• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.1
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• pp.1-5
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• 1987

The authors carried out an experiment to determine the vertical opening of the midwater trawl, which is the same used in the former experiment in this series of studies. To determine the vertical opening of otter board and front weight, three fish finders were used. A 200 KHz fish finder set on board the research vessel was used to sound the depth of water. A transmitter of 50 KHz fish finder was set through the shoe plate of otter board to determine the height of otter board from the sea bed, and a transmitter of another 50 KHz fish finder was set downwardly on the net pendant right before the front weight to determine the height of weight from the sea bed. The depth of otter board and weight were calculated by subtract the height of those from the depth of water, respectively. To determine the vertical opening of mouth, a transmitter of net recorder was set on the head rope and the vertical opening of that to ground rope was directly read on the recording paper. The results obtained can be summarized as follows: 1. The rate of the depth of otter board to the length of warp was in the range of 0.44 to 0.25, and the depth was linearly shoaled about 5m per 0.1m/sec of the towing speed or per 20rpm of the main engine. The rate of the observed depth to the calculated depth of otter board was in the range of 0.92 to 0.080 with a decreasing tendancy in accordance with the increase of towing speed. 2. The depth of head rope was 2 to 3m deeper than that of otter board, and the vertical opening of net mouth was in the range of 22 to 19m, with a decreasing tendancy in accordance with the increase of towing speed, 3. The difference of depth between front weight and otter board was about 20m and 22m respectively in the length of warp 100m and 150m without distinct change in accordance with the towing speed. The depth of front weight was 2 to 3m shallower than that of ground rope. 4. The changing range of depth of head rope according to the revolution of main engine was about 4m per 20rpm.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.4
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• pp.45-71
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• 1991

The landscape systems in Korean island settlements can be recognized as results of ingabitants' ecological adptation to the isolated environment with the limited natural resources. Both the fishery dominant industry in island society and ecological nature of its environments seem to have influenced on inhabitants' environmental cognition as well as the physical landscape of island villages such as its location, spatial pattern in each village, housing form and so on. This study was done mainly by both refering to the related documents and direct observations in case study areas, and results of the study can be summarized as follows. 1. In general, the landscape of an individual island seems to take more innate characteristics of island's own, corresponding to the degree of isolation from mainland. That is, while the landscape of island in neighboring waters takes both inland-like and island-innate landscape character at the same time, the one in the open sea far from land takes more innate landscape character of all island's own in the aspects of village location, land use and housing density etc. 2. The convex landform of most islands brings about more centrifugal village allocation than centripetal allocation in most inland villages. And thus most villages in each island face extremely diverse directions different from the south facing preference in most inland rural villages. 3. Most island villages tend to be located along the ecologically transitional strip between land and sea, so called 'line of life', rather than between hilly slope and flat land as being in most inland village locations. So they are located with marine ecology bounded fishing ground ahead and land ecology bounded agricultural site at the back of them. 4. The settlement pattern of the island fishing villages shows more compact spatial structure than that of inland agricultural villages, due to the absolute limits of usable land resources and the adaptation to the marine environment with severe sea winds and waves or for the easy accessability to the fishing grounds. And also the managerial patterns of public owned sea weed catching ground, which take each family as the unit of usership rather than an individual, seem to make the villagescape more compact and the size of Individual residence smaller than that of inland agricultural village. 5. The folk shrine('Dand') systems, in persrective of villagescape, represent innate environmental cognition of island inhabitants above all other cultural landscape elements in the island. Usually the kinds and the meanings of island's communal shrine and its allocative patternsin island villagescape are composed of set with binary opposition, for example 'Upper shrine(representing 'earth', 'mountain' or 'fire')' and 'Lower Shrine(representing 'sea', 'dragon' or 'water') are those. They are usually located at contrary positions in villagescape each other. That is, they are located at 'the virtical center or visual terminus(Upper shrine at hillside behind the village)' and 'the border or entrance(Lower Shrine at seashore in front of the village)'. Each of these shirines' divinity coincides with each subsystem of island's natural eco-system(earth sphere vs marine sphere) and they also contribute to ecological conservation, bonded with the 'Sacred Forest(usually with another function of windbreak)' or 'Sacred Natural Fountain' nearby them, which are representatives of island's natural resources.

• Journal of the Korean Society of Marine Environment & Safety
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• v.10 no.1 s.20
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• pp.61-67
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• 2004

This study described relationships between fluctuation of fishing conditions for common squid and oceanic conditions in the East Sea from 1990 to 1999. Annual catches of common squid have been higher since the late 1980s compared to the period of the late 1970s to the mid-1980s. These catches fluctuations might be related to the effect of regime shifts. Monthly catches of common squid appear the timing of a large catch from September to December and a poor catch from March to May. The monthly catches are also the highest in October and are the lowest in April. Annual stable fishing grounds for coefficient of variation below 1.0 are formed in waters around Guryongpo and Ullung Island Based on optimum water temperature for catch, $16^{\circ}C$, optimum water depth for catch shallow going north. It indicates that the optimum water depth of fishing work different of each area Fishing ground formation and horizontal water temperature appear the minimum $10{\sim}14^{\circ}C$ in April, the maximum $10{\sim}20^{\circ}C$ in October. If seem, that seasonal fluctuation of fishing ground is related to the extension of the Tsushima warm current in the East Sea.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.3
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• pp.119-126
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• 2003

Nitrate-N concentrations and the corresponding ${\delta}^{15}N$ values were determined with water samples collected periodically from artesian wells (3 and 6 m deep), underdrainage and gushout waters in a Welsh onion cultivated area in the Kushibiki Fan, Saitama Prefecture, Japan. Average $NO_3-N$ concentrations in waters from 3 and 6 m wells were 25.7 and $2.8mg\;L^{-1}$, whereas ${\delta}^{15}N$ values were 3.6 and 4.7‰, respectively. The $NO_3-N$ concentration and ${\delta}^{15}N$ value of the underdrainge water were $35.5mg\;L^{-1}$ and 6.6‰, reflecting rapid input of chemical fertilizers and farmyard manure. The mean values of $NO_3-N$ concentration and ${\delta}^{15}N$ in the gushout water flown out of the edge of Kushibiki Fan were $19.4mg\;L^{-1}$ and 7.9‰, respectively. As a results the ${\delta}^{15}N$ values of the gushout water were higher than those of the artesian wells and underdrinage water. The ${\delta}^{15}N$ values of total-N and $NO_3-N$ of the soils were 6.1 and 5.10‰, respectively, while those for nitrification-inhibitor containing fertilizer and slow-release fertilizers were -6.1 and -2.2‰, respectively.

• Economic and Environmental Geology
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• v.44 no.1
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• pp.49-57
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• 2011

Water budget analysis in the groundwater system was conducted in order to understand water budget distributions in the ground water system in Geum-gang watershed. The annual amounts of precipitation, runoff, evapotranspiration, dam storage change and water supply over the sub-watershed in Geum-gang watershed were evaluated the residual groundwater from 2002 to 2006, based on the water budget considering inflow and outflow. Then we are able to expect residual groundwater of each sub-basin. According to the result of study, the year 2003 and 2006 were recorded the highest and the lowest precipitation value, respectively. Average run-off percentage against precipitation was 60.44%. Annual evapotranspiration in each of years didn't show the remarkable variations but the values were high in the lower reaches of the basin. The residual waters in Geum-gang basin were determined to be 133.36 in 2002, 77.64 in 2003, -19.40 in 2004, -82.25 in 2005 and -128.07 mm in 2006. The residual water in Geum-gang basin was high in the main and up stream such as Maepo. Also the residual water showed low distributions in Nonsan and Seokhwa.

• Journal of Soil and Groundwater Environment
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• v.12 no.2
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• pp.1-8
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• 2007

A series of batch and column experiments were conducted for the development of biobarrier technology which can be applied to containment and reduction of contaminants in soil and ground waters. The growth kinetic constants of Pseudomonas fluorescens on glucose or molasses were determined using batch experiments. The maximum specific growth rate (Vmax) of P. fluorescens at $23^{\circ}C$ on glucose or molasses were $0.246\;hr^{-1}$ and $0.073\;hr^{-1}$, respectively. However, molasses was selected as carbon source due largely to the absence of lag phase of P. fluorescens growth on molasses and economic reason. In constant head column experiments, the hydraulic conductivity of the column soil reduced by $6.8{\times}10^{-3}$ times from $4.1{\times}10^{-2}cm/sec$ to $2.8{\times}10^{-4}cm/sec$ after the inoculation of P. fluorescens and administration of carbon source and nutrients. The biomass concentration was observed highest in the column inlet. Measurements of carbon source and electron accepter (dissolved oxygen) concentration showed that the growth of P. fluorescence, which is the main reason for hydraulic conductivity reduction, was limited not by the concentration of carbon source but by the concentration of electron acceptor.

• Ocean and Polar Research
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• v.25 no.2
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• pp.213-226
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• 2003

Kongsfjorden near Korean Arctic Station, Dasan, is a glacial fjord in the Svalbard archipelago, Arctic that is influenced by both Atlantic and Arctic water masses. During the Arctic field season August 2002, surface temperature, salinity, density, and phytoplankton biomass (chi a) was measured in Kongsfjorden. A total of 15 surface samples were collected for the phytoplankton related measurements. Chl a values ranged from 0.08 to 1.4mg chi a $m^{-3}$ (mean of 0.53mg chl a $m^{-3}$) in the overall surface stations. The highest values of the chi a concentrations (> 1.0mg chi a $m^{-3}$) were found near glacier in the northeastern part of Kongsfjorden. Nanoplanktonic (< $20{\mu}m$) phytoflagellates were important contributors for the increase of the chi a. The nano-sized phytoflagellates accounted for more than 90% of the total chi a biomass in the study area. Surface temperatures and salinities ranged from 2.5 to $7.18^{\circ}C$ (mean of $4.65^{\circ}C$) and from 22.55 to 32.97 psu (mean of 30.16 psu), respectively. The physical factors were not highly correlated with phytoplankton distribution. The character of surface water due to down-fjord wind was highly similar to phytoplankton distribution. Drifting ice, freshwater, and semdiment inputs from large tidal glaciers located in the inner part of Konsfjorden create steep physico- and biogeochemical environmental gradients along the length of this ford. The glacial inputs cause reduced biodiversity biomass and productivity in the pelagic community in the inner fjord. Primary production of benthic and pelagic microalgae is reduced due to the limited light levels in the turbid and mixed inner waters. The magnitude of glacial effects diminishes towards the outer fjord. Kongsfjorden is an important feeding ground fer marine mammals and seabirds. Especially, seabirds play the largest energy intake and also export nutrients for primary production of the marine microalgae. Kongsfjorden has received a lot of research attention as a site for exploring the impacts of climate changes. Dasan Station in Kongsfjorden will be an important Arctic site for monitoring and detecting future environmental changes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.2
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• pp.166-179
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• 1985

The seasonal distribution and migration of flying squid, Ommastrephes bartrami (LeSueur), in the North Pacific were studied by means of mantle length, surface temperature, and catch and effort data of the Korean drift gillnet fishery from 1980 to 1983. The water temperature for the best fishing ranged from $15^{\circ}\;to\;16^{\circ}C$ in May through July and from $13^{\circ}\;to\;18^{\circ}C$ in August through January. High densities of flying squid were found in the thermal fronts with $18^{\circ}C$ isotherm in August and with $15^{\circ}C$ isotherm in September. The densities of flying squid were higher in the western region than in the eastern region in the North Pacific. The high densities of flying squid in the northwestern Pacific were attributed to the high gradients of oceanographic properties in the region. Migration models for flying squid were hypothesized based on the monthly distributions of catch per unit net, mantle length compositions by statistical blocks, and the hydrographic features of the North Pacific. The large flying squid moved to the northern region and to the central Pacific region earlier than the small sized group in the northward migration period (from June to August). Flying squid begin the reverse southward migration from the Subarctic Frontal Zone in autumn with onset of cooling and the development of Oyashio Current. The large sized group starts their southward return migration from more northern waters than the small sized group but the former moves past the later ana reaches the spawing ground first.

• Journal of Environmental Science International
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• v.18 no.3
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• pp.245-254
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• 2009

In recent years, environmental pollution by phannaceuticals and personal care products (PPCPs) in the aquatic environment is of great concern worldwide. Recent studies have been reported to occur in a variety of environmental organisms such as surface, drinking and ground water, soils, sediments and hospitals. The purpose of this study was to evaluate the occurrence and environmental behavior of fourteen human PPCPs in surface waters of Mankyung River in South Korea. We were conducted to field survey for water quality and PPCPs analysis at November, 2006. PPCPs were analyzed by liquid chromatograph coupled with a tandem mass spectrometer (HPLC-MS/MS). The concentration of COD was measured to be 2.37$\sim$19.71 mg/L, which was belong to 4$\sim$5 grade in water quality criteria of lake. Station 2 that there is no pollution in upper stream, was appeared to lower concentration. The concentration of TN and TP, that is cause matter of eutrophication, were found to be 7.78$\sim$35.42 mg/L and 0.08$\sim$0.95 mg/L, respectively, which were exceeding 5 grade in Lake water quality criteria. The 11 kind of PPCPs compounds except levofloxacin and triclosan were detected to Mankyung river. PPCPs concentrations of STP(Sewer Treatment Plant) effluents and aquatic environment in Mankyung river have been detected in the range from dozens of ng/L to hundreds of ${\mu}g/L$ that by order of atenolol, carbamazepine, propranolol, Ibuprofen, erythromycin, ifenprodil, clarithromycin, mefenamic acid, fluconazole, indomethacin, disopyramide. PPCPs concentration of Station 1 and 5, which was influenced by Jeonju STP and Wanju STP, was detected high values. Station 2 that there is no pollution, showed lower values. Station 3 which joined Gosan stream and Jeonju stream and station 4 which influenced by stock wastewater was detected to low values.

• Korean Journal of Ichthyology
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• v.20 no.3
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• pp.190-197
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• 2008

Spatio-temporal distribution of eggs and larvae of Japanese anchovy Engraulis japonica in the southern sea of Korea was determined using data obtained from icthyoplanktonic surveys and oceanographic observations between Goheung Peninsula and Goeje Island from May to August 2007. Commercial anchovy catch and size composition from four local fishery cooperative associations were also analyzed in relation to the geographic distribution of eggs and larvae. The abundance of anchovy eggs increased from May to July and was lowest in August. Eggs were mainly distributed between Namhae Island and Goeje Island, where water temperatures were $15{\sim}24^{\circ}C$ and salinities were 32~35‰. In 2007 anchovy landings between Namhae Island and Goeje Island were 11,409 tons at Tongyeong association, 4,137 tons at Masan association, and 2,487 tons at Sacheon association. However, landings between Goheung and Yeosu Peninsula were only 4,411 tons (at Yeosu association). The catch by anchovy tow net was high in the area where eggs were abundantly distributed. This indicates that the distribution of egg density was directly correlated with recruitment of E. japonica. All growth stages were abundant in the study area, indicating that this area is a major spawning and growing ground of E. japonica in Korean waters.