• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.3
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• pp.207-215
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• 2011

An endosulfan degrading bacterial strain, K-1321, was isolated by endosulfan-enrichment culture from a seaside sediment collected at Dadaepo Beach, Busan, Korea. The strain was identified as a Serratia sp. based on the results of morphological, biochemical and 16S rDNA homology analyses. Serratia sp. K-1321 was able to completely degrade 50 ppm endosulfan in culture media and soil within 6 weeks at $25^{\circ}C$. GC/MS analysis revealed that endosulfan diol was an intermediate of the bacterial endosulfan degradation. Considering the above results, we concluded that Serratia sp. K-1321 utilized endosulfan as a carbon source and metabolized endosulfan via a less toxic pathway, such as the formation of endosulfan diol as an intermediate.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.5
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• pp.282-287
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• 2007

Chloroanilines are aromatic amines used as intermediate products in the synthesis of herbicides, azo-dyes, and pharmaceuticals. 3,4-dichloroaniline (DCA) is the degradation product of some herbicides (diuron, propanil, and linuron) and of trichlorocarbanilide, a chemical used as an active agent in the cosmetic industry. The compound, however, is considered a potential pollutant due to its toxicity and recalcitrant property to humans and other species. With the increasing necessity for bioremediation, we sought to isolate bacteria that degraded 3,4-DCA. A bacterium capable of growth on 3,4-DCA as the sole carbon source was isolated from seaside sediment using a dilution method with a culture enriched in 3,4-DCA. The isolated strain, YM-7 was identified to be Pseudomonas sp. The isolated strain was also able to degrade other chloroaniline compounds. The isolated strain showed a high level of catechol 2,3-dioxygenase activity on exposure to 3,4-DCA, suggesting that this enzyme is an important factor in 3,4-DCA degradation. The activity toward 4-methylcatechol was 53.1% that of catechol, while the activity toward 3-methylcatechol, 4-chlorocatechol and 4,5-chlorocatechol was 18.1, 33.1, and 6.9%, respectively.

• Analytical Science and Technology
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• v.15 no.6
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• pp.521-528
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• 2002

Neutron Activation Analysis (NAA) and Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) have been applied for the determination of inorganic elements in mud flat of south seaside in Korea. The analytical results of Al, Ca, Fe, Mg, K and Na by NAA were compared with those by ICP-AES. The results show that NAA is superior to ICP-AES for the determination of minor elements in sediment. Accordingly, NAA will play an important role in the analysis of environment samples such as mud flat and sediment having complex matrix.

• Journal of Ocean Engineering and Technology
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• v.20 no.6 s.73
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• pp.54-60
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• 2006

This study discusses characteristic of spatiotemporal changes of the sand barrier in the Nakdong estuarine for the last century, focusing on geomarphologic evolution and mobility of sand barriers in the view of coastal engineering. The Nakdong estuarine, the research subject, has a complexly changing natural environment by interaction between ground and marine elements such as ocean wave, tidal current, sediment, etc. Moreover, recently, unnatural geomorphologic changes (e.g., seaside reclamation, new harbor construction, etc.) has been radically increased in this area with increasing desire for coastal development. Because of this, its sand barrier has developed quite unstable condition. Therefore, to identify the development process of geomorphologic changes in this area, required is a close examination on historical characteristics of spatiotemporal changes of the sand barrier in relation to surrounding seaside reclamation and physical environmental changes. This study, based on the marine charts published in between 1927 and 1995 year, analyzes the length and area of the sand barrier for the last hundred years, and investigates the cause of the changes by looking into the change of water depth for the last two years and doing ocean-physical site observations. In conclusion, the sand barrier of the Nakdong estuarine expands toward the open sea by $7.4{\sim}26m$ in annual average, maintaining a fixed distance of $1,241{\sim}1.279m$, and its area is expected to increase about $2.8km^2$ annually. This is characterized by the wocean wave from the open sea and the discharge of Nakdong River.

• Journal of Environmental Impact Assessment
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• v.11 no.4
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• pp.247-258
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• 2002

This study aimed at verifying the grain-sized distribution of surface deposits in a tidal flat using multi-spectral Landsat TM. In this study, we employed the grain-sized analysis, PCA and unsupervised classification techniques for analyzing the distribution of deposits. As a result in this study, the unsupervised classification method using PCA image was found to be most useful in classifying tidal flat deposits using satellite data. This method is considerably effective in analyzing not only the aspects of distribution in terms of accumulated deposits and erosion, but also the changes in seaside topography and shoreline. The grain-sized distribution analysis indicates that the mud flat inside the Cheonsu-bay tidal flat is distributed, the mixed flat located in the middle, and the sand flat distributed near the sea. The sand flat is dominant around the southern part of Seomot isle and its beach. On the other hand, the mud and mixed flat is dominant on the western part. Likewise, the western coast of Seomot isle and its beach is significantly affected by waves facing the offshore. However, the eastern side of the bay could be a site for the evolution of tidal flat made of fine materials where it is less affected by ocean waves. These results show that multi-spectral satellite data are effective for the classification of distribution materials and environmental impact assessment and continuous monitoring. In particular, the research on environmental deposits can provide important decision-supporting information for decision-making on seaside development, by analyzing the progress of deposits and environmental changes.

• Korean Journal of Remote Sensing
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• v.23 no.6
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• pp.575-581
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• 2007

Suaeda japonica is the one of halophyte species which is widely spread in the Ganghwado tidal flat. Halophyte affects to the vertical development of wetland by enhancing the adhesion force of sediments. If demineralization of tidal flat proceeds, the colony of halophyte moves to the seaside where has relatively high salinity content. The change of halophyte zonation can be an environmental indicator to understand the landization of tidal flat. To interpret the spectral characteristics of halophyte, we measured the reflectance of suaeda japonica, reed and sediment around Donggumdo tidal flat in Ganghwado. First and second-derivation analysis was applied to these transformed spectra in order to identify which spectral ranges were distinguished with different coastal wetland vegetation and artificial structures. From the result, red reflectance peak of suaeda japonica were appeared at 600-650nm and greed reflectance peak of reed were appeared at 500-570nm. Spectra of sediments were continuously increased from 350-550nm without any absorption by chlorophyll. These reflectance were easily identified among the spectra of halophyte.