• Journal of Life Science
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• v.22 no.4
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• pp.466-471
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• 2012

Sixty individuals of the scallop $Patinopecten$ $yessoensis$ (Genus Pecten) were sampled to examine the genetic diversity and population structure of this species. Random amplified polymorphic DNA (RAPD) identified 109 genotypes and produced 79 polymorphic loci (72.8%). Total genetic diversity values ($H_T$) and interlocus variation in the within-population genetic diversity ($H_S$) were 0.254 and 0.178, respectively. On a per-locus basis, the proportion of total genetic variation due to differences among populations ($G_{ST}$) was 0.299. This indicated that about 70.1% of the total variation was within populations. The unique loci and bands of $P.$ $yessoensis$ were shown in only one population among the three countries. RAPD markers were very effective in classifying the natural population levels of $P.$ $yessoensis$ in Korea, China, and Japan. In addition, insights into the relative gene diversity among and within populations of $P.$ $yessoensis$ would be useful in breeding and for the development of strategies for animal genetic resources.

• The Journal of Fisheries Business Administration
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• v.32 no.2
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• pp.73-89
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• 2001

The market conditions of sea mustard is changing by overproduction, decreasing price, Import of blanched and salted sea mustard from China into Korea domestic market and increasing market share of sea mustard of China in Japan. In addition, the price support program in sea mustard aquaculture must be modified due to the restriction of domestic support by international organization such as WTO. There are two ways to solve those problems. First is that finding a way to solve the overproduction of sea mustard. One of possible ways is the production adjustment by Marketing Order. Second is that finding an alternative way to replace price support program. The possible way is Direct Payment instead of purchase stockpile system. To introduce marketing Order, outlook center, organization of self-management, production adjustment through output control measure, improvement of market structure, and education/publicity arc necessary. Also, to implement marketing order, setting a model business by government is required. There are two steps for implementation of marketing order. First step is to construct Order Committee including organization of producer, people related marketing. However, this committee must run by government for certain short-term. Second step is to improve quality of product and acceleration of demand. At visual point that enforcement of the first step is completed, government has process that government transfers Order Committees self-correcting. It is desirable that government only conduct the support acts such as quality improvement and acceleration of demand. Also, at early stage it is necessary to have aid system for marketing order For example, we can expect that income increase by production adjustment in long run. However, in short run the income of producer may decrease so, it is required to compensate his economic lose. For compensation, The useful means that can be utilized is direct payment. Direct payment is not continued policy. Also, when production adjustment policy such as Marketing Order has effective results, Direct Payment as an assistant measure must be reduced or abolished. Therefore, when production adjustment acts as an effective tool to control overproduction, Direct Payment system.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.6
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• pp.553-560
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• 2012

Hizikia fusiformis, a brown alga that is widely consumed in Korea, Japan, and China, possesses a number of potentially beneficial compounds, including antioxidants and anticoagulants. However, the molecular mechanisms of H. fusiformis in hepatoma cells have not been elucidated. This study investigated the antiproliferative effect and mechanism of action of a glycoprotein from H. fusiformis (HFGP) in HepG2 human hepatoma cells. In an MTS assay, 25 ${\mu}g/mL$ HFGP inhibited the proliferation of HepG2 cells by $52.36{\pm}2.37%$. HFGP caused the dose-dependent growth inhibition of HepG2 cells by inducing apoptosis and a sub-G1 phase arrest. The antiproliferative activity of HFGP was confirmed based on the expression of several apoptosis-related proteins, which was assessed by Western blot analysis. The expressions of Fas, Fas-associated death domain protein, Bax, and Bad was significantly up-regulated in HFGP-treated cells, and HFGP induced the translocation of Bax to mitochondria and the release of cytochrome c into the cytosol. Therefore, HFGP might be useful in the treatment of liver cancer.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.3
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• pp.197-201
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• 2002

The object of this study was to find out the probability of the abundance estimation by geographical parameters of fish school during the acoustic survey using scanning sonar. The acoustic survey was carried out in Funka Bay, off southern Hokkaido, Japan in December 1998. The 180-degree scanning sonar and the echo sounder were used simultaneously. The relationship was examined between geographical parameters (fish school area and volume) measured by sonar and area back scattering coefficient by the echo sounder. The obtained result showed positive correlation. Therefore, the use of geographical parameters of fish school is a useful method in estimating fish school abundance in the acoustic survey using sonar.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.2
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• pp.92-98
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• 2003

The quantification of fish school abundance was carried out by using luminance of pixel on scanning sonar image, and compared with the indices of fish school abundance e.g. school number, school area and weighted school area. The survey was carried out in Funka Bay off southern Hokkaido, Japan using research vessel Ushio-Maru during December 1999. A 180-degree scanning sonar with a frequency of 164kHz was used. The school number was counted both left and right 40-degree radial lines from the center of own vessel mark on a scanning image. The school area was measured approximately as an ellipse from the school length and width. The weighted school area was calculated by multiplying school area and average value of inner pixel luminance. A quantification of pixel luminance was also measured to integrate squared pixel luminance value on these lines. Fish school and school bottom were discriminated by the produced sonar echogram using pixel luminance value on these lines. The relationships between the quantified luminance value and other abundance indices such as school area and weighted school area revealed a good correlation. Therefore, the quantified luminance is a useful method in estimating fish school abundance in the acoustic survey using sonar.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.3
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• pp.185-192
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• 1991

The vertical distribution and chemical characteristics of water masses were measured along two south-north transects in the polar front region of the central Korean East Sea. In February, a thermocline was present at depth between 50m and loom at the southern sites of a landward A-transect, and its depth was gradually deepened northward. At an outside B-transect, a thermocline was observed at significantly deep depth of 300m to 400m at two northern stations(Stn. 10 and 11), though the depth of the southward stations was nearly identical to that at the northward stations on a A-transect. In September, there were vertically more various water masses, i.e. the Tsushima Warm surface water(TWSW) or more than $20^{\circ}C$, the Tsushima Middle water(TMW) with a range of $12{\~}17^{\circ}C$, the North Korea Cold Water(NKCW) with $1{\~}7^{\circ}C$ temperature, the Japan Sea Proper Water(JSPW) of less than $1^{\circ}C$, and the mixed water. The North Korea Cold Water could be distinguishable from the other waters, especially from the mixed water of the Tsushima Middle Water and the Japan Sea Proper Water by the pattern of $T-O_2$ diagram. For instance, the North Korea Cold Water had higher oxygen by $1{\~}2ml/l$ than those in the mixed water, although both the two water masses ranged $1{\~}7^{\circ}C$ in water temperature. AOU value was the highest in the JSPW and the lowest in the TWSW. Also, AOU indicated a nearly linear and negative correlation with water temperature. However, AOU data for two masses, the NKCW and the TMW, in September departed remarkably from a regression line. Moreover, the ratio of $$\Delta P/\Delta AOU)$ in September was about $0.45{\mu}g-at/ml$ and higher than the value observed in the open sea. This high value could be elucidated by two factors; intrusion of the NKCW with high oxygen and molecular diffusion of dissolved oxygen from the surface into the lower layer. AOU would be a useful tracer for water masses in the polar front area of the Korean East Sea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.4
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• pp.404-412
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• 1994

Radium isotopes were measured together with oceanographical parameters in the southern coastal region of the Korean East Sea during the period of September $2{\sim}8$, 1991. In September, there were various water masses vertically distributed in this region due to formation of strongly seasonal thermoclines. These water masses were characterized by activity of radium isotopes as well as water temperature and dissolved oxygen. Among the water masses, Japan Sea Proper Water(JSPW) below $1^{\circ}C$ had the highest Ra-226 activities but the lowest Ra-228 concentrations. However, Tsushima Surface Water (TSW) above $20^{\circ}C$ in water temperature had the highest Ra-228 which decreased sharply with depth. In TSW, Ra-228 activities were in the range of $194{\sim}270$ dpm/kl, which were approximately 10 times higher than JSPW. Activity ratios(A.R's) of Ra-228/Ra-226 were $1.9{\sim}2.6$ for TSW, $0.7{\sim}1.1$ for Tsushima Middle Water(TMW) of $12{\sim}17^{\circ}C\;to\;0.4{\sim}0.7$ for North Korea Cold Water(NKCW) with $1{\sim}7^{\circ}C$ and below 0.2 for JSPW. The Ra-228/Ra-226 ranged from 0.6 to 0.9 in the cold waters of $2{\sim}6^{\circ}C$, which were observed at depth of $65{\sim}120\;m$ in this study area. Radium isotopes provided a useful means of identifying origins of the cold water which occurred annually at intermediate or bottom layers in the southern coastal zone of the Korean East Sea. By plotting radium isotopes against water temperature, it could be observed clearly that the cold waters between $2{\sim}6^{\circ}C$ did not originate from the mixed water of JSPW and TMW but from NKCW.