• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.4
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• pp.366-371
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• 2011

The sea squirt Halocynthia roretzi is mainly cultured in Tongyeong, Southern coastal area of Korea. This study presents the physiological rates of respiration, excretion, feeding and assimilation efficiency of the sea squirt Halocynthia roretzi to analyze the SFG(scope for growth) and net growth efficiency, determined during 2007. Oxygen consumption and nitrogen excretion rates increased with a rise in temperature during the summer period whereas feeding rates decreased. The O:N ratio was high during winter(October to February). Assimilation efficiency showed an annual average of 75.4% during the experimental period, except during a period of elevated temperature in July to September(average $25^{\circ}C$). Net growth efficiency($K_2$) was 8.7 to 64.2% except for May to September, when temperature increased at the aquaculture farm. SFG was negative from May to September, reflecting high temperatures and low feeding rates during this period; its highest positive values occurred during winter.

• Korean Journal of Plant Resources
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• v.25 no.3
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• pp.323-328
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• 2012

This paper describes the potential use of deep sea water to stimulate seed germination in both common and Tartary buckwheat. Treatment of 10% deep sea water at $25^{\circ}C$ would slightly enhance germination of buckwheat seeds compared to non-DSW treatment and other temperature. In this study, the significant effects of photoperiod and temperature on seedling growth were also found in the HL treatment for the number of leaf, plant height, and plant fresh weight and LL treatment for root length and leaf size. Common buckwheat (Suwon No.1) showed higher rate (93%) of flowering plants in the HS and LL (93% of flowering rates) than those revealed in the HS and LS treatment, while the low percentage(67%) of plant flowering plants was shown in the LS treatment. All plants (100%) of a Korean landrace, Ahndong-jaerae showed flowers in the HS and LS treatment. HL and LL treatment status did not occur in the plant's flowering. Any Tartary buckwheat (KW45) plant did not yet flowered when it was 21 days-old.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.5
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• pp.583-590
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• 2015

Submarine cable installation is essentials for grid connection between existing power grid and newly produced electricity which will be from offshore wind farm in Southwest sea area of Korea. Especially, submarine cable route and protection method is designed in order to ensure the economical efficiency, workability and stability of submarine cable installation. On this paper, we will give the basic information about the submarine cable route and protection method of offshore wind farm which will be built in Southwest sea area of Korea. For this, we have a numerical simulation at high and low tide based on the third-generation wave model SWAN(Simulating WAves Nearshore) using the long term wave data from Korea Institute of Ocean Science and Technology(KIOST). The results of the study, year mean Hs is 1.03m, Tz is 4.47s and dominant wave direction is NW and SSW When the incident wave direction is NW(Hs: 7.0 m, Tp: 11.76s), the distribution of shallow water design wave height Hs was calculated about 4.0~5.0m at high tide and 2.0~3.0m at low tide. When the incident wave direction is SSW(Hs: 5.84 m, Tp: 11.15s), the distribution of shallow water design wave height Hs was calculated about 3.5~4.5m at high tide and 1.5~2.5m at low tide. The wave direction on a dominant influence in the section of longitude UTM 249749~251349(about 1.6 km) and UTM 251549~267749(about 16.2 km) in the submarine cable route are each NW and SSW. Prominently, wave focusing phenomenon appears between Wi-do and Hawangdeung-do, in this sea area is showing a relatively high wave hight than the surrounding sea areas.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.5
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• pp.379-387
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• 2012

In order to see the oceanographic conditions, the observations of aquaculture farm of ascidian in Youngdeuk, the east coast of Korea were conducted through 6 times-23 February, 6 April, 8 June, 19 August, 6 October and 20 December-in 2010. Surveys were conducted in 20 stations bimonthly using SBE 19 CTD instrument. The mixed layer depth (MLD) was deep in winter and shallow in summer. The cold water below $5^{\circ}C$ in temperature was occupied below thermocline through all season. The temperature was high in the southeastern area. The salinity was increased from the coast to the open sea. The halocline was distinct at 20 m depth in August and at 40 m depth in October. The lowest value of salinity was appeared at the depth of 10 m in October. In addition the value of precipitation minus evaporation denoted negative in October. These low saline water seemed to inflow to the coast from the open sea. Therefore the low saline water moved to the east coast of Korea. The EKWC may play an important role to convey the low saline water. It may affect the aquaculture farm along the coast as the mass mortality of ascidian. It needs to clarify the role and pathway of EKWC to transfer the low saline water along the east coast of Korea.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.2
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• pp.47-57
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• 2007

Real-time oceanographic information system was developed using platforms of aquaculture farms to examine causes of mass mortality of hatchery fishes, and to reduce the damage of mass mortality which has been occurred frequently off coast by abnormal change of ocean conditions. The system had the advantages of direct data distribution to fishermen at the farm and instant maintenance of equipments due to easy access to the farms and residents at the farms in comparison with offshore mooring buoy system. To avoid discontinued measurement of the system, repairs caused by malfunction of equipments, bimonthly preventive maintenances and daily monitoring of measured data were systematized. Confidence intervals calculated by a statistical method using accumulated data were applied to data management. Such activities could minimize discontinuance of measurement and keep information more trustful. In addition, the system has various ways of data distribution. Through homepage and e-mail in the internet, information was provided to public. Display units which were connected to equipments at the farm gave the measured data directly to fishermen, which guided them to run their farm scientifically. Finally large display unit was installed at a fish market and showed the measured data at the nearest station with tide and weather information. Proper region for aquaculture and wintering region were studied using temperature data obtained by the system in 2006. The system will contribute to reduce economic damage of coastal fishery and to understand coastal marine environment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.1026-1036
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• 2014

Real-time monitoring for environmental factors (temperature, salinity, chlorophyll-a, etc.) and fugacity of carbon dioxide ($fCO_2$) was conducted at an oyster Crassostrea gigas farm in Goseong Bay, south coast of Korea during 2-4th of November, 2011. Surface temperature and salinity were ranged from $17.9-18.7^{\circ}C$ and 32.7-33.8, respectively, with daily and inter-daily variations due to tidal currents. Surface $fCO_2$ showed a range of $390-510{\mu}atm$ and was higher than air $CO_2$ during the study period. Surface temperature, salinity and $fCO_2$ are showed significant correlations with chl.-a and nutrients, respectively. It means when chl.-a value is high in surface water of the oyster farm, active biological production consume $CO_2$ and nutrients from environments and produce oxygen, suggesting a tight feedback between biological processes and environmental reaction. Thus, factors affecting the surface $fCO_2$ were evaluated using a simple mass balance. Temperature and biological productions by phytoplankton are the main factors for $CO_2$ drawdown from afternoon to early night, while biological respiration increases seawater $CO_2$ at night. Air-sea exchange fraction acts as a $CO_2$ decreasing gear during the study period and is much effective when the wind speed is higher than $2-3m\;s^{-1}$. Future studies about organic carbon and biological production/respiration are required for evaluating the roles of oyster farms on carbon sink and coastal carbon cycle.

• Proceedings of the Korean Society of Community Living Science Conference
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• 2011.10a
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• pp.97-97
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• 2011

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1992.08a
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• pp.126-129
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• 1992

The most of nearshore areas along the coastline of the Sea of Japan are not blessed with the gulfs or natural reefs. So in those areas so many kinds of man-made Fish Aggregation Devices (FADs) and artificial aquatic habitats have been submerged to cultivate and proliferate the aquatic resources. However, to utilize the ocean space furthermore effectively, the technology of offshore aqua-culture must be developed by coastal engineers and oceanographers.(omitted)

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.323-329
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• 2002

The thermal effluent discharged from nuclear power plants can affect the offshore ecosystem change. The ability of measuring sea surface temperature in high resolution with Airborne MSS thermal spectral band(8.5 $\mu$m ~ 12.5 $\mu$m) and Landsat ETM+(10.4$\mu$m ~ 12.5 $\mu$m) gives us an information of spread range of thermal effluent. This information can be used as one of major factors fur analyzing the impact of the fish farm damage around the nuclear power plants. Every season from November 1999, this research has been conducted to investigate the extent of diffusion of thermal effluent discharged from KoRi, UlJin and WolSung Nuclear Power Plant located at the coastline of the East Sea of Korea.

• Journal of Environmental Science International
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• v.8 no.4
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• pp.503-507
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• 1999

To study the residue of organophosphorus pesticides in the ocean environment on the Cheju island, EPN[O-ethyl-O-4-nitrophenyl phenylphosphonothioate] and monocrotophos [Dimethyl-1-methyl-2-methyl carba-moylvinylphosphate] of organophosphorus pesticides are surveyed on coastal environment of Cheju city and Wimi in May and October 1996. The qualified limit detection of EPN and monocrotophos are 0.005ng/mL and 0.006ng/mL in the water by GC-FPD, respectively. The qualified limit detection of EPN and monocrotophos are 0.010ng/g and 0.012ng/g in the solid such as sediment and sea organism by GC-FPD, respectively. EPN and monocrotophos are not detected in seawater and sedimnet. Moreover EPN and monocrotophos are neither detected in seaweed cava (Ecklonia cava), Agar (Gelidium amansii), turban sell(Batillus cornutus) and sea urchin(Anthocidaris Crassispina). EPN, monocrotophos used in the farm on the Cheju island are not residued in the coastal environment in the Cheju island.