• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.2
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• pp.95-111
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• 2012

Relationship between plankton assemblage and environmental factors in a semi-closed Chunsu Bay was examined. Temporal changes in phytoplankton assemblage was rather drastic than those found in most Korean coastal area in the Yellow Sea primarily due to the seawater temperature (T) and nutrient input from the dikes nearby. Freshwater discharge seemed to cause winter time increase of Diatoms (February) and summer time increase of Dinoflagellates at surface (July to August). Structural change in cell size with time was also found in Diatom. Zooplankton community structure was also changed with season probably due to the food concentration, seawater temperature and salinity (S). From principal component analysis (PCA) of zooplankton distribution, it was postulated that seasonal environmental changes such as T and S could explain about 32% of variability in zooplankton distribution along with phytoplankton cell numbers, while freshwater discharge could explain about 17%. Comparing with past data of 1985-1986, 1991-1992, the distributional patterns and percent composition of major species, Acartia hongi, Paracalanus parvus sensu lato and Centropages abdominalis, were similar. However, the abundances have been increased more than three times. The composition of other taxa than copepods showed significant changes.

• Journal of the Korean Institute of Landscape Architecture
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• v.16 no.2
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• pp.1-7
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• 1988

Predicting treeform should be very important, eventhough it is difficult, step for landscape designers. This study was carried out to develop a method to classify the treeforms of landscape plants by numerical data. Twenty five treeforms are selected to be compared with 41 Zelkova serrata MAKINO, 26 Pinus strobus L., and 44 Magnolia denudata DESROUX. Statistical judgement was made by using X$^2$-Test. The results are summerized as follows. 1. Zelkova serrata was classified as B3 or C3. This species showed a tendency of changing from A type to B or C type, and the CL/CH ratio(canopy length/canopy height) is thought to be increased as aged. 2. pinus strobus was classified as D4-D5 and the CL/CH ratio tends to be increased as aged. 3. Magnolia denudata was classified as D4 and the change by aging was not observed clearly.

• Korean Journal of Environment and Ecology
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• v.29 no.3
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• pp.353-367
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• 2015

The goal of this study is to analyze the feedback structure of habitat changes of the Whooper Swan in Eulsukdo using system thinking to suggest a management plan for ecosystem health. Using the causal loop diagrams of population changes between Whooper Swan and other bird species in Eulsukdo, we found that the environmental changes in the roosting and foraging area affect the Whooper Swan's population. The causal loop diagrams of the Whooper Swan's roosting area indicated that the environmental changes (e.g., water level, noise, bird watching, and other experience activities) may influence their population density variation. In addition, the casual loop diagrams of the Whooper Swan's foraging area showed that the Whooper Swan's population was affected by various variables that included area factors such as surface area of freshwater, frozen water, salinity, and density of Scirpus planiculmis. Furthermore, through the integrated causal loop diagram, cumulative discharge of Nakdong estuary weir and building activities were identified as the variables that affect the population of the Whooper Swan. Thus, we selected this area as the strategic point to establish a management plan for the Whooper Swan's habitat. The results of this study will help in decision making of a long-term management plan for sustaining the environmental health of the ecosystem in Eulsukdo.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.3
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• pp.740-746
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• 2011

The variations of catch of anchovy and saury due to oceanic climate change in the Korean Seas were studied. This study area was $31^{\circ}{\sim}38^{\circ}$ N and $124^{\circ}{\sim}132^{\circ}$ E. And data (seawater temperature, salinity, dissolved oxygen) is used from NFRDI (National Fisheries Research and Development Institute) and SST (Sea Surface temperature) obtained to satellite images (NOAA/AVHRR) during 2000 to 2009. The spatial characteristics are analyzed by GIS (Geographic Information System). The results showed that the average of seawater temperature in the depth of 20m increased $1.45^{\circ}C$ in the South Sea and $0.83^{\circ}C$ in the East Sea, respectively. The maximal catch of anchovy was highest in summer (July~September) and winter (December~March), respectively, in compared with spring (April~June). Catch of anchovy has increased since 2000. The maximal catch of saury was highest in spring (May~June), in compared with spring (August~September). The increment of seawater temperature contributed to increase the catch of anchovy, but catch of saury was decrease in the same times.

• The Korean Journal of Malacology
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• v.28 no.1
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• pp.73-79
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• 2012

Seasonal changes in biochemical composition of muscle, gonad-viceral, mass and whole body of the cultured ark shell, Scapharca broughtonii in the Gamag bay of Yeosu city were studied from December 2008 to November 2009 in relation to environmental condition and reproductive cycles. Average monthly water temperature in the winter was in the range of $7-12^{\circ}C$ and $20-25^{\circ}C$ in the summer, while the salinity fluctuated in the range of 30.1%-33.8‰ on the average. Seasonal fluctuation of the concentration of nutrient salt was the highest in September ($13.04{\mu}g/L$) with average annual concentration of $4.6{\mu}g/L$. The main spawning season of the ark shell was during the months of July and August, and the gonads were in inactive stage during the winter. The gonad-visceral mass contained lower amounts of proteins than the other body parts. The most marked changes in body composition were lipids and carbohydrates within the gonad-visceral mass, and protein for each of the organs was relatively consistent throughout the year. All the parts in the visceral sac displayed the highest changes during the gametogenic cycle while the contents of moisture and lipid within the visceral act displayed somewhat inverse relations with each other. Moisture content was the lowest during the inactive stage during which the lipid content is the highest. The lipid content was the lowest immediately following spawning with increase in the moisture content as the lipid is being consumed. Protein mass within the visceral sac was low in comparison to the muscle mass. It is deemed that carbohydrates, lipids and proteins in the visceral sac play the major role as the source of energy during the development process of the gonads, and used for maintenance of base metabolism when available food is scarce.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.2
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• pp.105-118
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• 2000

Anchored measurements (12.5 hr) of suspended sediment concentration and other hydrodynamic parameters were carried out at two stations located at the entrance to Hampyung Bay in summer (August 1999). Tidal variations in water temperature and salinity were in the range of 26.0-27.9$^{\circ}C$ and 30.9-31.5, respectively, indicating exchange offshore and offshore water mass. Active tidal mixing processes at the entrance appear to destroy the otherwise vertical stratification in temperature and salinity in spite of strong solar heating in summer. On the contrary, suspended sediment concentrations show a marked stratification with increasing concentrations toward bottom layer. Clastic particles in suspended sediments consist mostly of very fine to fine silt (4-16 ${\mu}$m) with a poorly-sorted value of 14.7-25.9 ${\mu}$m. However, at slack time with less turbulent energy, flocs larger than 40 ${\mu}$m are formed by cohesion and inter-collision of particles, resulting in a higher settling velocity. Strong ebb-dominated and weak flood dominated tidal currents, in the southwestern and the northeastern part, respectively, result in a seaward residual flow of -10${\sim}$-20 cm $s^{-1}$ at station H1 and a bayward residual flow less than 5.0 cm $s^{-1}$ at station H2. However, mean concentration of suspended sediments at station H1 is higher at flood (95.0-144.1 mg $1^{-1}$) than in ebb (75.8-120.9 mg $1^{-1}$). On the contrary, at the station H2, the trend is reversed with higher concentration at the ebb (84.7-158.4 mg $1^{-1}$) than that at the flood (53.0-107.9 mg $1^{-1}$). As a result, seaward net suspended sediment fluxes ($f_{s}$) are calculated to be -1.7 ${\sim}$-$15.610^{3}$ kg $m^{-2}$ $s^{-1}$ through the whole water column. However, the stations H1 and H2 show definitely different values of the flux with higher ones in the former than in the latter. Alternatively, depth-integrated net suspended sediment loads ($\c{Q}_{s}$) for one tidal cycle are also toward the offshore with ranges of 0.37${\times}$$10^{3}$ kg $m^{-1}$ and 0.21${\times}$$10^{3}$ kg $m^{-1}$, at station H1 and H2, respectively. This seaward transport of suspended sediment in summer suggests that summer-time erosion in the Hampyung muddy tidal flats is a rather exceptional phenomenon compared to the general deposition reported for many other tidal flats on the west coast of Korea.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.143-144
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• 2003

봄철 해역에 따른 부착미세조류의 영양성분 변화를 알아보기 위하여 본 실험을 수행하였다. 실험은 울진, 부안, 완도, 부산 지역에서 봄철인 2~4월 동안 실시되었으며 실험간의 오차를 줄이기 위해 실험 시작일의 차이는 최대 10일 이내로 하였다. 배양을 위한 실험해역의 기초 조사로 배양지역 연안해수의 수온, 염분, pH, 총질소, 총인, Chlorophyll-a의 측정을 하였고 각 지역의 부착미세조류를 수확하여 영양분석을 하였다. 실험에 사용된 파판은 전복 종묘생산에 이용되는 규조배양용 파판과 틀을 이용하였고 실험기간은 총 8주 동안 실시하였다. 2주마다 파판을 수거한 뒤 부착된 미세조류를 부드러운 솔로 분리하여 원심 분리한 후 지방산과 아미노산의 측정을 하였다. 또 각 시료의 일정량을 Sedwick-rafter counting chamber를 이용하여 검경ㆍ계수한 후 이를 단위면적당 개체수(cells/$\textrm{cm}^2$)로 환산하여 biomass를 구하였다. 봄철 지역간의 수온의 범위는 13.9~16.6$^{\circ}C$를 보였으며 울진이 가장 높고 부안지역이 가장 낮았다. 염분은 부안지역의 염분이 평균 2$\textperthousand$ 이상 낮았으며 그 외의 지역은 큰 차이가 없었다. pH는 7.77~8.21의 범위를 보이고 있었으며 질산염 농토는 부산이 0.265mg/$\ell$로 최대값을 보였고 울진이 0.032mg/$\ell$로 제일 낮았다. 인산염 농도는 완도지역이 0.018mg/$\ell$로 최대치를 보였고 부안은 검출되지 않았다. Chlorophyll-a의 농도는 울진지역이 0.66mg/$\ell$으로 제일 낮았으며 부산이 2.69mg/$\ell$, 부안지역이 2.27mg/$\ell$ 로 높은 값을 보였다. 봄철 지역에 따른 부착미세조류의 아미노산 분석결과는 울진이 실험지역 중 제일 높은 총 아미노산과 필수아미노산의 함량을 나타냈으며 각 지역별로 울진은 4주에 20.3%, 부안은 8주째 8.1%, 완도는 8주째 4.7%, 부산은 6주째 10.4%로 서로다른 시기에 높은 아미노산의 함량을 나타냈다. 실험지역 부착미세조류의 지방산 결과를 보면 전 실험기간동안 지방산 중 대부분은 $C_{18}$이하의 포화 또는 불포화 지방산이 주를 이루고 있었으며 palmitic acid( $C_{16:0}$)와 palmitoleic acid( $C_{16:0}$)의 양이 전체 지방산 함량중 37.47~75.94%로 대부분을 차지하고 있었다. 그리고 n-3HUFA(high unsaturated fat쇼 acids)인 EPA는 부안지역이 2주째 20.85%로 전체 지역중 함량이 제일 높았고, 울진은 실험기간중 6주가 14.76%로 제일 높은 함량을 보였다. 완도는 6주에만 10.97%의 함량을 보였으며 부산지역의 시료에서는 EPA의 검출이 없었다. 봄철 각지역에 설치된 파판에서의 부착미세조류 출현량을 보면 2주째의 부착미세조류량은 부안이 8.3$\times$$10^3$ cells/$\textrm{cm}^2$로 가장 높았고 부산이 0.6$\times$$10^3$ cells/$\textrm{cm}^2$로 가장 낮았다. 울진의 경우 0.7$\times$$10^3$ cells/$\textrm{cm}^2$로 부산과 비슷하게 낮은 출현량을 보였고 완도는 2.4$\times$$10^3$ cells/$\textrm{cm}^2$였다. 4주째의 출현량은 울진지역이 471.1$\times$$10^3$ cells/$\textrm{cm}^2$로 가장 높았으며 부안, 완도, 부산 순으로 출현량이 낮았고 특히 부산은 1.2$\times$$10^3$ cells/$\textrm{cm}^2$로 가장 낮았다. 6주째의 출현량은 울진 지역이 368.6$\times$$10^3$ cells/$\textrm{cm}^2$로 가장 높았으며 부안 89.8$\times$$10^3$ cells/$\textrm{cm}^2$, 완도 25.1$\times$$10^3$ cells/$\textrm{cm}^2$, 부산 5.9$\times$$10^3$ cells/$\textrm{cm}^2$ 순이었다. 8주째의 경우에도 울진, 부안, 완도, 부산이 각각 255.8$\times$$10^3$ cells/$\textrm{cm}^2$, 157.8$\times$$10^3$ cells/$\textrm{cm}^2$, 44.3$\times$$10^3$ cells/$\textrm{cm}^2$, 1.1$\times$$10^3$ cells/$\textrm{cm}^2$로 4주, 6주의 경우와 같은 경향을 보였다.보였다.

• Journal of Animal Science and Technology
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• v.47 no.4
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• pp.513-524
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• 2005

This study was conducted to introduce recycling procedures of food waste(FW) as feed according to the dehydration, semi-dehydration fermentation and liquid fermentation methods through the on-site survey of companies related, to trace physico-chemical components and nutritional losses depending upon the processing stage for each method and finally to suggest more desirable methodology for the efficient utilization of FW as animal feed. For the dehydration method, dewatering of FW alone reduced(P<0.05) moisture(approximately 10%) and ether extract contents and increased(P<0.05) fiber contents. Dewatering and subsequent dehydration of FW decreased(P<0.05) contents of ether extract, limiting amino acids such as lysine, methionine and histidine, pepsin digestibility of protein by half, and NaCl content by 40%, increased(P<0.05) contents of fiber, crude ash, Ca and P, and did not alter(P>0.05) pH. The semi-dehydration fermentation method of FW did not affect(P>0.05) the chemical components, pepsin digestibility of protein, pH and NaCl content. For the liquid fermentation method, pasteurization and fermentation of FW decreased(P<0.05) contents of dry matter, ether extract, crude fiber, lysine and NaCl; however, it did not affect(P>0.05) other chemical components, pepsin digestibility of protein and pH. Among the processing methods, nutrient losses were highest for the dehydration method(25% of metabolizable energy loss, 12% of organic matter loss) and little for the semi-dehydration and liquid fermentation methods. The on-site survey of companies related revealed that the existence of foreign materials in FW products were problematic for all the three companies surveyed, thus it was necessary to develop a more efficient screener. Before feeding FW-containing diets to pigs, high quality of protein and energy feedstuffs needed to be fortified for the dehydration method. For the semi-dehydration fermentation method, the scientific diet formulation technology was required at the initial mixing stage. For the liquid fermentation method, possibly most energetic and proteinaceous feeds needed to be supplemented for the normal animal growth.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.5
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• pp.455-461
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• 2002

limiting nutrients for phytoplankton were determined by dissored inorganic nitrogen/phosphorous (DIN/DIP) in situ and algal bioassay experiment in the Seomjin River estuary during a study period from March 1999 to October 2001. DIN/DIP ranged from 14.7 to 681.1 during the study period. DIN/DIP was over 16 at the upper and middle estuarine region where salinity was lower than 25 psu and chlorophyll a concentration was high, probably indicating P-limitation in this region while the ratio was less than 16 at the high saline (> 25 psu) region, reflecting the supply of DIP from Gwangyang Bay and thereby indicating N-limitation at the lower estuarine region. These results suggested that the spatial distribution of DIN/DIP in the study region was controlled by the high supply of phosphate from Gwangyang Bay, the low input from Seomjin River and the active uptake by phytoplankton within the estuarine system. The bioassay experiments using Skeletonema costatum, Thalaasiosira rotula and in situ phytoplankton assemblage displayed relatively higher growth of phytoplankton in the P-added culture media, indicating P-limitation. This result was well consistent with the spatial distribution of inorganic nutrients. S. costatum showed a rapid adaptation to the low salinity compared to other phytoplankton species. This phenomenon seemed to account for the strong (> $90\%$ in total cell number) S. costatum bloom in autumn in this estuary. Moreover, although phytoplankton growth rate was higher in the P-added culture media at the end of culture experiment of in situ phytoplankton, the fast growth in the trace metal-added media at the beginning of the experiment suggested a possibility of limitation by other micro-nutrients such as trace metal and vitamin etc.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.1
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• pp.52-64
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• 1970

Fingerlings hatched from the eggs of the puffer, Fugu rubripes, which were spawned on May 21, 1969, and were cultivated. The results of their growth during 150 days, until October 25th, are summarized as follows: 1. The eggs began to hatch after 163 hours, at a water temperature of 15.9 to $17.4^{\circ}C$, and the hatching rate was $61.56\%$. 2. They reached the post-larval stage 6 to 7 days after hatching, and at this time a high mortality occurred. The mortality rate was 57.26 to $68.0\%$. 3. Sixteen days after hatching some of the larger fingerlings (6.7mm in total length) began attacking some of the smaller ones (4.6mm in to total length). 4. Twenty five to twenty eight days after hatching, the fish changed their food, and at this time a second high mortality occured. The total mortality rate amounted to 90.7 to $90.9\%$ of the total hatch. 5. After the fingerling stage. cannibalism occurs. The fish usually attack the caudal part of other fingerlings. It occurs regardless of body length and when the food supply is short. 6. The food coeffiicient at the age of 46 days (when body length is 53 to 68 mm) was 5.5 for short-necked clams, 8.5 for earth-worms, and 8.7 for fishes. 7. A third hish mortality occurred 53 to 63 days after hatching, the total mortality amounting to 95.76 to $97.34\%$, and the main cause of the mortality was found to be rickets resulting from nutritional deficiency 8. The growth rates were as follows: 2.68mm just after hatching, 3.84mm at the age of 10 days; 7.96mm after 25 days; 20.96mm or 130mg after 40 days; 73.68mm or 9.06g after 80 days: and 123mm or 31.8g after 150 days. 9. The water temperature during the above period was 15.7 to $28.4^{\circ}C$ with an average of $22.10^{\circ}C$ and the salinity was 25.53 to $34.50\%$ with an average of $32.07\%$, 10. The young of this species could endure well a wide range and sudden rise in salinity, and could survive easily when the salinity suddenly fell to $5\%$, but a considerable mortality occured when it fell to $3\%$. 11. When the fish were tranferred directly to fresh water from normal sea water they died out in 9 hours and 40minutes. However, when transferred from water of $5\%$ salinity at which they were reared for 54 days, they survived for 60 hours and 40 mimutes longer than in the former case.