• 한국산학기술학회논문지
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• 제21권7호
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• pp.1-11
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• 2020

2015년 평수기인 5월과 태풍 "두쥐안"이 통과한 직후인 10월 초에 낙동강 하구역에서 동물플랑크톤 군집과 환경특성을 조사하였다. 10월에 출현한 동물플랑크톤 군집의 우점종은 따개비 유생, 유공충류와 야광충이었고, 환경특성은 낙동강 하굿둑 수문개방에 의한 담수유입, 난류수 유입과 태풍통과에 의한 수괴혼합에 의해 영향을 받았다. 반면 평수기인 5월에는 모든 정점에서 저염분 해수가 강하게 분포하여 담수 기인 지각류(Evadne nordmanni, Podon polyphemoides)가 우점하여 분포하였다. 모든 시기에 울타리 섬을 기준으로 내측에서 표층염분이 가장 낮았고, 외측으로 가면서 증가하였다. 10월의 표층과 저층 평균수온이 동일하여, 수괴혼합이 활발함을 지시했고, 부유물질 평균농도는 5월보다 10월에 높았다. 5월의 영양염 농도가 엽록소-a 농도와 함께 10월에 비해 높았다. 그러나 동물플랑크톤 총 평균 개체수는 엽록소-a 농도와 관련된 시기적 차이가 없었으며, 집괴분석결과 동물플랑크톤 분포특성은 모든 시기에 염분분포와 관련되어 세 그룹(울타리 섬 내측, 중간측, 외측)으로 구분되었다. 본 연구결과는 조사시기동안 낙동강 하구역에서 관찰된 동물플랑크톤 군집의 시기적 분포특성이 상향적 조절(영양염-엽록소-a 농도-동물플랑크톤)보다 수문개방에 의한 담수유입, 난류수 유입정도 그리고 태풍통과 기인 수괴혼합과 관련있음을 지시하였다.

• 한국해양학회지:바다
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• 제19권4호
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• pp.265-271
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• 2014

시화호에서 식물플랑크톤 및 섬모충류의 포식자인 중형동물플랑크톤 개체수가 크게 증가하는 하계에 섬모충류의 초식압에 미치는 중형동물플랑크톤의 영향을 파악하기 위해 희석실험과 요각류 첨가 배양 실험을 병행하였다. 희석실험에서 섬모충류는 식물플랑크톤 생산량의 104%를 하루에 소비하였으나, 요각류 Acartia sinjiensis를 첨가한 실험구에서 섬모충류의 초식압은 19%로 크게 감소하였다. 이는 미소형식물플랑크톤의 주요 초식자인 $>20{\mu}m$ 빈섬모충류에 대한 중형동물플랑크톤의 선택적 섭이에 기인하는 것으로, 중형동물플랑크톤에 의해 섬모충류의 개체수가 강하게 지배되는 시기에는 섬모충류의 실제 초식압은 과대평가될 수 있음을 의미한다. 따라서 시화호에서 요각류 개체수가 크게 증가하는 춘계와 하계에는 식물플랑크톤의 초식자로서 섬모충류의 역할은 크게 감소될 것으로 판단되며, 초식자로서 섬모충류의 역할을 더 정확하게 평가하기 위해서는 섬모충류에 대한 중형동물플랑크톤의 포식압을 반드시 고려해야 할 것으로 보인다.

• Journal of the korean society of oceanography
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• 제32권3호
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• pp.145-155
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• 1997

The distribution of microzooplankton and hydrographic variables were measured in the Virginia portion of Chesapeake Bay and its major rivers. Samples were collected at 14 locations at monthly interval from September 1993 through December 1995. Ciliates were numerically dominated (>90%) and copepod nauplii comprised highest proportion of the total microzooplankton biomass (>77%). Copepod nauplii and ciliates were the most abundant at oligohaline water and rotifers at freshwater. Total microzooplankton density and biomass were usually higher at oligohaline stations than fresh water and polyhaline stations. Despite high nutrient concentration and phytoplankton density at eutrophic water, micro- and mesozooplankton biomass were low. Mesozooplankton were relatively abundant at polyhaline stations. The comparison between annual mean biomass of ciliates (12.7 ${\mu$}gC/1) and that of autotrophic picoplankton (13.5 {$\mu$}gC/1) revealed that ciliates were a major consumer of picoplankton production. The secondary production by ciliates was 12.7 ${\mu}$gC/1/day, representing 5% of the annual mean primary production in Chesapeake Bay, Total microzooplankton comprised 84% of the total zooplankton carbon content, representing five times higher than mesozooplankton biomass.

• Animal cells and systems
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• 제2권2호
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• pp.165-176
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• 1998

Seasonal changes in microzooplankton abundance were identified in the mesohaline Chesapeake Bay and several tributaries from July 1992 through December 1995. Ciliates numerically dominated, comprising over 90% of the total microzooplankton density and aloricate ciliates usually outnumbered loricate ciliates. Copepod nauplii accounted for the highest microzooplankton biomass (>75% in dry weight). Rotifers made small contributions to the total microzooplankton density and biomass (<5%). Time series analysis indicated a twelve month cycle in microzooplankton abundance, and mid-summer(August) peaks for copepod nauplii, and a spring through fall peaks (May-October) for ciliates. Rotifers showed two seasonal peaks: one in mid-summer(August) at the river stations and the other in mid-winter(February) at the mesohaline stations. Seasonal peaks of copepod nauplii and rotifers coincided with the mesozooplankton abundance peak. On the other hand, ciliate maximum usually occurred between the phytoplankton and mesozooplankton peaks. This pattern of microzooplankton seasonality suggests the intermediate trophic role of microzooplankton (especially ciliates) between the phytoplankton(especially picophytoplankton) and mesozooplankton in Chesapeake Bay and its tributaries.

• 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.

• 환경생물
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• 제26권4호
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• pp.355-366
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• 2008

전라남도 영광군 불갑천에 서식하는 동물 플랑크톤을 2006년 4월, 7월, 8월, 10월, 12월, 2007년 2월 6회에 걸쳐 총 5개의 정점에서 채집을 실시하였다 조사기간 동안 출현한 동물플랑크톤은 44개의 분류군이 나타났으며, 우점한 분류군은 요각류였다. 10월에는 31$\sim$53,230 indiv. m$^{-3}$로 조사기간 동안 최고의 정점간 출현 개체수를 보였고, 12월에는 16$\sim$97 indiv. m$^{-3}$로 출현한 개체수가 최소로 나타나 시 공간적인 변동을 보였다. 종 다양성 지수는 7월(1.072)이 가장 높게 나타났으며, 10월(0.386)이 가장 낮게 나타났다. 우점적으로 출현한 요각류는Psdudodiaptomus inopinus와 Macrocyclops albidus였다. 담수와 기수에 서식하는 P. inopinus는 2006년 8월$\sim$2007년 2월에 걸쳐 모든 정점에서 출현하였으며, 불갑천 지역에서 극우점하였다. 약 20$^{\circ}C$에서 가장 많은 개체수를 나타내며, 저염도(0.1$\sim$14.0 psu)에서 높은 개체수를 보이고, 고염도(16.9$\sim$24.0 psu)에서는 낮은 개체수만이 출현하는 것으로 보아 염분도에 따라 분포를 달리하였다. M. albidus는 2006년 4$\sim$8월에서 담수 지역에서만 출현하였고, 수온이 높아짐에 따라 적은 개체수가 출현하였다.

• 환경생물
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• 제27권4호
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• pp.425-432
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• 2009

전라남도 영광군 와탄천 지류에 서식하는 중형동물플랑크톤의 종조성과 풍부도, 요각류의 분포 및 환경과 관계를 조사하기 위하여 2006년 4월, 7월, 8월, 10월, 12월, 2007년 2월 6회에 걸쳐 총 8개의 정점에서 채집을 하였다. 조사 기간 동안 출현한 중형동물플랑크톤은 45개의 분류군으로 요각류는 29종, 지각류는 8종 등이 출현하였다. 우점하는 분류군 중 요각류는 2월에 13종으로 가장 많이 나타난 반면, 7월, 8월에는 4종으로 가장 적게 출현하였다. 중형동물플랑크톤의 출현개체수는 10월 ($31{\sim}127,587\;indiv.m^-3$)에 가장 높았으며, 12월 ($12{\sim}233\;indiv.m^-3$)에 가장 낮게 나타났다. 종 다양성 지수는 7월(0.671)이 가장 높게 나타났으며, 8월(0.368)이 가장 낮게 나타났다. 와탄천 지류에서 주요 우점종은 Acartia hongi로 나타났다. A. hongi는 2006년 4월, 12월, 2007년 2월에 출현하였다. 수온 약 $12.0^{\circ}C$에서 가장 많은 개체수를 나타내었고, 주로 염분도 30.0 psu 이상인 지역에서 많이 발생하였다. 담수지역에서는 지각류인 Polyphemus pediculus, Moina weismani가 06년 8월에 대량 발생하였다. 우점 분류군이었던 요각류는 집괴분석 결과 조사시기 별로 염분의 변화에 따라서 두개 또는 세개의 무리로 구분되었다. 연구지역에서 중형동물플랑크톤은 수문의 개폐에 따른 염분의 변화와 계절적 차이에 의한 수온이 출현종 조성과 출현 개체수에서 영향을 받았다.

• Ocean and Polar Research
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• 제43권1호
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• pp.45-51
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• 2021

Studies on marine zooplankton diversity and ecology are important for understanding marine ecosystem, as well as environmental conservation and fisheries management. DNA metabarcoding is known as a useful tool to reveal and understand diversity among animals, but a comparative evaluation with classical microscopy is still required in order to properly use it for marine zooplankton research. This study compared crustacean mesozooplankton taxa revealed by morphological analysis and metabarcoding of the cytochrome oxidase I (COI). A total of 17 crustacean species were identified by morphological analysis, and 18 species by metabarcoding. Copepods made up the highest proportion of taxa, accounting for more than 50% of the total number of species delineated by both methods. Cladocerans were not found by morphological analysis, whereas amphipods and mysids were not detected by metabarcoding. Unlike morphological analysis, metabarcoding was able to identify decapods down to the species level. There were some discrepancies in copepod species, which could be due to a lack of genetic database, or biases during DNA extraction, amplification, pooling and bioinformatics. Morphological analysis will be useful for ecological studies as it can classify and quantify the life history stages of marine zooplankton that metabarcoding cannot detect. Metabarcoding can be a powerful tool for determining marine zooplankton diversity, if its methods or database are further supplemented.

• Ocean and Polar Research
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• 제27권2호
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• pp.231-235
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• 2005

The European Iron Fertilization Experiment EIFEX studied the growth and decline of a phytoplankton bloom stimulated by fertilising $10km^2$ in the core of a mesoscale $(80{\times}120km)$ cyclonic eddy south of the Antarctic Polar Front with about 2 times 7 tonnes of iron sulphate. The phytoplankton accumulation induced by iron fertilization did not exceed $3{\mu}g\;chl\;a\;l^{-1}$ despite a draw down of $5{\mu}M$ of nitrate that should have resulted in at least double to triple the amount of phytoplankton biomass assuming regular Redfield-ratios for draw down after phytoplankton growth in the Southern Ocean. During EIFEX the fertilized core of the mesoscale eddy evolved to a hotspot for a variety of small and medium sized mesozooplankton copepods. In contrast to copepods, the biomass of salps (Salpa thompson)) that dominated zooplankton biomass before the onset of our experiment decreased to nearly extinction. Most of the species of the rnosozooplankton community showed extremely hiか feeding rates compared to literature values from Southern Ocean summer communities. At the end of the experiment, massive phytoplankton sedimentation reached the sea floor at about 3800m water depth.

• Ocean and Polar Research
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• 제26권2호
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• pp.351-360
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• 2004

To investigate latitudinal variations in the zooplankton community along the meridian line ($5^{\circ}N-12^{\circ}N$, $131.5^{\circ}W$), we measured temperature, salinity, nitrate, chlorophyll-a and zooplankton at depths above 200 m from July $10^{th}$ to $25^{th}$, 2003. For comparative analysis, data of the physico-chemical properties and chl-a were matched to the two sampling depths (surface mixed layer and thermocline depth-200 m) of zooplankton. Latitudinal differences in the mesozooplankton distribution were mainly influenced by divergence formed at a boundary line formed by currents of opposing directions, consisting of North Equatorial Current (NEC) and North Equatorial Counter Current (NECC). High concentrations of chl-a south of $9^{\circ}N$, caused by equatorial upwelling related nutrients, is thought to be affected by the role of this divergence barrier, supported by relatively low concentrations in waters north of $9^{\circ}N$. The latitudinal differences of the chl-a were significantly associated with the major groups of zooplankton, namely calanoid and cyclopoid copepods, appendicularians, ostracods, chaetognaths, invertebrate larvae, and others. And temperature significantly affected the latitudinal variation of radiolarians, siphonophores, salps and immature copepods. The latitudinal differences in the two factors, temperature and chl-a, which explained 71.0% of the total zooplankton variation, were characterized by the equatorial upwelling as well as the divergence at $9^{\circ}N$. The physical characteristics also affected the community structure and abundance of zooplankton as well as average ratios of cyclopoid versus calanoid copepods. The abundance of dominant copepods, which were consistent with chl-a, were often associated with the carnivorous zooplankton chaetognaths, implying the relative importance of bottom-up regulation from physical properties to predatory zooplankton during the study period. These results suggested that latitudinal distribution of zooplankton is primarily controlled by current-related divergences, while biological processes are of secondary importance in the northeastern Equatorial Pacific during the study period in question.