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Ra K.,Marine Environments and Conservation Research Division | Kim E.-S.,Oceanographic Measurement and Instrument Calibration Service Center | Kim J.-K.,Marine Environments and Conservation Research Division | Kim K.-T.,Marine Environments and Conservation Research Division | And 2 more authors.
Ocean and Polar Research | Year: 2013

Metal concentrations in creek water, sewer outlets and core sediments were analyzed to identify the potential origin of metal pollution and to evaluate the extent of metal pollution and potential toxicity of Lake Shihwa. Mean concentrations for dissolved metals in creek water and sewer outlets were 1.6~136 times higher than those in the surface seawater of Lake Shihwa. Metal concentrations in creek water from an industrial region were also higher than those from municipal and agricultural regions, indicating that the potential source of metal pollution in the study area might be mainly due to industrial activities. The vertical profiles of metals in core sediments showed an increasing trend toward the upper sediments. Extremely higher concentrations of metals were observed in the vicinity of Banweol industrial complex. The results of a geo-accumulation index indicated that Cu, Zn and Cd were highly polluted. By comparing the sediment quality guidelines such as TEL and PEL, six metals such as Cr, Ni, Cu, Zn, Cd and Pb levels in core sediments nearby industrial complex exceeded the PEL value. Mean PEL quotient (mPELQ) was used to integrate the estimate of potential toxicity for measured metals in the present study. Mean PELQs in core sediments from Lake Shihwa ranged from 0.2~2.3, indicating that benthic organisms nearby the industrial complex may have been adversely affected. Source


Lee J.-A.,Tong Yeong Marine Living Resources Research and Conservation Center | Lee J.S.,Oceanographic Measurement and Instrument Calibration Service Center | Kim J.-H.,Oceanographic Measurement and Instrument Calibration Service Center | Myoung J.-G.,Tong Yeong Marine Living Resources Research and Conservation Center | And 2 more authors.
Ocean and Polar Research | Year: 2014

The black scraper Thamnaconus modestus was a commercially important fish species in the 1980s, but suddenly its commercial significance decreased in the 1990s mainly due to continuous overfishing. Recently, in order to reverse the depleted stocks of the black scraper and help the species recover, seed production technology has emerged. This has led to the farming of the black scraper in several parts of the southern coast of Korea. Since detailed research on its metabolism in relation to water temperature has been scanty, this was the investigative focus of the present study. The standard metabolism rates of the black scraper (9-10 months old, total length = 22.6 ± 0.8 cm, wet weight = 140.3 ± 13.9 g) were measured at seven different water temperature settings (12, 15, 17, 20, 23, 26, 28°C) to understand the relationship between metabolism and water temperature. Relationships between water temperature (WT) and oxygen consumption rate (OCR) were obtained as SOCR (weight-specific oxygen consumption rate) = 0.0117WT - 0.0135 (r2= 0.9351) and IOCR (oxygen consumption rate per individual) = 1.8160WT - 5.4007 (r2= 9428). The Q10 (temperature sensitivity), an indicator of the sensitivity of biological function to temperature, was analyzed. In our experiment, when the water temperature increased, the Q10 value decreased. The Q10 value was 6.27 in waters where the temperature ranged from 12-15°C and this was much higher than the values obtained in waters where temperatures ranged between (1) 15-23°C and (2) 23-28°C. Consequently, it was shown that the black scraper is a warm water species and inhabiting waters in the temperature range from 15-28°C is deemed appropriate. Source


Lee J.S.,Oceanographic Measurement and Instrument Calibration Service Center | Kim E.-S.,Oceanographic Measurement and Instrument Calibration Service Center | Kahng S.-H.,Oceanographic Measurement and Instrument Calibration Service Center | Yoon S.-H.,Marine Environment Research Division | And 3 more authors.
Ocean Science Journal | Year: 2012

We have developed a novel miniature in situ microprofiler (NAFRI BelpI) for coastal and deep-sea studies. The BelpI can carry up to three oxygen microsensors, and it allows for simultaneous replicate measurements in a relatively small area. All functions can be controlled and programmed via a small magnetic bar and three reed switches; this feature facilitates the initial setup both onboard and underwater. The large LCD window shows basic information such as the movement intervals of the linear stage, number of replicate measurements, waiting time between measurements, and the pA from the microsensors. From high-resolution vertical profiles of oxygen in coastal sediment measured using the microsensors, the diffusivity boundary layer thicknesses was determined to be in the range 0. 30-0. 35 mm. In addition, the time-series measurement of oxygen profiles in permeable sandy sediment showed advective transport of oxygen into pore water by tidal agitation. Two examples of in situ measurement using a BelpI suggest that it can be widely applied to the study of the sediment-water interface. © 2012 Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Science+Business Media Dordrecht. Source


Sim B.-R.,Oceanographic Measurement and Instrument Calibration Service Center | Sim B.-R.,Korean University of Science and Technology | Kang D.-J.,Oceanographic Measurement and Instrument Calibration Service Center | Kang D.-J.,Korean University of Science and Technology | And 4 more authors.
Ocean and Polar Research | Year: 2014

This study examined the spatial and temporal variation of dissolved inorganic radiocarbon in the East Sea. Five vertical profiles of radiocarbon values were obtained from samples collected in 1999 in three basins (Japan Basin, Ulleung Basin, Yamato Basin) of the East Sea. Radiocarbon values decreased from 63- 85‰ at the surface to about -50‰ with increasing depth (up to 2,000 m) and were nearly constant in the layer deeper than 2,000 m in all basins. Radiocarbon values did not show significant basin-to-basin differences in the surface and the bottom layers. In the intermediate layer (200-2,000 m), however, they decreased in the order of Japan Basin > Ulleung Basin > Yamato Basin, which is consistent with the suggested circulation pattern in the intermediate layer of the East Sea. Radiocarbon was found to have decreased at ~2%/year in the surface water of the East Sea. In contrast, in the interior of the East Sea, radiocarbon values have increased with time in all three basins. In the Central Water, the annual increase rate was about 3.3‰, which is faster than the rates in the Deep and Bottom Waters. The radiocarbon in the Deep and Bottom Waters had increased until mid-1990s, after which time it has been almost constant. Source

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