• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.3
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• pp.185-200
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• 2021

The Marine Environment QA/QC management system has been operated since 2010 to secure the reliability of data and improve the analysis capabilities of measurement and analysis institutions. From 2010 to 2020, the cumulative number of measurement and analysis institutions participated in the QA/QC management system was 266. And the number of certificates issued by the ministry of oceans and fisheries is 182. A total of 32 reference materials for proficiency testing and interlaboratory comparisons have been developed. They were first developed focusing on items (Nutrients, COD) commonly analyzed in marine environmental measuring network, marine pollution impact surveys, sea area utilization impact assessment, deepsea water surveys, and information network on fishing ground environments. In addition, it is time to expand the filed of the QA/QC management system, such as seawater temperature, salinity, PCBs and PAHs in sediments, which are mainly analyzed in most monitoring programs. On-site assessment has been conducted for 162 laboratories according to ISO/IEC 17025 to evaluate their conformity of the quality management system and deficiency. In terms of management and technology requirements, about 4.2% of organizations showed insufficient division of duties among employees 8.7% of them revealed the lack of employee training. By test item, about 6.3% of organizations showed the lack of standard substance management and the state of the cleaning glassware was pointed out in about 5.4% of them. The QA/QC management system should be continuously supplemented by identifying the causes of nonconformities and area for improvement.

• Journal of Aquaculture
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• v.4 no.2
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• pp.111-128
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• 1991

In puan area the environmental surveys were carried out at two farms of hard clam, Meretrix lusoria from April 1987 to November 1978 in order to know heather the farm environments could be rehabilitated for the cultivation of hard clam or not. The range of temperature of surface seawater was $10.7{\~}27.4^{\circ}C$, pH $7.6{\~}8.2$, salinity $22.3{\~}30.3$ ppt, COD $0.20{\~}4.71\;mg/{\ell}$, sulfide $0.04{\~}0.22\;{\mu}g-at./{\ell}$, suspended solid $34.8{\~}199.3\;mg/{\ell}$ chlorophyll a $3.71{\~}49.02\;mg/m^3$, TIN $2.01{\~}24.47\;{\mu}g-a5./{\ell}$, phosphate $0.60{\~}11.03\;{\mu}g-at./{\ell}$ and silicate $4.04{\~}476.36\;{\mu}g-at./{\ell}$. The range of temperature of substratum (bottom soil) was $14.2{\~}29.7^{\circ}C$, pH $8.3{\~}9.5$, water content of substratum was $0.28{\~}0.49\;mg/g$ dried mud, COD $2.80{\~}50.94\;mg/g$ dried mud, total organic matter $1.05{\~}1.97\%$ concentration of total Kjedhal nitrogen $31.9{\~}194.9\;{\mu}g./{\ell}$ dried mud, and sulfide $0.032{\~}0.133\;mg/g$ dried mud. Fine sand was dominant ranging over $92{\~}95\%$ and silt and clay was $2.8{\~}8.1\%$ of the composition of substratum. Some residual agricultural chemicals, ${\alpha},\;{\beta},\;{\gamma}$-BHC, heptachlor, heptachlor-epoxide, aldrin, DDE, DDT and dieldrin were detected in hard clams collected from Puan areas. Especialy, more chemical were detected during the period of rainfalls. From above results, it is considered that the hard clam frams were not yet recovered from deteriorated conditions for aquaculture.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.11 no.2
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• pp.68-81
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• 2006

As one of the on-going projects to investigate the biogeochemical characteristics of tidal flat, we develop seasonal mass balance calculations (or DIP, DIN and DON in Gomso Bay. We have obtained 13-hours time-series data of salinity, tidal current, nutrients, and chlorophyll-a of seawater for spring, dry summer, rainy summer and winter during $1999{\sim}2000$. DIP of $-1.10{\times}10^6g\;P\;day^{-1},\;-4.50{\times}10^5g\;P\;day^{-1}$ was out-fluxed from the bay to the bay proper for spring and dry summer, respectively. Whereas $1.06{\times}10^4g\;P\;day^{-1}$ of net influx of DIP was found during winter and $2.72{\times}10^6g\;P\;day^{-1}$ of net influx was also found during the rainy summer. Therefore we suggest the role of Gomso tidal flat as a source of DIP fur the seasons of spring and summer, but as an opposite role during the rainy summer and winter but much smaller in magnitude. Except winter, the advection process by tidal current is found the most dominant flux among the diverse fluxes of DIP in the bay. Whereas ground water is estimated as the strongest flux of TDN except winter. TDN of $1.38{\times}10^7g\;N\;day^{-1},\;2.45{\times}10^6g\;N\;day^{-1},\;and\;4.65{\times}10^7g\;N\;day^{-1}$ was in-fluxed to the bay from the bay proper far spring, rainy summer and summer, respectively. Only $-1.70{\times}10^7g\;N\;day^{-1}$ of net out-flux was found during the winter. Therefore we suggest the role of Gomso tidal flat as a sink of TDN far the year round except winter.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.4
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• pp.213-228
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• 2009

This study was conducted to investigate spatio-temporal changes in macrobenthic community structure and benthic environmental conditions in Geoje-Hansa Bay, which is the greatest oyster producing site in Korea. Field survey for benthic environment and macrobenthos was seasonally carried out at 15 stations covering oyster farming sites and non-farming sites from February to November, 2008. The grain size of surface sediments was dominated by very fine silt with the mean phi of about $9\;{\Phi}$ and TOC was 1.9% on average. Mean dissolved oxygen content was 8.1 mg/L and lowest in August corresponding to the 2nd degree in seawater quality criteria. Total species number was 351 and mean density was $3,675\;ind./m^2$, both of which were dominated by polychaete worms. Spatio-temporal variation in above two biological variables was great with higher values seasonally in spring and spatially in channels rather than inner bay. Dominant species were Lumbrineris longifolia (21.3%), Aphelochaeta monilaris (17.8%) and Ericthonius pugnax(6.1%), all of which are typical species of organically enriched area. From the multivariate analyses, the whole macrobenthic community was distinguished into two groups of channel and inner bay group. Spatio-temporal changes of macrobenthic community in Geoje-Hansan Bay were related to those of TOC and acid volatile sulfide (AVS). Our results showed that Geoje-Hansan Bay should be intermediately affected by organic pollution, and that such organic enrichment was more remarkable at farming stations in the inner bay.