• 한국환경과학회지
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• 제19권11호
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• pp.1407-1421
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• 2010

This study was carried out to elucidate the relation between water quality and structure of the aquatic ecosystem in the agriculture reservoir Otae-ji from January to December in 2009. The proportion of forest was 46.98%, which means that non-point sources are major contributor of water pollution in this area. The annual mean COD(Chemical Oxygen Demand) in Otae-ji was $3.6mgL^{-1}$, indicating, level II of environmental standards and the trophic state was mesotrophic. Although total phosporus concentration in the reservoir was high in August due to large inflow of nutrients from outside the reservoir during monsoon season, there was no break out of significant algal bloom in the summer. The seasonal succession of phytoplankton showed that the dinophyta dominated in the the spring, chlorophyta in the summer, chrysophyta and chlorophyta in the autumn and chrysophyta in the winter. In case of zooplankton, rotifers dominated in the most seasons, but cladoceran(Bosmina longirostris) dominated in June and copepod(Nauplii) in August. The macrophyte plants showed diverse species compositon consisted of 3 varieties, 24 species, 23 genera, 15 families and 14 orders. The macroinvertebrates also showed various FFG(Functional Feeding Groups) such as GC(Gathering-Collector), P(Predator), SH(Shedder), FC(Filter-Collector) and PP(Plant-Piercer). Ecosystem stability analysis using aquatic insects was classified as Group I, which has high resilience and resistance indices. A total of 14 species of fish was collected but exotic species such as Lepomis macrochirus and Micropterus salmoides were not found in Otae-ji. In conclusion, the preservation of healthy food wed in the reservoir ecosystem is closely related to water quality management as well as effective prevention of algal bloom by helping good material circulation in aquatic ecosystems.

• 한국조경학회지
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• 제42권3호
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• pp.35-49
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• 2014

본 연구는 제천시에 위치한 솔방죽 습지생태공원의 조성 전과 후의 동물상을 비교하였다. 그 결과, 생태공원 조성에 따른 동물상의 변화는 야생성이 강한 종들이 감소하고, 일반종의 비율이 높아지는 것으로 나타났다. 또한 포유류, 양서 파충류와 같이 이동에 제약이 있는 종들은 생태공원 조성으로 늘어난 탐방객들에 의해서 점차 감소하고 있다. 그리고 어류는 공원 조성과정에서 저수지 물을 방류하고 작업하여 집단 폐사하는 사례가 있어 이에 대한 보완 작업이 필요하다. 곤충은 공원 조성 후에 조성된 화단의 꽃에서 꿀을 먹는 곤충과 습지 식물의 생육을 위하여 안정된 수계를 유지하고 있어, 이곳에서 서식하는 수서 곤충은 늘어난 것으로 나타났다. 이번 조사 결과, 주거지역과 인접한 농업용 저수지는 크기가 작은 경우가 많아 생태공원 조성시 이곳에서 생활하는 야생동물들에 대한 서식 공간 확보가 필요한 것으로 보인다. 또한 야생동물 서식처를 위하여 방문객들의 탐방로와 시설물 위치를 조정하여 저수지 일부 지역이 자연 상태로 유지할 수 있도록 하는 것이 고려되어야 한다.

• 한국습지학회지
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• 제3권1호
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• pp.19-28
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• 2001

본 조사는 1999년 10월부터 2000년 8월까지 경상북도 구담습지의 광덕교지역(St. 1), 양어장지역(St. 2), 구담교지역(St. 3) 세 곳의 저서성 대형무척추동물 군집을 파악하기 위해 실시되었다. 조사기간중 채집된 저서성 대형무척추동물은 총 3문 5강 11목 26과 38속 47종이며, 수서곤충은 5목 20과 38종으로 나타났으며, 깔따구류가 모든 조사지점에서 우점종으로 나타났다. 우점도는 St. 2에서 가장 높았고 St. 1에서 가장 낮았다. 우점도 지수 범위는 0.40~1.00(평균, 0.69)이었고, 종다양도 지수 범위는 0.04~3.40(평균, 1.98)로 조사되었다.

• Journal of Ecology and Environment
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• 제34권2호
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• pp.175-191
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• 2011

Colonization patterns and community changes in benthic macroinvertebrates in the Cheonggye Stream, a functionally restored stream in downtown Seoul, Korea, were studied from November 2005 to November 2007. Benthic macroinvertebrates were quantitatively sampled 15 times from five sites in the stream section. Taxa richness (59 species in total) increased gradually over the first year, whereas the density revealed seasonal differences with significantly lower values in the winter season and after flood events. The benthic macroinvertebrate fauna may have drifted from the upstream reaches during floods and from the Han River, arrived aerially, or hitchhiked on artificially planted aquatic plants. Oligochaeta, Chironommidae, Psychodidae, and Hydropsychidae were identified as major community structure contributors in the stream. Swimmers and clingers colonized relatively earlier in the upper and middle reaches, whereas burrowers dominated particularly in the lower reaches. Collector-gatherers colonized at a relatively early period throughout the stream reaches, and collector-filterers, such as the net-spinning caddisfly (Cheumatopyche brevilineata), predominated in the upper and middle reaches after a 1-year time period. Cluster analyses and multi-response permutation procedures demonstrated that the Cheonggye Stream shares more similarities with the Jungnang Stream than with the Gapyeong Stream. Detrended correspondence analysis and nonmetric multidimensional scaling demonstrated that physical environmental factors (depth, current velocity, dissolved oxygen, and pH) as well as nutrients (total nitrogen and total phosphorous), water temperature, and conductivity could affect the distribution of benthic macroinvertebrates in the study streams.

• Fisheries and Aquatic Sciences
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• 제12권1호
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• pp.1-5
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• 2009

Crude saponin, extracted from the starfish Asterias amurensis, was assessed for its capacity as a biological pesticide. As part of this analysis, its insecticidal and repellent activities, in addition to its acute and chronic toxicities were tested. In comparison with the control group, insecticidal activity of saponin against tobacco cutworm, Spodoptera litura, in kale, Brassica loeracea was low at 36.4%. Repellent activities of the extracted saponin against green peach aphid, Myzus persicae, and S. litura, on soybean leaf, Glycine max and kale were 65.6% and 35.0% at $1^{st}$ day, and 54.5% and 30.0% at $3^{rd}$ day, respectively. Acute and chronic toxicity analysis was carried out using acute immobilizatioin test and reproduction impairment test, respectively. The saponin had 48 h-$EC_{50}$ of $65.21{\mu}g/mL$. Twenty-one day accumulative reproduction after treatment was lower in Daphnia magna at $7{\mu}g/mL$ saponin (78 youngs), compared with the control group (129 youngs). These results indicate that the extracted saponin exhibited some toxicity and has potential as a repellent against insects.

• Fisheries and Aquatic Sciences
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• 제26권8호
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• pp.491-499
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• 2023

Lake Tinisu Abaya is home to some fish species. The lake's native fish species include Barbus and Tilapia zilli. Tilapia fish (Oreochromis niloticus L.) were stocked in Lake Tinishu Aabaya in 1997. This study aimed to investigate the feeding behaviors of O. niloticus in Lake Tinishu Abaya to develop an appropriate fisheries management approach in the lake. 428 O. niloticus fish samples (2.5 to 30.9 cm and 1.1 to 475 g) were collected to calculate the diet composition. Out of the total of 428 gut contents examined, 55 (12.85%) were found to be empty and 373 (87.15%) to be containing one or more food items. The diet behavior of the stocked fish in the study lake revealed that phytoplankton (39.5% by volume) and macrophytes (25.81% by volume) were the most noteworthy food items followed by detritus (14.39%) and zooplankton (12.95%). With increasing fish size, the importance of phytoplankton, macrophytes, and detritus increased while the contribution of zooplankton, insects, and other foods with an animal origin decreased. Seasonal variation in the diet composition of fish was evident (t-test; p < 0.05). Macrophytes, zooplankton, and detritus were the dominating food items during the wet season, while phytoplankton predominated during the dry season. This study demonstrated that O. niloticus had phytoplanktivores that primarily consumed phytoplankton and that the seasons and fish size had a significant impact on their feeding preferences. The diet of O. niloticus in Lake Tinishu Abaya comprised foods with both plant and animal origins. It concludes that the dietary habit of O. niloticus in the lake is, generally, the omnivorous type.

• The Korean Journal of Ecology
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• 제20권1호
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• pp.69-78
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• 1997

The development of stream ecology, especially the progress of that field in North America, has been briefly reviewed, and stream studies in Korea were analyzed through literature survey. During the last two decades, theoretical advances in stream ecology and understanding of the structure and function of stream ecosystem were made from the studies mainly in North America. Early studies (1960-1970) focused on determination of the environmental factors controlling the distribution and abundance of organisms dwelling in streams. Introduction of conceptual development, such as the functional feeding concept, river continuum concept, and nutrient spiraling was notable in the late 70's and the 80's. For last 20 years, experimentation approaches to apply ecological principles were very fruitful in the understanding of community structure. Even though studies on the stream ecosystem is Korea have a long history, most of works were concentrated on limited subjects: water quality, abundance and distribution of aquatic insects and fishes. Basic ecological attributes of stream organi는 and test of ecological principles have rarely been a subject of research topics. We must concentrate our effort to enhance our understanding of stream and river ecosystem through qualitative, experimental and interdisciplinary approaches.

• 한국습지학회지
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• 제10권3호
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• pp.133-139
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• 2008

도심하천은 도심개발과 오염으로 인해 기능이 점차 상실되고 있다. 본 연구는 도림천의 출현 동물상 및 식물상을 파악하여 도심하천의 건강성을 평가하는 지표종을 발굴하고, 습지보전지역의 가능성을 위한 방안을 토론하였다. 도림천에서 안양천에 이르는 구간에 총 113종의 식물종, 포유류 9종, 조류 23종, 양서류 4종, 파츙류 2종과 어류 2종이 관찰되었다. 육상곤충은 71종이 관찰되었으며, 습지식생은 매우 다양하며 총 4개의 권역으로 나누었으며, 도심하천의 특징을 나타내는 수변지역 및 습지식물권역(습지식물권역, 반습지식물권역, 습지주변초지 지역, 습지주변교목지역)에 대한 관리방안이 도출되었다.

• The Korean Journal of Ecology
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• 제2권1호
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• pp.9-14
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• 1978

The study was made to expand the knowledge of the ecology of Cobitis koreensis which is very common in the upper and middle part of rivers in western part of Korea. A number of C. koreensis are found in the creek of Jeonju-cheon located at Segjang-ri, Wanju-gun, Jeonrabug-do Province. The area studied has pebble bottoms. The flow velocity of the river ranges from 20cm to 40cm per second under normal conditions. The sex ratio of male to female was 1:1.34 and the female was 10~25mm larger than the male in total length. Length-frequencies in this population indicate that 20~40 mm fish group is underyearling, 40~60mm is a yearling, and 60~85mm is two-year-old. And the fish longer than 90mm in total length is regarded as being over three-year-old. Based on the ratio of gonadal weight to body weight, spawning in this species began in April and expanded well into June with water temperature 20~26。C, and the individuals became sexually mature over the two-year-old. The number of the eggs was counted from ten matured female fishes. The mean number of eggs in seven 72.6~81.4mm fishes was 908 (595-1, 229) and that of the rest three 86.0~89.0mm was 1, 674 (1, 337-2, 023). The contents of stomach in the other fifteen specimens captured in September 1977 were investigated. While the younger fed almost on the algae, the foods in the adult were largely aquatic insects.

• 한국물환경학회지
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• 제25권4호
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• pp.494-501
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• 2009

Probabilistic Ecological risk assessment (PERA) is extensive approach to qualify and quantify risk on the multi species based on species sensitivity distribution (SSD). As a while, deterministic ecological risk assessment (DERA) considers the comparison of predicted no-effect concentration (PNEC) and predicted exposure concentration (PEC). DERA is used to determine if there is potential risk or no risk, and it doesn't consider the nature variability and the species sensitivity. But PERA can be more realistic and reasonable approach to estimate likelihood or risk. In this study, we compared PERA used in developed countries, and proposed PERA applicable for the Korean water environment. Taxonomic groups were classified as "class" level including Actinopterygill, Branchiopoda, Chlorophyceae, Maxillapoda, Insects, Bivalvia, Gastropoda, Secernentea, Polychaeta, Monocotyldoneae, and Chanophyceae in this study. Statistical extrapolation method (SEM), statistical extrapolation method $_{acutechronicratio}$ ($SEM_{ACR}$) and assessment factor method (AFM) were used to calculate the ecological protective concentration based on qualitative and quantitative levels of taxonomic toxicity data. This study would be useful to establish the PERA for the protection of aquatic ecosystem in Korea.