• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.779-793
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• 2023

Intensive and long-term aquaculture activities in Korea have generated considerable amounts of organic matter, deteriorating the sedimentary environment and ecosystem. The Korean government enacted the Fishery Management Act to preserve and manage the environment of fish farms. Based on this, a fisheries environment assessment has been conducted on fish cage farms since 2014, necessitating the development of a scientific and objective evaluation method suitable for the domestic environment. Therefore, a benthic health index (BHI) was developed using the relationship between benthic polychaete communities and organic matter, a major source of pollution in fish farms. In this study, the development process and calculation method of the BHI have been introduced. The BHI was calculated by classifying 225 species of polychaetes appearing in domestic coastal and aquaculture areas into four groups by linking the concentration gradient of the total organic carbon in the sediment and the distributional characteristics of each species and assigning differential weights to each group. Using BHI, the benthic fauna communities were assigned to one of the four ecological classes (Grade 1: Normal, Grade 2: Slightly polluted, Grade 3: Moderately polluted, and Grade 4: Heavily polluted). The application of the developed index in the field enabled effective evaluation of the Korean environment, being relatively more accurate and less affected by the season compared with the existing evaluation methods like the diversity index or AZTI's Marine Biotic Index developed overseas. In addition, using BHI will be useful in the environmental management of fish farms, as the environment can be graded in quantified figures.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.1
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• pp.20-31
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• 2024

This study was conducted to investigate the changes in the structure of benthic communities resulting from aquaculture activities and to assess the benthic health status of surface sediment in Gangjin Bay, a region known for concentrated shellfish aquaculture on the southern coast of Korea. Survey stations were divided into longline culture, bottom culture, and non-cultivation areas. The spatiotemporal distribution of physiochemical factors such as the grain size, water temperature, salinity, and total organic carbon in Gangjin Bay showed no significant differences between sampling stations. However, the species number, density, and diversity were relatively lower at the sampling stations in the bottom culture areas than at the other stations throughout the entire survey period. Cluster analysis and principal coordinates analysis also clearly distinguished the benthic communities in the bottom culture areas from those in the other sampling areas. At the sampling stations in the longline culture and non-cultivation areas, Scolectoma longifolia and Sigambra tentaculata, which are indicator species of organically enriched areas, appeared as dominant species. However, excluding some stations influenced by physical factors such as the water depth and current speed, the occupancy rate was not high. The health assessment results, conducted using the fisheries environment assessment method, revealed good conditions with Grades 1 and 2 across the entire area. However, an examination of the spatiotemporal changes in benthic communities and the benthic health index indicated that the benthic environment in the bottom culture areas was affected by physical disturbances.

• Journal of Environmental Impact Assessment
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• v.29 no.2
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• pp.112-121
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• 2020

Organic pollution due to coastal development increases the distribution of organic pollution indicators (OPI) and disturbs benthic ecosystems by increasing the number of organic pollution indicators dominant in the target area. However, there is a little researches on the organic pollution levels of benthic ecosystems in subtidal target coast of all over Korea. Therefore, this study analyzed the distribution of macrobenthos in subtidal around the coast development sites of EIA, confirmed the distribution of OPI, and produced the benthic health index-map (organic pollution level) of all coasts of Korea. The benthic health index of the sites was calculated using the density of each OPI, and the image program was used for the benthic health index-map. Organic pollution levels varied by projects for EIA and OPI. Lumbrineris sp. was found to be dominant throughout the coast and correlated with the benthic health index in Korea. Through this study, we will be able to confirm the future organic pollution level in the subtidal ecosystems of the project for EIA through the results of research to macrobenthos in subtidal for EIA. In addition, the distribution of Lumbrineris sp. OPI can be used as an indicator to indirectly evaluate the organic pollution level of the development site.

• Journal of Marine Life Science
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• v.7 no.1
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• pp.21-28
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• 2022

Benthic animals are important indicators in benthic environmental quality assessment. This study investigated the environmental characteristics and the distribution pattern of benthic animals, and assessed the benthic ecosystem using AMBI (AZTI's marine biotic index) and WQI (water quality index) in the subtidal zone of Muan bay. Samplings were collected from 10 stations in the subtidal zone of Muan bay on summer. In the upper area of Muan bay, grain size was finer and organic content was higher than those of in the lower area. The pollution indicator organism such as Musculista senhousia, Theora fragilis and Lumbrineris longifolia were dominant at some stations. The benthic community was distinguished into three groups of upper, center and lower area of Muan bay, and which were coincided with the results by correlation analysis between organic matter content and benthic health assessment (WQI and AMBI). As a result of this study, the health condition of the subtidal zone in Muan bay were good. However, from the results that benthic animals were not evenly distributed, and also the opportunistic species appeared, the load of organic matter in Muan bay seems to be increasing.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.456-456
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• 2021

하상 변화는 유량이나 유사의 흐름에 따라 침식, 운반, 퇴적되어 변화하며, 하상변동에 의한 결과는 하천의 형태 (직렬,복렬, 곡렬 등)나 서식처의 구조 (여울과 소, 웅덩이, 습지 등) 형성 로 나타난다. 이어서 서식처 구조의 다양성은 생물다양성에 긍정적인 영향을 미친다. 본 연구에서는 수리 (유량이나 유사량)-지형(서식처 구조)-생태 (생물다양성)을 연계하여 관리하기 위한 생태적인 하천관리 프레임을 제시하기 위하여, 지형과 생물상의 관계를 우선 파악하고자 한다. 국내 하천은 수생태 건강성 평가 중 서식 및 수변환경 지수(HRI, Habitat and Riparian Index)를 활용하여 하천의 형상 및 자연성을 평가한다. 해당 지수는 하천의 자연성을 판단할 수 있으나 유량이나 유사량 등과 같이 수리적 조건과 연계하여 하천환경 변화를 예측하기 어렵기 때문에, 본 연구에서는 하천의 자연성을 판단하는 지형변수들을 제안하고, 생물상과 상관관계를 분석한다. 수질 변화가 급격하지 않는(년간 변화폭이 일정한) 금강 유역의 지천 (갑천, 미호천, 논산천, 유구천 등) 중 생태계 건강성 평가 지수가 산정되어 있는 지점을 기준으로 상·하류 약 5 km 구간들을 대상으로 한다. 지형 변수로는 (항공사진을 이용한)사주 비율(사주면적/제방 내 홍수터 면적), 사주 식생비율(식생면적/사주면적)과 사주 변동량(연간 사주 이동량), 서식처 구조의 다양성(여울, 소, 웅덩이 등), 기존의 서식 및 수변환경 지수 등을 활용하고, 생물 변수로는 저서동물지수(BMI, Benthic Macroinvertebrate Index), 저서동물의 우점도, 어류생물지수(FAI, Fish Assessment Index), 어류생물지수에 활용하는 국내종의 총 종수, 여울성 저서종수, 민감종수 등을 활용한다.

• Journal of Soil and Groundwater Environment
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• v.12 no.4
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• pp.16-24
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• 2007

An investigation on the polluted sediments in the Lake Sihwa and the benthos that inhabited on the sediments was conducted. Cost effective remediation alternatives were derived form the results of the investigation. The sediment samples taken from four sampling points out of thirteen showed relatively high heavy metal (particularly copper) concentrations which exceeded the Effects Range Low (ERL) of the National Oceanic and Atmospheric Administration, USA. The four sampling points were located in front of industrial complexes. Although the heavy metals appeared to have affected the growth of the benthos, the concentration of it did not exceed the criteria of dredging that were developed by Netherlands or the State of Washington, USA. However, contamination by organic matters and sulfur compounds was severe, which exceeded the criteria of dredging that were established in Japan. The sediments taken from the four sampling points which were contaminated with heavy metals showed higher organic matter content in general. The organic matters in the sediments depleted oxygen in summer, which appeared to be fatal to the benthos. A comprehensive analysis on the sediments, benthos, and other environmental impact from the contaminated sediments drew a conclusion that the benthonic environment of the Lake Sihwa needed a stepwise remediation, giving a particular emphasis on the clean up of the sediments upstram of the Lake which could cause odor problems to the nearby residential area.

• Journal of Environmental Impact Assessment
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• v.30 no.6
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• pp.355-360
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• 2021

As the domestic water management policy shifted from concentration-oriented water management to load management-centered Total Maximum Daily Load (TMDL), water quality and aquatic ecosystems brought changed. However, it was difficult to determine whether the water quality and the health of the aquatic ecosystem improved after the implementation of the TMDL due to changes in pollutant sources and discharge fluctuations ect, so the effect was analyzed using a log-linear model and biological indicators (Benthic Macroinvertebrates). As a result, BOD and T-P concentrations in the Jinwi River Watershed were reduced by 30% and 35%, showed the effect of improving water quality, however the benthic macroinvertebrates index (BMI) downgraded from grade D to grade E. Therefore, efforts to cultivate ecologicalrivers are necessary to upgrade the health of the aquatic ecosystem in the river watershed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.212-223
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• 2022

For the remediation and restoration of contaminated sediment at the West Sea-Byeong dumping site, dredged materials was dumped in 2013, 2014, 2016, and 2017. The physicochemical properties and benthic fauna in surface sediments of the capping area (5 stations) and natural recovery area (2 stations) were analyzed annually from 2014 to 2020 to evaluate the capping effect of the dredged materials. The natural recovery area had a finer sediment with a mean particle size of 5.91-7.64 Φ, while the sediment in the capping area consisted of coarse-grained particles with a mean particle size of 1.47-3.01 Φ owing to the capping effect of dredged materials. Considering that the contents of organic matters (COD, TOC, and TN) and heavy metals in the capping area are approximately 50 % lower (p<0.05) than that in the natural recovery area, it is judged that there is a capping effect of dredged materials. As a result of analyzing macrobenthic assemblages, the number of species and ecological indices of the capping area were significantly lower than that of the natural recovery area (p<0.05). The number of species and ecological indices at the capping area were increased for the first four years after the capping in 2013 and 2014 and then tended to decrease thereafter. It is presumed that opportunistic species, which have rapid growth and short lifetime, appeared dominantly during the initial phase of capping, and the additory capping in 2016 and 2017 caused re-disturbance in the habitat environment. In the natural recovery and capping areas, Azti's Marine Biotic Index (AMBI) was evaluated as a fine healthy status because it maintained the level of 2^nd grades (Good), whereas Benthic Pollution Index (BPI) remained at the 1^st and 2^nd grade. Therefore, capping of dredged materials for remediation of contaminated sediment in the dumping site has the effect of reducing the pollution level. However, in terms of the benthic ecosystem, it is recommended that the recovery trend should be monitored long-term. Additionally, it is necessary to introduce an adaptive management strategy when expanding the project to remediate the contaminated sediment at the dumping area in the future.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.440-447
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• 2013

The ecological health, based on the Index of Biological Integrity (IBI) and Qualitative Habitat Evaluation Index (QHEI) was evaluated in 10 stream sites of Southern Han River. Eleven parameters of 12 parameters (Karr 1981) were modified for the application of regional Korean circumstance. The ecological health, based on IBI grade, was in "good condition" and the IBI score ranged from 33 to 47. Nine parameters of the original 12-parameter metrics in QHEI model (Plafkin et al. 1989) were applied in the habitat assessment. The mean QHEI model values were judged as "partially supporting" and ranged from 75 (non-supporting) to 109 (supporting). Comparative analyses revealed that values of IBI and QHEI models were greater in Gj stream than Ig- and Dn streams. The analysis of fish compositions showed that the proportions of insectivore, omnivore, and carnivore were 61.9%, 19%, and 9.5%, respectively. According to tolerance guild analysis, sensitive species and tolerant species were 76.1% and 4.7%, respectively, indicating a healthy trophic state in terms of food chain. The analysis by habitat guild type indicated that riffle benthic species dominated (57.1%) when compared to water column species (28.5%). The introduced species and individuals with diseases or external abnormality were not observed. Overall, the model values of IBI and QHEI suggested that the ecological health was maintained well in this upstream region.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.43-43
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• 2018

수생태계는 다른 여러 생태계 중에서 가장 위험에 처해있으며, 기후변화로 인한 수온, 수문 수질의 변화는 수생태계와 담수 생물다양성에 가장 큰 영향을 미치는 요인 중 하나이다. 본 연구에서는 생물 생태학적으로 변화하는 세계적인 물 관리 패러다임에 따라 한강유역에서의 미래 수생태계 평가를 수행하였다. 본 연구의 목적은 수생태 건강성 관측자료와 수질자료, SWAT 모형을 이용하여 미래 기후변화에 따른 한강유역의 수생태를 평가하는 것이다. 본 연구에서 선정한 수생태계 건강성 조사자료로 국립환경과학원에서 8년간(2008년~2015년) 봄과 가을 2차례에 걸쳐 모니터링 한 부착돌말류(TDI), 저서형 대형무척추동물(BMI), 어류(FAI)에 대한 수생태 등급자료 및 해당 지점에 대한 수온 및 수질자료를 이용하였다. 수집한 결과를 DB(T-N, $NH_4N$, $NO_3N$, T-P, PO4P)에 대한 수생태 등급의 상관성을 분석하고 수온 수질인자에 따른 수생태 등급을 나타내어 미래 기후변화에 따른 수생태 건강성 평가 및 예측을 실시하고자 하였다. Soil and Water Assessment Tool (SWAT) 모형은 유역의 신뢰성 있는 유역 수문, 수질 모의 및 기후변화 영향평가를 위하여 활용되었다. SWAT 모형을 이용하여 한강유역의 다목적댐(3개), 발전용댐(1개), 다기능보(3개) 운영을 고려하였고, 237개의 표준유역으로 분할한 뒤 수문 및 수질 모의를 수행하였다. 모형의 적용성 평가를 위해 댐 및 보의 유입량, 증발산량, 토양수분, 지하수위, SS, T-N, T-P에 대하여 보정(2005~2009) 및 검증(2010~2015)을 수행하였다. 기후변화에 따른 수문, 수질 및 수생태 평가를 위해 기상청의 HadGEM3-RA RCP 4.5와 8.5 시나리오를 적용하였으며, 기준년(1975-2005)년에 대해 2020s(2010-2039), 2050s(2040-2069), 2080s(2070-2099)의 수생태를 평가하였다.