• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.3
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• pp.263-276
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• 2021

Marine benthic organisms have been used as the indicators for the environment assessment and recently considered as a very important component in the biodiversity and ecosystem restoration. In Korean waters, the quantitative data on marine benthos was used as one of major components for the marine pollution assessment for 50 years since 1970s. The species identification which is an important factor for the quantitative biological data was mainly performed by the marine benthic ecologists. This leads to the deterioration of the data quality on marine benthos from the misidentication of major taxonomic groups due to the lack of taxonomic expertise in Korea. This taxonomic problem has not been solved until now and remains in most data from national research projects on the marine ecosystems in Korean waters. Here we introduce the quality assurance and control (QA/QC) system for the marine biological data in UK, that is, NMBAQC (Northeast Atlantic Marine Biological Analytic and Quality Control) Scheme which has been performed by private companies to solve similar species identification problems in UK. This scheme asks for all marine laboratories which want to participate to any national monitoring programs in UK to keep their identification potency at high level by the internal quality assurance systems and provides a series of taxonomic workshops and literature to increase their capability. They also performs the external quality control for the marine laboratories by performing the Ring Test using standard specimens on various faunal groups. In the case of Korea, there are few taxonomic expertise in two existing national institutions and so they can't solve the taxonomic problems in marine benthic fauna data. We would like to provide a few necessary suggestions to solve the taxonomic problems in Korean marine biological data in short-terms and long-terms: (1) the identification of all dominant species in marine biological data should be confirmed by taxonomic expertise, (2) all the national research programs should include taxonomic experts, and (3) establishing a private company, like the Korea marine organism identification association (KMOIA), which can perform the QA/QC system on the marine organisms and support all Korean marine laboratories by providing taxonomic literature and species identification workshops to enhance their potency. The last suggestion needs more efforts and time for the establishment of that taxonomic company by gathering the detailed contents and related opinions from diverse stakeholders in Korea.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.3
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• pp.190-199
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• 2008

To investigate hydrographic structure and characteristics of the tropical ocean in the eastern and the western Pacific, CTD(Conductivity-Temperature-Depth) data along $131^{\circ}W$ and $137^{\circ}-142^{\circ}E$ in July-August 2005 were analyzed. Sea surface temperature along $131.5^{\circ}W$ in summer is highest in the Equatorial Counter Current(ECC) because of the high-temperature water greater than $28^{\circ}C$ moving through the ECC from the western Pacific to the eastern Pacific in spring and summer. Based on the evidence of the presence of low salinity and high dissolved oxygen water in the North Equatorial Current(NEC), we suggested that the low salinity water moved from the Gulf of Panama to the east of Philippine along the North Equatorial Current(NEC). The South Equatorial Current(SEC) had the most saline water from surface to deep layer because the saline water from the Subtropical South Pacific Ocean moved to the north. The salinity minimum layer was observed at 500-1500 m depth along $131.5^{\circ}W$. The water mass with the salinity minimum layer in the north of $5^{\circ}N$ came from the North Pacific Intermediate Water(NPIW) and that in the south of $5^{\circ}N$ came from the Antarctic Intermediate Water(AAIW), which was more saline than the NPIW. Cyclonic cold eddy with a diameter of about 200km was found in $4-6^{\circ}N$. Sea surface temperature along $131.5^{\circ}W$ in the eastern Pacific was lower than along $137^{\circ}-142^{\circ}E$ in the western Pacific; on the other hand, sea surface salinity in the eastern Pacific was higher than in the western Pacific. Subsurface saline water from the Subtropical South Pacific Ocean was less saline in the eastern Pacific than in the western Pacific. Salinity and density(${\sigma}_{\theta}$) of the salinity minimum layer south of $14^{\circ}N$ was higher in the eastern Pacific than in the western Pacific.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.363-367
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• 1983

Low salt fermented products of anchovy, Engraulis japonica, caught in the coasts of East Sea of Korea, were prepared tentatively and also discussed the retarding effect of rancidity of the product by the addition of BHA or red pepper. Fresh anchovies were purchased from Kichang fish market. The raw samples were mixed with $8\%$ table salt, $0.5\%$ lactic acid, $6\%$ sorbitol, $4\%$ ethyl alcohol and $0.02\%$ BHA or $0.5\%$ red pepper and filled in the glass bottles and sealed with the cap. Conventional fermented product of anchovy as a control was prepared from fresh anchovy and $20\%$ salt only. After preparation, the products were fermented for 90 days at room temperature. Amino-nitrogen, TBA value, peroxide value and viable counts of bacteria of these products were determined and also evaluation of their qualify was compared with control product by sensory evaluation during fermentation. Amino-nitrogen contents of the low salt products reached a peak in 55 days of fermentation, and the volatile basic nitrogen contents ranged $100\;mg\%$ even after 90 days of fermentation. Thiobarbituric acid value of the product with $0.02\%$ BHA showed a little increase up to 65 days of fermentation regardless of salt contents, while that of the control product increased sharply up to 65 days and then decreased gradually. BHA was effective on retarding rancidity of fermented products of anchovy and red pepper was also slightly effective. All the products showed the highest cell population in about 55 days of fermentation. Judging from the results of analysis and sensory evaluation, the low salt fermented product of anchovy could be prepared with $8\%$ salt, $0.5\%$ lactic acid, $6\%$ sorbitol, $4\%$ ethyl alcohol and $0.02\%$ BHA or $0.5\%$ red pepper to the fresh round anchovy.

• Weed & Turfgrass Science
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• v.7 no.1
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• pp.35-45
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• 2018

The seaweed Ulva spp., which is frequently bloomed in coastal areas, have negatively affected on marine ecosystem and industrial activities. Therefore, many researches have been conducted to solve this problem in the worldwide. In this study, we carried out several experiments to develop the methods for effectively controlling Ulva growth through an alone or mixture application of chemical and temperature. Three chemical mixtures ($H_2O_2$+N-vanillylnonanamide; $H_2O_2$+nonanoic acid; $H_2O_2$+sodium citrate), those had a synergistic effect to the death of Ulva australis (ULAUS), were found out. On the other hand, the death of ULAUS was significantly enhanced and accelerated as some chemicals were briefly treated with warm water of $40^{\circ}C$ rather than $25^{\circ}C$, showing that peracetic acid 100 ppm, sodium percarbonate 100 ppm, and hydrogen peroxide 30 ppm has a better activity than that of sodium chlorite 200 ppm and menadione sodium bisulfite 4 ppm. In addition, a strong synergistic effect to the death of ULAUS thallus was also observed when the sodium citrate 1,000 ppm (pH 3.0) or acetic acid 200 ppm (pH 3.5) solution prepared in f/2 medium were treated in a short time at $40^{\circ}C$. However, an additive effect was only appeared as pH values of their solutions were increased to 8.0. Taken together, It seemed that our results could be developed as one of an eco-friendly practical measures useful for alleviating Ulva bloom in the future.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.2
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• pp.224-230
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• 2014

Marine algae have long been recognized as a health and beauty food, based on its anti-tumor, anti-inflammatory and anti-obesity activities. In this study, methanol extracts were prepared from 10 different phaeophyta, after which DPPH radical scavenging and cytoprotective activities of HT-22 cells against ${\beta}$-amyloid protein ($A{\beta}$), which has neurotoxic effects, were investigated. In DPPH experiments, Ecklonia cava and Ishige okamurai showed strong ROS scavenging activities, whereas eight other phaeophyta including Petalonia binghamiae (P. bin) showed weak ROS scavenging activities. To validate the cytoprotective effects of 10 different phaeophyta in $A{\beta}$-induced HT-22 cells, protein expression levels of APP, BACE1, iNOS, phosphorylated ERK1/2, phosphorylated p38 and phosphorylated JNK1/2 were determined along with MTT assay. In the MTT assay, P. bin showed the best effective cytoprotective activity at a concentrations of $25{\mu}g/mL$, whereas Sargassum confusum, Colpomenia sinuosa, Myelophycus simplex, and Sargassum hemiphyllum showed potential. Determination of protein expression levels related to $A{\beta}$-induced neurotoxicity in the five selected phaeophyta showed that P. bin inhibited BACE1 and iNOS expression in $A{\beta}$-induced HT-22 cells. These results indicate that the cytoprotective effects of P. bin are mediated by suppressing the pathways involving $A{\beta}$-induced ERK and p38 activation.

• Journal of Wetlands Research
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• v.6 no.1
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• pp.133-147
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• 2004

Environmental quality(water and sediment) was analyzed in the tidal flat of Saemangum of Jeonbuk Province, the west coast of Korea, using the 101 sediment samples and 69 water samples collected in September 4~13, 2001. Major water quality parameters with the means of 69 surface water samples are as follows; $25.51{\pm}0.68^{\circ}C$ for water temperature, $29.88{\pm}5.01$ for salinity, $1.40{\pm}0.78mg/L$ for COD, $0.352{\pm}0.417mg/L$ for DIN, and $0.027{\pm}0.023mg/L$ for phosphate, respectively. Higher values were found at the subestuary of Dongjin and Mangyung River, and lower values at the Saemangum embayment and Gomso Bay. There was a significant negative correlation between salinity and the other water quality parameters(p<0.0001) such as COD, nutrients, SS and N/P. This correlation suggested that the major pollution sources be from terrestrial inputs through tributaries in this area. Principal component analysis clearly revealed a spatial variation of water quality; stations with higher values of nutrients and COD located subestuary of tributaries. 14 sediment quality parameters including 8 trace metals were measured using the 101 surface sediment samples. Average values for the parameters are as follows; Al $2.28{\pm}0.92%$, Cd $0.61{\pm}0.27ppm$, Cu $8.95{\pm}4.06ppm$, Fe $1.19{\pm}0.37%$, Mn $182.31{\pm}77.45ppm$, Ni $10.83{\pm}4.97ppm$, Pb $15.20{\pm}4.35ppm$, Zn $41.34{\pm}34.62ppm$, COD $2.68{\pm}1.85mg/g\;dry$, AVS $0.04{\pm}0.08mg/g\;dry$, IL $1.29{\pm}1.08%$, water content $24.11{\pm}4.49%$, TN $0.02{\pm}0.02%$, TC $0.22{\pm}0.30%$. Spatial variations of sediment quality were not clear as water quality. Some higher values were found at the subestuary of Gum River and lower values at the other area. There was a significant positive correlation between the heavy metal concentrations and organic materials within the sediment(p<0.05). Enrichment factors showed the ranges of 1~2 for most of the metals in the sediment except zinc(1~6), indicating no serious exogenous input of heavy metals in the study area. Also, the heavy metal concentrations in the sediment were within the ranges found at the natural marine environments.

• Journal of the Mineralogical Society of Korea
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• v.31 no.1
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• pp.1-12
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• 2018

A gravity core (RS14-C2) was collected at site RS14-C2 in the continental slope to the east of Pennell-Isellin Bank of the Ross Sea (Antarctica) during PNRA XXIX (Rosslope II Project) Expedition. In order to trace the sediment source, magnetic susceptibility (MS), sand fraction, and clay mineral compositions were analyzed, and AMS $^{14}C$ ages were dated. Core sediments consist mostly of hemipelagic sandy clay or silty clay including ice-rafted debris (IRD). AMS $^{14}C$ age of core-top indicates the modern and Holocene sediments. Based on AMS $^{14}C$ dating, sediment color, MS and sand fraction, core sediments are divided into interglacial and glacial intervals. The interglacial brown sediments are characterized by low MS and sand fraction, whereas the glacial gray sediments are characterized by high MS and sand fraction. Among clay mineral compositions of core sediments, illite is highest (61.8~76.7%), and chlorite (15.7~21.3%), kaolinite (3.6~15.4%), and smectite (0.9~5.1%) are in decreasing order, and these compositions are also divided into the interglacial and glacial/deglacial intervals. During the glacial period, the high content of illite and chlorite indicate sediment supply from the bedrocks of Transantarctic Mountains under the Ross Ice Sheet. In contrast, because of decreasing supply of illite and chlorite by the glacial retreat, smectite and kaolinite contents increased relatively during the interglacial period. During the interglacial period, smectite may be transported additionally by the northeastward flowing surface current from the coast of Victoria Land in the western Ross Sea. Kaolinite may be also supplied to the continental slope by the Antarctic Slope Current from the kaolin-rich metasedimentary rock outcropped on the Edward VII Peninsula.

• Journal of the Korean association of regional geographers
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• v.12 no.4
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• pp.449-460
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• 2006

This study aims to analyze distribution of natural lakes including lagoonal lake(lagoon) and tributary dammed lake(tributary lake) and calculate the size, morphology in order to interpret time-serial change of lakes using methodology of remote sensing images(1990s), GIS and topographic maps(1920s) in east coast of Korean Peninsular. Analysis results show that in 1990s, there are 57 natural lakes, with the total size of $75.62km^2$ over size $0.01km^2$. marine-origin lagoons are 48 with total size of $64.85km^2$, composing 85% of total natural lake, and the largest lagoon is Beonpo in Raseon City. Tributary lakes have been formed by damming of tributary channels by fluvial sand bars from main stream, located nearby at coastal zone, similar to lagoon sites. Large tributary lake, Jangyeonho, is developed in lava plateau dissection valley of Eorang Gun, Hamnam Province. There are more distributed at Duman River mouth$\sim$Cheongjin City, Heungnam City$\sim$Hodo Peninsular and Anbyeon Gun$\sim$Gangreung City. Geomorphometrically, correlation of size to circumference is very high, but correlation of size to shape irregularity is very low. The direction of lagoonal coast, NW-SE and NE-SW are predominated due to direction of tectonic structure and longshore currents. The length of the river into lake are generally short, maximum under 15km, and lake size is smaller, degree of size decreasing is higher. Geomorphic patterns of the lake location are classified as coast-hill range, coastal plain, coastal plain-channel valley, coastal plain-hill range and channel valley-hill range. During from 1920s to 1990s, change with lake size decreasing is highest at coastal plain-channel valley, next is coastal plain. Causes of the size decreasing are fluvial deposition from upper rivers and human impacts such as reclamation.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.90-104
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• 2001

This study is aimed to analyze and to evaluate the revegetation and soil conservation technology in desertification-affected sandy land, resulting from the project of "Studies on the desertification combating and sand industry development". Main native plants for combating desertification : The general characteristics of vegetation distribution in desertified regions are partially concentrated vegetation distribution types including the a) desert plants in low zone of desert or sanddune of depressed basin, b) salt-resistant plants around saline lakes, c) grouped vegetation with Poplar and Chinese Tamarix of freshwater-lakes, saline-lakes and river-banks, d) gobi vegetation of gravel desert and e) grassland and oasis-woods around the alluvial fan of rivers, etc. Generally, Tamarix ehinensis Lour., Haloxylon ammodendron Bunge., Calligonum spp., Populus euphratica Oliver., Elaeagnus angustifolia L., Ulmus pumila L., Salix spp., Hedysarum spp., Caragana spp., Xanthoceras sorbifolia Bunge., Nitraria tangutorum Bobr., Lespedeza bicolor, Alhagi sparsifolia Shap., Capparis spinosa L., Artemisia arenaria DC., etc. are widely distributed in desertified regions. It is necessary for conducting research in the native plants in desertified regions. Analysis of intensive revegetation technology system for combating desertification : In the wind erosion region, the experimental research projects of rational farming systems (regional planning, shelterbelts system, protection system of oasis, establishment of irrigation-channel networks and management technology of enormous farmlands, etc.), rational utilization technology of plant resources (fuelwood, medicinal plants, grazing and grassland management, etc.), utilization technology of water resources (management and planning of watershed, construction of channel and technology of water saving and irrigation, etc.), establishment of sheltetbelts, control of population increase and increased production technology of agricultural forest, fuelwood and feed, etc. are preponderantly being promoted. And in water erosion region, the experimental research projects of development of rational utilization technology of land and vegetation, engineering technology and protection technology of crops, etc. are being promoted in priority. And also, the experimental researches on the methods of utilization of water (irrigation, drainage, washing and rice cultivation, etc.), agricultural methods (reclamation of land, agronomy, fertilization, seeding, crop rotation, mixed-cultivation and soil dressing works, etc.) and biological methods (cultivation of salt-resistant crops and green manure and tree plantation, etc.) for improvement of saline soil and alkaline soil in desertified-lands are actively being promoted. And the international cooperations on the revegetation technology development projects of desertified-lands are sincerely being required.

• Korean Journal of Ecology and Environment
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• v.41 no.2
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• pp.216-227
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• 2008

To understand eutrophication in the upper regions of brackish Lake Sihwa with a limited water exchange, temporal and spatial distributions of pollutants in water and sediment were investigated from March to October in 2005 and 2006. Also, pollution levels of water and sediment were estimated by trophic state index (TSI) and sediment quality guideline (SQG). Total nitrogen (TN), total phosphorus (TP), organic matter (COD), and chlorophyll $\alpha$ (Chl-$\alpha$) concentrations in the surface waters were largely varied temporally and spatially, and the variations were highest in the middle areas where strong halocline was formed. Chl-$\alpha$ concentrations in the middle area were very high in April (>$900\;{\mu}g\;L^{-1}$) when algal blooms (red tides) occurred. The relationships between TN and Chl-$\alpha$ (r=0.31), and TP and Chl-$\alpha$ (r=0.65) indicated that the algal growth was primarily affected by phosphorus rather than nitrogen. The distribution of COD was similar to that of Chl-$\alpha$, indicating that the autochthonous organic matters may be a more important carbon source, especially in the middle areas. The brackish water regions were classified as eutrophic or hypertrophic based on their TSI values ($69{\sim}76$). In addition, the content of nutrients (especially TP) in surface sediments were classified as severe polluted state, except the upper areas. Major causes of the eutrophication observed were probably due to high nutrients loading from watersheds, the phosphorus release from anaerobic sediment, and long retention time by the limited water exchange through the sluice gates.