• Korean Journal of Ichthyology
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• v.31 no.2
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• pp.67-76
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• 2019

This study was conducted from 2017 to 2018 to determine habitat aspects of Acheilognathus signifier, an endangered species reintroduced (2010~2012) to Heukcheon Stream, a tributary of the Hangang River, Korea. A total of 329 individuals were collected in 2017 (two surveys) and 723 individuals were collected in 2018 (four surveys) at about 5 km habitat area, including the discharge station. A. signifier's habitat was about 0.4 to 1.2 meters deep in slow water flow upstream of the discharge area. It was a place with many boulders and cobbles. The spawning period was estimated from April to June in terms of spawning behavior and collected juvenile size. Sex ratio of females (438) and males (412) was 1 : 0.94. Estimated age of A. signifier based on their total length distribution during the spawning period (April) indicated that 1-, 2-, 3-year old groups and more than 4-year-old group were 32~43 mm, 50~61 mm, 62~75 mm, and 76~89 mm, respectively. Age-specific composition costs differed depending on the timing of the collection. They were relatively high in the order of first-year (juvenile)>third-year> and fourth-year or higher, showing a stable age structure. Thus, A. signifier reintroduced to Heukcheon Stream has successfully settled down and formed a stable population, showing a tendency to proliferate.

• Korean Journal of Ichthyology
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• v.32 no.2
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• pp.63-69
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• 2020

This study investigated spawning characteristics of Hangang bitterling, Rhodeus pseudosericeus inside the host mussel, Unio douglasiae sinuolatus at the Heukcheon Stream in Korea from April to June 2017. 327 mussels were collected, among them, 34 (14.1%) were spawned mussels of R. pseudosericeus with glochidia. The mean number of R. pseudosericeus embryos with or without glochidia by the mussel gill position was 5.0±3.58 (range, 1~8) vs. 2.8±2.13 (1~9) in the left outer demibranch, 1.5±0.96 (1~3) vs. 1.7±0.82 (1~3) in the left inner demibranch, 1.4±0.51 (1~2) vs. 2.1±1.85 (1~6) in the right inner demibranch, and 6.4±4.82 (1~20) vs. 3.0±1.86 (1~6) in the right outer demibranch. The frequency of R. pseudosericeus embryos with or without glochidia by the mussel gill position was 82.6% vs. 73.4% in the left outer demibranch, 17.4% vs. 9.4% in the left inner demibranch, 26.1% vs. 15.6% in the right inner demibranch, and 58.7% vs. 67.2% in the right outer demibranch. The mean number of R. pseudosericeus embryos with or without glochidia was 8.5±6.43 (1~23) vs. 4.5±3.38 (1~14). The number and frequency of R. pseudosericeus embryos were higher in the mussel with glochidia and the outer demibranchs than those without glochidia and with inner demibranchs.

• Microbiology and Biotechnology Letters
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• v.31 no.2
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• pp.177-181
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• 2003

Eleven bacterial strains which are able to utilize terephthalic acid as a carbon and an energy source for growth were isolated from the soil of 7 water quality evaluation points in Kyonggi area of Korea. Phthalic acid isomer degrading activity of the isolates from the 4 contaminated points was higher than those from the 3 clean points. Among 11 isolates, 4 isolates which have high terephthalic acid degrading activity and degrade two phthalic acid isomers were identified by partal 16S rDNA sequence determination. One of them was identified as Pseudomonas putida, and the others as Comamonas testosteroni. Thus a large number of phthalic acid isomer degrading bacteria in domestic soil were inferred as C. testosteroni. On the basis of these results, the PCR detection of C. testosteroni in soil was applied to monitor soil contamination by phthalic acid isomers. The DNA of C. test-osteroni extracted from 4 g soil was directly detected by PCR with C. testosteroni specific primer pair. The amount of PCR products was different according to sampling sites and more PCR products were obtained from contaminated sites than those from clean sites (Gulpo-chun＞Anyang-chun＞Hwangguji-chun>Shin-chun＞Huk-chun＞Pukhan-river>Kapyeong-chun). This result was coincided with that of the viable cell counts for terephthalic acid degrading bacteria.

• Korean Journal of Ichthyology
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• v.30 no.2
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• pp.100-106
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• 2018

The distribution aspect and extinction threat evaluation of the endangered species, Rhodeus pseudosericeus were investigated from 2012 to 2017 in Korea for the subject of this study. The number of appearance sites in the past literature of available and identified R. pseudosericeus was 26. During the study period, the samples of R. pseudosericeus were collected in 44 sites (Hangang River 35 sites, Sapgyocheon Stream 4 sites, Daecheoncheon Stream 5 sites) among the noted 214 sampling stations investigated. Among these, the newly appearance streams were Ilricheon Stream, Samsancheon Stream, Bangyecheon Stream and Hanpocheon Stream in the Hangang River. In addition, the habitats and populations in the upper Seomgang River (Hoengseong Dam), lower Heukcheon Stream, Muhancheon Stream and Daecheoncheon Stream decreased due to dam construction, river work, water pollution, and the spread of the exotic species Micropterus salmoides. The main habitat of R. pseudosericeus was the middle-upper stream of clean water with slow water velocity, sand-pebble bottoms and lots of aquatic plants. Given this evidence as noted for the 30.2% reduction in occupancy within 10 years, due to the qualitative decline of habitat, the overfishing risk of ornamental fish and the spread of M. salmoides, in this case R. pseudosericeus is considered to be Vulnerable (VU A2cde) based on the IUCN Red List categories and criteria.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.438-438
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• 2021

우리나라의 수질오염총량관리제도는 수계 내 모든 유역을 관리대상으로 동일 기준유량 조건에 동일한 대상물질로 관리하고 있지만, 본류는 지류의 영향을 받고 있으며 지류는 사람이 거주하는 지역 인근에 있어 본류 수질에 직접적인 영향을 미치고 있다. 이는 지류의 시급한 개선이 필요한 오염물질의 실질적인 관리가 어려워 이를 개선하기 위해 오염도가 높은 지류의 총량관리를 위한 지류총량제도의 추가 도입이 필요한 실정이다. 본 연구에서는 지류총량제 시행에 따른 효과를 예측하기 위해 팔당수계 유역을 소유역 단위로 분할하고 HSPF 모형을 적용하여 팔당수계 소유역 지류에서의 수질 변화 양상이 본류에 미치는 영향을 분석하였다. 연구대상지역은 팔당수계 중권역 유역(남한강 하류 유역, 경안천 유역, 북한강 하류 유역)으로 구분하고 유역 유출 및 수질 모델링은 지류하천을 포함하는 57개 소유역을 대상으로 수행하였다. 입력자료는 공간자료(표고, 경사, 토지이용, 토양도 등)와 기상자료(춘천, 양평, 이천, 수원관측소)는 2008년~2018년의 강수량, 최고기온, 최저기온, 평균풍속, 평균습도 등의 시단위 자료를 사용하였다. 모의결과, BOD는 남한강 하류유역의 주요 지천 유역인 복하천, 양화천, 청미천 및 흑천 유역에서 0.54~0.56mg/L의 범위로 주변 유역보다 높게 나타났으며, 경안천 유역은 경안천 유역의 중·하류 유역에서 2.63~4.22mg/L의 범위로 높게 나타났고, 북한강 유역은 조종천 하류 및 북한강 상류 유역에서 1.36~3.31mg/L의 범위로 주변 유역보다 높게 나타났다. T-P는 남한강 하류 유역은 주요 지천 유역인 복하천, 양화천, 청미천 유역에서 0.07~0.19mg/L의 범위로 주변 유역보다 높게 나타났고, 남한강 하류 유역의 중간 지점 유역인 한강(E1, E2, E4, E6)에서 높게 나타났다. 경안천 유역은 중·하류 유역의 좌안측 유역인 경안(A4, A3, B2, B1, F9)에서 0.1~0.14mg/L의 범위로 높게 나타났으며, 북한강 유역은 전체 유역에서 0.06mg/L 이하로 남한강 하류 및 경안천 유역보다 전반적으로 낮게 나타났다. 이와 같이 지류총량관리에 HSPF 모형의 적용은 가능하였으나 HSPF 모형을 이용한 소유역 단위의 유량 및 수질 예측을 위해서는 기존의 유량 및 수질 관측망을 소유역 단위로 좀 더 정밀하게 계획하는 것이 필요하다고 판단된다.