• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6B
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• pp.565-575
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• 2011

The purpose of this study was to quantitatively evaluate the expression of both multi-metric qualitative habitat evaluation index (QHEI) and biological integrity index (IBI) for artificial structures eco-artificial fish reef (EAFR) for fishes asylum and habitat. Especially, both experimental evaluation and biological verification were performed in Water and Environmental Center's outdoor test-bed of Korea Institute of Construction Technology located in Andong-city, Gyeongsangbuk-do. The experimental conditions reflecting the situation of domestic river include the flow rate (e.g., $0.0{\sim}1.5m\;s^{-1}$), the width (e.g., 1.0~3.0 m), the depth (e.g., 0.05~0.70 m), and variable bed materials. Both QHEI and IBI were monitored for 8 months from May to December 2010. Whereas QHEI values were highest at experimental points of the E~F with an average of 83.1, those were lowest at B~C with an average of 78.1. However, QHEI values inside EAFR were more than 98.9, regardelss of space and time, and indicated more than the highest good of the state (Good) in the habitat. Overally, IBI values showed similar trend with QHEI, but were 44.2 in the winter dry season, compared to 32.8 of QHEI values. IBI values Also, IBI values inside EAFR were greater than those at the experimental channel by 5.7 to 11.4% and 18.7 to 34.8% in flow and stagnant conditions, respectively, indicating that EAFR can secure asylum and habitat for fish during the dry season. For comprehensive aquatic ecosystem assessment, the experimental channel showed generally fair conditions (Fair~Good), whereas EAFR showed good conditions (Good), suggesting that EAFR can be applied to aquatic ecosystem restoration and improvement.

• Korean Journal of Ecology and Environment
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• v.51 no.1
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• pp.71-85
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• 2018

A recent topic of interest within ecology is ecosystem services that are importantly connected with biodiversity. Biodiversity is a fundamental component of ecological studies and has been the subject of many studies worldwide. However, studies on the diversity and distribution of freshwater fish were not undertaken in earnest until 2000, and the number of internationally available studies is therefore still limited. In this study, we used data from "The Survey and Evaluation of Aquatic Ecosystem Health (hereafter SEAEH)" within the framework of which whole water systems on the Korean peninsula are annually monitored to investigate and determine the current status of the diversity and distribution of freshwater fish, as well as to elucidate major factors impacting freshwater fish. A total of 130 species from 28 families were identified at around 953 sites in the SEAEH investigation of 2014. The species Zacco platypus (relative abundance: 28.2%) and Z. koreanus (19.3%) were identified as the most abundant species on the Korean peninsula, and besides these 20 endangered species, 51 endemic species and 4 exotic species were also collected. Highest (96 species) and lowest (72 species) diversity were identified in the Han River Watershed and the Yeongsan/Seomjin River Watershed, respectively. The mean endemic rate was 32.7%, which is higher than the previous rate determined in 1995. The exotic species Micropterus salmoides, Lepomis macrochirus and Carassius cuvieri were found in the whole river system except north Yeongdong, whereas Oreochromis niloticus occurred only at three sites due to the cold water temperatures in winter. Totally, 28 species were found to be translocated to different water systems not connected with known original habitats, most translocations occurring in the Nakdong River and the Yeongdong region. Among the translocated species, Opsariichthys uncirostris amurensis, and Erythroculter erythropterus were dominantly distributed in the mid- to lower reaches of Nakdong River where they may be harmful to the native fish assemblages due to their strong predation. The construction of weirs in connection with the "4 River Project" generated changes in fish assemblages before, during and after the project, resulting in altered habitat condition. Especially, a decrease in the number of endemic species and an increase in the abundance of lentic species were seen. Human-induced global warming will allow exotic species requiring high water temperatures to adapt to the environmental conditions of the Korean peninsula, which may enhance the diversity of native fishes and create changes in distribution. For the establishment of realistic and efficient management and protection strategies for Korean freshwater fish, SEAEH, which produces fundamental and quantitative data for Korean streams, is an important and necessary tool.

• The Korean Journal of Pesticide Science
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• v.16 no.1
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• pp.62-68
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• 2012

This study evaluated the screening level assessment of ecological health using four biomarkers and four bioindicators of Misgurnus anguillicaudatus as a indicator species in agricultural area of South Korea during May-June 2011. The endocrine disrupting chemical (EDC) indicators, such as vitellogenin (VTG) and gonado-somatic index (GSI), were not significantly changed in the agricultural site (p>0.05), indicating no effects. The biomarkers and bioindicators were compared between two sites of reference site (RS) and the agricultural site (AS) for screening assessment of ecological health. The ethoxyresorufin-O-deethylase (EROD) activity, acetylcholinesterase (AChE) activity, and DNA damage were significantly changed in the AS compared with the RS (p<0.05). But the individual level bioindicators such as condition factor (CF), hepato-somatic index (HSI), and gonado-somatic index (GSI) were not significantly different from reference site (RS). These results may indicate impairments of ecological health by toxic chemicals and environmental conditions. Current this study is based on screening assessment of biochemical and individual level biomarkers and bioindicators, so further study is required additional biomarkers and population or community level bioindicators for more specific health assessments in agricultural areas.

• Korean Journal of Agricultural Science
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• v.30 no.1
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• pp.41-58
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• 2003

This study was conducted to investigate bird community and to suggest a proper way how to manage protect bird community in Gap stream. The survey was carried out over four sections by the line transect method and point counts method from September 2001 to August 2002. Natural stream region as Gasuwon Bridge - Mannyeon Bridge are observed birds were 11 orders 29 families 67 species, Artificial stream region as Mannyeon Bridge - Daedeok Bridge are observed birds were 6 orders 10 families 30 species, Daedeok Bridge - Wonchon Bridge are 8 orders 12 families 28 species, Wonchon Bridge - Gap Stream Bridge are 8 orders 18 families 40 species. All the observed birds in artificial stream region are 8 orders 19 families 47 species. Number of species in natural stream region was higher than artificial stream region owe to a various habitat environment such as forest, cultivated land, streamside forest, sandy plain, gravelly field, reedy field etc. and can not add with the interface and the usage of the human. Number of species in artificial stream region was lower than natural stream region owe to a simple habitat environment and the water ecosystem is severed with embankment block and grass plot with the land ecosystem. The furtherance of various habitat environment which considers the ecosystem like the natural stream as the water ecosystem is joined together with the land ecosystem is desired to attract various wildbirds in Gap stream. The design is desired with the maintenance of the stream to consider the stream corridor which plays ecological important role as connect the fragment habitats.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.880-884
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• 2009

여름철 강우시 저수지로 유입하는 고탁도의 하천수는 저수지 주변 수체에 비해 낮은 수온과 높은 부유물질 농도(SS)로 인해 상대적으로 높은 밀도를 가지며, 저수지 내에서 동일 밀도층을 따라 분포하며 밀도류를 형성하게 된다. 탁수는 대부분 장기간 저수지에 체류하며 수질과 수생태계에 큰 영향을 주게 된다. 따라서 저수지로 유입한 탁수의 밀도류 거동특성을 파악하는 것은 저수지 운영, 수질관리 및 수생태계 보호를 위한 관리대책 수립에 있어서 중요한 요소이다. 본 연구의 목적은 횡방향 평균 2차원 수치모델을 이용하여 초기수위별 다양한 유량규모에서 소양호로 유입하는 밀도류의 거동특성(유입경계지점 수심($h_0$), 침강점 수심($d_p$)과 거리($X_p$), 분리점 수심($d_s$), 중층류 관입두께($h_i$), 댐 축 도달시간($t_a$), 희석율(${\beta}$))을 분석하여 저수지 수질관리를 위한 의사결정지원 기초정보를 제공하는데 있다. 밀도류의 거동분석을 위해 사용된 유량조건은 그동안 소양호에서 발생한 홍수크기를 바탕으로 7개의 등급으로 나누었으며, 각각의 유량조건별 수문곡선은 2007년 수문사상 중 7월 30일부터 8월 30일까지의 수문사상을 바탕으로 수정가우시안 공식을 사용하여 산정하였다. 탁수 거동 특성의 모의는 서로 다른 초기 수위 및 유량조건하에서의 탁수거동을 나타냈고, SS농도 25 mg/L 이상을 기준으로 하여 탁수층의 $d_p$, $X_p$, $d_s$, $h_i$, $t_a$, ${\beta}$를 산정하였다. 일반적으로 유량규모가 커질수록 $d_p$와 $d_s$는 증가하였고, $X_p$는 댐 축으로부터 가까워짐이 확인되었으나, 동일 유량규모에 대해 초기 수위가 증가함에 따라 $X_p$는 대체로 댐으로부터 멀어졌다. $h_i$는 유량규모가 증가함에 따라 완만하게 증가하는 경향을 보였고, $t_a$는 초기수위가 EL. 165 m일 때 유량이 2,000 CMS 미만인 경우 댐 앞까지 도달하지 못하는 것으로 나타났으며, 나머지 수위조건에서는 유량이 3,000 CMS 미만인 경우 댐 앞까지 도달하지 못하는 것으로 나타났다. 유량 규모에 따라 $X_p$가 0 km인 지점과 19 km인 지점에서의 ${\beta}$ 값을 산정한 결과 일반적으로 유량규모가 커질수록 유입수의 희석효과는 작아지며 초기수위가 커질수록 증가하는 경향을 나타냈다. 연구 결과는 탁수 발생 초기 저수지 운영 실무자들이 유량규모 및 초기 수위조건에 따른 밀도류의 거동특성을 신속히 예측하는 목적으로 사용될 수 있다.

• Korean Journal of Environment and Ecology
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• v.26 no.6
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• pp.970-979
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• 2012

The purpose of study was to analyze the ecological health of the Namcheon Stream using Index of Biotic Integrity(IBI) Qualitative Habitate Evaluation Index(QHEI) and Water quality condition. Diatom samples were collected from ten sampling sites in the stream at total four times in 2006 and 2007. To assess ecological health of the stream, it was used modify metrics proposed by USEPA(1999). IBI values of the stream averaged 23 which was judged as a "fair". Physical habitate evaluation analysis showed that QHEI values in the stream averaged 57 indicating a "poor" condition. Water quality condition in the stream averaged "II" indicating a "a little good" condition In conclusion, ecological health of the Namcheon Stream was "fair" condition that means habitate minimally disturb in the aquatic environment and relatively good water quality. Especially, St. 6 St. 7, St. 8, and St. 9 showed that QHEI values in the stream averaged 47 indicating a "poor" condition. St. 6 exists mostly to interfere with the flow of the river piers and artificial beams around. They are also serious disturbance at riverbed structure in aquatic ecosystems. St. 10 was good about habitate condition however, it was disturbance of aquatic ecosystems due to nutrient. It is suggest that St. 10 needs to be managed for nutrient inflows.

• Korean Journal of Ecology and Environment
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• v.42 no.3
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• pp.271-279
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• 2009

Vinyl chloride (VC) is a known human carcinogen, and it is released to multi-environmental media via several exposure routes. VC was potentially evaluated as a water quality pollutant based on human health risk assessment in Korean water environments. In this study, we investigated physicochemical and toxicological properties of VC, human health and ecological risk assessment, and the regulation of VC as a water quality pollutant in developed countries. Currently there are no standard or guideline values of VC in Korean legal system for the protection of human health and aquatic ecosystem, except that it is designated as a specific toxic substance and a water quality pollutant. Human health risk assessment of VC was previously performed based on the limited water quality monitoring data. The monitoring level of VC in Korean water system is more higher than other countries'. VC was assessed as potential hazardous chemical based on the US EPA's cancer risk assessment. There were a few ecotoxicity data of VC available using very limited kinds of aquatic organisms, and the toxicity results obtained seem to be overestimated without considering the losses of VC in open exposure system. Therefore it is needed to monitor the VC in various areas and to carry out the ecotoxicity research using multi-level organisms. We expect that these results can be useful information for implementing VC as a water quality pollutant in legal system for the protection of human health and aquatic ecosystem in near future.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.419-428
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• 2013

The objectives of this research were to determine ecological characteristics and chemical gradients in two different loach populations-Misgurnus anguillicaudatus ($M_a$) and Koreocobitis rotundicaudata ($K_r$). Eight chemical parameters were compared to test the chemical preferences between the two species. The population of Kr occurred more in better water quality, compared to the $M_a$-population. The $M_a$-population co-occurred more with tolerant species (TS) and omnivores, whereas the $K_r$-population co-occurred more with sensitive species (SS) and insectivores. The differences in the tolerance and trophic composition matched well with the result of stream health assessment, based on the multi-metric model of Index of Biological Integrity (IBI). The IBI value in habitat with the $M_a$-population was "19.6" (range: 8~40) indicating a fair condition, and the IBI values of $K_r$-population was 29.4 (range: 12~40) indicating good condition. Similar results were found in physical habitat health analysis (QHEI). Overall, data analysis showed that the $M_a$-population belong to the tolerant species and $K_r$-population belong to sensitive species in the tolerance classification.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.370-375
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• 2013

Exotic species in aquatic ecosystem generate various problems domestically as well as globally. Largemouth bass (Micropterus salmoides) which is a well-known exotic species globally, acts as a substantial disturbance factor on the native fish communities in Korea due to the high predation pressure and hence designated as a ecologically harmful species by Ministry of Environment. In this study, we investigated the impact of largemouth bass on Korean native fish population, crucian carp (Carassius auratus), to identify responses of the prey fish. Two fish species were collected at seven reservoirs distributed at the Nakdong River catchment area, and changes in length-frequency and length-weight relationship (LWR) were analysed depending on existence of large-mouth bass. At bass absent sites, ratio of under age 1 year individuals were small, and over age two years were dominant. Conversely, normal length-frequency distribution pattern was identified at bass absent sites. The LWR of crucian carp (fish smaller than total length of 160 mm were only considered as it is frequently consumed by bass predation) was different depending upon bass existence. The value of parameter b at bass absent reservoirs was 2.909, which was smaller than that of bass present reservoirs, 3.100. Our results imply that crucian carp at bass present reservoirs presented a different strategy to survive from predation by bass, through relatively rapid growth. We propose that other native species might have similar growth strategies like crucian carp.

• Korean Journal of Environment and Ecology
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• v.35 no.5
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• pp.503-524
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• 2021

A largemouth bass (Micropterus salmoides) is an ecosystem disturbance fish species at the highest rank in the aquatic ecosystem, causing a serious imbalance in freshwater ecosystems. Although various attempts have been made to eradicate and control largemouth bass, no effective measures were found. Therefore, it is necessary to find an approach to maximize the effective population reduction based on the unique characteristics of largemouth bass. This study used the transcriptome analysis to derive 182,887 unigene contigs and select 12 types of final target sequences for applying the CRISPR/Cas9 system in the genes of IZUMO1 and Zona pellucida sperm-binding protein, which are proteins involved in sperm-egg recognition. After synthesizing 12 types of sgRNA capable of recognizing each target sequence, 12 types of Cas9-sgRNA ribonucleoprotein (RNP) complexes to be used in subsequent studies were prepared. This study searched the protein-coding gene of sperm-egg through the Next Generation Sequencing (NGS) and edited genes through the CRISPR/Cas9 system to induce infertile individuals that produced reproductive cells but could not form fertilized eggs. Through such a series of processes, it successfully established a composition development process for largemouth bass. It is judged that this study contributed to securing the valuable basic data for follow-up studies to verify its effect for the management of ecological disturbances without affecting the habitat of other endemic species in the same water system with the largemouth bass.