• 한국물환경학회지
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• 제35권1호
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• pp.28-34
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• 2019

This study analyzed the occurrence pattern of Dolichospermum (= Anabaena) in the Bukhan river from March 2012 to December 2014 in order to identify the genotypes of Dolichospermum. Furthermore, 16S rRNA were analyzed to identify the genotypes of Dolichospermum that occurred in 2015 which were then compared to the reference sequence deposited at NCBI. During this period, the occurrence of Dolichospermum was highly correlated to water temperature. In the year 2012 and 2013, Dolichospermum appeared in Lake Cheongpyeong (CP), Sambong (SB), and Lake Paldang (P2) between July and August. However, in 2014, it appeared in SB and P2, but not in CP. This reduction in appearance was attributed to the decreased inflow to Lake Uiam as a result of low rainfall in 2014 as compared to 2012. In July 2015, the Dolichospermum 16S rRNA genotype was confirmed in five locations; Lake Cheongpyeong (CP), Seojong (SJ), Songchon Sewage Treatment Plant (SC), Joan (P4), and Lake Paldang (PD). Anabaena crassa of spiral clone, A. planctonica of linear clone, and A. circinalis of spiral clone exhibited high genetic similarity with the reference sequence. The 16r RNA genotype showed approximately 3 % sequence variation between the locations and were more similar to each other in locations that were closer.

• 한국패류학회지
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• 제2권1호
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• pp.10-12
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• 1986

Pettancylus nipponicus (freshwater limpet) collected from the Lake Choon Cheon were cultrued in aquarium and studied in the respects of an egg deposition and the developmental characters of cleavage. The species were collected only in the Lake Uiam and Choon Cheon and easily sampled on the debris like vinyls and cans. Those smooth surfaces were suitalble substrata for attaching. P. nipponicus, about 4 mm in adult, deposited an egg in one calcareous egg-capsule on the aquarium walls, while many eggs are surrounded in a jelly-like egg-envelope in the most gastropods. And another special features was that an egg-capsule was consisted of two valves and the suture was opended as hatching. A diameter of its egg was $55{{\mu}m}$ and the length of an egg capsule was $620{{\mu}m}$ and $510{{\mu}m}$ in long and short diameter, respectively. It took about 8 hours from beginning cleavage to 16-cell stage and about one year to become an adult.

• 한국패류학회지
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• 제2권1호
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• pp.26-29
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• 1986

Corbicula fluminea, one of the 2 species in the family Corbiculidae living in the Lake Uiam, was used as an experimental material and the embryonic development and the structure of glochidia of this species were investigated. This freshwater mussels was oviparous, but some ovoviviparous: incubated their youngs in the inner-demibranchs or outer-demibranchs, however, chiefly used the inner-demibranchs as brood-pouch. The average time required from a fertilized egg to two-cell stage, veliger stage, and glochidium was 76 minutes, 3 hours, and 17 hours, respectively, The mean size of glochidium was $168{\mu}m$ in shell height, $195{\mu}m$ in shell lengh, $114{\mu}m$ in hinge legth and the form of glochidium was D-type and had no hooks or hooklets for attaching to fish like Unioidae.

• 한국패류학회지
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• 제5권1호
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• pp.29-34
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• 1989

의암호에서 채집된 작은애칭이(Anodonta aracaeformis)와 펄조개(Anodonta woodiana despecta)의 유생을 줄납자루(Acheilognathus yamatautae), 돌고기(Pungtungia heizi), 붕어(Carassius auratus)를 숙주로 하여 인위 감염 시킨 결과는 다음과 같다. 1. 펄조개 glochidium 의 부착기간은 줄납자루, 돌고기에 각각 10일과 9일이었고 작은대칭이glochidium은 붕어에 21일간 부착하였다.2. 펄조개, 작은 대칭이 glochidium은 숙주의 가슴지느러미와 아가미에 높은 부착률을 나타내었다.3. 펄조개glochidium의 부착전과 후의 크기 변화는 없었으나 작은 대칭이 glochidium의 경우는 각고, 각장, 인대길이의 부착전 평균 크기가 0.345mm, 10365mm, 0.271mm에서 21일 이후 이탈 직전의 평균 크기는 0.373mm, 0,386mm, 0.290mm로 외형적인 크기 증가를 나타내었다.4. 펄조개 glochidium감염에 대한 숙주의 민감성은 줄납자루가 돌고기보다 높게 나타났다.5. 펄조개 glochidium은 부착후 2일, 작은대칭이는 8일째부터 기관 형성을 관찰할 수 있었다.

• 한국물환경학회지
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• 제33권6호
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• pp.670-679
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• 2017

An experiment to study the effect of temperature, light, and dredging on release of nutrients downstream from Gongjicheon in the Uiam reservoir was carried out in the laboratory using sediments from different depths. At various water temperatures, dissolved total nitrogen was not released, but the average nutrient flux of dissolved total phosphorus was increased (0.034 at $15^{\circ}C$, 0.005 at $20^{\circ}C$, 0.154 at $25^{\circ}C$, $0.592mg/m^2/d$ at $30^{\circ}C$). Dissolved total phosphorous was released in controlled darkness. In contrast, in controlled light, the concentrations of dissolved total phosphorous and dissolved total nitrogen in the overlying water steadily decreased during the study period (70 d), because they were continuously consumed by the growth of photosynthetic algae. However, there was no significant relationship between water nutrient concentration, nutrient release, and the depth of the sediment. We concluded that the dredging of sediment would not affect the nutrient release rate of the sediment, because there were no significant differences in the nutrient concentrations released from the sediment. When the sediment was removed from the surface to 20 cm in depth, the nutrients were not transferred to the water body, implying that the sediment removal had little effect on secondary pollution.

• 한국물환경학회지
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• 제23권1호
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• pp.72-80
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• 2007

The seasonal variation of organic matter and the oxidation efficiency of BOD and COD were investigated in several reservoirs and rivers located in the Han River system from March 2005 to April 2006. The concentrations of TOC in the Dong River, the Myeongjicheon stream and the Han-River varied with season. Mean concentration of TOC in the lotic environment ranged from 1.9 to 6.8 mgC/L. Oxidation efficiencies calculated from carbon were approximately 12.6 to 27.1% for BOD and 27.2 to 75.0% for COD, respectively. DOC to TOC ratio in the rivers ranged from 64.3 to 79.0%. Epilimnetic TOC concentrations in two clear and deep lakes (Lake Soyang and Paro) ranged from 2.0 to 2.8 mgC/L. TOC concentrations in the lower three dams (Lake Chunchon, Uiam, and Chungpyung) were relatively high that ranged from 3.4 to 3.7 mgC/L.Oxidation efficiencies in five lakes ranged from 10.6 to 17.2% for BOD and 32.6 to 49.5% for COD, respectively. The range of DOC to TOC in Lake Soyang and Paro was approximately 69. 0 to 73.4%. The ratios of lower three dams ranged from 48.2 to 62.3%. The differences among the lakes seemed to be asociated with limnological and hydrological characteristics of the lakes.

• 한국패류학회지
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• 제31권3호
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• pp.171-178
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• 2015

의암호에 서식하고 있는 말조개의 성장과 산란생태를 파악하기 위하여, 2014년 3월부터 2015년 2월까지 상대성장식, 생식소 발달단계에 따른 생식주기와 군성숙도의 월별변화를 조사하였다. 각장에 대한 각고, 각폭, 전중, 육중간의 상대성장식에서 상관계수 ($R^2$) 는 0.814-0.944로 높은 상관관계를 나타내었다. 말조개의 생식소는 소화맹낭의 주변부와 족부로 연결되는 망상결체조직에 분포하며 자웅이체로, 성숙한 난과 정자는 수관을 통해 아가미 반새에서 수정되어 수정란을 아가미의 보육낭에서 부화시켜 체외로 방출하는 난태생종이었다. 서식 지역의 월별 평균수온은 $3.9-25.9^{\circ}C$ 범위였다. 월별 비만도는 0.16-0.22 범위로 하계인 8월-9월에 낮은 값을 보이다가 10월부터 증가하여 11월과 1월에 0.22로 정점을 보였다. 월별 육중량비는 21.3-31.4%로 비만도의 월별 변화와 같은 경향을 나타내었다. 생식소지수는 0.00-4.00 범위를 나타내었고, 4월-7월까지 정점을 보인 후 8월부터 급격히 감소하였다. 생식년주기는 분열증식기 (11-1월), 성장기 (2-3월), 성숙기 (2-5월), 산란기 (4-9월), 회복기 (8-12월)로 구분되어 하계산란종이었다. 의암호산 말조개의 산란기는 4-9월 (주산란기 4-7월) 이였으며, 군성숙 각장은 29.4 mm였다.

• Ecology and Resilient Infrastructure
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• 제3권2호
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• pp.143-151
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• 2016

호안 보강 (armoring)은 하천, 호수 및 저수지의 호안 침식을 방지하기 위하여 일반적으로 사용하는 공학적 기법이다. 호안 보강은 육역-수역 경계부를 변경하고, 호안 근처의 지형, 수문, 퇴적물 조성 및 수질을 변화시켜서 호안 식생에 영향을 미친다. 본 연구에서는 대형 저수지인 의암호의 육역-수역 경계부에서 인위 교란이 호안 식생의 군집 구조와 분포에 미치는 영향을 파악하고자 하였다. 의암호의 호안선은 60% 이상이 콘크리트 옹벽, 사석, 돌망태로 보강되어 있었다. 탈경향대응 분석 (DCA)의 결과에 의하면 보강에 의하여 바뀌어진 호안의 식생 구조가 수생식물 우점 생태계에서 습생식물 우점 생태계로 변화하였다. 호안 보강은 육역-수역 경계부에서 점진적 연속성을 파괴하였고 외래식물의 생물침입을 초래하였다. 2010부터 2013년까지 호안 식생의 분포 면적은 수생식물은 감소하였고 습생식물은 증가하였다. 결론적으로 의암호에서 보강, 도로 건설, 휴양 등과 같은 인간 교란은 호안 식생에서 육역화, 횡단 연속성의 상실, 생물침입을 초래하였다. 그러므로 호안 생태계의 특이성을 보전하기 위하여 호안 수생식물 식생대을 확대할 수 있도록 호안 보강 구조물을 철거하거나 재조성하여야 할 것으로 생각된다.

• 생태와환경
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• 제46권1호
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• pp.135-144
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• 2013

본 연구는 청정수역으로 알려져 있던 북한강 수계에서 저수온기에 우점한 남조류 Anabaena spiroides 현존량과 이취미 물질인 지오스민 (geosmin)에 대해 조사하고 환경인자와의 통계적 분석을 통하여 A. spiroides의 증식 특성을 알아보고자 하였다. 2011년 11월 말에 A. spiroides가 과다증식하였는데 출현지역은 의암호 내의 공지천 유입부 부터 하류의 팔당호까지 그 범위가 넓고 하류로 확산되는 특성을 보였다. 저수온기에 수온 상승과 체류시간 증가 등의 물리학적 수환경 변화가 남조류 A. spiroides의 과다증식에 영향을 미쳤다. A. spiroides 현존량은 팔당호에서 $11,325cells\;mL^{-1}$로 최대증식을 보였으며, 수온이 $4^{\circ}C$ 이하로 내려가면서 A. spiroides 현존량이 급격히 감소하였다. 수환경 요인 중에서 수온 하강이 A. spiroides 현존량 감소에 가장 큰 영향을 준 인자였다. 남조류의 대사물질로 이취미의 원인물질인 Geosmin은 팔당호에서 최대 $1,640ng\;L^{-1}$ 농도를 나타냈다. 북한강 수계에서 Geosmin 농도는 A. spiroides와 매우 유의한 상관관계를 보여 A. spiroides에 의해 이취미가 유발되었음을 시사하였다.

• 한국물환경학회지
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• 제25권6호
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• pp.840-848
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• 2009

Spatial and temporal distributions of POC and DOC were surveyed in the North Han River system, Korea The proportion of algal cells was calculated in four reservoirs (Lakes Soyang, Paro, Chunchon, and Uiam). Monthly average DOC concentrations ranged from 1.5 to 2.3 mg C/L, and POC showed larger variation than DOC (range 0.3 to 1.9 mg C/L). The average proportion of POC in TOC was higher than those of typical natural lakes. Due to the influence of the Asian summer monsoon, the seasonal variation in POC concentration depended on heavy rain events occurring during the summer. POC concentrations increased during the summer monsoon season due to turbid storm runoff laden with debris, while DOC concentrations did not increase. The highest POC concentrations were observed in Lake Soyang in 2006 when a severe rain event occurred. In two deep stratified reservoirs (Lake Soyang and Paro) storm runoffs formed an intermediate turbidity layer with high POC and chlorophyll concentrations which is thought to originate from terrestrial debris and periphyton transported by inflowing streams. The proportion of algal cells in total POC was much lower than for most natural lakes, and it varied with season; low in the monsoon season and high in dry seasons with algal blooms. An analysis of POC concentration and chlorophyll a concentration showed that the ratio of POC/Chl.a varied from 24 to 80.