonellopsis nipponica, Favella taraikaensis) occurred from 10 to 15$^{\circ}C$ and 2 species (Codonella amphorella, Leprotintinnus neriticus) occurred from 5 to 3$0^{\circ}C$. Many species occurred from 10.1 to 25.0$\textperthousand$ of salinity. Four species (Tintinnopsis acuminata, T. angulata, T. sp. 10, T. sp. 11) occurred in freshwater only, while four species (Tintinnopsis rapa, T. baltica, T lata, Codonella sp.) occurred from 0.1 to 31.2$\textperthousand$ of salinity.

• Korean Journal of Ichthyology
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• v.34 no.3
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• pp.186-200
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• 2022

In order to understand the species composition and distribution characteristics of larval assemblages in the East Sea, Korea, larvae were collected at 13 stations every other month from February to December 2018. Fish larvae were identified through DNA barcoding along with morphological methods, and as the result, a total of 104 taxonomic groups appeared during the survey. Among these, Engraulis japonicus, which accounted for 76.2% of the total population, was the most dominant species, followed by Maurolicus japonicus, which accounted for 15.0%. In addition, Ammodytes personatus, Champsodon snyderi, Scomber japonicus and Echelus uropterus appeared more frequently than other taxa. The above six species accounted for 93.2% of the total catch. The number of taxa and the amount of larvae collected in the survey area were higher during the high water temperature periods (June to October) than during the low water temperature periods (February, April and December). Analysis of similarity (ANOSIM) showed a statistically significant difference in monthly larval assemblages. The results of the canonical correspondence analysis (CCA) show that the distributions of larval community were mainly affected by sea surface temperature during low water temperature periods, and various environmental factors such as salinity, dry weight of zooplankton, and the concentrations of nutrients during high water temperature periods.