• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.222-230
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• 2016

HEMIRE is a 6,000-meter-class remotely operated vehicle (ROV) that has been developed for observation and sampling of objects of interest on the deep seabed. We first carried out deep-seabed exploration around the slopes of the Hupo Bank and the Ulleung Basin in the East Sea in June 2015. Over two weeks, a total of 10 dives were made from a support ship, the R/V Onnuri, at eight stations with water depth ranging between 194 and 2,080 m. The dive times ranged from 1 to 6 hours, depending on the operating conditions. We obtained the following results: 1) video images of the deep seafloor; 2) red snow crab density data (a major fishery resource) and inventories of deep-sea fauna, including an unrecorded organism; 3) specific topographies such as canyons slopes; 4) an undisturbed sediment core obtained using a push corer; and 5) observations of the seabed surface covered with discarded anthropogenic waste material.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.4
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• pp.256-264
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• 2014

This study was carried out to estimate the benthic environments and polychaetous community in Garolim Bay, through five field surveys from April 2006 to April 2007. Garilim Bay is a semi-enclosed bay and composed of a biramous tidal channel and nearby wide tidal flats. Surface sediment in the inner bay was composed of fine grained particles whereas that in the mouth area of bay was of coarse grained ones. Benthic polychaete worms were the most dominant taxa occupying 65.1% of total benthic macrofauna. Species number was higher in the inner bay than mouth and outer area of bay, and in the bay higher on the tidal flat than channel area. Density was higher on the tidal flat than channel area. Dominant polychaetous species were Prionospio sp., Heteromastus filiformis, Lumbrineris longifolia and so on, which is known as opportunistic species. Prionospio sp. and H. filiformis inhabited mainly on the tidal flats in inner bay, while L. longifolia in the channel area and mouth of the bay. Cluster analysis and nMDS showed the typical inner-to-outward distribution of station groups, which indicated the sequential difference of the species composition of each station group. To assess the benthic healthiness of Garolim Bay by AMBI and BPI analysis, the benthic condition was analyzed from slightly polluted in the outer and mouth of the bay to moderately polluted in the inner bay. Assumed from dominant species composition and benthic healthiness condition, benthic environments of Garolim Bay was slightly unstable and disturbed and organic enrichment was currently underway by massed fisheries farms.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.16 no.4
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• pp.246-253
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• 2011

In this study, we investigated the effect of freshwater discharge on benthic community in Nakdong estuaries. The sediment was dominated by sand except few channels where heterogenetic sediment composition was observed. Sediment composition was rarely affected by freshwater discharge during the rainy season; however, organic content in the sediment slightly increased after the rainy season. Macrobenthic species composition differed spatially. For instance, species composition decreased after the rainy season near the barrage. Benthic community analysis revealed three groups, in which the first group was found between barrage and sand bars located at the mouth of estuary, the second group was observed outside the sand bars, and the last group was found in the channel. Opportunistic benthic species indicative of organic pollution, such as Sinocorophium sinensis, Magelona japonica, and Heteromastus filiformis, dominated areas close to the barrage. Organic pollution by freshwater discharge appears to be responsible for the emergence of opportunistic benthic species, and this influenced areas from the mouth of bay to sand bars. Outside the sand bars, freshwater discharge did not seem to have affected species composition.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.882-895
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• 1997

Changes in the benthic communities have been studied to investigate the environmental effects before and after the construction of Shihwa Dike in the West coast of Korea. It is suggested that sequential changes in macrofaunal assemblages progressed in two sucressional directions. In the Shihwa lake under the influence of organic enrichment. First, the appearance of 'azoic tone' or 'grossly polluted zone' developed in the area of less than 6 m in depth resulted from the severe dissolved oxygen depletion due to the eutrophication from the increased organic loading. Second, the 'polluted zone' characterized by the proliferation of the opportunistic species in organically enriched area, was found in the vicinity of the industrial discharges and nearby fluvial inputs. This benthic community succession in the Shihwa lake seemed to be caused by the various ecological events such as an eutrophication in this organically enriched environment after construction of the dike and other physico-chemical parameters like salinity and dissolved oxygen in the bottom water, which may be influenced by the irregular surface water discharge and dilution by outer seawater inflow through the water gate of the dike. On the other hand, the benthic communities in the outside of the dike showed that the species richness was more than doubled and the abundance increased almost seven times more than that before the dike construction. This may be a typical characteristics of the initial phase in benthic eutrophication, suggesting that an increased organic input area may have been reponsible for this faunal change in the study area.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.3
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• pp.157-165
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• 2015

This study investigated and compared sediment properties and macrobenthic community structures within heated effluent plumes at the discharge areas of Kori Nuclear Power Plant (KNPP) and Sinkori Nuclear Power Plant (SNPP) in Korea, which have different thermal effluent discharge systems. There were significant differences in sand, clay and organic carbon contents between sediments at the two discharge areas. Species richness and abundance of macrobenthos were higher at the SNPP discharge area than at that of the KNPP, although the values at both areas were comparable to previous studies in coastal areas of eastern Korea.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.525-525
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• 2016

도심지역의 대단위 주거 단지 조성에 따른 다양한 하천 생태계에 대한 문제가 야기되어 하천 생태계에 대한 환경영향평가가 때때로 시도되고 있다. 토지이용의 변화에 따라 유역의 물순환 경향이 달라지고 이로 인하여 하천 수생태계에 영향이 달라지게 된다. 본 연구에서는 토지이용 변화와 물순환 변수인 유량인자와 하천 수생태환경의 상관관계를 조사해 보고자 하였다. 대상 유역으로는 한강 하류지역인 서울특별시 주변의 30개 소유역을 대상으로 하였으며, 일유량 자료와 BMI 지수, 유역의 불투수율등을 사용하였다. 또한 환경부에서 제공하고 있는 2012-2014년 자료중 한강 유역에서 조사된 저서성대형무척추동물지수 관측소와 유랑 관측소와 일치하는 33개 지점을 선정하여 유량지표와 생태환경 지수와의 관계를 조사 분석하였다. 본 연구에서는 수생태환경을 나타낼 수 있는 지수인 저서성대형무척추동물지수 (Benthic Macroinvertebrates Index, BMI)를 조사하여 자료를 구축하고, 토지이용변화와 유량변화에 따른 BMI 지수의 영향을 조사하고, 토지이용 변수와 수문학적 변수와의 상관관계를 조사하고자 하였다. 유역의 불투수율과 마찬가지로 일평균 유량, 0.5년 초과빈도, 0.1년 초과빈도, 0.01년 초과빈도 유량과 BMI 지수와의 상관관계를 조사하였다. 이러한 상관관계 도출을 통하여 유역의 개발에 따른 하천 수생태에 영향을 수문변수 중의 하나인 유량지표로 유추 할 수 있으며 수생태에 대한 영향을 저감할 수 있는 저감 방안으로 유량자료를 사용할 수 있을 것으로 기대할 수 있다.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.2
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• pp.93-101
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• 2007

In order for bioremediate the benthic layer in polluted inner Bay, the effects of irradiance and wave-length irradiated from light emission diode (LED) on the growth of benthic diatom Nitzschia sp. (Hakozaki Bay strain of Japan) were investigated. The Nitzschia sp. was cultured under blue LED (450 nm), yellow LED (590 nm), red LED (650 nm) and fluorescent lamp (mixed wavelengths). At $25^{\circ}C$ and 30 psu, the growth of Nitzschia sp. showed its peak at $20\;{\mu}mol\;m^{-2}\;s^{-1}$ (blue LED) and $40\;{\mu}mol\;m^{-2}\;s^{-1}$ (fluorescent lamp), and was inhibited at the irradiance higher than that irradiance. Nitzschia sp. in yellow LED and red LED is fitted by a rectangular hyperbolic curve because no photoinhibition was observed under maximum irradiance used in this study. The irradiance-growth curves were described as ${\mu}=-0.46{\exp}(1-I/6.32)+0.46-0.00043I,\;(r^2=0.98)$ under blue LED, ${\mu}=0.42(I+7.87)/(I+58.9),\;(r^2=0.99)$ under yellow LED, ${\mu}=0.39(I+3.39)/(I+21.6),\;(r^2=0.94)$ under red LED, ${\mu}=-0.38{\exp}(1-I/7.23)+0.38-0.00016I,\;(r^2=0.96)$ under fluorescent lamp. Maximum specific growth rate of blue LED, yellow LED, red LED and fluorescent lamp was $0.44\;day^{-1},\;0.42\;day^{-1},\;0.39\;day^{-1}$ and $0.37\;day^{-1}$, respectively. The absorption coefficient ($a_{ph}$) of Nitzschia sp. was similar under all the wavelengths (400 nm-700 nm), although maximum $a_{ph}$ was $0.0224\;m^2\;mg\;chi.\;{\alpha}^{-1}$ in 472 nm and $0.0179\;m^2\;mg\;chi.\;{\alpha}^{-1}$) in 663 nm. The results may indicate the possibility of environmental improvement around the benthic layer in polluted coastal area because microphytobenthos growth is stimulated by means of irradiated blue LED at the benthic boundary layer during both autumn and winter, and yellow LED, which might have been suppressed growth of harmful algae, at the layer during both spring and summer.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.1
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• pp.9-23
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• 2007

To investigate the degree of pollution using the species composition of benthic community and environments, the present study was conducted in Jinhae Bay, May of 1998. In Jinhae Bay, benthic macrofaunal community was investigated on the base of the samples from 67 stations. The main facies of the surface sediment was silty clay and clay. The total species number and the mean density of macrobenthic animals were 255 species and 984 $ind./m^2$, respectively. There were 90 species and 773 $ind./m^2$ of polychaetes as the most major faunal group in Jinhae Bay. At the region between the eastern mouth of Jinhae Bay and Gadeok Is., the species number and density were higher, while lower at the western area of Jinhae Bay. The most dominant benthic macrofauna in Jinhae Bay was the polychaetes, Lumbrineris longifolia(16.9%), and followed by polychaetes Tharyx sp.(6.7%), Clone teres(4.7%), Glycinde sp.(4.2%), bivalves Theora fragilis(4.0%), crustaceans Corophium sp.(4.0%) and so on. The most of the predominant species appeared mainly on the region between the eastern mouth of Jinhae Bay and Gadeok Is. Cluster analysis based on the macrobenthic faunal composition showed that Jinhae Bay could be divided into three station groups: The western Jinhae Bay(Station group A), the mouth of Jinhae Bay(Station groupe B), and offshore area between Gadeok Is. and Geoje Is.(Station group C). The mouth of Jinhae Bay had the highest mean species number and the mean density, and its important species was Lumbrineris longifolia. The offshore area between Gadeok Is. and Geoje Is. had medium mean species number and the mean density. The western Jinhae Bay had the lowest mean species number and the mean density. The distribution of BPI and BC values, used to assess benthic pollution, showed similar patterns. According to the classification proposed by Borja et al.(2000), the stations of the western inner-bay were heavily polluted sites, the stations between mouth of the bay and the offshore area were slightly polluted sites, and the stations of the other area were meanly polluted sites. Benthic community healthiness of the western Jinhae Bay was classified to 'Transitional to pollution' by BC values. The degree of pollution in Jinhae Bay may have extended gradually from the western Jinhae Bay to the mouth of the bay.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.4
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• pp.287-304
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• 2007

This study was carried out to investigate spatio-temporal variations of benthic environment and macrobenthic polychaete communities in Gamak Bay where excessive organic matters from untreated sewage effluents and fish and shellfish farming activities have been accumulated in certain regions. Such environmental variables as sediment composition, organic content, acid volatile sulfide and dissolved oxygen content etc. were measured and polychaete specimens were taken in September 1999 and February 2000. In September 1999, organic contents were up to three times higher in the northwestern part of the bay and the area closed to Gukdong harbor than in the rest of the bay. In particular, benthic environment of the northwestern part of the bay was extremely deteriorated by the occurrence of hypoxia and highly concentrated sulfide. Of 28 stations investigated in summer, 5 stations located in the northwestern part were azoic. In the rest of the stations, a total of 119 polychaete species were sampled with a mean density of 900 $ind./m^2$. While species richness was higher in the entrance and central part of the bay where water exchanges with open sea were relatively active, density was higher in the moderately enriched stations neighbouring Gukdong harbor and fish farms where such potential indicators of organic pollution as Aphelochaeta monilaris, Lumbrineris longifolia were largely dominant. In February 2000, a total of 81 polychaete species appeared with a mean density of 2,802 $ind./m^2$ from 12 stations sampled in winter. Azoic areas were recolonized by Capitella capitata, Pseudopolydora paucibranchiata and Dipolydora socialis which showed maximum density in the innermost station. On the other hand, the rest of the stations were dominated by Euchone alicaudata and Praxillella affinis. The configuration of the stations sampled in summer and winter on the multidimensional scaling plots reflected the position of each stations within the bay in which there were great differences in organic content, sulfide concentration and oxygen content rather than in sediment composition. Therefore, heterogeneities in polychaete community structure in Gamak Bay were primarily influenced by the degree of the disturbance depending on the position within the bay.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.52-52
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• 2021

안동호는 상류지역의 휴·폐광산과 비점오염원으로부터 발생하는 각종 오염물질이 유입되고 있어, 호소 부영양화에 대한 문제가 계속 제기되고 있다. 이러한 안동호의 수환경은 댐 하류 유역과 같은 수계의 임하호의 수환경에도 영향을 미치기 때문에, 안동호 수질 및 수생태 건강성 평가가 계속 수행되고 있다. 본 연구에서는 SWAT-WET(Soil ad Water Assessment Tool-Water Ecosystems Tool)을 이용하여, 안동호의 수질 및 수생태 건강성을 평가하고자 한다. 이를 위해 안동댐 유역(1,584 km²)을 대상으로 SWAT 모형을 구축하였으며(2010~2019년), 댐의 운영을 고려하여 도산 관측소(안동댐 유입지점)와 안동1 관측소(안동댐 하류지점)의 실측 유량 및 수질(SS, T-N, T-P)에 대한 검보정을 수행하였다. SWAT 검보정 결과, 유유출량의 R², NSE(Nash sutcliffe efficiency)는 각각 0.76, 0.74 이상, SS, T-N, T-P의 R²는 각각 0.71, 0.81, 0.62 이상으로 분석되어 적용성을 확인하였다. 그리고 검보정한 SWAT의 유출량 및 수질 결과를 1차원 수생태계 모델인 WET에서 안동호의 유입자료로 적용하여, 안동호의 수심에 따른 수온, 수질, 저서동물 등의 수환경 결과를 모의할 예정이다. SWAT-WET 모의 결과는 수온, 수질, 저서동물 관측값과 비교하여 SWAT-WET 모델의 적용성을 평가하고, 안동댐의 상류 유출 특성 변화에 따른 안동호의 수질 및 수생태 건강성을 평가할 예정이다.