• Journal of Ecology and Environment
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• 제37권4호
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• pp.225-229
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• 2014

Feeding behavior of Temora turbinata was investigated through laboratory experiments with special emphasis on its food preference and consequent clearance rate on diatom and microbial components given as common natural food assemblage of coastal area (Uchiumi, Uwa Sea, Japan). Among available prey items, T. turbinata showed the highest clearance rate for Thalassiosira spp. ($0.23{\pm}0.08L\;Temora^{-1}day^{-1}$) followed by Chaetoceros spp. ($0.11{\pm}0.03L\;Temora^{-1}day^{-1}$), but clearance rates for other diatom, Nitzschia spp. was lower (0.03 to $0.07L\;Temora^{-1}day^{-1}$). Bacterial abundances showed no response against 24-h feeding of T. turbinata. Feeding of T. turbinata on heterotrophic nanoflagellates (HNF) was apparent when clearance rates of T. turbinata on diatoms were relatively low, but T. turbinata did not consume HNF as well as ciliates with Thalassiosira spp. of which clearance rate was highest. The results suggest that HNF and ciliates are possible supplementary prey item for T. turbinata, but their contribution as food sources can be limited by the presence of other prey items such as preferable diatom species.

• Ocean Science Journal
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• 제43권2호
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• pp.67-79
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• 2008

We investigated the relationship between mesoscale spatial distribution of environmental parameters (temperature, salinity, and sigma-t), chlorophyll-a concentration and mesozooplankton in the Yellow Sea during May 1996, 1997, and 1998, with special reference to Yellow Sea Bottom Cold Water (YSBCW). Adult calanoid copepods, Calanus sinicus, Paracalanus parvus s.l., Acartia omorii, and Centropages abdominalis were isolated by BVSTEP analysis based on the consistent explainable percentage (-32.3%) of the total mesozooplankton distributional pattern. The copepods, which accounted for 60 to 87% of the total abundances, occupied 73-78% of the copepod community. The YSBCW consistently remained in the northern part of the study area and influenced the spatial distribution of the calanoid copepods during the study periods. Abundances of C. sinicus and P. parvus s.l., which were high outside the YSBCW, were positively correlated with the whole water average temperature (p<0.01). In contrast, the abundances of C. abdominalis and A. omorii, which were relatively high in the YSBCW, were associated with the integrated chl-a concentration based on factor analysis. These results indicate that the YSBCW influenced the mesoscale spatial heterogeneity of average temperature and integrated chl-a concentration through the water column. This consequently affected the spatial distribution pattern of the dominant copepods in association with their respective preferences for environmental and biological parameters in the Yellow Sea during spring.

• 생태와환경
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• 제57권2호
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• pp.111-122
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• 2024

Zooplankton biomass is essential for understanding the quantitative structure of lake food webs and for the functional assessment of biotic interactions. In this study, we aimed to propose a biomass (dry weight) estimation method using the body length of cyclopoid copepods. These copepods play an important role as omnivores in lake zooplankton communities and contribute significantly to biomass. We validated several previously proposed estimation equations against direct measurements and compared the suitability of prosomal length versus total length of copepods to suggest a more appropriate estimation equation. After comparing the regression analysis results of various candidate equations with the actual values measured on a microbalance-using the coefficient of variation, mean absolute error, and coefficient of determination-it was determined that the Total Length-DW exponential regression equation [W=0.7775×e^2.0183L; W (㎍), L (mm)] could be used to calculate biomass with higher accuracy. However, considering practical issues such as the morphological similarity between species and genera of copepods and the limitations of classifying copepodid stages, we derived a general regression equation for the pooled copepod community rather than a species-specific regression equation.

• Journal of the korean society of oceanography
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• 제39권1호
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• pp.1-13
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• 2004

The Yellow Sea Warm Current (YSWC) and the Yellow Sea Cold Bottom Water (YSCBW) are two protruding features, which have strong influence on the community structure and distribution of zooplankton in the Yellow Sea. Both of them are seasonal phenomena. In winter, strong north wind drives southward flow at the surface along both Chinese and Korean coasts, which is compensated by a northward flow along the Yellow Sea Trough. That is the YSWC. It advects warmer and saltier water from the East China Sea into the southern Yellow Sea and changes the zooplankton community structure greatly in winter. During a cruise after onset of the winter monsoon in November 2001 in the southern Yellow Sea, 71 zooplankton species were identified, among which 39 species were tropical, accounting for 54.9 %, much more than those found in summer. Many of them were typical for Kuroshio water, e.g. Eucalanus subtenuis, Rhincalanus cornutus, Pareuchaeta russelli, Lucicutia flavicornis, and Euphausia diomedeae etc. 26 species were warm-temperate accounting for 36.6% and 6 temperate 8.5%. The distribution pattern of the warm water species clearly showed the impact of the YSWC and demonstrated that the intrusion of warmer and saltier water happened beneath the surface northwards along the Yellow Sea Trough. The YSCBW is a bottom pool of the remnant Yellow Sea Winter Water resulting from summer stratification and occupy most of the deep area of the Yellow Sea. The temperature of YSCBW temperature remains ${\leq}{\;}10^{\circ}C$ in mid-summer. It is served as an oversummering site for many temperate species, like Calanus sinicus and Euphaisia pacifica. Calanus sinicus is a dominant copepod in the Yellow Sea and East China Sea and can be found throughout the year with the year maximum in May to June. In summer it disappears in the coastal area and in the upper layer of central area due to the high temperature and shrinks its distribution into YSCBW.

• Ocean and Polar Research
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• 제23권3호
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• pp.245-253
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• 2001

To investigate the community structures and the their seasonal variation of phytoplankton and zooplankton, a study was conducted at 6 selected stations during the period from April 1999 to October 2000 in the marine ranching ground off Tongyeong. One hundred ninety species of phytoplankton were identified, including 146 diatoms, 38 dinoflagellates, 4 silicoflagellates and 2 euglenophytes. Phytoplankton standing crops varied extensively by months and stations, ranging from $3.0{\times}10^4\;cells/l\;to\;1.0{\times}10^6\;cells/l.$. The dominant species varied from the vertical distribution as well as seasonal changes. In April and July 1999, Skeletonema costatum and Ceratium fusus were predominant in both the surface and the bottom water columns. Leptocylindrus danicus was the dominant species in April and June 2000, and Thalassiosira spp. were also predominant in bottom waters in June 2000. Pseudonitzschia pungens and Chaetoceros spp. were the dominant species at both surface and near bottom waters in August and October 2000, respectively. Zooplankton abundance was comparatively high in April and July in 1999, and April, June, and October in 2000, but extremely low in November 1999. The density of dominant zooplankton was higher in 2000 than in 1999. Copepods were the most predominant group except for July 1999 when the bivalve larvae showed extremely high abundance. Acartia omorii and Oithona similis were the dominant or subdominant copepod species mainly in April 2000, and June/July, while O. davisae and O. plumifera had peaks in August and October 2000. Corycaeus affinis and Paracalanus sp. also showed higher peaks in April and June (or July), even though they occurred in all sampling time. Centropages abdominalis occurred abundantly only in April 1999. Oikopleura dioica, a gelatinous zooplankton, was another important zooplankton, showing high density in all samples except in July 1999.

• 한국해양학회지
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• 제28권1호
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• pp.24-34
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• 1993

동물플랑크톤의 계절별 분포 특성을 파악하기 위하여 황해 중동부해역을 대상으로 1987년 4월부터 1988년 6월까지 두달 간격으로 조사를 실시하였다. 이 기간중 총 18속 24종의 동물플랑크톤이 동정 되었게, 이중 12속 17종이 요각류였다. 출현한 동물플랑 크톤중 Noctiluca scintillans가 연안역 정점에서 계절에 따라 전체 동물플랑크톤 군 집에 큰 영향을 미쳤으며, 일부 요각류의 분포를 배제하는 것으로 사료되었다. 동물플 랑크톤 출현양의 30-60.4%를 차지하는 요각류 군집 개체수의 계절별 변화양상은 연안 역 정점이 외해역 정점보다 생태환경의 다양함을 보여주었다. 요각류중 Acartia omorii가 4월과 6월에 Paracalanus parvus가 8월부터 12월까지, Corycaeus affinis가 12월에 각각 우점종으로 출현하였다. 난류 지표중인 Sagitta enflata가 8월부터 12월 까지 조사 해역에 출현하여 본 해역에 대한 난류의야 향을 시사하였으며, 이러한 측면 에서 난수성인 Doliolum sp. 의 10월의 다량 출현도 의미있는 결과였다. 동물플랑크톤 에 대한 종조성 및 양적 분포의 계절적 특성은 수괴의 계절적 변화에 따라 영향을 받 는 것으로 나타났다.

• Ocean and Polar Research
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• 제41권3호
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• pp.135-145
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• 2019

We investigated the mass occurrence of the salp Salpa fusiformis during spring in the southern waters of Korea and the northern East China Sea. Abundance of S. fusiformis and dominant taxonomic groups including copepods, ostracods, euphausiids, and appendicularian was examined along with environmental factors (e.g., temperature, salinity, and chlorophyll-a concentration). The abundance of S. fusiformis at 27 stations ranged from 0 to $183\;inds\;m^{-3}$. Both aggregate and solitary forms of S. fusiformis occurred with a mean abundance of $62\;inds\;m^{-3}$ and $4\;inds\;m^{-3}$, and mean body length of 6.5 mm and 15.4 mm, respectively. Redundancy analysis showed that the abundance of S. fusiformis was negatively correlated with chlorophyll-a concentration, indicating the intensive grazing impact of S. fusiformis on phytoplankton. While the abundance of S. fusiformis increased, the species diversity of zooplankton community decreased. The abundances of total copepods and the dominant copepod species (e.g., adults and/or copepodites of Paracalansus parvus s.l., Calanus sinicus, Oithona similis, and Corycaeus affinis) also decreased with the increase of S. fusiformis abundance. However, the abundance of ostracods, euphausiids, and appendicularians was not affected by the mass occurrence of the salps. These results suggest that the mass occurrence of S. fusiformis in spring could negatively affect ecosystem conditions by changing trophodynamics in the zooplankton community.

• 생태와환경
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• 제45권3호
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• pp.278-288
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• 2012

팔당호에서의 동물플랑크톤 군집 구조와 천이는 몬순기후에 의한 강우사상의 변화와 수리 수문학적 요인의 영향을 크게 받았다. 봄과 가을, 겨울 동안에는 강우량이 적은 평수기 혹은 갈수기로 팔당호의 수리학적 체류시간이 길어짐에 따라 수체가 안정되어 동물플랑크톤 군집 변화는 온대호수에서의 계절적인 천이 과정을 그대로 반영하였다. 봄철에 크기가 작고 세대교번이 빠른 윤충류가 급속히 증가하여 연중 최대 개체수를 나타냈으며, 이후 몸체가 큰 요각류와 지각류로 천이되었다. 봄에는 윤충류가 우점하여 점유율이 90% 이상으로 나타났으며 제1우점종은 Keratella cochlearis였다. 요각류는 주로 유생(Copepodid, Nauplius)의 형태로 존재하였으며 지각류는 Bosmina longirostris가 주로 출현하였다. 여름에는 집중호우의 영향으로 수체가 교란되고 팔당댐의 수문조작에 따른 방류량 증가로 동물플랑크톤이 하류로 떠내려가 동물플랑크톤 개체수는 급감하였다. 집중호우 이후 수체가 안정화됨에 따라 동물플랑크톤 군집 회복은 성장이 빠른 윤충류를 위주로 이루어졌으며 가을 이후 수온 변화에 따라 동물플랑크톤 군집 밀도가 점차 감소하고 겨울에는 요각류 유생(Copepodid, Nauplius)의 우점 비율이 증가하였다. 불완전한 개방형 생태계를 이루고 있는 팔당호의 특성상 동물플랑크톤 군집 변화는 기상 변화와 수리 수문학적 요인에 크게 영향을 받고 있었으며, 특히 여름에는 국지성 집중호우의 빈도와 수량에 따라 동물플랑크톤의 군집 변화가 크게 좌우되었다.

• Ocean and Polar Research
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• 제31권2호
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• pp.199-212
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• 2009

The community structure of meiofauna was surveyed from six stations in sand mining area near around Sungapdo, Taean five times from April-December, 2007. Ten meiofaunal taxa in total, comprising 5-9 taxa per station were recovered. Nematodes were dominant from four stations in April and from five stations in May. In June, copepods were dominant from all stations except station two, from which sarcomastigophorans were predominant. Copepods were also dominant from three stations in October and four stations in December. The mean density of meiofauna per $10\;cm^{-2}$ was the highest in October (130 individuals) and lowest (68 individuals) in April. Meiofauna mean biomass per $100\;cm^{-2}$ was $3.80-75.26{\mu}gC$ from each station, with the monthly mean biomass being lowest in April ($11.97{\mu}gC$) and highest in October ($39.50{\mu}gC$). The highest biomass was recorded at station five in October ($75.26{\mu}gC$). Eleven families of harpacticoid copepods occurred Ameiridae and Ectinosomatidae were the most frequent. The mean diversity index was 1.21 from all the stations, 1.22 from the sand mining stations, and 1.19 from the reference stations. The nematode:copepod (N/C) ratio was 1.57 from the sand mining stations and 1.37 from the reference stations. Non-metric multidimensional scaling analysis divided the community into group A (station one, non-sand mining and reference area) and groups B and C in the sand mining area. The present study reports similar numbers of taxa but lower density and biomass of meiofauna compared to previous studies in Korean waters. The variability of the diversity index and N/C ratio may indicate large fluctuation of meiofauna depending on temporal and spatial conditions of the environment in the study area.

• 한국해양학회지:바다
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• 제7권2호
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• pp.51-59
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• 2002

섬진강 하구역에서 염분 경사에 따른 동물플랑크톤의 종 조성과 양적 분포를 계절별로 조사하였다. 하구역이라 하나 전 계절 연안역에서 흔히 볼 수 있는 종들이 주를 이루고 있었으며, 전 계절 담수 유래종은 매우 미약하였다. 평균 총량으로 봄에 3,000 개체/m$^3 $이상의 많은 개체수가분포하며 여름에 다소 감소하나 여전히 많은 개체수 분포를보이고 가을에 약 500 개체/m$^3$수준으로 감소하였다가 겨울부터 증가하는 계절적 변동을 보였다. 염분 범위에 따라 저염분역(염분 5 psu이하), 중염분역(5~18 psu), 고염분역(18 psu 이상)으로 나누어 살펴보면, 계절의 진행에 따라 가장 많은 양의 동물플랑크톤이 출현하는 염분역이 일정하게 유지되지 않고 있으며, 종 조성에서도 계절별 지역별로 차이를 보였다. 가을철에는 요각류가 저염분역에서 우세하나 고염분역으로 가면서 갑각류 이외의 종들이 우세하였고, 겨울철에는 전 지역에서 요각류가 우세하였다. 봄철에는 대상 해역이 중염분역과 고염분역으로만 구분되었는데, 중염분역에서는 요각류, 고염분역에서는 야광충이 우점하였다. 여름철에는 저염분역에서는 요각류가, 중염분역과 고염분역에서는 야광충이 더 많았다. 요각류 군집만을 대상으로 염분 구역별 주요 우점 종을 열거하였고, 이들의 출현수온, 염분 범위와 가장 많은 출현량을 보인 지역의 수온 염분을 제시하였다. 이들 요각류의 염분 내성 범위는 매우광범위하게 나타나 지시종의 개념이 요각류에 있어서는 출현 유무라는 정성적인 개념보다는 양의 많고 적음이라는 정량적인 개념에서 사용되어져야 할 것으로 여겨졌다.이 맞닿는 지역으로 Sternaspis scutata가 가장 우점하였다. 과거의 연구와 비교해 보면, 저서다모류군집은 출현종수, 서식밀도와 우점종에 있어서 큰 변화를 보였다. 과거의 조사결과에서는 우점종이 Sternaspis scutata와 Eteone longa이었으나, 본 조사에서는 이 종들의 서식밀도가 감소하였다. 반면에 잠재적 유기물 오염 지시종으로 알려진 Lumbrineris longifolia와 Heteromastus filiformis가 서식밀도는 낮지만 새롭게 우점종으로 대두하였다. 이러한 사실들로 볼 때, 득량만은 한국의 다른 만들과는 달리 아직까지 오염이 덜한 해역인 것으로 사료되나, 환경관리에 주의를 요하는 것으로 판단된다. 공간분포는 다양한 무기 환경 요소들 가운데 일차적으로 저층수의 염분에 의해 영향을 받으며, 이차적으로 퇴적상에 의해 영향을 받고 있음을 알 수 있다.한 결과, $CH_4$ 농도의 증가율이 무안과 태안 지역에서 각각 연간 16.5, 14.8 ppb로 가장 높게 관측되었다. 관측점 주변에 복잡한 배출원의 작용이 가능하다는 점을 감안하여, 무안지역의 $CH_4$ 농도변화와 풍향과의 연계성을 비교해 보았다. 이 결과에 의하면, 동풍계열의 풍계가 나타날 때 고농도의 값이 나타났으며, 청정한 공기가 유입되는 남서풍의 풍계시에는 비교적 낮은 $CH_4$ 농도가 유지되었다. 이처럼 $CH_4$의 장주기적 분포특성은 연구대상지역의 복잡한 배출${\cdot}$소별작용과 연계되어 매우 다양하고 독특한 형태를 띠고 있음을