• Title/Summary/Keyword: oceanic ecosystem

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Phytohydrographic Plankton Studies during the First Half of the 20th Century in Korean Neritic Seas (20세기 전반 한국 근해역 플랑크톤의 식물수문학적 연구)

  • PARK, JONG WOO;KIM, HYUNG SEOP;YIH, WONHO
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.24 no.3
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    • pp.483-494
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    • 2019
  • From the cosmopolitan superiority of the as the first world map completed in 1402 with surprisingly detailed images and contents on the Africa Continent it is reasonable to think that the Koreans in early fifteen century were already with highly up-to-date perspectives on the universe and world history and cultures. However, some 490 year later the first phytohydrographic plankton investigation in the neritic seas of Korea was performed by a Japanese company with sampling points covering from Tokyo Bay through Jeju neritic waters to Shanghai estuary, which was in turn preceded by the first oceanographic investigation other than the simple mapping Koreans seas by using two French sailboats. The first phytohydrographic plankton investigation in Korean seas were behind the world first oceanic plankton exploration, the German Plankton Expedition, by 25 years. Starting from the oceanographic investigation including phytohydrographic samplings in the whole Yellow Sea in 1915 the full-scale phytohydrographic plankton studies were tried in Korean seas which is well represented by the 1921 oceanographic investigation on the whole East Sea with 80 sampling stations. In 1932 two separate oceanographic investigations followed, one in the East Sea where 78 stations from Busan to southern Sakhalin Island were simultaneously visited by 50 research vessels for the physical, chemical, and biological oceanographic studies, and the other one in southern coast and western East Sea of Korea where ocean current observation as well as plankton sampling were made in 120 stations to understand the relationship between the ocean current and plankton distribution in the region. In 1933-1934 more intensified investigations on phytohydrography were carried out particularly in the East Sea as an integral part of the basic marine ecosystem studies for the Myeong-Tae (Alaska Pollock) resources estimation. Scientists' attitude for the marine investigation and research activities seemed to be almost unchanging even to the year 1943, which could be reflected by the fact that publication of the results from the investigations performed in 1945 were finally done in 1967 at Tokyo. Some 70 years later from the mid-twenty century we might be standing on the turning-point of "need to be prepared" for the new era of changing paradigm by reviewing, archiving, and analyzing the prior information big data from the previous ocean observation and biohydrographic investigations. At the same time each professional societies for the above mentioned sciences might trigger a continuous project to reorganize and update the records on related bibliography and its history every 30 years.

Evaluation of the Sediments Contamination in the Lake Sihwa (시화호 퇴적토의 오염도 평가 및 효과적 관리방안)

  • Kim, Seung-Jin;Bae, Woo-Keun;Shin, Kyung-Hoon;Choi, Dong-Ho;Baek, Seung-Chun;Yoon, Seung-Joon;Choi, Hyung-Joo
    • 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.

Monitoring of the Estuary Sand Bar Related with Tidal Inlet in Namdaecheon Stream using Landsat Imagery (Landsat 위성 영상을 활용한 강원도 양양군 남대천 연안 하구사주 갯터짐 환경 모니터링)

  • Jang, Jiwon;Eom, Jinah;Cheong, Daekyo;Lee, Changwook
    • Korean Journal of Remote Sensing
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    • v.33 no.5_1
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    • pp.481-493
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    • 2017
  • Estuary sand bar of Namdaecheon Stream is located in Yangyang-gun, Gangwon-do in Korea. This unique place is situated between end of Namdaecheon Stream and East Sea. It is an important environment area of the global ecosystem from the transition zone of land and marine environments by forming a variety of coastal circumstance. Some endemic species should be protected which is appearing in the Namdaecheon Stream because of preservation for future generations. Especially, the salmon return to this stream as adults in order to breed which is more than 70 % of the salmon in Korea peninsular. The monitoring of estuary sand bar is need to analyze ecological environment and sustainable development with time. First of all we represents a different shape of estuary sand bar of Namdaecheon Stream from 1984 to 2015 using Landsat satellite imagery series. Particularly movement of the "tidal inlet" is most important factor to investigate the condition of the change for estuary sand bar. The location of tidal inlet is compared with precipitation, height of tide and oceanic current data according to time variation.

Study on Contration Distribution of HCB and DDTs in River Sediments of Korea (국내 주요 수계 표층 퇴적물 중 HCB와 DDTs의 농도분포 특성에 관한 연구)

  • Park, Jong-Eun;Lee, Sang-Chun;Hong, Jong-Ki;Kim, Jong-Guk
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.5
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    • pp.335-344
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    • 2012
  • Hexachlorobenzene (HCB) and Dichloro-Diphenyl-Trichloroethane (DDT) were determined in surface sediments collected from main rivers of Korea. Concentration of HCB in sediments ranged from 0.41 to 3.82 (average 1.58) ng/g, 0.08 to 6.09 (average 0.90) ng/g, 0.02 to 0.97 (average 0.30) ng/g, 0.28 to 0.59 (average 0.42) ng/g and 0.23 to 0.48 (average 0.32) ng/g in Han river, Nakdong river, Geum river, Yeongsan and Seomjin river respectively. The DDTs concentration was ranged from 0.67 to 14.20 (average 4.76) ng/g, N.D. to 10.36 (average 1.81) ng/g, N.D. to 7.26 (average 1.87) ng/g, N.D. to 3.12 (average 1.08) ng/g and 0.02 to 2.04 (average 0.56) ng/g in Han river, Nakdong river, Geum river, Yeongsan and Seomjin river respectively. In comparison with the concentration of HCB and DDTs in other studies, the values in sediments of this study were lower than those of other countries. Comparison with that Sediment quality guideline (SQG) of National Oceanic and Atmospheric Administration (NOAA), the HCB levels of this study were very lower than Effect Range Low (ERL) value. In the case of DDTs, the concentrations of 46 points were higher than ERL (1.58 ng/g). It have not harmful effect on ecosystem of the sediment, however ongoing monitoring of sediments is deemed necessary.

Establishment of Thermal Infrared Observation System on Ieodo Ocean Research Station for Time-series Sea Surface Temperature Extraction (시계열 해수면온도 산출을 위한 이어도 종합해양과학기지 열적외선 관측 시스템 구축)

  • KANG, KI-MOOK;KIM, DUK-JIN;HWANG, JI-HWAN;CHOI, CHANGHYUN;NAM, SUNGHYUN;KIM, SEONGJUNG;CHO, YANG-KI;BYUN, DO-SEONG;LEE, JOOYOUNG
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.22 no.3
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    • pp.57-68
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    • 2017
  • Continuous monitoring of spatial and temporal changes in key marine environmental parameters such as SST (sea surface temperature) near IORS (Ieodo Ocean Research Station) is demanded to investigate the ocean ecosystem, climate change, and sea-air interaction processes. In this study, we aimed to develop the system for continuously measuring SST using a TIR (thermal infrared) sensor mounted at the IORS. New SST algorithm is developed to provide SST of better quality that includes automatic atmospheric correction and emissivity calculation for different oceanic conditions. Then, the TIR-based SST products were validated against in-situ water temperature measurements during May 17-26, 2015 and July 15-18, 2015 at the IORS, yielding the accuracy of 0.72-0.85 R-square, and $0.37-0.90^{\circ}C$ RMSE. This TIR-based SST observing system can be installed easily at similar Ocean Research Stations such as Sinan Gageocho and Ongjin Socheongcho, which provide a vision to be utilized as calibration site for SST remotely sensed from satellites to be launched in future.

Counting Harmful Aquatic Organisms in Ballast Water through Image Processing (이미지처리를 통한 선박평형수 내 유해수중생물 개체수 측정)

  • Ha, Ji-Hun;Im, Hyo-Hyuk;Kim, Yong-Hyuk
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.6 no.3
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    • pp.383-391
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    • 2016
  • Ballast water provides stability and manoeuvrability to a ship. Foreign harmful aquatic organisms, which were transferred by ballast water, cause disturbing ecosystem. In order to minimize transference of foreign harmful aquatic organisms, IMO(International Maritime Organization) adopted the International Convention for the Control and Management of Ship's Ballast Water and Sediments in 2004. If the convention take effect, a port authority might need to check that ballast water is properly disposed of. In this paper, we propose a method of counting harmful aquatic organisms in ballast water thorough image processing. We extracted three samples from the ballast water that had been collected at Busan port in Korea. Then we made three grey-scale images from each sample as experimental data. We made a comparison between the proposed method and CellProfiler which is a well known cell-counting program based on image processing. Setting of CellProfiler is empirically chosen from the result of cell count by an expert. After finding a proper threshold for each image at which the result is similar to that of CellProfiler, we used the average value as the final threshold. Our experimental results showed that the proposed method is simple but about ten times faster than CellProfiler without loss of the output quality.

Ecological Investigations on the Managed Forests in Northwestern Europe and Tree Seed-Orchard System (북구(北歐)의 우량임분(優良林分)의 생태(生態) 및 채종원(採種園) 체계(體系)에 관(關)한 연구(硏究))

  • Kim, Chi Moon
    • Korean Journal of Agricultural Science
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    • v.9 no.1
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    • pp.239-249
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    • 1982
  • The outlines of superior stands, including species mixed, age classes, canopies, and ecological conditions of the stands, were examined in the forests of west Germany, Sweden, and Netherland. The establishment schemes of tree seed orchards for the production of high genetic quality seed were also investigated in the present study. 1. The meteorological conditions, abundant in precipitation and high in relative humidity, prove it to be oceanic climate characteristics in the Scandinavia located in high latitude and north-western part of Europe. The photo periodical characteristics following to day-length and the frost times determine the patterns of tree growth and distribution as well as the tree adaptability due to bud-setting and bud-flushing in Sweden forest. 2. The European forests are generally characterized by dense multistoried forest type composed of upper stories of tall tree species such as Norway spruce, fir, Scots pine and beech, lower stories of shade tolerant poles and saplings of spruce, fir, beech, and floor vegetations covered with birch, oak and hornbeam etc. 3. The single tree selection method and group shelterwood method are commonly applied for silvicultural system but shelterwood method and clearcutting method practiced partially in limited area. Badischer Femelschlagbetrieb and Bayerischer Femelschlagbetrieb are popularized to the regeneration of Schwarzwald but selection method applied in part. 4. Tree cuttings are properly limited so as not to exceed annual increment volume for the sustained yield and the preservation of ecosystem in European forest management. Land preservation and recreation function are more interested with the promotion of wood production in the forest management. 5. Careful attentions are paid to the reforestation of the introduced exotic species, such as Douglas-fir, red oak, pines from America, Japanese larch, Italian poplar etc., with concern against the insect and pest damage, and the meteorological damage. 6. Some intensive studies on tree improvement, such as selection of plus tree, selection of plus stand for seed collection, provenance trial, progeny test of clone, hybrid seed orchard for clone complexing, are performed in the countries and the great part of the seed required for reforestation are supplied from the seed orchard established in Sweden and Netherland.

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Blue Carbon Resources in the East Sea of Korea and Their Values and Potential Applications (동해안 블루카본 자원의 가치와 활용방안)

  • Yoon, Ho-Sung;Do, Jeong-Mi;Jeon, Byung Hee;Yeo, Hee-Tae;Jang, Hyeong Seok;Yang, Hee Wook;Suh, Ho Seong;Hong, Ji Won
    • Journal of Life Science
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    • v.32 no.7
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    • pp.578-587
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    • 2022
  • Korea, as the world's 7th largest emitter of greenhouse gases, has raised the national greenhouse gas reduction target as international regulations have been strengthened. As it is possible to utilize coastal and marine ecosystems as important nature-based solutions (NbS) for implementing climate change mitigation or adaptation plans, the blue carbon ecosystem is now receiving attention. Blue carbon refers to carbon that is deposited and stored for a long period after carbon dioxide (CO2) is absorbed as biomass by coastal ecosystems or oceanic ecosystems through photosynthesis. Currently, there are only three blue carbon ecosystems officially recognized by the Intergovernmental Panel on Climate Change (IPCC): mangroves, salt marshes, and seagrasses. However, the results of new research on the high CO2 sequestration and storage capacity of various new blue carbon sinks, such as seaweeds, microalgae, coral reefs, and non-vegetated tidal flats, have been continuously reported to the academic community recently. The possibility of IPCC international accreditation is gradually increasing through scientific verification related to calculations. In this review, the current status and potential value of seaweeds, seagrass fields, and non-vegetated tidal flats, which are sources of blue carbon on the east coast, are discussed. This paper confirms that seaweed resources are the most effective NbS in the East Sea of Korea. In addition, we would like to suggest the direction of research and development (R&D) and utilization so that new blue carbon sinks can obtain international IPCC certification in the near future.