Feeding Behavior of One-year-old Silver Carp, Hypophthalmichthys molitrix, on Dominant Phytoplankton During a Summer in the Enclosure of Shallow-hypertrophic Lake

최민규,김백호,Choi, Min-Kyu,Takamura, Noriko,Kim, Baik-Ho 한국하천호수학회 2000 생태와 환경 Vol.33 No.4

수심이 얕은 부영양호수에서 우점하는 식물플랑크톤에 대한 1년생 백련어의 섭식특성을 조사하고자, 1997년 5월 23일부터 9월 18일까지 호수의 연안에 4개의 enclosure를 설치하고, 어류투입 이후의 각 enclosure수중과 어류의 장 내용물 중의 식물플랑크톤 군집의 변화를 비교하였다. 조사기간동안 각 enclosure의 수온, 플랑크톤의 총생물량, 어류 아가미의 여과공 등은 시간에 따라 른 변화가 없었으며, 어류성장은 주로 투입된 어류의 밀도에 의존되었다. 어류의 내용물에 의하면, 저밀도 투입 enclosure에서 수중과 어류 전장간의 플랑크톤군집의 유사도가 높게 나타났으며(p<0.05), 전체적으로 모든 enclosure에서 크기가 큰(>$100,000{\mu}m^3$) 식물플랑크톤-Oscillatoria, Anabaena, Melosira등은 어류투입이후 크게 감소되지 않았다. 어류의 먹이선택지수(${\alpha}$)와 플랑크톤의 크기 (Ingestion unit)사이에도 매우 낮은 상관성을 보였다(r = 0.001, p>0.5). 식물플랑크톤의 분석결과, 백연은 남조나 녹조에 비해 규조를 더 선호하였는데, 이는 규조의 세포벽이 다른 조류에 비해 소화과정동안 쉽게 파괴되지 않고, 저배율의 현미경적시야에서도 간단히 확인된다는 점 등,선택지수를 과대평가하게 되는 단점이 있기 때문에 백련어의 먹이습성에 대한 방법론적 개선이 필요하다고 판단된다. The feeding behavior of 1-year-old silver carp, Hypophthalmichthys molitrix (Val.) on phytoplankton species in a shallow hypertrophic lake was studied from 22 May to 18 September, 1997. Over the experimental period, the filter-pore sizes of the fish, the total biomass of the phytoplankton and the water temperature in each enclosure changed little with time. The fish biomass in each enclosure increased with time, while their percentage of weight gain correlated negatively to the stocking density, due perhaps to competition for prey. An analysis of gut contents of silver carp showed a strong similarity between the algal communities in the foregut and the water, and was significant for the fish enclosure with a low density (p<0.05). The presence of silver carp rarely suppressed the abundance of phytoplankton such as Oscillatoria, Anabaena and Melosira even at high ingestion levels. There were weak relationships between the IU values of each phytoplankton and the selectivity of fish on them (r = 0.001, p>0.5). There was no doubt that the silver carp fed unselectively when cyanobacteria populations were high, even though the selectivity index for diatoms was slightly higher than those for cyanobacteria, green algae and cryptomonads. Improvements in methodologies are needed to clearly understand and generalize the feeding behavior of silver carp.

상수원의 오염에 대한 식물플랑크톤의 오수생물학적 연구 - 만경강 상류 하천 및 저수지를 중심으로 -

최민규,김백호 ( Min Kyu Choi,Baik Ho Kim ) 한국환경생물학회 1994 환경생물 : 환경생물학회지 Vol.12 No.2

Phytoplankton community and its physicochemical parameters were investigated at three reservoirs and four streams in the upper part of the Mankyeong River System from July, 1993 to June, 1994 on seasonal interval. Totally, 322 taxa were classified and composed of 33 families, 82 genera, 263 species , 52 varities and 7 forma Among them, 135 taxa of Bacillariophyceae was the highest record during this study. Total standing biomass of 1.11×10 exp (7)cells/㎖ was enumerated, and the high peak was in summer as 3.16×1010 exp (7)cells/㎖(28.5%), and also, reservoirs more higher than streams in biomass. Melosira granulata was much dominated and totally, 4.9×10 exp (5)cells/㎖ was counted As a whole, nine taxa of fourth species including Cyclotella meneghniana in streams and five taxa with Melosira varians in reservoirs were also domianted Synedra ulna and Melosira granulata were distributed either at stream or reservoirs. Species diversity indices(H` ) were showed the maximum at station 5 as above 2.0 without seasonality and the lowest at station 6 and 7 as below 1.0 in spring and summer. Similarity indices among sampling stations were the peak as 0.58 between station 4 and 5, the lowest between station 6 and 7 located at the same stream. In view of correlation between biological and physicochemical conditions at three reservoirs, station 3 and 6 were more related with organic nutrient, in other hand, station 7 was dependent with physicochemicals such as water temperature and dissolved oxygen. And also, water qualities of station and 6 with regard to total biomass of the major dominant species were ranged from oligotrophic to eutrophic, while station 3 on summer and autumn was eutrophic. The degree of pollution tolerance scores(PTS) was ranged from degree 1 to 4 Several bioindicators newly introduced, three common species were Melosira granulata, Synedra ulna and Melosira varians. Two taxa of Gomphonema olivaceum and Cyclotella meneghniana were showed only in degree 2, and also, two taxa of Achnanthes subsalsa and Melosira italica var. tenuissima were distributed only in degree 3. Microcystis aeruginosa was well dominated at eutrophic state as below degree 3. From this above results, we may evaluate the degree of water quality based on bioloical and physicochemical conditions that station 1 in summer and autumn was oligotrophic state as degree 1, station 3 in summer and winter was α-mesosaprotrophic as degree 3, and totally showed β-mesosaprotropnic as degree 2.

주암호의 식물플랑크톤의 출현과 동태

최민규,김백호,정연태,위인선 ( Min Kyu Choi,Baik Ho Kim,Yeun Tai Chung,In Sun Wui ) 한국하천호수학회 1994 생태와 환경 Vol.27 No.1

A short-term survey was carried out to understand the species composition and standing biomass of phytoplankton in Lake Chuam, where severe the eutrophication have took place on summer, 1992. Totally 130 taxa of phytoplankton were collected and consisted of 6 classes, 10 orders, 7 suborders, 23 families, 55genera, 116 species, 13 varieties and 1 forma. Phytoplankton compositions in each class were divided in 57 taxa of Chlorophyceae (43.8%), 44 taxa of Bacillariophyceae (33.9%), 20 taxa of Cyanophyceae (15.4%), 6 taxa of Euglenophyceae (4.6%), 2 taxa of Dinophyceae and 1 taxa of Chrysophyceae. The composition of species and standing biomass was reached to maximum, 72.31% and 42.67% at Site 3, respectively. Dominant species were Microcystis aeruginosa (51.65%), Melosira granulata (4.96%). The next major phytoplankton except these two species were ceratium hirundinella, Eudorina elegans, Anabaena flos-aquae, Dictyosphaerium pulchellum, Coelastrum microporum, Coelasphaerium kuetzingianum, and staurastrum paradoxum var. longipes. These groups were 73.1% of total biomass. And also, species diversity was high at Site 3 throughout the sampling times. Coelastrum-Coelasphaerium-Eudorina-Staurastrum assemblages were much distributed in centering of Site 3, the upper part of lake, inflowed sufficient nutrient from many tributaries. Especially, the high frequency (2.7% of totals) of Staurastrum paradoxum var. longipes was very interesting and new to Korea. In physicochemical factors, suspended solids, electric conductivity and chlorophyll a were reached the maximum, 34.5mg/l, 103μhmos/Cm, 6.7mg/m^3 only at Site 3 in June, closely associated with green algal assemblages. But other data were not showed any relationship between biological and physical conditions of phytoplankton community. The above mentioned results indicate that Lake Chuam has a wide range from eutrophic to oligotrophic state according to Hutchinson(1967), and divided into two regions, Site 1,2 and Site 3 in a view of phytoplankton distribution and biomass and its environmental condition. We conclude that Site 3 was in situation of considerable organic pollution.

Fine Structure of Blue-green Algae, Microcystis aeruginosa Kutzing

최민규,김백호,문연자,정연태,이종빈,위인선,Choi, Min-Kyu,Kim, Baik-Ho,Mun, Yeun-Ja,Chung, Yeun-Tai,Lee, Jong-Bin,Wui, In-Sun Korean Society of Electron Microscopy 1996 Applied microscopy Vol.26 No.4

In order to understand the morphological differences between two different organic loadings by its upstream, and to compare with other algal groups with references, the fine structure of blue-green algae, Microcystis aeruginosa Kitzing, taken from two branches, Tongbok and Bosung stream of Lake Chuam, Korea pennisula was examined. It showed extinct differences in most physicochemical factors between both branches, except water temperature and pH values. The concentrations of total phosphorus in Tongbok branch were twice as those of Bosung. M. aeruginosa cells were enumerated totally $1.2X10^4cells/ml$ and these individuals in branch of Tongbok were close to two times as much as Bosung. In light and electron microscopy, natural M. aeruginosa colonies formed irregular shape and non-directional array in amorphous matrix. They were consisted of many kinds of cells, youngs or olds in cell division, solitary, and various size of cells. Each cell ranged from 2.61 to $5.40{\mu}m$ in diameter, and averaged as $3.54{\pm}0.19{\mu}m$. In cytoplasm, they contained a number of inclusions in various size, shape and appearances. Among them, polyhedral bodies or carboxysomes, a structured granules, photosynthetic lamellae or thylakoids, and gas vacuoles were prominent and easy to recognize. Although it was failed to find the definable morphological variations in the ultrastructure of M. aeruginosa in terms of algal habitual environments, some useful characters were founded, outer layer of cell wall, polyhedral bodies and gas vacuoles, in blue-green algal classification and taxonomy. 주암호의 유입하천중 이화학적 조건이 서로 다른 보성천과 동복천에서 채집된 남조 Microcystis aeruginosa Kutzing의 미세구조에 대한 형태학적 관찰을 시행하여 다음과 같은 결과를 얻었다. 수온과 pH를 제외한 다른 환경요인들은 두지점간에 큰 차이를 보였다. M. aeruginosa의 광학 및 전자현미경적 관찰 결과, 세포는 부정형 군체를 형성하며, 투명한 점액질로 싸여 있었다. 세포는 난형 또는 구형에 가깝고, 크기는 $2.61{\sim}5.40{\mu}m$의 범위로서, 평균 $3.54{\pm}0.19{\mu}m$였다. 세포질내에는 많은 다양한 구조물을 가지고 있으며, polyhedral bodies(carboxysomes), polyphosphate, cyanophycin granules 외에 photosynthetic lamellae와 gas vacuoles 등이 비교적 뚜렷하였다. 두 채집장소간의 형태학적 차이는 보이지 않았으나, 영양염류 수준이 높은 표본에서 polyphosphate와 cyanophycin granules이 숫적 증가를 보였다. 세포분열은 이분법으로 초기에 정중앙부의 좌우로부터 합입이 일어났으며, 주로 세포벽의 제1층과 제2층이 관여하였다. 세포벽의 외부층은 크게 두가지 형태의 filaments층이 잘 발달되어 있었다.

노닐페놀류와 분변계스테롤을 이용한 부산연안 퇴적물의 하수 오염도 평가

최민규 ( Min Kyu Choi ),이인석 ( In Seok Lee ),황동운 ( Dong Woon Hwang ),윤세라 ( Se Ra Yoon ),정래홍 ( Rae Hong Jung ) 한국환경분석학회 2014 환경분석과 독성보건 Vol.17 No.2

Surface sediment samples collected from Busan coastal area of Korea were analyzed for molecular markers of organic wastewater compounds, i.e., fecal sterols including coprostanol (COP) and nonylphenolic compounds(NPs), to assess anthropogenic contamination and to characterize the main routes of wastewater to the coast. Concentrations of COP, a marker of municipal wastewater contamination, ranged from 7.61 to 11,684ng/g dry weight in sediments, while concentrations of NPs (nonylphenol, and nonylphenol mono- and di-ethoxylates), a marker of industrial wastewater contamination, ranged from 50.5 to 2,166 ng/g dry weight in sediments. Their detection in all of the sediments indicates widespread pollution by wastewater. Moreover, relatively high levels of COP and NPs in the present study suggest significant pollution by both urban and industrial wastewater input, compared with previous results. The spatial distribution of COP levels was statistically similar to that of NPs, indicating that these compounds may have similar discharge points, transport, mixing, and deposition in the coastal area. Levels of COP and NPs were much higher at stations close to the ports, and rivers that pass through the urban center of Busan City. These results suggest that considerable amount of wastewater compounds are discharged through direct input, combined sewer overflows, and urban runoff to Busan Habor.

분변계 스테롤을 이용한 남해안 패류양식어장(여자만과 강진만)의 퇴적물내 분변오염도 평가

최민규 ( Min Kyu Choi ),이인석 ( In Seok Lee ),황동운 ( Dong Woon Hwang ),김형철 ( Hyung Chul Kim ),김예정 ( Ye Jung Kim ),김숙양 ( Sook Yang Kim ) 한국수산과학회 2013 한국수산과학회지 Vol.46 No.4

Eight fecal sterols were analyzed in surface sediments collected from shellfish farming areas in Yeoja Bay and Gangjin Bay, Korea, to evaluate sewage-derived fecal pollution. The concentrations of coprostanol, a good marker of sewage-derived organic contamination, in sediments were in the range of 10-530 ng/g-dry in Yeoja Bay, and 10-190 ng/g-dry in Gangjin Bay. Coprostanol levels were markedly higher in the inner bay than in the outer bay. These levels were lower than those reported in urbanized bays in Korea, however, they were comparable to levels in other shellfish farming areas including Gamak Bay. A multivariate analysis of the ratios of other sterols suggested that the sterols originated from sewage and plankton/benthos. Sewage was the dominant source at stations located close to the river mouth and wastewater treatment plant (WWTP) outfalls, and plankton/benthos was the primary source in the outer bay. These results suggest that management of point sources, e.g., WWTP as well as non-point sources, e.g., riverine inputs is important for improving the water quality in Yeoja Bay and Gangjin Bay.

유기염소계 살충제의 대기-토양간 분배

최민규(Min-Kyu Choi),천만영(Man-Young Chun) 환경독성보건학회 2007 환경독성보건학회지 Vol.22 No.4

This paper was studied to investigate the equilibrium state between organochlorine pesticides (OCPs) concentration of air and soil, and to know whether soil is a secondary pollution source of OCPs in air or not. The OCPs concentration of air (C<SUB>air</SUB>) and soil (C<SUB>soil</SUB>) is not related to molecular weight, vapor pressure (P<SUB>L.</SUB>) and octanol-air partition coefficient (K<SUB>oa</SUB>). The slope of the regression line between soil-air partition coefficient (K<SUB>sa</SUB>) and scavenging coefficient (C<SUB>soil</SUB>/C<SUB>air</SUB>) was 0.2952, which the OCPs concentration between air and soil did not reached to the equilibrium state. The soil/air fugacity quotients (f<SUB>soil</SUB>/f<SUB>air</SUB>) of p.p'-DDT/DDD/DDE and β-HCH (0.30~0.67), which is smaller than I, means the deposit of OCPs from air to soil. However, f<SUB>soil</SUB>/f<SUB>air</SUB> of heptachlor, heptachlor epoxide, α/γ-chlordane, trans-nonachlor, endosulfan sulfate and α/γ-HCH (1.90~73.25), which is greater than I, means that soil is secondary pollution source of OCPs in air.

압전 작동기로 구동되는 젯팅 디스펜서의 설계 및 제어

최민규(Min-Kyu Choi),구오흥(Quoc Hung Nguyen),윤보영(Bo-Young Yun),최승복(Seung-Bok Choi) 한국소음진동공학회 2006 한국소음진동공학회 학술대회논문집 Vol.2006 No.11

연구보문 : 자연과학; 벼 무논점파 재배시 입모 향상을 위한 물관리 방법

최민규 ( Min Kyu Choi ),구본일 ( Bon Il Ku ),강신구 ( Shin Gu Kang ),상완규 ( Wan Gyu Sang ),백남현 ( Nam Hyun Back ),김영두 ( Young Doo Kim ),박홍규 ( Hong Kyu Park ),최원영 ( Weon Young Choi ),박태선 ( Tae Seon Park ),김보경 ( B 한국국제농업개발학회 2013 韓國國際農業開發學會誌 Vol.25 No.3

Water management and weed control in rice direct seeding on puddled paddy surface is important for seedling establishment and early growth. To develop management method for enhancing seedling stands and weed control, three experiments were conducted with rice variety Hopum (midmaturing) at experimental station of National Institute of Crop Science, in Iksan in 2010-2011. In experiment 1, germinated rice seeds were sowed on 1, 2, 3, and 4 days after puddling to find the optimum drying days of paddy surface. The average numbers of seedling stands in 2 and 3 days drying were 117 and 114 per m2, respectively, and those were higher than in the 1 and 4 days. Plant height and root length were increased as drying up to 3 days, but decreased in the 4th day. In experiment 2, non-irrigation and intermittent irrigation started 2, 4, and 6 days after seeding were evaluated. The average numbers of seedlings in intermittent irrigation from 2 and 4 days after seeding were 117 and 113 per m2, respectively. The seedlings in irrigation after 6 days was 92 per m2, and 84 per m2 in non-irrigation. Shoot lengths were highest in the irrigation treatments of 2 days and 4 days after seeding. In experiment 3, herbicide was treated on 10, 12, 14, and 16 days after seeding. Rice seedling and root length was increased in the later herbicide treatments. Weeds were not occurred until the 12 days, but observed in the later two treatments. According to these findings, drying paddy for 3 days after puddling, intermittent irrigating after 2 days from seeding, and herbicide treatment on 12 days after seeding is recommended for direct seeding on puddled paddy surface.

토양 중 유기염소계 살충제의 농도

최민규 ( Min Kyu Choi ),천만영 ( Man Young Chun ) 한국환경분석학회 2007 환경분석과 독성보건 Vol.10 No.3