• Ocean and Polar Research
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• 제24권1호
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• pp.55-61
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• 2002

Eelgrass, Zostera marina L. widely spreads throughout all the coastal areas of the Korean Peninsula. However, some previously reported eelgrass populations disappeared. The disappearance was probably caused by anthropogenic disturbance such as reclamation and pollutant or exceeded nutrient release. Eelgrass beds occurred from the intertidal to the subtidal zone, mainly in lagoon, estuaries, ports, barrier reef and bays. Eelgrass beds were also found at the intertidal mud and sand flats, subtidal mud and sandbank in more exposed areas. Habitat characteristics of eelgrass beds distributed on the coasts of the Korean Peninsula varied among coast areas. Eelgrass distributed constantly throughout the southern coast of Korea, while the distribution was limited at lagoon, bay, port, or barrier reef on the eastern coast, because of steep water depth and high wave energy in that coast. On the western coast, eelgrass mainly appeared at the intertidal and subtidal zones in islands. Sediment characteristics of the Z. marina beds varied with locality, tidal current and water motion. Sediments of Z. marina beds were composed of sand, muddy sand, sandy mud and mud. Mean grain size ranged from 1.5 to 4.1 phi.

• 한국패류학회지
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• 제9권2호
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• pp.16-22
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• 1993

Contamination of heavy metals in water and sediments along Mangyeong Gang(river) has reached up to critical level The object of the study is to elucidate somed molluscs which inhabit along the river on respect to the modulatory role in reducing the pollution. For the purpose, molluscs which are common in numbers and biomass in the area were collected, and Cadmim(Cd) was subjected as a reference metal in the experiment. The corresponding species were; Cipango;aludina chinensis (muddy snail) and Scapharca subcrenata (seashell). As methods, sample species were kept in laboratory under the natural condition as possible. Soil were brought from the site of the collection, dried autoclaved and wetted with ordinary water. It wad utilized as media to maintain the collected species in vitro all the way of the experiment. CdCI$^{2}$ was mixe in the medium according to experimental design. On the result obtained in the study, it is summarized that molluscs which inhabit along Mangyeong Gang(river)consume heavy mital-containing matters, so far Cd is concerned in the study. The amout of Cd concentration in tissues of the benthic natured invertebrates were dose and time related, and MT-Cd was also similar trend. Thus, Cd may eventually combine with low molecular protein forming metalloprotein, then reduce the toxicity of the heavy metal.

• Journal of Species Research
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• 제11권1호
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• pp.38-46
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• 2022

This study is based on crane fly specimens collected during more than 80 years, starting from 1938 through 2019, in the Republic of Korea and Democratic People's Republic of Korea and are in collections maintained at the United States National Museum, Smithsonian Institution, Washington DC, USA; the Snow Entomological Museum, University of Kansas, Lawrence, KS, USA; and the National Institute of Biological Resources, Incheon, South Korea. Pilaria crane flies are aquatic and semiaquatic, developing in fast running and stagnant water bodies and in wet muddy places at the margins of water pools. Such habitats usually prevail at lower altitudes, but these areas most often are used for agriculture and human settlement, making natural habitats scarce and fragmented. Pilaria crane flies are rare, thus it is not surprising that genus was left unnoticed by previous researchers. The genus Pilaria Sintenis, 1889 with two species P. melanota Alexander, 1922 and P. simulans Savchenko, 1983, is a new record for the Korean Peninsula. We present general information on the genus, redescriptions of species based on Korean specimens, illustrations of both sexes, elevation range, period of activity, habitat information, general distribution, and a distribution map for the Korean Peninsula for each species.

• 한국지구과학회지
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• 제45권4호
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• pp.338-348
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• 2024

In the mid-eastern part of the Yellow Sea, large-scale shelf ridges originated from erosion on sand-mud successions that have been presently eroded by strong tidal currents. A three-layered in situ geoacoustic model is provided down to 50 m for the subbottom sedimentary succession of a 45 m water depth using the Hamilton method. The succession is divisible into two-type units of Type-A and Type-B using high-resolution seismic profiles with a deep-drilled YSDP-104 core of 44.0 m in depth below the seafloor. Type-A unit mainly comprises sandy or gravelly sediments, whereas Type-B unit mostly consists of tidal muddy sediments with some thinner sand beds. P-wave speed values are positively compatible with the mean grain size and sediment type of the core sediments. For actual modeling, the geoacoustic property values of the models were compensated to in situ depth values below the seafloor. The detailed geoacoustic model contributes to simulating sound transmission through the sedimentary successions in erosional shelf ridges of variable geoacoustic properties distributed in shallow-water environments of the mid-eastern Yellow Sea.

• 한국해양환경ㆍ에너지학회지
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• 제12권3호
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• pp.202-208
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• 2009

갯벌과 주변 연안역 사이의 물질순환, 특히 영양염 순환에 있어서의 갯벌의 역할을 이해하기 위해 서해 남부 해역의 대표적 갯벌인 함평만 입구에서 4차례(2008년 8월 5일과 18일, 2008년 10월 28일, 2009년 2월 9일)에 걸쳐 조위변화에 따른 영양염 변동을 조사하였다. 연구 결과에 의하면 수온은 조위변화에 따라 여름철 간조시 높고 만조시 낮은 반면, 가을과 겨울철은 간조시 낮고 만조시 높아 여름과 대조적인 경향을 보인다. 염분은 조위가 상승함에 따라 외해수가 유입되어 여름/겨울철에 만조시 높고, 간조시 낮은 일반적인 경향을 보이는 반면, 가을철에는 만조시 낮고 간조시 높은 반대의 경향을 보인다. 모든 계절에서 만조와 간조시 염분의 차는 0.3 psu미만이였다. 한편 함평만에서 관측된 모든 영양염은 조위변화에 따라 여름철 만조시 낮고 간조시 높은 반면, 겨울철은 만조시 높고 간조시 낮아 여름철과 반대의 패턴을 보인다. 특징적으로 가을철은 조위변화에 따른 뚜렷한 농도변동을 보이지 않았다. 이러한 결과는 함평만 갯벌이 여름철에는 영양염의 공급원으로 겨울철에는 영양염의 제거원으로 작용하고 있음을 보여준다. 이와 같은 영양염 계절별 조위변동은 외해수와 갯벌에서의 영양염 농도 차이를 반영하는 것으로 갯벌과 외해수 사이의 상호 복합적인 요인에 의해 나타나는 것으로 사료된다.

• 생태와환경
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• 제41권1호
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• pp.73-80
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• 2008

본 연구에서는 고탁도의 사육조건에서 탁수가 어류의 조직과 생리에 미치는 영향을 조사하기 위하여 참갈겨니의 아가미와 신장을 사용하였다. 탁도가 높고 사육기간이 길어질수록 아가미에서는 이차 새변의 간격이 불규칙해지고, 곤봉화, 부종, 상피세포의 박리가 나타났으며 새변 사이에는 이물질의 부착이 두드러지게 관찰되었다. 신장조직에서도 탁도의 증가에 따라 사구체가 수축되고 있으며 보우만 주머니의 공간이 넓게 관찰되었다. 고탁도의 탁수가 아가미와 신장 조직 내 항산화효소의 활성에 미치는 영향을 조사해 보면 SOD활성은 아가미와 신장 조직에서 고탁수로 감에 따라 활성이 증가하였으나 CAT와 GPX의 활성은 주로 신장에서 높은 활성을 나타내었다. 즉 고탁수의 스트레스에 의해 생성되는 유해한 라디칼은 주로 신장 조직의 항산화효소에 의해 제거하는 것으로 사료된다. 탁도 변화에 따라 어체에 축적되는 미량 중금속 농도의 경우 탁도가 매우 높은 1,000 NTU에서는 대조실험군 어류에 비해 중금속의 함량이 급격히 증가되는 경향을 보이고 있다. 이러한 결과로 보아 장기간 고탁도가 유지된다면 아가미와 신장 조직은 비정상적인 형태로 변형되고 중금속은 체내에 급격히 축적됨으로 치명적인 유해 작용을 나타낼 수 있을 것으로 생각된다.

• 환경영향평가
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• 제18권6호
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• pp.461-467
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• 2009

This paper provides two case studies of environmental impacts with socio-economic values. The first case is on flood protection levees conducted from 2003 to 2004 in Phu Tan district, An Giang province. The impacts were found by comparing full flood protection levees area (FFPL) to non-full flood protection levees area (NFFPL). Participatory Rural Appraisal (PRA) tools per each group of rich, middle, and poor people were used to list the impacts. Then, major impacts were selected by ranking and interviewing 60 households per site, and assessed by Cost Benefit Analysis (CBA) in rice production from 1996 to 2002 between two areas. The tested research indicated moving system of NFFPL to that of FFPL lost about 11 million VND/ha/year. The second case is on impacts of Penaeid shrimp farming conducted in Duyen Hai District, Tra Vinh Province in 2004-2005. Ninety households and 12 local officials were interviewed. Four PRAs were conducted and 36 water samples were taken inside and outside shrimp pond to measure values of DO, COD, Fe total, TSS, N-$NO_3{^-}$, N-$NH_4{^+}$, P-$PO{_4}^{3-}$, and Chlorophyll-a. Research results showed only 36.7% of the households got profit from shrimp farming. Highest financial efficiency was 0.72 for the semi-intensive system. Tested water indicators showed surface water quality did not match Vietnamese standard for surface water in coastal area (TCVN 5943-1995) and in rain. The water was very muddy and contaminated by organic aluminum. Summarily, the impacts were clarified more obviously via adding socio-economic values to assessment. Importantly, the values were transformed to household's income which is an indicator for policy-makers to consider the impacts obviously. Besides, data of different group of people impacted are cases contributing to consideration of the impacts in an appropriate social level.

• 한국물환경학회지
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• 제31권6호
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• pp.644-652
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• 2015

In this study the releasing of nutrients from sediments of Nak-dong River were investigated. We perfomed lab-scale simulation experiments using field sediment and ware. Nutrients, orgarni matter, particle size of the sediments and nutrients of released water were analyzed. Analyzed results of the sediments, mainly composed of mS(muddy Sand) sedimentary facies and IL were 2.46~6.83%, T-N were 1.189~2.492 mg/kg, and T-P were 333~726 mg/kg in the study area. Analyzed results of the nutrients of released water, pH and TOC were each 7.8~9.2% and 31.7~40.8% decreased after 20 days. T-N increased steadily, and NH₃-N increased steadily then decreased, at this time NO₃-N increase. Also NH₃-N increased steadily, then decreased at this time. Furthermore release of phosphorus were mostly decreased.

• 한국환경보건학회지
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• 제35권3호
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• pp.220-225
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• 2009

This study evaluates the water quality of the river near the alpine farmland in the upper Naerin stream, which is a typical stream of the upper Bukhan River with muddy water generation, by the flow examination, it aims to estimate the characteristics of nonpoint sources flowing out from the investigated area and figure out effective methods to reduce them. According to the result of water quality examination, the average BOD of the area not affected by the cultivated land among the areas of the upper Naerin River was 0.47mg/l, and total phosphorous was 0.007mg/l; thus, it maintained the cleanliness level of Ia. The average BOD of the area with the alpine farmland was 0.52mg/l, which was similar to the one of the non-cultivated land. But total phosphorous concentration was 0.023mg/l, which was more than three times higher than the area belonging to level II due to the effect of fertilizer ingredients discharged from the cultivated land. About the loadings of the investigated area generated from each of the pollution sources, BOD was 878.5kg/day and total phosphorous was 79.7kg/day. Moreover, for the load density, BOD was $2.22kg/day.km^2$ and total phosphorous was shown as $0.20kg/day.km^2$. Regarding the rates generated from nonpoint sources like land among the loadings per pollution sources, BOD was 54%, total nitrogen was 91%, and total phosphorous was 73.4%. Therefore, it was shown that most of the nutrients were produced from the nonpoint sources. The level of BOD runoff loading in the Jaun River area, where nonpoint sources were mainly generated, was 37.1kg/day and total phosphorous was 1.33kg/day. The flow rates to the generated amount were estimated as 10.5% and 4.7% each.

• 한국재난정보학회 논문집
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• 제14권2호
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• pp.165-173
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• 2018

연구목적 : 유적지와 같은 지역은 과거 산으로 둘러 쌓인 구릉지 등에 분포할 경우 강우시 매립층에 분포하는 흙은 투수능력이 떨어져 물이 원활히 배수되지 못하고 표층부의 함수비가 증가하여 지반의 질퍽임 현상이 많이 나타나고 있다. 본 연구는 강우시 배수가 불량하여 유적지에 분포하는 문화재의 기초 뿐만 아니라 상부구조물에도 큰 영향이 예상되어 배수불량의 원인을 파악하고자 하였다. 연구방법 : 현장에서 각종 지반조사 및 현장투수시험 그리고 지하수 모니터링을 통해 그 상관성을 분석하여 매립층의 배수에 대한 불량 원인을 파악하였다. 연구결과 : 본 연구결과 배수불량 원인은 부지내 지하수위가 매우 얕은 심도에 형성되어 있으며, 지표부 및 매립층의 토질은 투수성이 불량한 상태로 강우시 지하로 지표수가 침투되기에는 매우 부적합한 수리지질학적 여건임을 확인할 수 있었다.