• Animal Systematics, Evolution and Diversity
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• 제25권3호
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• pp.215-225
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• 2009

Three harpacticoid species of the family Miraciidae are reported from neritic and brackish waters in Korea: Amphiascus kawamurai Ueda and Nagai, 2005, Schizopera clandestina (Klie, 1924) and Schizopera neglecta Akatova, 1935. Amphiascus kawamurai is newly recorded from Korea. Redescription is provided with the systematic accounts and illustrations of them.

• 한국해양학회지
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• 제15권2호
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• pp.89-99
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• 1980

The major source of nutrients in both the Gamagyang Bay and the Yeoja Bay is mixing. However, water discharges also seem to contribute significant quantities which may influence local phytoplankton growth. Data collected inn the study area shows that natural fluctuations in the environmental conditions of the entire area play a dominant role in determining the phytoplankton populations of the two Bays. The predominating phytoplankton forms are neritic diatom species including some dinoflagellate species in summer. Neritic groups are relatively more abundant in inner areas of the Bays. The oceanic groups and species are seasonal, and associated with advective effects. One neritic species is of overwhelming numerical importance and occurs when a specific seasonal conditions is formed. Species cycles in the two Bays may be regarded as largely the result of successional changes or cycles of autochthonous species introduced by advective processes.

• Ocean and Polar Research
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• 제34권2호
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• pp.219-228
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• 2012

Tintinnid species distribution has been monitored in the northern East China Sea (ECS) in the summer of 2006 through 2011. This is used to understand the water mass movements in the northern ECS. The warm oceanic tintinnid species had largely spread in 2007 in the area, indicating that there was greater warm water extension into the northern ECS. However the extension of neritic water within the Changjiang diluted water mass has strengthened in 2008 and 2010 because the neritic species distribution had relatively grown in both years. These annual results based on the biological indicators of tintinnid species are well matched with the salinity change in the area. The warm oceanic species, Dadayiella ganymedes had frequently occurred over the study years and had shown a significant relationship with the salinity change. This is valuable as a key stone species for monitoring the intrusion of the Kuroshio within the northern ECS. Information from tintinnid biological indicators can support physical oceanography data to confirm ambiguous water mass properties.

• 한국제4기학회지
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• 제8권1호
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• pp.33-42
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• 1994

The study area is filled up by alluvium which can be classified into lower and upper beds by the facies of deposits and their degree of weathering. The lower bed is not of marine but of fluvial. The upper bed is mainly composed of clay and silt or fine sand beds col-ored dark or dark gray which are of neritic or brackish yielding mollusca fossils. The oyster(Crassostrea ariakensis) obstained from the depth of 3m below the present sea level in the upper bed was dated at 4,100 110Y.B.P. and the veneridae(Meretrix lamarck) 1m height above the present delta plain in the old sand bar was dated at 1,700 85Y,B,P. It is therfore concluded that the study area a small kern col of terrestri-al basin prior to postglacial age had experienced the Holocene transgression. Consequently the study area is considered to have been progressively formed under neritic or brackish circumstance before 1,700Y.B.P.

• 환경생물
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• 제20권2호
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• pp.118-129
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• 2002

가막만에 출현하는 동물플랑크톤을 계절별(2001년 4 월, 7월, 9월, 12월)로 Norpac 네트를 이용하여 수직 채집하였다. 우점적으로 출현한 분류군은 4월과 12월에 요각류, 7월에 요각류와 지각류, 9월에 야광충이었다. 출현 개체수는 22-17,197 indiv. $m^{-3}$으로 시.공간적으로 변동폭이 매우 컸다. 요각류의 우점종은 4월에 Eurytemora pacifica, Acartia omorii, Centropages abdominalis, Calanus sinicus, 7월에 Labidocera rotunda와 A. erythraea, 9월에 A. erythraea와 Paracalanus parvus s. 1., 12월에 A. omorii와 E. pacifica로 주로 내만종으로 변하였다. 그러나, 9월에 외양종인 Eucalanus sp.와 Neocalnus sp. 또한 다수 출현하였다. 이와 같은 출현 경향은 가막만이 폐쇄성 내만임에도 불구하고 동물플랑크톤의 분포 특성은 내만수 이외에 계절적으로 외만수의 영향을 강하게 받고 있음을 암시하고 있다.

• 자원환경지질
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• 제11권1호
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• pp.21-37
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• 1978

The depositional environment of the Manhang and the Geumcheon Formation of the Pennsylvanian Gomog Croup is revealed to the shallow neritic marine milieu in this paper also as the results of Park (1963), Cheong(1975) and Kim (1976), through the analyses of stratigraphy, paleocurrent, properties of cross-beddings and sedimentational features. The formations contains some possible terrestrial sediments suggesting the paralic environment, which are however not recognized definitely within them. The paleocurrent analysis is made to the Manhang Formation only. The paleocurrent of the formation is known to belong to the shallow neritic longshore current. The paleocurrent analysis is based chiefly on the cross-bedding analysis, and subordinately on the texture of elastic coarse sediments. The paleocurrent mean is determined to $269^{\circ}$, that is, from east to west, of which direction is interpreted to the right angle to the slope of the basinal depository plane and also the parallel with die depositional strike, according to Klein (1960) and Selley's (1968) criteria. The variance value of paleocurrent directions of the Manhang Formation in the whole area studied is 6,374, and the values range from 3,394 to 6,957 according to the dirstricts. The paleocurreut pattern of the whole area shows polymodel, and the patterns in each district range from trimodel to quadrimodel. Those models approach to the shallow marine or paralic model of Tohill and Picard (1966), Picard and High (1968 a), Pisnak (1957) and Pettijohn (1962). The mean value of maximum inclinations of cross-beddings of the whole area is $19.9^{\circ}$ with the standard deviation of 8.4, and ranges from $15.6^{\circ}$ to $21.7^{\circ}$ in the districts. Comparing the histogram showing the frequency distribution of the maximum inclinations of cross-beddings of the Manhang Formation with the Pettijohn's (1962) histogram, it is found that the model approaches to his marine model. The Pennsylvanian Gomog Group of the coalfield is considered to have had been deposited in the pseudogeosynclinal zone on the plateau by the transgression of the Tethyan sea caused by the epirogenic movements during the Pennsylvanian Period.

• 한국수산과학회지
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• 제56권1호
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• pp.54-65
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• 2023

Effect of environmental factors on the seasonal variations of zooplankton communities was investigated in the semi-closed Yeoja Bay, Korea from February, April to August, and November 2021. Out of a total 49 species of zooplankton were collected with a predominant of neritic copepods (mainly Paracalanus orientalis, Acartia omorii, Acartia ohtsukai, Centropages abdominalis, Ditrichocorycaeus affinis, and Oithona sp.), accounting for 58.9% of the total abundance of zooplankton. The diversity indices indicated a relatively highest in July, suggesting that diversity is influenced by seasonal temperature, N. scintillans, and neritic copepods species. A cluster analysis with non-metric multidimensional scaling revealed four groups of zooplankton communities. The February sample clustered into Group A, having the lowest mean total abundance and species diversity of zooplankton, consisting mainly of N. scintillans located the whole region. Cluster Group B from the spring season (April to May) and contained the species diversity with some neritic copepods. Cluster Group C from the summer season (June to August) mainly comprised P. orientalis, A. ohtsukai, Oithona sp., and hydromedusae. Cluster Group D from the autumn season (November) mainly comprised P. orientalis, Temora discaudata. Redundancy analysis indicated that abundance is positively correlated with temperature, salinity, and pico chlorophyll-a concentrations. This study showed that planktonic larvae (such as branchyura larvae) and some copepods (including A. omorii, A. ohtsukai, C. sinicus, and C. abdominalis) were significantly vulnerable to zooplankton community of temperature, salinity, and pico chlorophyll-a concentrations.

• 자원환경지질
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• 제45권4호
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• pp.407-429
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• 2012

도미분지에 위치한 도미-1공과 소라-1공을 대상으로 와편모조류 미화석, 유기물상 분석 및 탄성파자료 해석을 통한 지층대비의 방법으로 연구지역의 층서와 고환경을 해석하고, 그 결과를 일본 북서 큐슈지역의 기존 연구결과와 비교하였다. 생물상변화를 토대로 상부에서부터 Ecozone A, Ecozone B(Barren zone), Ecozone C, Ecozone D(Barren zone)로 각각 4개의 생태층서대로 나누었다. 표준화석에 의한 지질시대는 2개 시추공 모두 하부로부터 에오세 - 올리고세, 마이오세, 플라이오세 - 플라이스토세 시기로 나타났다. 유기물상에 의한 고환경은 상부에서 시작하여 다음과 같이 5개로 나누었다; Association I(Inner neritic), Association II(Freshwater), Association III(Inner neritic), Association IV(Freshwater), Association V(Swamp). 두 개의 시추공 자료를 토대로 일본 측 생층서 자료와 비교 한 결과, Heteraluacacysta campanula, Tubiosphaera galatea 등의 에오세 - 올리고세 표준화석이 양측 연구 모두 동일하게 나타나고, 두 지역의 군집조성이 유사함을 확인하였다. 이는 도미분지와 일본의 북서 큐슈 지역의 고제3기층 발달사에 서로 연관성이 있음을 시사한다.

• 한국해양학회지:바다
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• 제15권4호
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• pp.176-183
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• 2010

본 연구는 대한해협에서 유종섬모충류의 종조성과 시간적 변동 양상을 파악하기 위하여 2007년 1월부터 12월까지 2개 정점에서 17회에 걸쳐서 수행되었다. 조사기간 동안 출현한 유종섬모충류는 총 22속 51종으로 연안종과 외양종은 각각 9속 27종과 14속 24종이 관찰되었으며 정점 간 종조성의 차이가 있었다. 정점 1에서는 연안종의 출현이 우세하였던 반면에 정점 2에서는 외양종이 우세하였다. 계절별로 동계와 춘계에는 연안종이, 하계와 추계에는 외양종이 비교적 많이 출현하였다. 출현빈도에 따른 최우점종인 Stenosemella nivalis와 S. pacifica은 연안종으로써 전 조사기간에 걸쳐서 출현하였으며, Acanthostomella norvegica, Amphorellopsis acuta, Epilpocyloides ralumensis, Protorhabdonella curta 등 많은 외양종들은 33 psu 이하 저염기와 $24^{\circ}C$ 이상 고수온기인 7월~10월에 집중적으로 출현하였다. 유종섬모충류의 현존량은 0~1,845 cells $L^{-1}$의 범위를 보였으며, 저염 및 고수온기인 하계와 추계에 높은 현존량을 보였고 정점 l에서 정점 2에 비해 높았다. 직접상관분석 및 다중회귀분석결과, 유종섬모충류(특히, 외양종)는 전반적으로 식물플랑크톤(엽록소-a) 보다는 수온 및 염분과 유의성 있는 상관성을 보였으며, 수온과 염분이 현존량 분포에 영향을 주는 중요한 환경요인임을 암시하였다. 본 연구결과 연구해역의 복잡한 해황이 유종섬모충류 현존량 및 종 조성 분포에 중요한 영향을 주었던 것으로 판단된다.

• Journal of the korean society of oceanography
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• 제34권3호
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• pp.144-150
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• 1999

Slope sedimentation on the modern west Florida continental margin is controlled by pelagic carbonate accumulation and off-shelf sedimentation of neritic carbonates and terrigenous fines. Production and deposition of pelagic carbonates by planktonic foraminifera and coccoliths have played a significant role in the total slope sedimentation and are mainly promoted by sea-surface productivity. Organic carbon data reflect the relatively high biological productivity in surface waters, indicating high accumulation of biogenic calcareous sediments. The surface-water productivity in the study area is supported by the relation among microfossil assemblages, carbonate mineralogy and sedimentary organic carbon.