• 환경생물
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• 제38권1호
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• pp.1-15
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• 2020

본 연구는 침입종 사향쥐의 국내 자연생태계 정착 여부를 확인하였다. 아울러 관리전략 수립과 현장 관리에 필수적인 관리대상지역과 기초적인 행동특성 정보, 서식지 이용에 관한 자료를 제공하고자 하였다. 이를 위해 해외의 사향쥐 관리 동향을 파악하여 정착 단계에 따른 관리 방향을 검토하였다. 그리고 국내 72개 사육농가의 위치정보를 확보하였고, 실태조사를 통해 경기도, 충청남도, 경상북도, 세종특별자치시 소재 5개 지역을 자연 유출 가능성이 높은 지역으로 제시하였다. 또한, 2016년부터 2018년까지 3년간 동일 지점에 서식하는 개체를 모니터링하였다. 2018년 모니터링 지역에서 포획한 개체의 연령이 1.2년생으로 확인되었으며, 2012년 이후 해당지역에 추가적인 개체 보충이 없었다는 사실에 근거하여 국내 자연생태계에 사향쥐가 정착한 것으로 판단하였다. 국내 자연에 정착한 사향쥐는 0.0027 ㎢ (MCP 95%)의 작은 행동권을 나타내었으며, 봄철과 가을철 규칙적인 이동성을 보이는 것으로 나타났다. 사향쥐의 서식이 관찰된 지역은 서식환경의 교란이 높게 발생한 지역이었으며, 사향쥐의 흔적 출현 빈도는 부엽식물과 부유식물의 생육이 왕성한 개방수역과 개체의 은신처로 활용 가능한 습생목본 식생유형에서 높게 확인되어 이들의 생태적 특성과 섭식 습성이 그대로 반영되었다. 국제적인 침입종 사향쥐가 국내 생태계에 정착하였고, 향후 확산이 우려되는 만큼 정부 차원의 선제적 대응과 과학적 관리를 위한 필수 자료 구축이 검토될 필요가 있다.

• 한국농림기상학회지
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• 제16권3호
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• pp.233-245
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• 2014

복잡지형에서의 에디 공분산 방법을 이용한 플럭스 관측에 있어서 가장 중요하면서도 어려운 문제 중에 하나가 야간 이산화탄소($CO_2$) 플럭스 자료 보정이다. 본 연구에서는 복잡산림지형에 위치한 두 KoFlux 관측지(광릉의 활엽수림과 침엽수림 관측지, GDK와 GCK)의 2009년도 플럭스 타워 자료에 대표적인 야간 자료 보정 방법인 마찰속도 보정 방법, 광 반응 곡선 보정 방법, 이류를 고려한 반 고셀 보정 방법을 적용한 결과를 평가하였다. 계산된 $CO_2$ 플럭스(생태계호흡, 총일차생산, 순생태계교환)는 방법에 따라 그 크기와 계절변동에 차이를 보였는데, 그 차이는 관측지 별로 다르게 나타났다. 각 방법에서 나온 결과들을 선행연구에서 보고된 결과들과의 비교와 함께, 기상학적인 접근뿐만 아니라 생태학적인 접근을 통해 검증하였다. 검증 결과, 이러한 차이의 원인은 야간 자료 보정 과정에서 선별된 자료의 일부가 이미 배수류에 의한 $CO_2$ 이류의 영향을 받았기 때문인 것으로 추측된다. GDK의 광 반응 곡선 방법의 결과를 제외한 나머지 $CO_2$ 플럭스 결과들은 아시아의 다양한 생태계에서 보고된 값들의 범위에 포함되었다. 본 연구는 현재 배포된 플럭스 자료들은 개선의 여지가 있으며, 최신 자료의 올바른 사용을 위한 자료 사용자와 자료 생산자 간의 소통의 중요성을 상기시켜 준다.

• Journal of Ecology and Environment
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• 제38권4호
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• pp.529-536
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• 2015

This study was performed to provide important basic data for the preservation and management of Scopura laminata, a species endemic to Korea, by elucidating the spatial characteristics of its present, potential, and future distribution areas. Currently, this species is found in the Odaesan National Park area of South Korea and has been known to be restricted in its habitat due to its poor mobility, as even fully grown insects do not have wings. Utilizing the MaxEnt model, 20 collection points around Odaesan National Park were assessed to analyze and predict spatial distribution characteristics. The precision of the MaxEnt model was excellent, with an AUC value of 0.833. Variables affecting the potential distribution area of S. laminata by more than 10% included the range of annual temperature, seasonality of precipitation, and precipitation of the driest quarter, in order of greatest to least impact. Compared to the current potential distribution area, no significant difference in the overall habitable area was predicted for the 2050s or 2070s. It was, however, demonstrated that the potential habitable area would be reduced in the 2050s by up to 270.3 km from the current area of 403.9 km; further, no potential habitable area was anticipated by the 2070s according to our predictive model. Taken together, it is anticipated that this endemic species could be significantly affected by climate changes, and hence effective countermeasures are strongly warranted for the preservation of habitats and species management.

• Ocean and Polar Research
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• 제35권3호
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• pp.205-217
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• 2013

We investigated the population dynamics of Aurelia aurita in Sihwa Lake from April to October in 2009. Salinity ranged from 5.9 to 30.7 psu at the surface. Abundance of mesozooplankton ranged from 3 to 111,874 indiv. $m^{-3}$. Ephyrae occurred from April to May with the peak in abundance occurring on 17 April. Maximum density of ephyrae was observed near the power transmission towers that are known to be habitats of polyps. Mortality of ephyrae was lower than in other areas because of the abundant prey concentration and the absence of predators. Young medusae occurred from April to July with the peak in abundance occurring on 8 May. Adult medusae occurred from May to July with the peak in abundance on 25 June and they disappeared before the rainy season. Planula occurred only in May and June with the peak in abundance on 25 June. Growth rates of Aurelia aurita ranged from -0.06 to 0.34 $d^{-1}$, and decreased rapidly after May. The period in which adult medusa occurred was restricted, compared with those in other area in Korea (e.g., Masan Bay) and Japan (e.g., Tokyo Bay). In the period of this study, the available food was limited in June and salinity decreased to ca. 20 psu in May because of the beginning of the wet season. We assumed that the exceptionally short period of occurrence of the medusa may be a response of adults to changes in temperature, salinity or food limitation which leads to the precocious maturation of young medusa and the release of planula and that the brief occurrence of medusa was caused by an abrupt decrease in activity after the release of planula.

• Journal of Ecology and Environment
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• 제31권3호
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• pp.233-241
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• 2008

Functional feeding groups (FFGs) of benthic macroinvertebrates are guilds of invertebrate taxa that obtain food in similar ways, regardless of their taxonomic affinities. They can represent a heterogeneous assemblage of benthic fauna and may indicate disturbances of their habitats. The proportion of different groups can change in response to disturbances that affect the food base of the system, thereby offering a means of assessing disruption of ecosystem functioning. In this study, we used benthic macroinvertebrate communities collected at 650 sites of 23 different water types in the province of Overijssel, The Netherlands. Physical and chemical environmental factors were measured at each sampling site. Each taxon was assigned to its corresponding FFG based on its food resources. A multilayer perceptron (MLP) using a backpropagation algorithm, a supervised artificial neural network, was applied to evaluate the influence of environmental variables to the FFGs of benthic macroinvertebrates through a sensitivity analysis. In the evaluation of input variables, the sensitivity analysis with partial derivatives demonstrates the relative importance of influential environmental variables on the FFG, showing that different variables influence the FFG in various ways. Collector-filterers and shredders were mainly influenced by $Ca^{2+}$ and width of the streams, and scrapers were influenced mostly with $Ca^{2+}$ and depth, and predators were by depth and pH. $Ca^{2+}$ and depth displayed relatively high influence on all four FFGs, while some variables such as pH, %gravel, %silt, and %bank affected specific groups. This approach can help to characterize community structure and to ecologically assess target ecosystems.

• 한국환경보건학회지
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• 제32권3호
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• pp.227-234
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• 2006

There has been increasing concern in recent years about the occurrence, fate and toxicity of pharmaceutical products in aquatic environment. Although these compounds have been detected in a wide variety of environmental samples including sewage effluent, surface waters, ground water and drinking water, their concentrations generally range from the low ppt to ppb levels. It is therefore often thought to be unlikely that pharmaceuticals will have a detrimental effect on the environment. This study was conducted to determine the endocrine disruption effects of the several pharmaceutical residues in water using adult Japanese medaka (Oryzias latipes). The common antibiotics were used sulfa durgs (sulfamethoxazole and sulfamethazine) and tetracycline drugs (oxytetracycline and tetracycline). Positive control that was induced Vtg (vitellogenin) in male fish was used $17\beta$-estradiol. Vtg was qualified and quantified through Western blotting and ELISA. After SDS gel electrophoresis, the dominant protein band was identified to molecular weight approximately 205 kDa in whole body samples of vitellogenic female. In female medaka exposed to $17\beta$estradiol, there was no significant difference in total protein induction. In contrast, three to five day exposure of male fish to $17\beta$-estradiol resulted in more than 60.0% increase of total protein compared to that of control males (p<0.01). In case of antibiotics, female fish didn't show significant difference, but male fish was showed significant difference. In addition, Vtg induction in male fish was observed with all the test chemicals. On concentrations greater than 0.1 ppm of sulfamethoxazole, 1 ppm of sulfamethazine, 1 ppm of oxytetracycline and 20 ppm of tetracycline, Vtg induction was increased in a dose response manner. This study is one of the early reports suggesting potential endocrine disruption mechanism of antibiotic pharmaceutical products in aquatic ecosystem. Although the effect concentrations obtained from this study were high as unrealistically as in environments, it is endocrine disruption that we should be considered as one of the important consequences of pharmaceutical contamination at water environment, and warrants due attention in future researches.

• 환경영향평가
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• 제17권4호
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• pp.225-233
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• 2008

An Environmental Specimen Bank (ESB) is an archive for samples that can be used to document and assess the quality of the environment in which we live. An ESB program looks at changes in the concentration of human and environmental specimens over long periods of time through retrospective analysis of archived samples of a particular area collected at regular intervals. The idea of ESB was first proposed by German and American scientists in the early 1970s and has been established since 1979 in Germany, USA, and Japan. Korea plans to establish a National Environmental Specimen Bank (NESB) in 2010. The NESB will be able to assess and improve the quality of analytical measurements as well as to compare the past and current environmental quality as a time capsule. The concept and design for the NESB facility was developed and its Standard Operation Procedures (SOPs) are being developed based on an evaluation of ESBs and SOPs of Germany, USA, and Japan. Environmental specimens proposed for banking are based on typical representatives of every level of the food chain from each type of ecosystem that are widely distributed thus enabling comparisons between different sampling areas. Through retrospective analysis of environmental specimens, the NESB will improve the reliability of environmental monitoring, ecological risk assessment, and health impact assessment.

• Journal of Plant Biotechnology
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• 제44권4호
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• pp.462-471
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• 2017

Thiamine pyrophosphate (TPP), the active form of thiamine is a cofactor for enzymes involved in central metabolism pathways. However, it is also known to have a role as a stress signaling molecule in response to environmental changes. Anabaena sp. and N. oculata are microorganisms which are abundantly found in Malaysia's freshwater and marine ecosystem. However, not much studies have been done especially in regards to thiamine biosynthesis. This work aimed to amplify of gene transcripts coding for thiamine biosynthesis enzymes besides looking at the expression of thiamine biosynthesis genes upon stress application. Various stress inducers were applied to the cultures and RNA was extracted at different time points. The first two genes, ThiC and ThiG/Thi4 encoding enzymes of the pyrimidine and thiazole branch respectively in the thiamine biosynthesis pathway were identified and amplified. The expression of the genes were analysed via RT-PCR and the intensity of bands were analysed using ImageJ software. The results showed up to 4-fold increase in the expression of ThiC and ThiG gene transcript as compared to control sample in Anabaena sp. ThiC gene in N. oculata showed an expression of 6-fold higher as compared to control sample. In conclusion, stresses induced the expression of the gene coding for one of the most important enzymes in thiamine biosynthesis pathway. This is an agreement with the hypothesis that overexpression of thiamine is crucial in assisting plants to combat abiotic stresses.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 국제학술대회
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• pp.345-350
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• 2005

Acute toxicities of five pharmaceutical products were evaluated with aquatic microbes, invertebrates, and fish. The test pharmaceuticals, i.e., cimetidine, carbamazepine, diltiazem, acetaminophene, and metformin have been often detected in aquatic environment, but theire cological hazard on receptors of various trophic levels has seldom been evaluated. In the present study, we conducted acute toxicity assays with a marine bacterium, Vibrio fischeri, an invertebrate, Daphnia magna, and a fish, Japanese medake (Oryzias latipes). In general, D. magna, showed the most sensitive response to the test chemicals. Diltiazem exhibited the lowest EC50 value after 96 hr of exposure at 7.6 mg/L, followed by cimetidine >acetaminophen > metformin = carbamazepine in an order of decreasing susceptibility. With the fish, diltiazem and carbamazepine showed the 96 hr EC50 values at 14.1${\sim}$35.4 mg/L while acetaminophen, cimetidine, and metformin did not cause 50% mortality at 100 mg/L. Similar pattern was noted with the Microtox Assay, with which the median effective concentrations for acetaminophen, cimetidine, and metformin were found at the range between 301.8 and 755.4 mg/L. Carbamazepine and diltiazem exposure to the microbes resulted in EC50 values around 50 mg/L. Predicted no effect concentrations (PECs) of these pharmaceuticals derived from the EC5O values obtained from this study, and predicted environmental concentrations (PECs) obtained from available literatures were utilized to estimate ecological risks of the test compounds. No test pharmaceuticals resulted in risk quotients (PEC/PNEC) greater than 1, which suggests no serious potential ecological concerns. It should be noted however that further studies including the refinement of PEC derivation, identification and toxicity assessment of the metabolites and/or their interactions with other stressors may be warranted to better understand the environmental consequences of the residual pharmaceutical discharge to the waterway.

• Ocean and Polar Research
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• 제35권2호
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• pp.147-155
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• 2013

The purpose of this study is to investigate seasonal difference in linear trends in satellite-derived chlorophyll-a concentration (Chl-a) and their related environmental changes in the South Sea of Korea (SSK) and East China Sea (ECS) for recent 15 years (Jan. 1998~Dec. 2012) by analyzing climatological data of Chl-a, Rrs(555), sea surface wind (SSW) and nutrient. A linear trend analysis of Chl-a data reveals that, during recent 15 years, the spring bloom was enhanced in most of the ECS, while summer and fall blooms were weakened. The increased spring (Mar. - May) Chl-a was associated with strengthened winter (Dec. - Feb.) wind that probably provided more nutrient into the upper ocean from the deep. The causes of decreased summer (Jun. - Aug.) Chl-a in the northern ECS were uncertain, but seemed to be related with the nutrient limitation. Recently (after 2006), low-salinity Changjiang diluted water in the south of Jeju and the SSK had lower phosphate that caused increase in N/P ratio with Chl-a decrease. The decreased fall (Sep. - Nov.) Chl-a was associated with weakened wind that tends to entrain less nutrient into the upper ocean from the deep. This study suggests that phytoplankton in the ECS differently changes in response to environmental changes depending on season and region.