• 한국해양학회지
• /
• 제29권2호
• /
• pp.132-144
• /
• 1994

부산항 해역의 지표성 요각류의 분포 및 11∼22개의 분류군에 속하는 동물플랑크 톤 군집을 다양도 및 집괴분석으로 분석하였으며 이들 생물학적 결과를 수온, 염분, COD, TIN의 분포와 연관시켜 부산항 해역의 해양환경을 고찰하였다. 네 무리의 요각류 들이 출현하였으며, 이들은 난류성 외양종무리인 Acrocalanus gacilis, Euchaeta plana, pareuchaeta russell and Pleuromamma gracilis 연안성 저온종인 Centropages abdominalis, 한류성 종인 Metridia lucens, 오염지표종인 Acartia omorii였다. 부산 항 외항의 경우, 10월에는 난류 외양성 종들이, 1월과 4월에는 연안 저온성종들이 우 세하였다. 내항으로 접근할수록 오염지표종인 Acartia omorii의 분포가 우세하였으며 COD 및 TIN의 분포 또한, 외항에서 내항으로 가면서 높아지는 경향을 나타내었다. 반 면에 다양도는 외항에서 내항으로 가면서 낮아지는 경향을 나타내었다. 집괴분석에서 10월과 7월에는 3개의 해역으로 그리고 1월과 4월에는 2개의 해역으로 나뉘어졌다. 해 역 I로 대벌되어진 부산 외항 해역은 외양수의 영향을 받는 해역으로 다양도가 높으 며, A. omorii의 밀도가 낮고 요각류의 조성률이 높게 나타났다. 외항에서 내항으로 가면서 대별되어 진 해역 II와 III은 해역 II에서 III으로 가면서 점차적으로 다양도 가 낮아지며, A. omorii의 밀도는 높아지는 특성을 나타내었다. 또한, 요각류의 조성 률이 낮아지며, 4월에는 해역 II에서 원생동물인 Noctiluca scintillans가 최우점군이 였다. 그리고 7월에 해역 III에서는 지각류가 취우점군이였다. 지표성 종들의 분포와 집괴분석에서 나뉘어진 해역은 해양 환경과 밀접한 관계를 나타내었다.

• 생태와환경
• /
• 제56권1호
• /
• pp.70-82
• /
• 2023

본 연구에서는 국내 3개 호소에서 채집된 동물플랑크톤을 이용하여 호소생태계 건강성 평가에 적합한 동물플랑크톤 지수를 선별해내고자 하였다. 미국 EPA의 National Lake Assessment에서 사용된 후보지수를 국내 적용에 적합하도록 변형하였다. 변형된 지수를 MMI 개발 개요에 맞춰 개별 지수의 적합성 평가, 교란 요인에 대한 반응성 평가, 각 범주 내 중복 지수의 제거 과정을 거쳐 최종적인 후보지수를 선별하여 제시하였다. 6개 범주 내에서 범주별 최대 5개의 지수가 선별되어 최종적으로 19개 지수가 제시되었으며, 모든 분류군에서 종 다양성이, 대형 지각류와 요각류의 경우 생체량이, 소형 지각류와 윤충류의 경우에는 개체밀도가 효과적인 평가 지표로써 사용될 수 있는 것으로 분석되었다. 본 연구에서는 동물플랑크톤을 이용한 국내 호소 건강성 평가 지수의 개발에 있어 적합한 방법을 제시하여 이후 동물플랑크톤 MMI 연구에 활용될 수 있도록 하였다.

• 환경생물
• /
• 제33권2호
• /
• pp.223-229
• /
• 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.

• 수산해양기술연구
• /
• 제53권1호
• /
• pp.107-113
• /
• 2017

The feeding habits of larval (5.0~27.0 mm SL) Clupea pallasii were examined and 1,523 individuals were collected from November 2010 to March 2011 in the coastal water of Eastern Jinhae Bay, Korea. Larval C. pallasii were fed mainly on copepods that constituted 55.2% in IRI. Monogeneans were the second largest prey component, another prey items tintinnids, cladocerans and ostracoda. The results of analysis in ontogenetic changes exhibit high during the daytime, two small size classes (${\leq}10mm$, 10~15 mm) mainly fed copepods. while the percentage of coperpods decreased, monogeneans ratio increased in 15~20 mm size class. Feeding rate in diel difference of larval C. pallasii were high during the daytime.

• 한국수산과학회지
• /
• 제48권4호
• /
• pp.498-506
• /
• 2015

We examined the feeding habits of larval Clupea pallasii using 148 specimens collected from December 2010 to April 2011 in the Nakdong River estuary, Korea. We found that larval C. pallasii [8.3-26.0 mm NL (notochord length)] are carnivorous, consuming mainly copepods, rotifers, cirripeds, and free-living flatworms (Macrostomida). Their diet also include small quantities of shrimp nauplii, tintinnids, cladocerans, and larval bivalves, among other food sources. To evaluate ontogenetic changes in dietary composition, we split larvae into four size groups: 8-12 mm, 12-16 mm, 16-20 mm, and > 20 mm NL. Rotifers were the most important prey items for the smallest group, but all other groups predominantly consumed copepods. The largest group frequently preyed on rotifers, cirripeds and flatworms, in addition to copepods. Larvae also showed bi-modal feeding, with peaks in the late afternoon and at midnight, wherein the mean number of prey per individual peaked at 1,800-1,900 h.

• 환경생물
• /
• 제38권2호
• /
• pp.231-247
• /
• 2020

The seasonal variation in the zooplankton community and hydrographic conditions were examined in three regions (inner, central, and outer regions) of Gamak Bay, Korea. Zooplankton samples were collected over a period of 12 months from January to December 2006. The hydrographical parameters of temperature, salinity, chlorophyll-a concentrations, dissolved oxygen, and chemical oxygen demand were measured. The total zooplankton density varied from 411 to 58,485 ind. m^-3, with peaks in early summer. A total of 65 taxa accounted for approximately 86.9% of the annual mean zooplankton density: Noctiluca scintillans (30.9%) Paracalanus parvus s. l.(24.3%), Acartia omorii(11.9 %), Eurytemora pacifica (5.7%), cladocerans (4.1%), cirriped larvae (3.8%), Oithona similis (3.7%), and Pseudevedne tergestina(2.5%). Copepods dominated numerically throughout the year and comprised 54.3% of the total zooplankton. Most of the dominant copepods showed a well-defined seasonal pattern. The density and diversity of zooplankton in Gamak Bay were influenced by the hydrographic environment that was subject to significant spatial and temporal variations. Multivariate statistics showed that seasonal temperature was the most significant predictor of zooplankton taxa, density, and diversity, as well as the density of dominant taxa. Our results suggest that fluctuations in the zooplankton populations, particularly copepods, followed progressive increments in the temperature and COD concentrations.

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

• 한국관개배수논문집
• /
• 제18권1호
• /
• pp.33-43
• /
• 2011

Jundae reservoir has basin area of 234ha, average depth of 3.77m and total storage of $619{\times}10^3m^3$, and is located in Dangin-gun, Chungcheongnam-do. The water quality of Jundae reservoir exceeded the IV grade of water quality standard as available for irrigation water in COD, TN, TP, Chl-a. COD and Chl-a were higher in spring season, because the algal bloom by phytoplankton increased. And the algal blooms in October by inflow non-point pollution during summer rainy season. The most dominant zooplankton was rotifers during study period at all stations. Dominant species were Keratella cochlearis, Polyarthra spp., and Trichocerca spp. We successfully established 2 isolated clone cultures as predator. One is Rotifer, Euchlanis sp. and another is cladocerans, Bosmina sp. To test the removal rate of 2 cultures against Microcystis aeruginosa, we inoculated Euchlanis sp. and Bosmina sp. separately when the abundance reached at $1.0{\times}10^6$cells/ml. Euchlanis sp. removed M. aeruginosa around 98.9% and Bosmina sp. removed it around 98.4%. They are useful grazers for controling algae blooms, Euchlanis sp. and Bosmina sp. feeding on M. aeruginosa highly.

• 생태와환경
• /
• 제36권4호통권105호
• /
• pp.420-426
• /
• 2003

지난 3년간(2000-2002), 식물플랑크톤 생체량의 역동적인 변화와 높은 투명도가 봄의 중순 기간 동안 낙동강 하류 부분에서 반복적으로 관찰되었다. 윤충류들은(Brachionus, Keratella, Polyarthra), 봄의 중순과 늦봄 기간 동안에 급격히 증가하였다. 늦봄 기간 동안 수체의 잔류시간의 중가 (약 20일 정도)와 수온의 상승시기에, $10^{\circ}C$로 부터 $20^{\circ}C$ 이상, 지각류의 증가를 나타내었다. 봄의 중순 높은 식물플랑크톤 생체량 시기 이후, 짧은 기간(약 1-2주)동안 낮은 식물플랑크톤 생체량과 높은 세키 투명도가 본 조사지점에서 나타났다. 봄 기간 동안 동물플랑크톤의 섭식률은 매우 높으며, 이러한 동물플랑크톤의 높은 섭식 활성도는 식물플랑크톤 동태를 조절하는 것으로 사료된다. 본 연구 결과는 강의 수체가 다소 정체되어 있는 봄 기간 동안 식물플랑크톤 생체량의 조절은 동물플랑크톤의 섭식에 의해 조절될 수 있음을 시사한다.

• ALGAE
• /
• 제20권2호
• /
• pp.133-140
• /
• 2005

Daily variation of phytoplankton community and environmental parameters were investigated at the lower Nakdong River (Mulgum) from January 2002 to December 2003 to investigate the dynamics of a phytoplankton community in detail. The daily results of water quality in this investigation showed pH (8.1 $\pm$ 0.7), DO (10.3 $\pm$ 2.7 $mg{\cdot}l^{-1}$), water temp. (18.8 $\pm$ 7.4°C), BOD (2.4 $\pm$ 1.0 $mg{\cdot}l^{-1}$), COD (5.3 $\pm$ 1.2 $mg{\cdot}l^{-1}$) and chl. a (43.5 $\pm$ 35.1 mg ${\cdot}m^{-3}$). The results of nutrient factors were the following: TN (3.1 $\pm$ 0.8 $mg{\cdot}l^{-1}$), NO3-N (2.5 $\pm$ 0.5 $mg{\cdot}l^{-1}$), TP (90 $\pm$ 48 ${\mu}g\;{\cdot}\;l^{-1}$), PO4-P (43 $\pm$ 30 ${\mu}g\;{\cdot}\;l^{-1}$). Dominant phytoplankton species during the study period were diatom (Stephanodiscus hantzschii, Aulacoseira granulata var. angustissima and A. italica) and cyanobacteria (Microcystis aeruginosa, Aphanizomenon flos-aquae). The small centric diatom, Stephanodiscus hantzschii, was repeatedly dominant from late fall to the following spring (mean and maximum cell density, 2.3 × 103 $\pm$ 3.8 × 103, 4.5 × 105 cells $ml^{-1}$, respectively). Pinnate diatom, Aulacoseira granulata var. angustissima and A. italica, were frequently observed all season except January to March. Cyanobacteria, Microcystis aeruginosa and Aphanizomenon flos-aquae, proliferated in summer of 2002 except in 2003 due to heavy precipitation. The dominant zooplankton species (March-early May) was rotifer (Brachionus, Keratella, Polyarthra) and cladocerans (Diaphanosoma). The daily observed dynamics of the phytoplankton community in the lower Nakdong River in this study may play an important role in increasing the detailed resolution of limnological information and serving as ecological data for future studies.