• Journal of Environmental Science International
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• v.12 no.11
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• pp.1181-1187
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• 2003

Hibiscus hamabo, called "Hwang-geun", growing about 3m in height is a deciduous shrub or subtree of Malvaceae. Because the number of these species is very limited in the world, the Ministry of Environment has designated H. hamabo as a preserved plant. The Korea Forest Service also protects it strictly by law since H. hamabo is an out-of-the-way plant and possibly may be exterminated soon in Korea. Investigation for distribution and ecological characteristics of the habitat for H. hamabo was carried out on Soan Island. Two wild H. hamabo were found at the forest edge (equation omitted) along the sea coast located in the southern part of Soan Island and this was the first report in the Korean academic world. These two wild H. hamabos were growing in a naturally inhibited area. The diameters at the base were 12cm and 15cm. The Tree heights were 150cm and 210cm and the number of branches of each wild H. hamabo was 4 and 7. However, the present condition of these plants was not good. Environmental conditions of the naturally inhibited area of H. hamabo were very mild because it is located at the edge of the forest and is always sunny during the daytime since the slope of the inhibited area is facing South. The ground drained very well since the soil was made of gravels and sand. Because the percent of vegetation of the subtree layer where H. hamabo was growing was 40%, the cover degree and sociability of flex crenata trees and Eurya japonica were found to be high. In the naturally inhibited area of H. hamabo, a dominant value of Rubus parvifolius in the lower part of the herb layer was very high and many plants in Compositae, such as Artemisia princeps var. orientalis and Erigeron annuus, were also present. A dominant value of liana, such as Vitis thunbergii var. sinuata, Rosa multiflora, Clematis terniflora and Hedera rhombea, and Gramineae plants that rhizomes were well developed and aggressively propagated, such as Miscanthus sinensis var. purpurascens, Phragmites communis, Spodiopogon cotulifer and Oplismenus undulatifolius which were surveyed as high, too. These results imply that H. hamabo might be exterminated soon through a natural selection if the proper management of the naturally inhibited area of H. hamabo is not conducted continually.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.4
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• pp.177-188
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• 1989

The purpose of this study was to investigate the detoxifying effect on PSP-infested sea mussel, Mytilus edulis, by heating treatment and correlation between the PSP toxicity and the environmental conditions of shellfish culture area such as temperature, pH, salinity, density of Protogonyaulax sp. and concentration of inorganic nutrients such as $NH_4-N,\;NO_3-N,\;NO_2-N\;and\;PO_4-P$. This experiment was carried out at $Suj\u{o}ng$ in Masan, Yangdo in Jindong, $Hach\u{o}ng\;in\;K\u{o}jedo\;and\;Gamch\u{o}n$ bay in Pusan from February to June in $1987\~1989$. It was observed that the detection ratio and toxicity of PSP in sea mussel were different by the year even same collected area. The PSP was often detected when the temperature of sea water about $8.0\~14.0^{\circ}C$. Sometimes the PSP fox of sea mussel was closely related to density of Protogonyaulax sp. at $Gamch\u{o}n$ bay in Pusan from March to April in 1989, but no relationship was observed except above duration during the study period. The concentration of inorganic nutrients effects on the growth of Protogonyaulax sp., then effects of $NO_3-N$ was the strongest among them. When the PSP-infested sea mussel homogenate was heated at various temperature, the PSP toxicity was not changed significantly at below $70^{\circ}C$ for 60 min. but it was proper-tionaly decreased as the heating temperature was increased. For example, when the sea mussel homogenate was heated at $100^{\circ}C,\;121^{\circ}C$ for 10 min., the toxicity was decreased about $67\%\;and\;90\%$, respectively. On the other hand, when shellstock sea mussel contained PSP of $150{\mu}g/100g$ was boiled at $100^{\circ}C$ for 30 min. with tap water, the toxicity was not detected by mouse assay, but that of PSP of $5400{\mu}g/100g$ was reduced to $57{\mu}g/100g$ even after boiling for 120 min.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.2
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• pp.138-144
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• 2013

Large and small marine accidents which are related to vessel's navigation are happening continuously and these maritime accidents have caused loss of lives and properties, and serious maritime environmental pollution damage. It is also true that maritime pollution damage is increasing due to these accidents, probability of growth of seaborne volume and complicated maritime traffic environment. Korea, recently, is developing an evaluation index which can assess sea risk through the evaluation of maritime traffic environment and provide danger and general information with relation to maritime traffic environment on target sea area to evaluate maritime traffic safety. In this paper, we intend to confirm the validity of maritime traffic safety on the basis of vessel navigator's risk consciousness and various sailing conditions by using the ship handling simulator. To confirm the validity of sailing vessel's maritime traffic safety, we use analysis of variance. By using analysis of variance, we analyze vessel navigator's characteristics, distance, speed and encounter type between vessels. Through multiple comparison of each factor's risk difference, we can confirm the change of numerical value of risk difference in statistical aspect.

• Journal of Navigation and Port Research
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• v.30 no.1 s.107
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• pp.97-104
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• 2006

Recently the first stage qf construction for Busan new port emerged over the sea surface at the north container terminal site. With this, there are lot of discussions and debates on increasing the water depth at the approaching channel and mooring basin from the existing 15m to 18m by dredging work in order to be able to serve 12,000TEU containership, and at the same time, correction to the reclamation plan of hinterland at the part of Undong Bay qf the new port site. Since the attack of typhoon 'Maemi' in 2003, it is expected that the design wave parameters for coastal and harbor structures in this area would be somewhat changed and so the extreme wave condition at each terminal and tranquility of berthing area does, and therefore, it is necessary to analyze the tranquility at each berth Hence in this study, we constructed a wave model for these conditions and performed simulation together with the circulation model simulation, compared with the field data collected The result showed the increase of the harbor response throughout the basin but not severe condition However, a certain location needs to be prepared for the rough sea condition when a severe typhoon hit the site.

• Ocean and Polar Research
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• v.33 no.spc3
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• pp.349-358
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• 2011

In order to ascertain latitudinal variation of lipid contents and compositions in copepods, we collected warm water copepod species (Euchaeta sp. and Pleuromamma spp.) from four different regions from low (sub-tropical) to mid (temperate) latitudes in the Northwest Pacific Ocean. Total lipid contents of Pleuromamma spp. were about 11 $ug{\cdot}ind^{-1}$ with little latitudinal variation, whereas Euchaeta sp. showed slightly higher lipid content (20 $ug{\cdot}ind^{-1}$) than Pleuromamma spp. with latitudinal gradient (low at subtropic and high at temperate). Wax esters, known as the major storage lipid classes, were found to be the dominant lipid classes (accounting for more than 35% of total lipids) in Euchaeta sp., whereas in Pleuromamma spp., phospholipids, known as cellular membrane components, were the dominant lipid classes. However, the exception was specimens from warm pool region exhibiting dominance in storage of lipids as a form of triacylglycerols. Among fatty acids, polyunsaturated fatty acids (PUFA), especially docosahexaenoic acid (DHA : 22:6(n-3)) (about 35% of total fatty acids), were most abundant in Euchaeta sp., while saturated fatty acids (SAFA), specially hexadecanoic acid (16:0) (about 30% of total fatty acids), were most abundant in Pleuromamma spp.. Among the neutral fraction of lipids, phytol, originated from the side chain of chlorophyll, was found in all samples which generally indicate active copepods feeding on algae. While only trace amounts of short-chain fatty alcohols were found in Pleuromamma spp., significant amounts of fatty alcohols were found in Euchaeta sp.. Particularly, significant amounts of long chain monounsaturated fatty alcohols (20:1 and 22:1), generally found in cold water species, were found in Euchaeta sp. from low latitudes. The latitudinal variation of trophic lipid markers in these copepods could be significantly related with in-situ food availability and species-specific diet preference. The result of this study suggests that the lipid contents and compositions in copepods may not only indicate their nutritional condition and feeding ecology but also provide insight into species-specific living strategies under different environmental conditions (i.e. water temperature, food availability).

• Journal of Navigation and Port Research
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• v.28 no.10 s.96
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• pp.947-953
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• 2004

As a large scale port development in coastal waters proceeds step by step and populations in the vicinity of port are getting increased, the issue on 'how to dispose the treated municipal water and wastewater in harbor' brings peoples' concern. The submarine outfall system discharges the primary or secondary treated effluent at the coastline or in deep water, or between these two. The effluent, which has a density similar to that of fresh water, rises to the sea surface forming plume or jet, together with entraining the surrounding sea water and becomes very dilute. We intended in this paper to investigate the impact on dilution of effluent and the behavior of flume under the conditions of the seasonal and spatial temperature variations, which have not been noticeable in designing effective marine outfall system. To predict and analyze the behaviour and dilution characteristics of plume not just with the effluent temperature, but also with the seasonal variation of temperature of surround water, CORMIX( Cornell Mixing Zone Expert System)-GI have been applied. The results should be used with caution in evaluation the mixing zone characteristics of discharged water. We hope to help for the effective operation of outfall system, probable outfall design, protection of water quality, and warm water discharges from a power plant, etc.

• Journal of Microbiology and Biotechnology
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• v.25 no.2
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• pp.238-246
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• 2015

A unicellular red microalga was isolated from environmental freshwater in Korea, and its morphological, molecular, and biochemical properties were characterized. Morphological analysis revealed that the isolate was a unicellular biflagellated green microalga that formed a non-motile, thick-walled palmelloid or red aplanospore. To determine the taxonomical position of the isolate, its 18S rRNA and rbcL genes were sequenced and phylogenetic analysis was performed. We found that the isolate was clustered together with other related Haematococcus strains showing differences in the rbcL gene. Therefore, the isolated microalga was classified into the genus Haematococcus, and finally designated Haematococcus sp. KORDI03. The microalga could be cultivated in various culture media under a broad range of pH and temperature conditions. Compositions of the microalgal cellular components were analyzed, and its protein, carbohydrate, and lipid compositions were estimated to be 21.1 ± 0.2%, 48.8 ± 1.8%, and 22.2 ± 0.9%, respectively. In addition, D-glucose and D-mannose were the dominant monosaccharides in the isolate, and its amino acids were composed mainly of aspartic acid, glutamic acid, alanine, and leucine. Moreover, several polyunsaturated fatty acids accounted for about 80% of the total fatty acids in Haematococcus sp. KORDI03, and the astaxanthin content in the red aplanospores was estimated to be 1.8% of the dry cell weight. To the best of our knowledge, this is the first report of an Haematococcus sp. isolated from Korea, which may be used for bioresource production in the microalgal industry.

• Korean Journal of Ichthyology
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• v.12 no.1
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• pp.46-53
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• 2000

Artificial gonadal maturation and spawning inducement of striped knife-jaw Oplegnathus fasciatus were studied. Effects of water temperature and photoperiod under different regims on gonadal activity and maturation of three years old O. fasciatus were investigated histologically. In experiment I (Exp. I), water temperature was gradually increased from $14.5^{\circ}C$ to $21.0^{\circ}C$ and photoperiod was also gradually increased from 10 : 30 L to 15 : 30 L from December 1996 to February 1997 and this conditions were maintained till April. In experiment II (Exp. II), water temperature was increased in the same way from Exp. I and photoperiod was controlled as natural condition till early March and then increased to 15 : 30 L immediately. Control fish were reared in net-cage culture system in the sea from December 1996 to April 1997. Gonadal activity was initiated by increasing water temperature in both Exp. I and II from January. In Exp. I, gonadal maturation and spawning were induced from February when water temperature and photoperiod reached at $21.0^{\circ}C$ and 15 : 30 L, respectively. In Exp. II, complete gonadal maturation was not induced until early March but after treated by compensatory long photoperiod (15 : 30 L), the gonad was matured and subsequently spawning occurred.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.3
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• pp.271-282
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• 2012

Early osteological development of the skull, vertebral column, and fins, and squamation in the spotted sea bass, Lateolabrax maculates, were studied under extensive larval rearing conditions. The first ossification during cephalic skeleton development began with the premaxillary, dentary, and parasphenoid at 6.4 mm Total length (Notochord length 6.1 mm) and was completed by 25.2 mm TL (Standard length 20.3 mm). Ossification of the cartilaginous caudal complex started simultaneously in the urostyle and two preural centra at 12.2 mm TL (10.4 mm) and it was completely ossified by 32.0 mm TL (26.4 mm). The principal caudal fin rays, with a count of 9/8, began to ossify at 11.6 mm TL (10.2 mm) and the procurrent caudal fin rays, with counts of 4 (upper) and 3 (lower), started to ossify by 12.6 mm TL (10.9 mm). Ossification of these parts was completed by 21.4 mm TL (17.5 mm). Ossification of the vertebral column was first observed in the first to fourth centra at 8.3 mm TL (7.5 mm) and was fully completed by 21.7-35.0 mm TL (17.8-29.3 mm). The pectoral girdle started to ossify by 5.6 mm TL (5.4 mm) and was completed by 26.8 mm TL (21.8 mm). Eight pectoral fin rays were ossified at 11.6 mm TL (10.2 mm) and 16-18 rays were fully ossified by 13.8 mm TL (12.0 mm). Also, the dorsal, anal, and pelvic fin rays started to ossify at 12.2 mm TL (10.4 mm) and were completed by 12.8 mm TL (11.2 mm), 23.8 mm TL (19.4 mm), and 13.8 mm TL (12.0 mm), respectively. Ossification of the anal and dorsal pterygiophores initially occurred by 12.6 mm TL (10.9 mm) and 14.3 mm TL (12.2 mm), and was completed by 21.4 mm TL (17.5 mm) and 19.3 mm TL (15.9 mm), respectively. Squamation started at three centers of differentiation: the middle region of the trunk, the anterior of the caudal peduncle, and on the caudal peduncle at 23.8 mm TL (19.4 mm). The body was covered with scales, except the snout, at 57.2-60.2 mm TL (SL 47.1-49.2 mm).

• Ocean and Polar Research
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• v.31 no.2
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• pp.199-212
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• 2009

The community structure of meiofauna was surveyed from six stations in sand mining area near around Sungapdo, Taean five times from April-December, 2007. Ten meiofaunal taxa in total, comprising 5-9 taxa per station were recovered. Nematodes were dominant from four stations in April and from five stations in May. In June, copepods were dominant from all stations except station two, from which sarcomastigophorans were predominant. Copepods were also dominant from three stations in October and four stations in December. The mean density of meiofauna per $10\;cm^{-2}$ was the highest in October (130 individuals) and lowest (68 individuals) in April. Meiofauna mean biomass per $100\;cm^{-2}$ was $3.80-75.26{\mu}gC$ from each station, with the monthly mean biomass being lowest in April ($11.97{\mu}gC$) and highest in October ($39.50{\mu}gC$). The highest biomass was recorded at station five in October ($75.26{\mu}gC$). Eleven families of harpacticoid copepods occurred Ameiridae and Ectinosomatidae were the most frequent. The mean diversity index was 1.21 from all the stations, 1.22 from the sand mining stations, and 1.19 from the reference stations. The nematode:copepod (N/C) ratio was 1.57 from the sand mining stations and 1.37 from the reference stations. Non-metric multidimensional scaling analysis divided the community into group A (station one, non-sand mining and reference area) and groups B and C in the sand mining area. The present study reports similar numbers of taxa but lower density and biomass of meiofauna compared to previous studies in Korean waters. The variability of the diversity index and N/C ratio may indicate large fluctuation of meiofauna depending on temporal and spatial conditions of the environment in the study area.