• Title/Summary/Keyword: Limnology

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Accumulation and Inhibitory Effects of Microcystin on the Growth of Rice and Broccoli

  • Maejima, Kazuhiko;Muraoka, Terukazu;Park, Ho-Dong
    • Korean Journal of Ecology and Environment
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    • v.47 no.spc
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    • pp.19-30
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    • 2014
  • Microcystins (MCs) produced by cyanobacteria are severe hepatotoxins for mammalian and protein phosphatase inhibitors. Irrigation water for grain and vegetables is often contaminated with cyanobacteria and microcystin during warm seasons. We assessed the effects of various concentrations (0, 0.01 to $10{\mu}gmL^{-1}$) of microcystin-LR (MC-LR) and microcystin-RR (MC-RR) exposure on Oryza sativa (rice) and Brassica oleraces var. italica (broccoli). The $EC_{50}$ of leaves and roots of rice was 0.9 and $1.1{\mu}gMC-LRmL^{-1}$, respectively. The no observed effect level (NOEL) of rice was less than $0.1{\mu}gmL^{-1}$ ($100{\mu}gL^{-1}$). The $EC_{50}$ of the stems and roots of broccoli was 8.7 and $7.2{\mu}gMC-RRmL^{-1}$, respectively. There was no difference in the germination rate of broccoli among microcystin-RR concentrations. After exposure to 0, 0.01 to $10{\mu}gmL^{-1}$ MC-RR for seven days, 14, 89 and 154 ng mg-1 (dry weight) MC-RR accumulated in B. oleracea. These $EC_{50}$ values showed that microcystin-LR and -RR affected the growth of rice and broccoli. These findings suggest that MC is carried into terrestrial ecosystems via irrigation, and that the biota of higher ecological niches can be influenced by MC through bioaccumulation. Therefore, a guideline for MC concentrations in irrigation water should be set using the NOEL.

Isolation of Bacteria Associated with Fresh Sponges in Lake Baikal (바이칼 호수에 서식하는 담수 스폰지 내 공생세균의 분리)

  • Cho, Ahn-Na;Kim, Ju-Young;Ahn, Tae-Seok
    • Korean Journal of Ecology and Environment
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    • v.47 no.spc
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    • pp.39-47
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    • 2014
  • Sponge in Lake Baikal is an unique organism. Microorganisms in sponges are assumed as precious resources for bioactive materials. For understanding the bacterial community in Baikalian sponges by cultivation, 92 strains of bacteria were isolated from lake water and 2 species of sponges, Baikalospongia sp. and Lubomirskia sp., Thirty five bacterial strains are isolated from ambient water near the sponge, 27 bacterial strains from Baikalospongia sp., 30 bacterial strains from Lubomirskia sp.. As a result, 78.3% and 57.6% of isolated bacterial strains has amylase and protease activity respectively, while strains with cellulose and lipase activities were 38.0% and 34.8%. By 16S rRNA sequence analysis of selected strains, 13 strains which were isolated from Baikalospongia sp. were belong to Pseudomonas spp.. Whereas, 14 strains which were isolated from Lubomirskia sp. were Pseudomonas spp., Buttiauxella agrestis, Pseudomonas fluorescens, Yersinia ruckeri, Bacillus spp., Paenibacillus spp., Bacillus thuringiensis, Bacillus simplex, Brevibacterium spp., Acinetobacter lwoffii. In culture media, Pseudomonas spp. dominance was supposed that according to allelophathy.

Echolocation Call Differences among Local Populations of Greater Horseshoe Bats (Rhinolophus ferrumequinum) (관박쥐 (Rhinolophus ferrumequinum)의 지역개체군 간 반향정위 (Echolocation)의 차이)

  • Jang, Dooly;Kim, Sun-Sook;Yoo, Jeong-Chil
    • Korean Journal of Ecology and Environment
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    • v.49 no.4
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    • pp.385-392
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    • 2016
  • Geographical isolation may lead to the populations having different ecological characteristics. Geographic isolation have been known to cause echolocation call differences in bats. In order to look at geographic differences of echolocation calls of Great Horseshoe Bats (Rhinolophus ferrumequinum), populations of inland and Jeju island habitats were examined in Korea. The study areas were some abandoned mines in the inland and caves of Jeju island, which were known as rest sites of Great Horseshoe Bats during the active season. Recording was done in two ways: Hand-held, Free-flying. Recording pulse was analyzed into five parameters: Maximum Frequency (FMAX), Minimum Frequency (FMIN), Peak Frequency (PF), Duration (D), Inter pulse Interval (IPI). Interestingly, The present study shows that the difference in echolocation between the inland and island populations. The PF of bats inhabited inland was 69 kHz. but, the PF of bats inhabited island (Jeju) was 71 kHz. There was a difference between regions. Discriminant analyses also showed clear difference between the inland and the island populations. Especially, PF of Korea population is lower than that of Europe (82 kHz) and higher than that of Japan (65 kHz).

Distribution of Toxic and Non-toxic Microcystis in Korean Water Supply (국내 주요 상수원지에서 독성 및 비독성 Microcystis의 분포 특성)

  • Lee, Kyung-Lak;Shin, Yuna;Lee, Jaean;Lee, Jae-Kwan;Kim, Han Soon
    • Korean Journal of Ecology and Environment
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    • v.49 no.4
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    • pp.393-399
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    • 2016
  • This study was conducted to investigate whether the presence of mcy gene and microcystin production are related to morphological characteristics of Korean Microcystis species. We isolated 6 different species of Microcystis (M. aeruginosa, M. ichthyoblabe, M. flos-aquae, M. novacekii, M. viridis and M. wesenbergii) from drinking water supply dams (Yeongchun, Ankei, Gachang), and used microscopic method for morphological identification, molecular method for amplifying a partial region of mcyB gene and ELISA method for microcystin analysis. In the present study, 80% of M. aeruginosa strains contained mcy gene, followed by 45% (10 strains) of M. icthyoblabe, 33% (1 strain) of M. wesenbergii, and 11% (4 strains) of M. flos-aquae. Each percentage of mcy gene in Microcystis morphospecies was similar to that of microcystin production in Microcystis morophospecies. In conclusion, the present study shows that molecular method using mcy gene primers can be used as an indirect indicator for the monitoring of toxic cyanobacteria (Microcystis).

Preliminary Application of Molecular Monitoring of the Pacific Herring (Clupea pallasii) Based on Real-time PCR Assay Utilization on Environmental Water Samples

  • Kim, Keun-Yong;Heo, Jung Soo;Moon, Seong Yong;Kim, Keun-Sik;Choi, Jung-Hwa;Yoo, Joon-Taek
    • Korean Journal of Ecology and Environment
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    • v.54 no.3
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    • pp.209-220
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    • 2021
  • Pacific herring, Clupea pallasii, a keystone species with significant ecological and commercial importance, is declining globally throughout much of its range. While traditional fishing equipment methods remain limited, new sensitive and rapid detection methods should be developed to monitor fisheries resources. To monitor the presence and quantity of C. pallasii from environmental DNA (eDNA) extracted from seawater samples, a pair of primers and a TaqMan® probe specific to this fish based on mitochondrial cytochrome b (COB) sequences were designed for the real-time PCR (qPCR) assay. The combination of our molecular markers showed high specificity in the qPCR assay, which affirmed the success of presenting a positive signal only in the C. pallasii specimens. The markers also showed a high sensitivity for detecting C. pallasii genomic DNA in the range of 1 pg~100 ng rxn-1 and its DNA plasmid containing COB amplicon in the range of 1~100,000copies rxn-1, which produced linear standard calibration curves (r2=0.99). We performed a qPCR assay for environmental water samples obtained from 29 sampling stations in the southeastern coastal regions of South Korea using molecular markers. The assay successfully detected the C. pallasii eDNA from 14 stations (48.2%), with the highest mean concentration in Jinhae Bay with a value of 76.09±18.39 pg L-1 (246.20±58.58 copies L-1). Our preliminary application of molecular monitoring of C. pallasii will provide essential information for efficient ecological control and management of this valuable fisheries resource.

Development and Assessment of Specific and High Sensitivity Reverse Transcription Nested Polymerase Chain Reaction Method for the Detection of Aichivirus A Monitoring in Groundwater (지하수 중 Aichivirus A 모니터링을 위한 특이적 및 고감도 이중 역전사 중합효소연쇄반응 검출법 개발 및 평가)

  • Bae, Kyung Seon;Kim, Jin-Ho;Lee, Siwon;Lee, Jin-Young;You, Kyung-A
    • Korean Journal of Ecology and Environment
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    • v.54 no.3
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    • pp.190-198
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    • 2021
  • Human Aichivirus (Aichivirus A; AiV-A) is a positive-sense single-strand RNA non-enveloped virus that has been detected worldwide in various water environments including sewage, river, surface, and ground over the past decade. To develop a method with excellent sensitivity and specificity for AiV-A diagnosis from water environments such as groundwater, a combination capable of reverse transcription (RT)-nested polymerase chain reaction (PCR) was developed based on existing reported and newly designed primers. A selective method was applied to evaluate domestic drinking groundwater samples. Thus, a procedure was devised to select and subsequently identify RT-nested PCR primer sets that can successfully detect and identify AiV-A from groundwater samples. The findings will contribute to developing a better monitoring system to detect AiV-A contamination in water environments such as groundwater.

Effects of Sources and Quality of LED Light on Response of Lycium chinense of Photosynthetic Rate, Transpiration Rate, and Water Use Efficiency in the Smart Farm

  • Lee, Seungyeon;Hong, Yongsik;Lee, Eungpill;Han, Youngsub;Kim, Euijoo;Park, Jaehoon;Lee, Sooin;Jung, Youngho;You, Younghan
    • Korean Journal of Ecology and Environment
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    • v.52 no.2
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    • pp.171-177
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    • 2019
  • Smart farm is a breakthrough technology that can maximize crop productivity and economy through efficient utilization of space regardless of external environmental factors. This study was conducted to investigate the optimal growth and physiological conditions of Chinese matrimony vine (Lycium chinense) with LED light sources in a smart farm. The light source was composed of red+blue and red+blue+white mixed light using a LED system. In the red+blue mixed light, red and blue colored LEDs were mixed at ratios of 1:1, 2:1, 5:1, and 10:1, with duty ratios varied to 100%, 99%, and 97%. The experimental results showed that the photosynthetic rate according to the types of light sources did not show statistically significant differences. Meanwhile, the photosynthetic rate according to the mixed ratio of the red and the blue light was highest with the red light and blue LED ratio of 1:1 while the water use efficiency was highest with the red and blue LED ratio of 2:1. The photosynthetic rate according to duty ratio was highest with the duty ratio of 99% under the mixed light condition of red+blue+white whereas the water use efficiency was highest with the duty ratio of 97% under the mixed light of red+blue LED. The results indicate that the light source and light quality for the optimal growth of Lycium chinense in the smart farm using the LED system are the mixed light of red+blue (1:1) and the duty ratio of 97%.

Effect of Habitat Diversity through Comparison of Spider Diversity between Upland and Paddy Fields in Agroecosystems of South Korea (농업생태계인 밭과 논에서 거미의 다양성 비교를 통한 서식지 중요성 연구)

  • Nam, Hyung-Kyu;Song, Young-Ju;Eo, Jinu;Kim, Myung-Hyun
    • Korean Journal of Ecology and Environment
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    • v.52 no.2
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    • pp.151-160
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    • 2019
  • The study of spiders that function as predators in agroecosystem can broaden the understanding of agroecosystems. This study investigated the effect of heterogeneity at different spatial scales on richness and abundance of spiders in upland and paddy fields. We collected 48 samples using pitfall traps at upland and paddy fields, respectively. The total species richness of spiders estimated by sample- and coverage-based rarefaction and extrapolation curves. The total species richness was high in the upland fields at the total study sites, whereas the average species richness per study site was high in the paddy fields. We confirmed that the diversity enhancement of spiders was influenced by the structural complexity of habitat at field-scale, and crop diversity at broader scale.

First Report on the Natural Movement of Introduced Turtle, Trachemys scripta elegans (국내로 유입된 외래생물 붉은귀거북(Trachemys scripta elegans)의 자연적인 이동 첫 보고)

  • Koo, Kyo Soung;Baek, Hae-Jun;Kim, Su Hwan;Jang, Hoan-Jin;Kim, Dae-In;Sung, Ha-Cheol
    • Korean Journal of Ecology and Environment
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    • v.52 no.1
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    • pp.9-12
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    • 2019
  • The red-eared slider (Trachemys scripta elegans) is the one of the most popular pets, and the most commonly traded species in the world. It is designated as an ecosystem disturbance species that has been managed in South Korea. To date, no reports of natural or anthropogenic migration and spreading of T. s. elegans in South Korea are available. In the present study, we estimated the expected route and the movable path of one female T. s. elegans found in Namsan-myun, Gyeongsan-si, Gyeongsangbuk-do. Based on the movable path, the potential destination of the female turtle was estimated to be about 282 m and 468 m away. Therefore, the moving distance of the red-eared slider to the nearest water system will be at least 606 m and at most 792 m. Our results provide the first evidence about the natural migration and spreading of exotic turtles. This study can serve as a basis for the management and countermeasures against the introduced of T. s. elegans and other exotic species in South Korea.

Quantitative Zooplankton Collection Methods for Various Freshwater Ecosystems and Their Applications (담수생태계 특성을 고려한 동물플랑크톤 정량 조사법의 비교와 활용)

  • Oh, Hye-Ji;Chang, Kwang-Hyeon;Jeong, Hyun-Gi;Go, Soon-Mi;La, Geung-Hwan;Kim, Hyun-Woo
    • Korean Journal of Ecology and Environment
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    • v.52 no.3
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    • pp.231-244
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    • 2019
  • Zooplankton is essential biological assemblage in understanding the structure and function of aquatic ecosystems, since it plays as a linkage between primary producers and higher trophic level organisms such as fish. Although zooplankton has planktonic characteristics, the sampling and treatment methods for its community analyses are more complicated and variable compared with phytoplankton due to its high diversity in body size and species-specific depth selection behaviors. In the present paper, we reviewed representative classical methods for field sampling and treatments of freshwater zooplankton in relation with quantification of its community structure, and suggested appropriate methods depending on various research objectives.