• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.4
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• pp.467-487
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• 2013

Long-term and systematic monitoring of phytoplankton is important, as phytoplankton serve as indicators of water quality status in aquatic environments. In the present study, the plankton community structure of the Nakdong River estuary over the past 30 years was investigated by literature survey to provide references for the occurrence of planktonic species. A total of 876 species from 18 taxonomic lineages were reported and, among them, 569 species were identified to occur seasonally at the Mulgeum, Seonam and Eulsukdo sites. Diatoms and chlorophytes were dominant in the microscopic studies. The 54 species at the Mulgeum and the 96 species at the Eulsukdo sites have not been reported since the river barrage construction in 1987. The majority of reports speculate that there has been a change in the aquatic environment, particularly the plankton community structure, due to operation of a river barrage since 1987.

• Proceedings of the KSRS Conference
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• v.1
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• pp.138-141
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• 2006

In developing algorithms to retrieve the sea surface temperature (SST) and sea surface wind speed from the Advanced Microwave Scanning Radiometer (AMSR) aboard the AQUA and the Advanced Earth Observation Satellite-II (ADEOS-II), data from the SeaWinds aboard ADEOS-II were helpful. Since features of the ocean microwave emission (Tb) related with ocean wind are not well understood, in case of using only AMSR data, combination of AMSR and SeaWinds revealed pronounced features about the ocean Tb. Two results from combinations of the two sensors were shown in this paper. One result was obtained at wind speeds over about 6m/s, in which the ocean Tb varies with the air-sea temperature difference, even though the SeaWinds wind speed is fixed at the same values. The ocean Tb increases as the air-sea temperature difference becomes negative, i.e., the boundary condition becomes unstable. This result indicates that the air temperature should be included in AMSR SST algorithm. The second result was obtained from comparison of two wind speeds between AMSR and SeaWinds. There is a small difference of two wind speeds, which might be related with several mechanisms, such as evaporation and plankton.

• Journal of Environmental Health Sciences
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• v.7 no.2
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• pp.97-105
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• 1981

Water Pollution of Gwangju Stream was examined for four months from 22 March 1981 to 7 June, 1981. For checking the water pollution, 6 sampling positions were selected 5 from main stream. We assumed that the water pollution of Gwangju stream was due to the organic materials, which came from the domestic sewage. The apparatus for this test were pH meter (Orion model 301), Dissolved Oxygen & Temperature meter(Delta model 1010). The results we obtained are as follows: 1. The average range for mid-stream(sp. 3, 4) was 3. 10~2.73ppm of Dissolved Oxygen(DO), 80.23~102.95ppm of Biochemical Oxygen Demand (BOD), 195. 10~165.90ppm of Suspended Solid (SS), 6.6~6.7 of pH. 2. The plankton identification in this survey period showed Cyanophyceae is 4 genera 5 species, Bacillariophycea 11 genera 14 species, Chlorophyceae 8 genera 15 species and Zooplankton 6 genera 7 species: total 29 genera 41 species. 3. To appear dominant plankton in polluted water, there were Paramecium, Euglena and Oscillatoria. 4. The results of biological water analysis were as follows: st. 1 was B-mesosaprobic to oligosaprobic, but st. 4 and st. 5 at stream in the midtown area seemed to be polysaprobic.

• Korean Journal of Environmental Biology
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• v.28 no.2
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• pp.86-94
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• 2010

This study compares and contrasts the dynamics of plankton in 31 temperate lakes and reservoirs, and considers particularly the biomass ratio of zooplankton to phytoplankton and ecological model application. A total of 89 species of zooplankton were identified (70 rotifers, 14 cladocerans and 5 copepods) and a total of 554 species of phytoplankton were identified (176 Bacillariophyceae, 237 Chlorophyceae, 68 Cyanophyceae, and 73 other algal taxa). The total plankton abundance and species diversity were showed distinctive spatial and seasonal variation. Annual average phytoplankton density was $7,350{\pm}15,592$ cells $mL^{-1}$ (n=124), and the lowest was $855{\pm}448$ cells $mL^{-1}$ (n=4), while the highest was $72,048{\pm}13,4631$ cells $mL^{-1}$ (n=4). For zooplankton, small rotifer groups dominated the study sites, and approximately 3~10 species appeared in the study sites. Statistical analysis and an ecological model application revealed that the size of reservoirs affected the structure size of plankton community, i.e. relatively large number of species were found in smaller reservoirs. From this result, we can conclude that management strategy for the reservoir environment has to be focused more on small-size reservoirs, in terms of plankton community ecology.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.5
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• pp.358-368
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• 2011

Responses of plankton populations to nutrient enrichment in mesocosm experiments in Shihwa lake were simulated using FVCOM. Dissoloved oxygen module was added to the FVCOM to simulate impacts of its decreased levels. The ecological model included the major components of the pelagic ecosystem including nutrients, phytoplankton (pico-, nano-, micro-), zooplankton (two groups of protozoa, mesozooplankton), particulate organic matter, dissolved organic matter and bacteria, and was calibrated using trophodynamic data collected from Gyeonggi Bay and Shihwa Lake. The model was able to reproduce major responses of plankton populations to nutrient enrichment, including phytoplankton of different size groups, change of dominance of protozoa from < 20 ${\mu}m$ oligotrichs to scuticociliates, and reponses to bacteria and low levels of dissolved oxygen in water column of the mesocosms.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.6
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• pp.459-471
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• 1991

The community structure and micro-scale distribution of plankton in relation to hydrography were investigated in Masan Bay, Korea in October 1989. Warmer and less saline waters with stratification was located in the inner part of the Pudo Strait, and chlorophyll-a and nutrients were higher. Both phytoplankton biomass and nutrients was changed dramatically around the Strait. Offshore/oceanic species in phytoplankton i.e., Chaetoceres decipiens, Rhizosolenia stolterforthii, Rhizosolenia styliformis and Ceratium trichoceros and zooplankton i.e., Sagitta enflata, Oncaea uenusta and Oikopluera longicaudata occurred mainly in well mixed waters of the outer part. This suggests that discontinuous layer seems to play an important role as an approximate border for the plankton population. This layer was located between Station 3 and Station 4 near the Pudo Strait, since the layer consisted of a series of micro-scale discontinuties of salinity and dissolved inorganic nutrients gradient. Phytoplankton patchs of more than 801e1 were found only in the inner part of the bay. Depletion of silicate caused by a rapid assimilation of phytoplankton in the inner part of the bay seemed to be responsible for the decline of blooms.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.362-369
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• 2013

Phytoplankton and zooplankton communities were investigated from 8 weir sites of the Nakdong River system to provide basic information on plankton community after weir construction and to estimate its effects on major water quality parameters. The relationship between plankton community structure and environmental factors was analysed with CCA (Canonical Correspondence Analysis). The results suggested that discharge and total phosphorus and nitrogen concentrations are important factors determining the phytoplankton species composition. For zooplankton community, the difference in discharge between September and October induced different distribution pattern of zooplankton community with more homogeneous distribution with extreme dominance of rotifers during the high discharge season. Chlorophyll a concentration representing phytoplankton biomass has been suggested as the main environmental factor affecting zooplankton community followed by COD and total nitrogen concentration.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.3
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• pp.248-262
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• 2021

Marine planktonic ciliates include two major groups, loricated tintinnids and naked oligotrichs. The study of marine ciliate plankton in Korea began with taxonomic efforts on tintinnids based on the morphology of lorica, a vase-shaped shell. Despite polymorphism in the lorica, it is utilized as a key characteristic in identification of tintinnid species. However, oligotrichs have been studied only recently in Korea due to challenges associated with the observation of ciliary arrangements and the technical development for cell staining. Species diversity and phylogenetic classification of the ciliates have been informed by recent advances in morphological and molecular analyses. Illustrations of the planktonic ciliate in Korea have been published on the basis of taxonomic data of tintinnids and oligotrichs. Planktonic ciliates acting as the major consumers of pico- and nanoplankton as well as the prey of mesozooplankton, has been monitored by spatial and temporal investigations in Korean coastal waters. A practical approach addressing the limitations and potential of marine ciliate studies in Korea is proposed here to improve the data quality of planktonic ciliates, providing an enhanced basis for quality control of ciliate monitoring.

• Animal Systematics, Evolution and Diversity
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• v.26 no.1
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• pp.67-70
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• 2010

Some physonect and cystonect siphonophores were collected from the East Sea ($36^{\circ}30'124'N$ and $130^{\circ}06'446'E$) with horizontal plankton net on May and Oct. 2001. Among them the following two species were turned out to be new to the Korean fauna: Bathyphysa grimaldii Bedot, 1893; Agalma okenii Eschscholtz, 1825.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.1-4
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• 2002

This article presents the unique characteristics of cavitation, those are very high pressure and very high temperature even in a very short time. Such the high-pressure causes the destruction of material, which sometimes brings a severe problem to fluid machinery. However, if we look the cavitation from the different direction, such the high pressure can be used to various applications. The author presents two examples of the utilization of cavitation recently done at the Toyo University. Those are 'dispersion of spilled oil' and 'killing planktons'.