• 환경생물
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• 제23권2호
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• pp.93-97
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• 2005

Zooplankton dynamics were investigated based on samples collected monthly during the period between November 1998 and October 1999 at 15 stations in Gwangyang and Sachon Bay. Zooplankters were quantitatively collected with horizontal towing through the surface and oblique hauling from the bottom to surface at each station, simultaneously. A total of 88 taxa of zooplankton were distributed and 60 taxa were identified to species. Copepods showed the prosperity in species number of 52 species. Number of taxa occurred in samples hauled obliquely always showed $2\~5$ more species than those captured in the surface except for stations near the Namhae bridge. In waters near Namhae bridge, fast current seemed to mix waters vertically. Seasonally these differences were more distinct in the spring and summer than those in other seasons possibly due to the stratification in warmer seasons. In quantitative aspects, differences between two layers seemed to be obscure. Spatial and temporal variations in species diversity of copepods showed more prosperity in pelagic realm than those in the surface. Our collection carrying out in day time might be one of the important reason to cause these differences in zooplankton dynamics between two layers.

• 환경생물
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• 제20권4호
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• pp.312-315
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• 2002

Impact of artificial illumination on zooplankton dynamics has been studied in Tongyong marine ranch during the period from August 1998 to August 1999. Monthly sampling has been carried out to collect zooplankters from both natural waters and artificially illuminated waters at night. A total of 48 taxa of zooplankton occurred during the study. Copepods showed the prosperity in species number with 21 species. Every sample from illuminated waters consisted of move than 15 species except February while less than 15 species in samples from natural waters during the winter. Benthic amphipods occurred abundantly in illuminated waters. Zooplankton abundance was revealed to be increased in illuminated waters mainly due to the gathering of amphipods (4,500 indiv. $m^{-3})$ in September and October. Twenty times of zooplankton abundance was recorded in illuminated waters when compared with that in natural ones in September due to the gathering: of amphipods and ten times by the explosion of N. scintillans in August 1999. However, no distinct difference in the abundance was observed between two waters in the winter. Zooplankton gathering with artificial illumination seemed to be effective in amphipods, while copepods were hardly affected by the artificial illumination at night.

• 생태와환경
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• 제39권1호통권115호
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• pp.52-61
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• 2006

본 연구는 지난 10여년간의 (1994 ${\sim}$ 2003) 주간격의 자료를 이용한 자가조직화 지도 (SOM) 방법으로 낙동강 하류역 (물금: 낙동강 하구언으로부터 27 km 상류지점)에서 동물플랑크톤 군집 동태에 대한 계절별 유형화 분석을 하는데 목적이 있다. 담수생태계내의 먹이망에서 동물플랑크톤 군집의 역할은 매우 중요하나, 다른 군집 구성원들과의 비교 연구는 다소 미진하게 진행되었다. 비선형 모형 알고리즘인 SOM을 동물플랑크톤 군집 역동성과 강 환경 인자들과의 상관관계 파악을 위하여 적용하였다. 육수학적 환경 인자 (수온, 용존산소, pH, 세키투명도, 탁도, 클로로필 a 농도, 유량 등) 들을 동물플랑크톤 군집 구조(윤충류, 지각류 및 요각류)의 계절적 변화 유형파악을 위하여 사용하였다. 학습된 SOM 모형은 육수학적 환경인자와 연관 지어 지도상에 동물플랑크톤을 배치되었다. 동물플랑크톤의 주요 세 군집들은 계절별 변화 유형에 있어서 높은 유사성을 가지고 있었다. 다양한 육수학적 환경인자 중, 수온은 동물플랑크톤 군집 역동성과 매우 높은 연관관계를 나타내었다(특히, 지각류). SOM 모형은 여름기간 증가된 강 유량에 의해서 동물플랑크톤을 매우 저해하는 요인으로 표현되었다. 클로로필 a 농도는 우점한 초식성 동물플랑크톤 활성도에 의해 지도상에서 구획되었다. 본 연구는 비선형 방법을 이용한 육수학적 환경요인과 동물플랑크톤 역동성을 연관 지어 소개하였으며, 이러한 정보는 먹이망이라는 관점에서 볼 때, 강 생태계 관리에 유용한 정보로 활용될 것으로 사료된다.

• 환경생물
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• 제33권2호
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• pp.223-229
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• 2015

Pre-monsoon dynamics of zooplankton community were investigated in the downstream of the Gagok stream flowing into the East Sea of Korea. Monthly sampling was carried out to collect zooplankters at five sites in the stream during the period between April and July 2014. Dissolved oxygen contents exceeded $7.0mg\;L^{-1}$ all the time. Water temperature was in a range of 15.7 to $24.9^{\circ}C$ and pH 7.4 to 8.8, respectively. A total of 75 taxa consisted of 36 species of rotifers, 16 species of cladocerans, 16 species of copepods, four kinds of aquatic insects, two kinds of decapods and one nematod was occurred. One species of marine copepod and one cladoceran, and one species of brackish rotifer and one copepod distributed at the station located in the stream mouth. Zooplankton abundance showed to vary from 42 to 4202 individuals $m^{-3}$ due to the explosion of aquatic insects and Alona sp. at site 2 located in the downstream in April. Heavy rainfall during the monsoon period seems to decrease the zooplankton abundance caused by diffusion and drifting to the sea. Species diversity indices were generally high between 1.2~2.3 and were recorded to be high at the downstream throughout the study period. With the zooplankton dynamics, the influence of the input of sea waters into the stream seemed to be confined to some hundred meters of the stream mouth facing the East Sea.

• 한국물환경학회지
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• 제23권3호
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• pp.339-347
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• 2007

Zooplankton community dynamics were studied after establishment of an artificial vegetation island (AVI) in Lake Paldang, from April 2005 to November 2006. There were distinct seasonal and inter-annual changes of total zooplankton abundance at the survey site. Total zooplankton abundance rapidly increased in spring and fall, while it remained low throughout winter. During summer, the dynamics of zooplankton community seemed to be largely affected by hydrological parameters such as, precipitation and inflow. Total zooplankton abundance and biomass below AVI was much higher than that of pelagic zone (L1) in Lake Paldang. Copepoda and cladocera represented the main bulk of the zooplankton community from summer to fall at the both sites. Copepods were more dominant at AVI area, while cladocera were more dominant at pelagic zone (L1). Water quality, prey and habitat condition, species competition between zooplankton seemed to play important roles in dominance of the copepoda and cladocera in zooplankton community at AVI area. Our results conclude that artificial vegetation island provide the stable habitat and besides phytoplankton, diverse food to zooplankton, and consequently influence the diversity and richness of zooplankton community.

• 생태와환경
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• 제38권3호통권113호
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• pp.412-419
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• 2005

낙동강 중류 지점에서 (왜관, 낙동강 하구언으로부터 175 km 상류 지점) 1998년 1월부터 2002년 12월까지 동물플랑크톤 군집 동태 및 환경요인 들과의 상관관계에 대해서 조사하였다. 조사지점에서의 동물플랑크톤의 계절별 변화와 연간 변화는 매우 뚜렷하였으며(ANOVA, p<0.01), 1998년과 2002년을 제외하고는 1999년부터 2001년까지 3년 동안 유사한 동물플랑크톤 양상을 나타내었다. 조사기간 동안 연 평균 윤충류의 개체수는 43${\pm}76 ind. $L^{-1}$ (평균${\pm}$ s.d., n = 118)이며, 요각류 (1.6${\pm}$4.8 ind. $L^{-1}$)와 지각류 (0.4${\pm}$1.2 ind. $L^{-1}$) 순으로 나타났다. 윤충류 군집내에서는 Brachionus spp. Polyarthra spp., Colurella spp., Keratella spp.와 Trichocerca spp. 등이 우점하였다. 이러한 종들은 전체 총 윤충류의 개체수에 대한 상대 풍부도의 80% 이상을 차지하였다. 조사지점 내 총 동물플랑크톤 개체수는 봄과 가을에 급격히 증가 하였으며, 겨울 동안에는 낮은 개체수를 유지하였다. 여름기간 동안, 동물플랑크톤 동태는 수문학적 요인에 의해 크게 영향을 받는 것으로 파악된다. 조사구획 내 동물플랑크톤의 동태는 내적요인 (동물플랑크톤의 먹이상태, 예: 식물플랑크톤 생체량) 보다는 외적 요인 (강의 수문학적 요인)들에 의해서 보다 더 큰 영향을 받는 것으로 사료된다.

• Journal of applied mathematics & informatics
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• 제32권5_6호
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• pp.555-566
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• 2014

In this paper, we formulate two chemostat type models of phytoplankton and zooplankton population dynamics with instant nutrient recycling to study the role of viral infection on phytoplankton. The infection is transmitted only among phytoplankton population and it makes them more vulnerable to predation by zooplankton. It is observe that the chemostat system is very stable in the absence of viral infection but the presence of viral infection make the chemostat system sensitive with respect to the grazing rate of infected-phytoplankton by zooplankton. Further, if the grazing rate is less than certain threshold the system remain stable and exhibits Hopf-bifurcation after crossing it.

• 생태와환경
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• 제35권2호통권98호
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• pp.141-144
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• 2002

The construction of river mouth dam has prevented seawater from backwarding to upstream in Kum river estuary since 1990. Field observation on environmental factors, and zooplankton and phytoplankton dynamics have been carried out three times with two month interval in the summer and autumn in 2000 at three selected stations in Kum river estuary. Blockade of seawater flowing backward to upstream caused sharp contrast of zooplankton fauna and phytoplankton flora between upstream and downstream of the river mouth dam. Freshwater cladocerans i.e., Bosmina longisrostris and Daphnia galeata dominated in the upstream, and marine copepods of Acartia omorii and Paracalanus crassirostris occurred abundantly in downstream of the dam. Freshwater diatoms did not distributed in the downstream of the dam except Melosira varians, while marine diatom of Cylidrotheca closterium occurred in benthic waters bath in upstream and downstream of the dam. The construction of the river mouth dam seems to play an ecological role to blockade the input of marine organism into the upstream in Kum river estuary.

• 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.

• 한국생태학회:학술대회논문집
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• 한국생태학회 1999년도 국제 Symposium 및 '99 춘계 공동 학술 발표대회
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• pp.76.1-76.1
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• 1999